<1> UI - 732EV-0001 DD - ISI Document Solution: 732EV AU - Trebst A MA - achim.trebst@ruhr-uni-bochum.de RA - Trebst A TI - Function of beta-carotene and tocopherol in photosystem II [Review] SO - Zeitschrift fur Naturforschung C-A Journal of Biosciences. 58(9-10):609-620, 2003 Sep-Oct. AS - Z.Naturforsch.(C) 2003 Sep-Oct;58(9-10):609-620 PU - VERLAG Z NATURFORSCH, POSTFACH 2645, W-7400 TUBINGEN, GERMANY IS - 0939-5075 MH - Chlorophyll triplet MH - D1 protein turnover MH - Singlet oxygen. MH - Synechocystis sp pcc-6803 MH - Singlet oxygen production MH - Thylakoid protein-phosphorylation MH - Photosynthetic reaction-center MH - Reaction centers MH - Chlamydomonas-reinhardtii MH - Angstrom resolution MH - Triplet formation MH - In-vivo MH - Hydroxyphenylpyruvate dioxygenase. AB - New and known structural and functional insights in the role of beta-carotene and of alpha-tocopherol in photosytem II are reviewed. A concept is presented connecting the failure of P680 triplet quenching by beta-carotene with the formation of singlet oxygen and its scavenging in the turnover of the D1 protein and by tocopherol in the maintenance of PS 11 structure and function. [References: 102] LG - English PT - Review SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Trebst A Ruhr Univ Bochum D-44827 Bochum Germany Ruhr Univ Bochum D-44827 Bochum Germany <2> UI - 731LF-0004 DD - ISI Document Solution: 731LF AU - Sievers M AU - Uermosi C AU - Fehlmann M AU - Krieger S MA - m.sievers@hsw.ch RA - Sievers M TI - Cloning, sequence analysis and expression of the F1F0-ATPase beta-subunit from wine lactic acid bacteria SO - Systematic & Applied Microbiology. 26(3):350-356, 2003 Sep. AS - Syst. Appl. Microbiol 2003 Sep;26(3):350-356 PU - URBAN & FISCHER VERLAG, BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY. URL: http://www.urbanfischer.de IS - 0723-2020 MH - F1f0-atpase beta-subunit MH - Atpd MH - Lactic acid bacteria MH - Ta-cloning. MH - Coli atp synthase MH - Oenococcus-oeni MH - Malolactic fermentation MH - Nucleotide-sequence MH - Leuconostoc-oenos MH - Energy MH - Operon MH - Catalysis MH - Complex MH - Mutants. AB - The nucleotide sequences of the genes encoding the F1F0-ATPase beta-subunit from Oenococcus oeni, Leuconostoc mesenteroides subsp. mesenteroides, Pediococcus damnosus, Pediococcus parvulus, Lactobacillus brevis and Lactobacillus hilgardii were determined. Their deduced amino acid sequences showed homology values of 79-98%. Data from the alignment and ATPase tree indicated that O. oeni and L. mesenteroides subsp. mesenteroides formed a group well-separated from P. damnosus and P. parvulus and from the group comprises L. brevis and L. hilgardii. The N-terminus of the F1F0-ATPase beta-subunit of O. oeni contains a stretch of additional 38 amino acid residues. The catalytic site of the ATPase P-subunit of the investigated strains is characterized by the two conserved motifs GGAGVGKT and GERTRE. The amplified atpD coding sequences were inserted into the pCRT7/CT-TOPO vector using TA-cloning strategy and transformed in Escherichia coli. SDS-PAGE and Western blot analyses confirmed that O. oeni has an ATPase beta-subunit protein which is larger in size than the corresponding molecules from the investigated strains. [References: 24] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Sievers M Hochsch Wadenswil Wadenswil Switzerland Hochsch Wadenswil Wadenswil Switzerland Lallemand SA Blagnac France <3> UI - 731LF-0007 DD - ISI Document Solution: 731LF AU - Freitas M AU - Rainey FA AU - Nobre MF AU - Silvestre AJD AU - da Costa MS MA - milton@ci.uc.pt RA - da Costa MS TI - Tepidimonas aquatica sp nov., a new slightly thermophilic beta-proteobacterium isolated from a hot water tank SO - Systematic & Applied Microbiology. 26(3):376-381, 2003 Sep. AS - Syst. Appl. Microbiol 2003 Sep;26(3):376-381 PU - URBAN & FISCHER VERLAG, BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY. URL: http://www.urbanfischer.de IS - 0723-2020 MH - Tepidimonas aquatica MH - Beta-subclass MH - Proteobacteria MH - Slightly thermophilic. MH - Deoxyribonucleic-acid MH - Genus thermus MH - Bacteria MH - Strains MH - Homology MH - Springs MH - Dna. AB - A bacterial isolate, with an optimum growth temperature of about 50 degreesC, was recovered from a domestic hot water tank in Coimbra. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain CLN-1(T) is a member of the P-Proteo bacteria and represents a new species of the genus Tepidimonas. The major fatty acids of strain CLN-1(T) are 16:0, 17:0 cyclo and 16:1 omega7c. Ubiquinone 8 is the major respiratory quinone, the major polar lipids are phosphatidylethanolamine, and phosphatidylglycerol. The new isolate is aerobic and facultatively chemolithoheterotrophic. Thiosulfate and tetrathionate are oxidized to sulfate in the presence of a metabolizable carbon source. Strain CLN-1(T) grows on amino acids and organic acids, but this organism does not assimilate carbohydrates. Glycerol is the only polyol assimilated. Resinic acids, namely abietic acid, dehydroabietic acid and isopimaric acid are not degraded. On the basis of the phylogenetic analyses, physiological and biochemical characteristics, we propose that strain CLN-1(T) represents a new species for which we offer the name Tepidimonas aquatica. [References: 22] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: da Costa MS Univ Coimbra, Dept Zool, Dept Bioquim P-3001401 Coimbra Portugal Univ Coimbra, Dept Zool, Dept Bioquim P-3001401 Coimbra Portugal Univ Coimbra, Dept Zool, Ctr Neurociencias P-3001401 Coimbra Portugal Louisiana State Univ, Dept Sci Biol Baton Rouge, LA USA Univ Coimbra, Dept Zool Coimbra Portugal Univ Aveiro, Dept Quim Aveiro Portugal <4> UI - 731LF-0008 DD - ISI Document Solution: 731LF AU - Doronina N AU - Darmaeva T AU - Trotsenko Y MA - trotsenko@ibpm.serpukhov.su RA - Trotsenko Y TI - Methylophaga natronica sp nov., a new alkaliphilic and moderately halophilic, restricted-facultatively methylotrophic bacterium from Soda Lake of the Southern Transbaikal Region SO - Systematic & Applied Microbiology. 26(3):382-389, 2003 Sep. AS - Syst. Appl. Microbiol 2003 Sep;26(3):382-389 PU - URBAN & FISCHER VERLAG, BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY. URL: http://www.urbanfischer.de IS - 0723-2020 MH - Methylophaga natronica sp nov. MH - Moderately haloalkaliphilic methylotroph MH - Ribulose monophosphate pathway MH - Osmoprotectants. MH - Methanol-utilizing bacteria MH - Deoxyribonucleic-acid MH - Thermal-denaturation MH - Marine methylotrophs MH - Genus methylophaga MH - Methylobacillus MH - Osmoadaptation MH - Oxidation MH - Biology. AB - A new, moderately haloalkaliphilic and restricted-facultatively methylotrophic bacterium (strain Bur2(T)) with the ribulose monophosphate pathway of carbon assimilation is described. The isolate, which utilizes methanol, methylamine and fructose, is an aerobic, Gram-negative, asporogenous, motile short rod multiplying by binary fission. It is auxotrophic for vitamin B-12, and requires NaHCO3 or NaCl for growth in alkaline medium. Cellular fatty acids profile consists primarily of straight-chain saturated C-16:0, unsaturated C-16:1 and C-18:1 acids. The major ubiquinone is Q-8. The dominant phospholipids are phosphatidylethanolamine and phosphatidylglycerol. Diphosphatidylglycerol is also present. Optimal growth conditions are 25-29 degreesC, pH 8.5-9.0 and 2-3% (w/v) NaCl. Cells accumulate ectoine and glutamate as the main osmoprotectants. The G + C content of the DNA is 45.0 mol%. Based on 16S rDNA sequence analysis and DNA-DNA relatedness (25-35%) with type strains of marine and soda lake methylobacteria belonging to the genus Methylophaga, the novel isolate was classified as a new species of this genus and named Methylophaga natronica (VKM B-2288(T)). [References: 35] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Trotsenko Y Russian Acad Sci, GK Skryabin Inst Biochem & Physiol Microorgan Pushchino 142290 Moscow Region Russia Russian Acad Sci, GK Skryabin Inst Biochem & Physiol Microorgan Pushchino 142290 Moscow Region Russia <5> UI - 731PX-0011 DD - ISI Document Solution: 731PX AU - Dovzhenko A AU - Dal Bosco C AU - Meurer J AU - Koop HU MA - morgunok@yahoo.de RA - Dovzhenko A TI - Efficient regeneration from cotyledon protoplasts in Arabidopsis thaliana SO - Protoplasma. 222(1-2):107-111, 2003. AS - Protoplasma 2003;222(1-2):107-111 PU - SPRINGER-VERLAG WIEN, SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA. URL: http://www.springer.co.at IS - 0033-183X MH - Arabidopsis thaliana MH - Cotyledon MH - Protoplast culture MH - Shoot regeneration. MH - Plastid transformation MH - Plant-regeneration MH - Leaf protoplasts MH - Chlorophyll-fluorescence MH - Culture MH - Mutants MH - Identification. AB - An efficient and fast regeneration system from cotyledon protoplasts was established for Arabidopsis thaliana accessions C24, Columbia, and Wassilewskija. Culture conditions and media compositions were optimised for the development of protoplasts embedded in thin alginate layers. Unexpectedly, the absence of cytokinins had a positive effect on cell development. Moreover, combined adjustment of alpha-naphthylacetic acid and dicamba concentrations resulted in high plating efficiencies of up to 30%, followed by shoot regeneration within only 19 days after protoplast isolation. The protocol is reproducible, efficient, extremely fast, and regenerated plants are fertile. Thus, this cotyledon-based system could prove useful for studying plant cell and molecular biology in A. thaliana. [References: 20] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Cell & Developmental Biology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Dovzhenko A Zentrum Angew Biowissensch Sonnenstr 5 D-79104 Freiburg Germany Univ Munich, Dept Biol 1, Bereich Bot Munich Germany <6> UI - 732WY-0005 DD - ISI Document Solution: 732WY AU - Yoo SD AU - Greer DH AU - Laing WA AU - McManus MT MA - m.t.mcmanus@massey.ac.nz RA - McManus MT TI - Changes in photosynthetic efficiency and carotenoid composition in leaves of white clover at different developmental stages SO - Plant Physiology & Biochemistry. 41(10):887-893, 2003 Oct. AS - Plant Physiol. Biochem 2003 Oct;41(10):887-893 PU - EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER, 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE. URL: http://www.elsevier.nl IS - 0981-9428 MH - Carotenoids MH - Leaf development MH - Leaf senescence MH - Photosynthetic yield MH - Photosystem ii MH - Trifolium repens MH - White clover. MH - Ribulose-1,5-bisphosphate carboxylase MH - Xanthophyll cycle MH - Leaf development MH - Zeaxanthin accumulation MH - Energy-dissipation MH - Festuca-pratensis MH - Senescent leaves MH - Hordeum-vulgare MH - Chlorophyll-a MH - Plants. AB - Changes in photosynthetic capacity and efficiency, and in carotenoid composition have been examined during leaf ontogeny in the pasture legume white clover, Trifolium repens (L.). Leaf chlorophyll, measured as mug(-1) FW, was used as an indicator of leaf maturity, with maximum levels of the pigment denoting the mature-green phase of leaf development, and an observed decrease in chlorophyll content accompanying leaf senescence. For chlorophyll a and b, a constant ratio (a/b) between the two pigments was observed in mature-green leaves, and in the early stages of senescence while the ratio increased during the later stages of leaf senescence. Measurement of the net photosynthetic CO2 assimilation rate (P-N) as mumol m(-2) s(-1) revealed a decrease in the photosynthetic rate that correlated with the decrease in total chlorophyll content. Measurement of chlorophyll fluorescence in vivo revealed that the optimal quantum efficiency of PSII (Fv/Fm) did not decline significantly, but the effective quantum efficiency of PSII in the light ((Fm' - Ft)/Fm') did decrease significantly, with a concomitant increase in non-photochemical quenching (NPQ). In terms of changes in the accessory pigments during senescence, the total pool of carotenoids decreased when expressed per unit leaf area, but not as rapidly as total chlorophyll such that the chlorophyll/carotenoid ratio decreased. The relative abundance of the carotenoids comprising the xanthophyll cycle, zeaxanthin (Z), violaxanthin (V) and antheraxanthin (A) altered during leaf ontogeny. In mature-green leaves, violaxanthin was the more abundant pigment, but as leaf senescence progressed, zeaxanthin became the most abundant pigment, and the ratio of (Z + A)/(Z + A + V) increased. These results are discussed in terms of the role of the xanthophylls cycle in the protection of PSII during leaf senescence. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved. [References: 40] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: McManus MT Massey Univ, Inst Mol BioSci Private Bag 11222 Palmerston North New Zealand Massey Univ, Inst Mol BioSci Palmerston North New Zealand Hort & Food Res Inst New Zealand Palmerston North New Zealand Hort & Food Res Inst New Zealand Auckland New Zealand <7> UI - 733AB-0011 DD - ISI Document Solution: 733AB AU - Calatayud A AU - Iglesias DJ AU - Talon M AU - Barreno E MA - angeles.calatayud@uv.es RA - Calatayud A TI - Effects of 2-month ozone exposure in spinach leaves on photosynthesis, antioxidant systems and lipid peroxidation SO - Plant Physiology & Biochemistry. 41(9):839-845, 2003 Sep. AS - Plant Physiol. Biochem 2003 Sep;41(9):839-845 PU - EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER, 23 RUE LINOIS, 75724 PARIS CEDEX 15, FRANCE. URL: http://www.elsevier.nl IS - 0981-9428 MH - Antioxidant MH - Ascorbate MH - Chlorophyll fluorescence MH - Gas exchange MH - Malondialdehyde MH - Ozone MH - Spinacia oleracea. MH - Chlorophyll-a fluorescence MH - Glutathione-reductase MH - Quantum yield MH - Plants MH - Chloroplasts MH - Fumigation MH - Ascorbate MH - Responses MH - Air MH - Temperature. AB - The photosynthesis response, antioxidant systems and lipid peroxidation were studied in leaves from spinach plants (Spinacia oleracea L.) in response to ozone fumigation, ambient air and charcoal filtered air treatments. The photosynthetic activity was tested through gas exchange and chlorophyll a fluorescence measurements. Ambient air and ozone fumigation caused a decrease in the photosynthetic rate (25% and 63%, respectively) mainly due to a reduced mesophyll activity, as evidenced by the increased intercellular CO, concentration. These data agree with a large reduction in the non-cyclic electron flow (7% and 16%), a lower capacity to reduce the quinone pool and a higher development of non-photochemical quenching upon high O-3 concentration. The results suggest that the oxidative stress produced, together with the stimulation of superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate peroxidase (APX, EC 1.11.1.11) activities and the increase in lipid peroxidation (20% and 36%, respectively), generated an alteration of the membrane properties. (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved. [References: 39] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Calatayud A Univ Valencia, Fac Ciencias Biol, Dept Bot Vegetal C Dr Moliner,50 Valencia 46100 Spain Univ Valencia, Fac Ciencias Biol, Dept Bot Vegetal Valencia 46100 Spain IVIA, Dept Citricultura Valencia 46113 Spain <8> UI - 732ZE-0017 DD - ISI Document Solution: 732ZE AU - Riekhof WR AU - Ruckle ME AU - Lydic TA AU - Sears BB AU - Benning C MA - benning@msu.edu RA - Benning C TI - The sulfolipids 2 '-O-acyl-sulfoquinovosyldiacylglycerol and sulfoquinovosyldiacylglycerol are absent from a Chlamydomonas reinhardtii mutant deleted in SQD1 SO - Plant Physiology. 133(2):864-874, 2003 Oct. AS - Plant Physiol 2003 Oct;133(2):864-874 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Rhodobacter-sphaeroides MH - Phosphate limitation MH - Udp-sulfoquinovose MH - Deficient mutant MH - Photosystem-ii MH - Biosynthesis MH - Diacylglycerol MH - Arabidopsis MH - Gene MH - Transformation. AB - The biosynthesis of thylakoid lipids in eukaryotic photosynthetic organisms often involves enzymes in the endoplasmic reticulum (ER) and the chloroplast envelopes. Two pathways of thylakoid lipid biosynthesis, the ER and the plastid pathways, are present in parallel in many species, including Arabidopsis, but in other plants, e.g. grasses, only the ER pathway is active. The unicellular alga Chlamydomonas reinhardtii diverges from plants like Arabidopsis in a different way because its membranes do not contain phosphatidylcholine, and most thylakoid lipids are derived from the plastid pathway. Here, we describe an acylated derivative of sulfolipid, 2'-O-acyl-sulfoquinovosyldiacylglyceroI (ASQD), which is present in C. reinhardtii. Although the fatty acids of sulfoquinovosyldiacylglycerol (SQDG) were mostly saturated, ASQD molecular species carried predominantly unsaturated fatty acids. Moreover, directly attached to the head group of ASQD was preferentially an 18-carbon fatty acid with four double bonds. High-throughput robotic screening led to the isolation of a plasmid disruption mutant of C. reinliardtii, designated Deltasqd1, which lacks ASQD as well as SQDG. In this mutant, the SQD1 ortholog was completely deleted and replaced by plasmid sequences. It is proposed that ASQD arises from the sugar nucleotide pathway of sulfolipid biosynthesis by acylation of the 2'-hydroxyl of the sulfoquinovosyl head group. At the physiological level, the mutant showed increased sensitivity to a diuron herbicide and reduced growth under phosphate limitation, suggesting a role for SQDG and/or ASQD in photosynthesis as conducted by C. reinliardtii, particularly under phosphate-limited conditions. [References: 31] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Benning C Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Michigan State Univ, Dept Energy, Plant Res Lab E Lansing, MI 48824 USA Michigan State Univ, Dept Plant Biol E Lansing, MI 48824 USA <9> UI - 732ZE-0018 DD - ISI Document Solution: 732ZE AU - Focke M AU - Gieringer E AU - Schwan S AU - Jansch L AU - Binder S AU - Braun HP MA - braun@genetik.uni-hannover.de RA - Braun HP TI - Fatty acid biosynthesis in mitochondria of grasses: Malonyl-coenzyme A is generated by a mitochondrial-localized acetyl-coenzyme A carboxylase SO - Plant Physiology. 133(2):875-884, 2003 Oct. AS - Plant Physiol 2003 Oct;133(2):875-884 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Acyl-carrier protein MH - Polyacrylamide-gel electrophoresis MH - Nadh-ubiquinone oxidoreductase MH - Neurospora-crassa mitochondria MH - Plant chloroplast biogenesis MH - Coa carboxylase MH - Lipoic acid MH - Subcellular-localization MH - Binding-protein MH - Pea leaves. AB - We present biochemical evidence for the occurrence of a 250-kD multifunctional acetyl-coenzyme A carboxylase in barley (Hordeum vulgare) mitochondria. Organelles from 6-d-old barley seedlings were purified by differential centrifugation and Percoll density gradient centrifugation. Upon analysis by two-dimensional Blue-native (BN)/SDS-PAGE, an abundant 250-kD protein can be visualized, which runs at 500 kD on the native gel dimension. A similar 500-kD complex is present in etioplasts from barley. The mitochondrial 250-kD protein is biotinylated as indicated by specific reaction with an antibody directed against biotin. Peptide sequence analysis by electrospray ionization tandem mass spectrometry of the 250-kD proteins from both organellar fractions revealed amino acid sequences that are 100% identical to plastidic acetyl-coenzyme A carboxylase from wheat (Triticum aestivum). The 500-kD complex was also detected in wheat mitochondria, but is absent in mitochondrial fractions from Arabidopsis. Specific acetyl-coenzyme A carboxylation activity in barley mitochondria is higher than in etioplasts, suggesting an important role of mitochondria in fatty acid biosynthesis. Functional implications are discussed. [References: 55] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Braun HP Univ Karlsruhe Kaiserstr 12 D-76128 Karlsruhe Germany Univ Karlsruhe D-76128 Karlsruhe Germany Gesell Biotechnol Forsch mbH D-38124 Braunschweig Germany Univ Hannover, Inst Angew Genet D-30419 Hannover Germany Univ Ulm D-89069 Ulm Germany <10> UI - 732ZE-0020 DD - ISI Document Solution: 732ZE AU - Collakova E AU - DellaPenna D MA - dellapen@msu.edu RA - DellaPenna D TI - The role of homogentisate phytyltransferase and other tocopherol pathway enzymes in the regulation of tocopherol synthesis during abiotic stress SO - Plant Physiology. 133(2):930-940, 2003 Oct. AS - Plant Physiol 2003 Oct;133(2):930-940 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Synechocystis sp pcc-6803 MH - P-hydroxyphenylpyruvate dioxygenase MH - Vitamin-e content MH - Alpha-tocopherol MH - Chlorophyll degradation MH - Plastoquinone synthesis MH - Spinach-chloroplasts MH - Oxidative stress MH - Biosynthesis MH - Arabidopsis. AB - Tocopherols are amphipathic antioxidants synthesized exclusively by photosynthetic organisms. Tocopherol levels change significantly during plant growth and development and in response to stress, likely as a consequence of the altered expression of pathway-related genes. Homogentisate phytyltransferase (HPT) is a key enzyme limiting tocopherol biosynthesis in unstressed Arabidopsis leaves (E. Collakova, D. DellaPenna [2003] Plant Physiol 131: 632-642). Wild-type and transgenic Arabidopsis plants constitutively overexpressing HPT (35S::HPT1) were subjected to a combination of abiotic stresses for up to 15 d and tocopherol levels, composition, and expression of several tocopherol pathway-related genes were determined. Abiotic stress resulted in an 18- and 8-fold increase in total tocopherol content in wild-type and 35S::HPT1 leaves, respectively, with tocopherol levels in 35S::HPT1 being 2- to 4-fold higher than wild type at all experimental time points. Increased total tocopherol levels correlated with elevated HPT mRNA levels and HPT specific activity in 35S::HPT1 and wild-type leaves, suggesting that HPT activity limits total tocopherol synthesis during abiotic stress. In addition, substrate availability and expression of pathway enzymes before HPT also contribute to increased tocopherol synthesis during stress. The accumulation of high levels of beta-, gamma-, and delta-tocopherols in stressed tissues suggested that the methylation of phytylquinol and tocopherol intermediates limit a-tocopherol synthesis. Overexpression of gamma-tocopherol methyltransferase in the 35S::HPT1 background resulted in nearly complete conversion of gamma- and delta-tocopherols to alpha- and beta-tocopherols, respectively, indicating that gamma-tocopherol methyltransferase activity limits alpha-tocopherol synthesis in stressed leaves. [References: 51] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: DellaPenna D Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA <11> UI - 732ZE-0021 DD - ISI Document Solution: 732ZE AU - Michalecka AM AU - Svensson AS AU - Johansson FI AU - Agius SC AU - Johanson U AU - Brennicke A AU - Binder S AU - Rasmusson AG MA - allan.rasmusson@cob.lu.se RA - Rasmusson AG TI - Arabidopsis genes encoding mitochondrial type IINAD(P)H dehydrogenases have different evolutionary orgin and show distinct responses to light SO - Plant Physiology. 133(2):642-652, 2003 Oct. AS - Plant Physiol 2003 Oct;133(2):642-652 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Rotenone-insensitive nadh MH - Neurospora-crassa mitochondria MH - Plant-mitochondria MH - Saccharomyces-cerevisiae MH - Nad(p)h dehydrogenases MH - Complex-i MH - Escherichia-coli MH - Alternative oxidase MH - Electron-transport MH - Inner membrane. AB - In addition to proton-pumping complex I, plant mitochondria contain several type II NAD(P)H dehydrogenases in the electron transport chain. The extra enzymes allow the nonenergy-conserving electron transfer from cytoplasmic and matrix NAD(P)H to ubiquinone. We have investigated the type II NAD(P)H dehydrogenase gene families in Arabidopsis. This model plant contains two and four genes closely related to potato (Solanum tuberosum) genes nda1 and ndb1, respectively. A novel homolog, termed ndc1, with a lower but significant similarity to potato nda1 and ndb1, is also present. All genes are expressed in several organs of the plant. Among the nda genes, expression of nda1, but not nda2, is dependent on light and circadian regulation, suggesting separate roles in photosynthesis-associated and other respiratory NADH oxidation. Genes from all three gene families encode proteins exclusively targeted to mitochondria, as revealed by expression of green fluorescent fusion proteins and by western blotting of fractionated cells. Phylogenetic analysis indicates that ndc1 affiliates with cyanobacterial type II NADH dehydrogenase genes, suggesting that this gene entered the eukaryotic cell via the chloroplast progenitor. The ndc1 should then have been transferred to the nucleus and acquired a signal for mitochondrial targeting of the protein product. Although they are of different origin, the nda, ndb, and ndc genes carry an identical intron position. [References: 57] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Rasmusson AG Lund Univ, Dept Cell & Organ Biol Biol Bldg,Solvegatan 35B SE-22362 Lund Sweden Lund Univ, Dept Cell & Organ Biol SE-22362 Lund Sweden Lund Univ, Dept Plant Biochem SE-22100 Lund Sweden Univ Ulm, Abt Mol Bot D-89069 Ulm Germany <12> UI - 732ZE-0042 DD - ISI Document Solution: 732ZE AU - Muller-Moule P AU - Havaux M AU - Niyogi KK MA - niyogi@nature.berkeley.edu RA - Niyogi KK TI - Zeaxanthin deficiency enhances the high light sensitivity of an ascorbate-deficient mutant of Arabidopsis SO - Plant Physiology. 133(2):748-760, 2003 Oct. AS - Plant Physiol 2003 Oct;133(2):748-760 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Violaxanthin de-epoxidase MH - Xanthophyll cycle MH - Photooxidative damage MH - Chloroplasts MH - Energy MH - Dissipation MH - Plants MH - Acid MH - Peroxiredoxin MH - Biosynthesis. AB - The ascorbate content of plants is usually increased in high light (HL), implying a function for ascorbate in the acclimation of plants to HL. Nevertheless, the importance of ascorbate in HL acclimation has not yet been tested directly. Here, we report on the acclimation process of an ascorbate-deficient Arabidopsis mutant to HL. The mutant vtc2 has only 10% to 30% of wild-type levels of ascorbate, and it is also slightly deficient in feedback de-excitation (qE), a photoprotective mechanism that causes the dissipation of excess light as heat. The vtc2 mutant was unable to acclimate to HL, when transferred from low light to HL. Its mature leaves bleached, and it showed an increased degree of lipid peroxidation and photoinhibition. In parallel, we tested the photosensitivity of an ascorbate-deficient xanthophyll cycle mutant, vtc2npq1, which also lacks zeaxanthin and nearly all qE. The double mutant bleached sooner and had higher degrees of lipid peroxidation and photoinhibition than the vtc2 mutant. This was in contrast to the npq1 single mutant that showed only slight deviations from the wild-type phenotype under the conditions used. These results demonstrate the antioxidant role of ascorbate in the acclimation process to HL and point to the relative importance of ascorbate in comparison with other photoprotective processes, such as specific xanthophylls or feedback de-excitation. The results also provide further support for the proposed role of zeaxanthin as an antioxidant and lipid stabilizer. [References: 45] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Niyogi KK Univ Calif Berkeley, Dept Plant & Microbial Biol Berkeley, CA 94720 USA Univ Calif Berkeley, Dept Plant & Microbial Biol Berkeley, CA 94720 USA Univ Mediterranee, Commissariat Energie Atom 163, Unite Mixte Rech Ctr Natl Rech Sci,Commissariat E, Lab Ecophysiol Photosynth,Dept Ecophysiol Vegetal F-13108 St Paul Les Durance France <13> UI - 732ZE-0044 DD - ISI Document Solution: 732ZE AU - Pietrini F AU - Iannelli MA AU - Pasqualini S AU - Massacci A MA - angelo.massacci@ibaf.cnr.it RA - Massacci A TI - Interaction of cadmium with glutathione and photosynthesis in developing leaves and chloroplasts of Phragmites australis (Cav.) Trin. ex steudel SO - Plant Physiology. 133(2):829-837, 2003 Oct. AS - Plant Physiol 2003 Oct;133(2):829-837 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 0032-0889 MH - Metal-substituted chlorophylls MH - Hydrogen-peroxide MH - Ascorbate peroxidase MH - Electron-transport MH - Oxidative stress MH - Wheat seedlings MH - Higher-plants MH - Water plants MH - Tolerance MH - Mechanisms. AB - We investigated how the presence of cadmium (Cd) at the emergence of Phragmites australis Trin. (Cav.) ex Steudel plants from rhizomes interacted with leaf and chloroplast physiological and biochemical processes. About 8.5 nmol Cd mg(-1) chlorophyll was found in leaves, and 0.83 nmol Cd mg(-1) chlorophyll was found in chloroplasts of plants treated with 50 mum Cd. As a result, a 30% loss of chlorophyll was measured concomitantly with a comparable percentage reduction in light-saturated photosynthesis. Rubisco content and activity were lowered by 10% and 60%, respectively. Antioxidant activity was stimulated by Cd treatment and was associated with an increase in the glutathione and pyridine pools, and with a larger pool of reduced glutathione. It is suggested that the glutathione pool and its predominance in the reduced state protected the activity of many key photosynthetic enzymes against the thiophilic binding of Cd. Chloroplast ultrastructure was not significantly altered with 50 muM treatment and the efficiency of photosystem 11, measured as the fluorescence ratio F-v/F-m, remained high because F-0 and F-m were proportionally decreased. In plants treated with 100 mum Cd, all effects were exacerbated, but F-v/F-m remained close to that of control leaves and the glutathione and pyridine nucleotides pools were lowered. The results suggest that glutathione exerted a direct important protective role on photosynthesis in the presence of Cd. [References: 52] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Massacci A Inst Agroenvironm & Forest Biol Via Salaria Km 29300 I-00016 Monterotondo Rome Italy Inst Agroenvironm & Forest Biol I-00016 Monterotondo Rome Italy Univ Perugia, Dept Plant Biol & Environm Biotechnol I-16121 Perugia Italy <14> UI - 732FP-0012 DD - ISI Document Solution: 732FP AU - Cheng ZG AU - Sattler S AU - Maeda H AU - Sakuragi Y AU - Bryant DA AU - DellaPennaa D MA - dellapen@pilot.msu.edu RA - DellaPennaa D TI - Highly divergent methyltransferases catalyze a conserved reaction in tocopherol and plastoquinone synthesis in cyanobacteria and photosynthetic eukaryotes SO - Plant Cell. 15(10):2343-2356, 2003 Oct. AS - Plant Cell 2003 Oct;15(10):2343-2356 PU - AMER SOC PLANT BIOLOGISTS, 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA. URL: http://www.aspb.org IS - 1040-4651 MH - Synechocystis sp pcc-6803 MH - Vitamin-e MH - Homogentisate phytyltransferase MH - Spinach-chloroplasts MH - Hydroxyphenylpyruvate dioxygenase MH - Dependent methyltransferases MH - Functional-analysis MH - Alpha-tocopherol MH - Sequence motifs MH - Arabidopsis. AB - Tocopherols are lipid-soluble compounds synthesized only by photosynthetic eukaryotes and oxygenic cyanobacteria. The pathway and enzymes for tocopherol synthesis are homologous in cyanobacteria and plants except for 2-methyl-6-phytyl-1,4-benzoquinone/2-methyl-6-solanyl-1,4-benzoquino ne methyltransferase (MPBQ/MSBQ MT), which catalyzes a key methylation step in both tocopherol and plastoquinone (PO) synthesis. Using a combined genomic, genetic, and biochemical approach, we isolated and characterized the VTE3 (vitamin E defective) locus, which encodes MPBQ/MSBQ MT in Arabidopsis. The phenotypes of vte3 mutants are consistent with the disruption of MPBQ/MSBQ MT activity to varying extents. The ethyl methanesulfonate-derived vte3-1 allele alters tocopherol composition but has little impact on PQ levels, whereas the null vte3-2 allele is deficient in PO and alpha- and gamma-tocopherols. In vitro enzyme assays confirmed that VTE3 is the plant functional equivalent of the previously characterized MPBQ/MSBQ MT (SII0418) from Synechocystis sp PCC6803, although the two proteins are highly divergent in primary sequence. SII0418 orthologs are present in all fully sequenced cyanobacterial genomes, Chlamydomonas reinhardtii, and the diatom Thalassiosira pseudonana but absent from vascular and nonvascular plant databases. VTE3 orthologs are present in all vascular and nonvascular plant databases and in C. reinhardtii but absent from cyanobacterial genomes. Intriguingly, the only prokaryotic genomes that contain VTE3-like sequences are those of two species of archea, suggesting that, in contrast to all other enzymes of the plant tocopherol pathway, the evolutionary origin of VTE3 may have been archeal rather than cyanobacterial. In vivo analyses of vte3 mutants and the corresponding homozygous Synechocystis sp PCC6803 sII0418::aphII mutant revealed important differences in enzyme redundancy, the regulation of tocopherol synthesis, and the integration of tocopherol and PQ biosynthesis in cyanobacteria and plants. [References: 48] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: DellaPennaa D Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Michigan State Univ, Dept Biochem & Mol Biol E Lansing, MI 48824 USA Penn State Univ, Dept Biochem & Mol Biol University Pk, PA 16802 USA <15> UI - 731LZ-0007 DD - ISI Document Solution: 731LZ AU - Klaidman L AU - Morales M AU - Kem S AU - Yang J AU - Chang ML AU - Adams JD MA - jadams@hse.use.edu RA - Adams JD TI - Nicotinamide offers multiple protective mechanisms in stroke as a precursor for NAD(+), as a PARP inhibitor and by partial restoration of mitochondrial function SO - Pharmacology. 69(3):150-157, 2003 Nov. AS - Pharmacology 2003 Nov;69(3):150-157 PU - KARGER, ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND. URL: http://www.karger.ch IS - 0031-7012 MH - Nicotinamide MH - Adenosine-5 '-triphosphate MH - Nicotinamide adenine dinucleotide MH - Glutathione MH - Mitochondrial respiration. MH - Focal cerebral-ischemia MH - Respiratory-chain activity MH - Rat-liver mitochondria MH - Dna strand-breaks MH - Poly(adp-ribose) polymerase MH - Cell-death MH - Forebrain ischemia MH - Energy-metabolism MH - Pyruvate-dehydrogenase MH - Oxidative stress. AB - The purpose of the current study was to investigate aspects of improved bioenergetic function using nicotinamide during stroke. Using a global ischemia-reperfusion mouse model, ATP was depleted by 50% in the brain. The use of nicotinamide to provide a large reserve of brain NAD(+) restored ATP levels to 61% of control levels. Alternatively, using nicotinamide as a PARP inhibitor restored ATP levels up to 72%. However, using a large reserve of NAD(+) in the brain together with PARP inhibition proved to be additive, restoring ATP to 85% of control levels during the first critical 5 min of reperfusion. NAD(+) and ATP levels correlated almost exactly. Brain mitochondrial function was also examined after cerebral ischemia-reperfusion. State 3 respiration of complex I was found to be abolished. However, this was a non-permanent inhibition of activity in vitro, since (NADH ubiquinone oxideroductase) complex I activity in these mitochondria was restored upon the addition of NADH. In vivo, the use of increased brain NAD(+) and PARP inhibition was able to partially restore mitochondrial respiration. Taken together, the results show that nicotinamide offers a substantial protective role in terms of preservation of cellular ATP and mitochondrial NAD-linked respiration. Copyright (C) 2003 S. Karger AG, Basel. [References: 51] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Pharmacology & Toxicology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Adams JD Univ So Calif, Sch Pharm 1985 Zonal Ave,PSC 508 Los Angeles, CA 90089 USA Univ So Calif, Sch Pharm Los Angeles, CA 90089 USA <16> UI - 732TF-0016 DD - ISI Document Solution: 732TF AU - Quaiser A AU - Ochsenreiter T AU - Lanz C AU - Schuster SC AU - Treusch AH AU - Eck J AU - Schleper C MA - schleper@bio.tu-darmstadt.de RA - Schleper C TI - Acidobacteria form a coherent but highly diverse group within the bacterial domain: evidence from environmental genomics SO - Molecular Microbiology. 50(2):563-575, 2003 Oct. AS - Mol. Microbiol 2003 Oct;50(2):563-575 PU - BLACKWELL PUBLISHING LTD, 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND. URL: http://www.blackwell-science.com IS - 0950-382X MH - Ribosomal-rna genes MH - Archaeon cenarchaeum-symbiosum MH - Agrobacterium-tumefaciens MH - Soil bacteria MH - Waste-water MH - Identification MH - Populations MH - Cultivation MH - Community MH - Virulence. AB - Acidobacteria have been established as a novel phylum of Bacteria that is consistently detected in many different habitats around the globe by 16S rDNA-based molecular surveys. The phylogenetic diversity, ubiquity and abundance of this group, particularly in soil habitats, suggest an important ecological role and extensive metabolic versatility. However, the genetic and physiological information about Acidobacteria is scarce. In order to gain insight into genome structure, evolution and diversity of these microorganisms we have initiated an environmental genomic approach by constructing large insert libraries directly from DNA of a calcerous grassland soil. Genomic fragments of Acidobacteria were identified with specific 16S rDNA probes and sequence analyses of six independently identified clones were performed, representing in total more than 210 000 bp. The 16S rRNA genes of the genomic fragments differed between 2.3% and 19.9% and were placed into two different subgroups of Acidobacteria (groups III and V). Although partial co-linearity was found between genomic fragments, the gene content around the rRNA operons was generally not conserved. Phylogenetic reconstructions with orthologues that were encoded on two of the six genomic fragments (PurF, PurL, PurB and formamidopyrimidine-DNA glycosylase) confirmed the coherence of the acidobacterial phylum. One genomic fragment harboured a cluster of eight genes which was syntenic and highly homologous to genomic regions in Rhodopseudomonas palustris and Bradyrhizobium japonicum, including a conserved two-component system. Phylogenetic analysis of the putative response regulator confirmed that this similarity between Rhizobiales and Acidobacteria might be due to a horizontal gene transfer. In total, our data give first insight into the genome content and diversity of the ubiquitously distributed but poorly characterized phylum of Acidobacteria. Furthermore they support the phylogenetic inferences made from 16S rRNA gene libraries, suggesting that Acidobacteria form a broad group in the same sense and with a similar diversity as that of many well-studied bacterial phyla. [References: 55] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Schleper C TH Darmstadt, Inst Microbiol & Genet Schnittspahnstr 10 D-64287 Darmstadt Germany TH Darmstadt, Inst Microbiol & Genet D-64287 Darmstadt Germany Max Planck Inst Dev Biol D-72076 Tubingen Germany BRAIN Aktiengesell D-64673 Zwingenberg Germany <17> UI - 733FC-0005 DD - ISI Document Solution: 733FC AU - Wadhams GH AU - Warren AV AU - Martin AC AU - Armitage JP MA - armitage@bioch.ox.ac.uk RA - Armitage JP TI - Targeting of two signal transduction pathways to different regions of the bacterial cell SO - Molecular Microbiology. 50(3):763-770, 2003 Nov. AS - Mol. Microbiol 2003 Nov;50(3):763-770 PU - BLACKWELL PUBLISHING LTD, 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND. URL: http://www.blackwell-science.com IS - 0950-382X MH - Escherichia-coli cell MH - Rhodobacter-sphaeroides MH - Chemotaxis protein MH - Localization MH - Chemoreceptor MH - Phosphorylation MH - Identification MH - Behavior MH - Homologs MH - Chew. AB - Components of bacterial chemosensory pathways which sense via transmembrane receptors have been shown to localize to the cell poles. Many species, however, have operons encoding multiple putative chemosensory pathways, some including putative cytoplasmic receptors. In-genome fusions to single or multiple genes encoding components of two chemosensory pathways in Rhodobacter sphaeroides, cheOp(2) and cheOp(3), revealed that while sensory transducing proteins associated with transmembrane receptors and encoded on cheOp(2) were targeted to the cell poles, the proteins associated with putative cytoplasmic receptors and encoded on cheOp(3) were all targeted to a cytoplasmic cluster. No proteins were localized to both sites. These data show that bacteria target components of related pathways to different sites in the cell, presumably preventing direct cross-talk between the different pathways, but allowing a balanced response between extracellular and cytoplasmic signals. It also indicates that there is intracellular organization in bacterial cells, with specific proteins targeted and localized to cytoplasmic regions. [References: 31] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Armitage JP Univ Oxford, Dept Biochem S Parks Rd Oxford OX1 3QU England Univ Oxford, Dept Biochem Oxford OX1 3QU England <18> UI - 733FC-0007 DD - ISI Document Solution: 733FC AU - Balabas BE AU - Montgomery BL AU - Ong LE AU - Kehoe DM MA - dkehoe@bio.indiana.edu RA - Kehoe DM TI - CotB is essential for complete activation of green light-induced genes during complementary chromatic adaptation in Fremyella diplosiphon SO - Molecular Microbiology. 50(3):781-793, 2003 Nov. AS - Mol. Microbiol 2003 Nov;50(3):781-793 PU - BLACKWELL PUBLISHING LTD, 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND. URL: http://www.blackwell-science.com IS - 0950-382X MH - Subunit phycocyanobilin lyase MH - Calothrix sp pcc-7601 MH - Cyanobacterium calothrix MH - Alpha-subunit MH - Adapting cyanobacterium MH - Phycoerythrin operon MH - Multigene family MH - Action spectra MH - Messenger-rna MH - Expression. AB - The dramatic modifications of photosynthetic light harvesting antennae called phycobilisomes that occur during complementary chromatic adaptation in cyanobacteria are controlled by two separate photosensory systems. The first system involves the signal transduction components RcaE, RcaF and RcaC, which appear to make up a complex multistep phosphorelay. This system controls the light responsive expression of the cpcB2A2H2I2D2, cpeBA and cpeCDE operons, which encode phycobilisome proteins. The second system, which is not yet characterized, acts in concert with the first but only regulates the light responses of cpeBA and cpeCDE. We have generated and characterized a new mutant class, named the Tan mutants. In at least one member of this class, light-regulated RNA accumulation patterns are altered for cpeBA and cpeCDE, but not for cpcB2A2H2I2D2. Thus this mutant contains a lesion that may impair the operation of the second system. We demonstrate that several Tan mutants are the result of improper expression of the gene cotB. CotB has limited similarity to lyase class proteins, particularly those related to NblB, which is required for degradation of phycobilisomes in other cyanobacteria. Possible roles of CotB in the biogenesis of phycobilisomes are discussed. [References: 49] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Kehoe DM Indiana Univ, Dept Biol Bloomington, IN 47405 USA Indiana Univ, Dept Biol Bloomington, IN 47405 USA <19> UI - 732RQ-0004 DD - ISI Document Solution: 732RQ AU - Smith LD AU - Negri AP AU - Philipp E AU - Webster NS AU - Heyward AJ MA - l.smith@aims.gov.au RA - Smith LD TI - The effects of antifoulant-paint-contaminated sediments on coral recruits and branchlets SO - Marine Biology. 143(4):651-657, 2003 Oct. AS - Mar. Biol 2003 Oct;143(4):651-657 PU - SPRINGER-VERLAG, 175 FIFTH AVE, NEW YORK, NY 10010 USA. URL: http://www.springer-ny.com IS - 0025-3162 MH - Great-barrier-reef MH - Anemone aiptasia-pallida MH - Chlorophyll fluorescence MH - Larval metamorphosis MH - Photosystem-ii MH - Copper MH - Zooxanthellae MH - Stress MH - Fertilization MH - Tributyltin. AB - The 184-m cargo ship 'Bunga Teratai Satu' ran aground on Sudbury Reef, within the Great Barrier Reef Marine Park, on 2 November 2000. Although no cargo or fuel was lost, the ship remained aground for 12 days and a large quantity of antifoulant paint containing tributyltin (TBT), zinc, and copper was scraped from the hull during the grounding and subsequent refloating operation. This resulted in extensive contamination of the reef sediments for up to 250 m surrounding the grounding site. Two laboratory-based experiments assessed the impact of contaminated sediments on the survival of both newly settled corals of Acropora microphthalma and branchlets of A. formosa. Newly settled corals exposed to sediments containing 8.0 mg kg(-1) TBT, 72 mg kg(-1) Cu, and 92 mg kg(-1) Zn or greater suffered significantly higher mortality after 72 h, compared to control or low-concentration treatments. Coral recruits exposed to 40 mg kg(-1) TBT (Sn), 306 mg kg(-1) Cu, and 403 mg kg(-1) Zn were all killed within 38 h. Branchlets from adult corals exposed to sediments with a high concentration of contaminants (TBT 160 mg kg(-1), Cu 1,180 mg kg(-1), and Zn 1,570 mg kg(-1)) suffered significant mortality (38%), whereas branchlets placed in treatments with lower levels of contaminants suffered no mortality. Visual bleaching of the branchlets was observed at high contaminant levels, but an overall reduction in the symbiotic zooxanthellae populations was not observed in surviving corals. The photosynthetic yields of light-adapted zooxanthellae remained constant in live branchlets, indicating that the TBT-contaminated sediment may be more toxic to the host than the symbiont. Our results show that antifoulant contamination at ship-grounding sites has the potential to cause major mortality of resident coral communities and can have a negative impact on the recovery of adult populations. [References: 35] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2003 week 45 IN - Reprint available from: Smith LD Australian Inst Marine Sci POB 83 Fremantle 6959 Australia Australian Inst Marine Sci Fremantle 6959 Australia Australian Inst Marine Sci Townsville Qld 4810 Australia Alfred Wegener Inst Polar & Marine Res D-27568 Bremerhaven Germany <20> UI - 733EZ-0004 DD - ISI Document Solution: 733EZ AU - Minahk CJ AU - Morero RD MA - rdmore@unt.edu.ar RA - Morero RD TI - Inhibition of enterocin CRL35 antibiotic activity by mono- and divalent ions SO - Letters in Applied Microbiology. 37(5):374-379, 2003. AS - Lett. Appl. Microbiol 2003;37(5):374-379 PU - BLACKWELL PUBLISHING LTD, 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND. URL: http://www.blackwell-science.com IS - 0266-8254 MH - Antibiotic peptide MH - Bacteriocin MH - Enterocin MH - Environmental conditions MH - Peptide uptake. MH - Amino-acid-sequence MH - Listeria-monocytogenes MH - Bacteriocins MH - Purification MH - Temperature MH - Nisin MH - Ph. AB - Aim: The aim of this work was to study the influence of different cations on the enterocin CRL35 activity. Methods and Results: The antilisterial activity of enterocin CRL35 was tested by performing viability curves and measuring the dissipation of the proton motive force by fluorescent methods upon the addition of Ca2+, Mg2+, Li+, K+ and Na+ chlorides. The peptide uptake by sensitive cells was studied in the different conditions as well. The addition of calcium and magnesium chlorides (0.5-2 mmol l(-1)) induced an inhibition of the peptide activity. Potassium, sodium and lithium chlorides have an inhibitory effect as well, but at different range of concentration compared with divalent cations (50-150 mmol l(-1)). Interestingly, we found a differential protection effect among monovalent ions, KCl being almost nonprotective, meanwhile LiCl shows the stronger effect and NaCl has an intermediate effect. The ion effect depends on the pH, being more efficient in acidic media. Both mono and divalent ions inhibited the ability of the peptide to dissipate the transmembrane electric potential and pH gradient. Furthermore, the peptide uptake was also inhibited. Conclusions: The enterocin CRL35 activity is strongly dependent on the pH and the nature of the salts present in the medium. Significance and Impact of the Study: These findings will allow definition of the best system in which this peptide can be applied as biopreservative. [References: 15] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Biotechnology & Applied Microbiology in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Morero RD Chacabuco 461 RA-4000 San Miguel De Tucuman Tucuman Argentina Univ Nacl Tucuman, Consejo Nacl Invest Cient & Tecn, Inst Super Invest Biol, Dept Bioquim Nutr RA-4000 San Miguel De Tucuman Tucuman Argentina Inst Quim Biol Dr Bernabe Bloj San Miguel De Tucuman Tucuman Argentina <21> UI - 730YF-0037 DD - ISI Document Solution: 730YF AU - Munge B AU - Das SK AU - Ilagan R AU - Pendon Z AU - Yang J AU - Frank HA AU - Rusling JF MA - James.Rusling@uconn.edu RA - Frank HA TI - Electron transfer reactions of redox cofactors in spinach Photosystem I reaction center protein in lipid films on electrodes SO - Journal of the American Chemical Society. 125(41):12457-12463, 2003 Oct 15. AS - J. Am. Chem. Soc 2003 Oct 15;125(41):12457-12463 PU - AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA. URL: http://pubs.acs.org IS - 0002-7863 MH - Square-wave voltammetry MH - Photosynthetic reaction centers MH - Biomembrane-like films MH - Iron-sulfur cluster MH - Cytochrome p450(cam) MH - F-b MH - Direct electrochemistry MH - Cyclic voltammetry MH - Polyion films MH - Complexes. AB - Thin film voltammetry was used to obtain direct, reversible, electron transfer between electrodes and spinach Photosystem I reaction center (PS I) in lipid films for the first time. This reaction center (RC) protein retains its native conformation in the films, and AFM showed that film structure rearranges during the first several minutes of rehydration of the film. Two well-defined chemically reversible reduction-oxidation peaks were observed for native PS I in the dimyristoylphosphatidylcholine films, and were assigned to phylloquinone, A(1) (E-m = -0.54 V) and iron-sulfur clusters, F-A/F-B (E-m = -0.19 V) by comparisons with PS I samples selectively depleted of these cofactors. Observed E-m values may be influenced by protein-lipid interactions and electrode double-layer effects. Voltammetry was consistent with simple kinetically limited electron transfers, and analysis of reduction-oxidation peak separations gave electrochemical rate constants of 7.2 s(-1) for A, and 65 s(-1) for F-A/F-B. A catalytic process was observed in which electrons were injected from PS I in films to ferredoxin in solution, mimicking in vivo electron shuttle from the terminal F-A/F-B cofactors to soluble ferredoxin during photosynthesis. [References: 61] LG - English PT - Article SB - Current Contents(R)/Life Sciences Current Contents(R)/Physical, Chemical & Earth Sciences CC - Chemistry & Analysis in Current Contents(R)/Life Sciences. Chemistry in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Frank HA Univ Connecticut, Dept Chem U-60 Storrs, CT 06269 USA Univ Connecticut, Dept Chem Storrs, CT 06269 USA Univ Connecticut, Ctr Hlth, Dept Pharmacol Farmington, CT 06032 USA <22> UI - 733FL-0005 DD - ISI Document Solution: 733FL AU - Kadlecek P AU - Rank B AU - Ticha I MA - iticha@natur.cuni.cz RA - Ticha I TI - Photosynthesis and photoprotection in Nicotiana tabacum L. in vitro grown plantlets SO - Journal of Plant Physiology. 160(9):1017-1024, 2003 Sep. AS - J. Plant Physiol 2003 Sep;160(9):1017-1024 PU - URBAN & FISCHER VERLAG, BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY. URL: http://www.urbanfischer.de IS - 0176-1617 MH - Ascorbate-glutathione cycle enzymes MH - Chlorophyll a fluorescence MH - Light stress MH - Net photosynthetic rate MH - Photoautotrophy and photomixotrophy MH - Photoinhibition MH - Sucrose MH - Xanthophyll cycle pigments. MH - Xanthophyll cycle MH - Oxidative stress MH - Gene-expression MH - Mehler reaction MH - Photosystem-ii MH - Photoinhibition MH - Leaves MH - Chloroplasts MH - Light MH - Photoautotrophy. AB - Nicotiana tabacum L. plantlets were cultured in vitro photoautotrophically (0 % sucrose) and photomixotrophically (3 % or 5 % sucrose) at two irradiances (80 or 380 mumol m(-2) s(-1)) with the aim of investigating the effect of these culture conditions on photosynthetic parameters and on protective systems against excess excitation energy. In plantlets grown photoautotrophically under higher irradiance photoinhibition was demonstrated. These plantlets had a decreased chlorophyll (Chl) a + b content and Chl a/b ratio, an increased content of xanthophyll cycle pigments and a higher deepoxidation state, a decreased maximum photochemical efficiency of photosystem II (PS II) and actual photochemical efficiency of PS II, and an increased non-photochemical quenching. In the photoautotrophically grown plantlets and those photomixotrophically grown with 3 % sucrose, the increase of growth irradiance from 80 to 380 mumol m(-2) s(-1) stimulated the activities of ascorbate-glutathione cycle enzymes with the exception of ascorbate peroxidase. Ascorbate peroxidase activity was not affected by the increase in growth irradiance but a significant decrease with increasing sucrose concentration was evident. The higher concentration of sucrose in the medium (5 %) in combination with the higher irradiance inhibited photosynthesis (decrease in Chl a + b content and net photosynthetic rate) but no significant changes in activities of ascorbate-glutathione cycle enzymes were found. These results suggest that exogenous sucrose added to the medium improved high irradiance and oxidative stress resistance of the plantlets but the effect of sucrose is concentration dependent. [References: 31] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Ticha I Charles Univ, Fac Sci, Dept Plant Physiol Vinicna 5 CZ-12844 Prague 2 Czech Republic Charles Univ, Fac Sci, Dept Plant Physiol CZ-12844 Prague 2 Czech Republic Humboldt Univ, Inst Biol D-10099 Berlin Germany <23> UI - 733FL-0009 DD - ISI Document Solution: 733FL AU - Spundova M AU - Popelkova H AU - Ilik P AU - Skotnica J AU - Novotny R AU - Naus J MA - matousko@prfnw.upol.cz RA - Spundova M TI - Ultra-structural and functional changes in the chloroplasts of detached barley leaves senescing under dark and light conditions SO - Journal of Plant Physiology. 160(9):1051-1058, 2003 Sep. AS - J. Plant Physiol 2003 Sep;160(9):1051-1058 PU - URBAN & FISCHER VERLAG, BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY. URL: http://www.urbanfischer.de IS - 0176-1617 MH - Chlorophyll fluorescence MH - Chloroplast ultra-structure MH - Leaf senescence MH - Photosystem ii. MH - Chlorophyll fluorescence MH - Rice leaves MH - Photosynthetic apparatus MH - Biochemical-changes MH - Pigment synthesis MH - Leaf senescence MH - Wheat leaves MH - Cotyledons MH - Seedlings MH - Ultrastructure. AB - Changes in the chloroplast ultra-structure and photochemical function were studied in detached barley (Hordeum vulgare L. cv. Akcent) leaf segments senescing in darkness or in continuous white light of moderate intensity (90 mumol m(-2) s(-1)) for 5 days. A rate of senescence-induced chlorophyll degradation was similar in the dark- and light-senescing segments. The Chl a/b ratio was almost unchanged in the dark-senescing segments, whereas in the light-senescing segments an increase in this ratio was observed indicating a preferential degradation of light-harvesting complexes of photosystem II. A higher level of thylakoid disorganisation (especially of granal membranes) and a very high lipid peroxidation were observed in the light-senescing segments. In spite of these findings, both the maximal and actual photochemical quantum yields of the photosystem II were highly maintained in comparison with the dark-senescing segments. [References: 44] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Plant Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Animal & Plant Sciences in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Spundova M Palacky Univ, Dept Expt Phys Tr Svobody 26 Olomouc 77146 Czech Republic Palacky Univ, Dept Expt Phys Olomouc 77146 Czech Republic Palacky Univ, Fac Med, Ctr Micoscop Methods Olomouc 77520 Czech Republic <24> UI - 730YH-0033 DD - ISI Document Solution: 730YH AU - Nonella M AU - Mathias G AU - Tavan P MA - tavan@physik.uni-muenchen.de RA - Tavan P TI - Infrared spectrum of p-benzoquinone in water obtained from a QM/MM hybrid molecular dynamics simulation SO - Journal of Physical Chemistry a Molecules. 107(41):8638-8647, 2003 Oct 16. AS - J. Phys. Chem. A 2003 Oct 16;107(41):8638-8647 PU - AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA. URL: http://pubs.acs.org IS - 1089-5639 MH - Bacterial reaction centers MH - Photosynthetic reaction-center MH - Ftir difference spectroscopy MH - Adapted multipole method MH - Rhodobacter-sphaeroides MH - Vibrational frequencies MH - Liquid water MH - Electrostatic interactions MH - Protein dynamics MH - Binding-sites. AB - The accurate description of vibrational spectra of isolated dye molecules such as quinones has become a standard task in computational chemistry due to the progress of density functional theory. This is by no means the case for solution spectra. To contribute to this issue, we have carried out a QM/MM hybrid molecular dynamics (MD) simulation of p-benzoquinone in water, so as to derive its IR spectra. We have explored two different computational procedures that allow the calculation of an IR spectrum from such a dynamics simulation. One is based on Fourier transforms of autocorrelation functions and the other on instantaneous normal-mode analyses of snapshots. We show that both approaches are valid and yield similar vibrational frequencies. For a detailed comparison of computed bandwidths and intensities, however, our 17.5 ps QM/ MM-MD trajectory turned out to be too short. The analysis of the trajectory also demonstrates that, on the average, three water molecules form distinct solvation shells around each of the quinone C=O groups. These hydrogen bonded water molecules exchange on a time scale of about 2.5 ps. Computations on small, rigid quinone-water clusters compare reasonably well with the dynamics approach concerning the spectral positions of the quinone IR bands. Of course, the inhomogeneous broadening of IR bands, which is covered by the dynamics calculations, is inaccessible to the static cluster approach. [References: 44] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physical Chemistry/Chemical Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Tavan P Univ Munich, Lehrstuhl Biomol Opt Oettingenstr 67 D-80538 Munich Germany Univ Munich, Lehrstuhl Biomol Opt D-80538 Munich Germany <25> UI - 733FW-0001 DD - ISI Document Solution: 733FW AU - Kim D AU - Osuka A MA - dongho@yonsei.ac.kr, osuka@kuchem.kyoto-u.ac.jp RA - Kim D TI - Photophysical properties of directly linked linear porphyrin arrays [Review] SO - Journal of Physical Chemistry a Molecules. 107(42):8791-8816, 2003 Oct 23. AS - J. Phys. Chem. A 2003 Oct 23;107(42):8791-8816 PU - AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA. URL: http://pubs.acs.org IS - 1089-5639 MH - Photosynthetic reaction-center MH - Exciton delocalization length MH - Resonance raman-spectroscopy MH - Energy relaxation dynamics MH - Light-harvesting arrays MH - Pump-probe spectroscopy MH - Zn-tetraphenylporphyrin MH - Optical-properties MH - Electronic states MH - Dihedral angle. AB - A variety of porphyrin arrays connected by diverse linkers have been envisaged and prepared for the applications in molecular photonics and electronics. From a viewpoint of operational requirements, the porphyrin arrays should have the very regular pigment arrangements which allow a facile light energy or charge flow along the arrays but do not result in the alteration of individual properties of the constituent pigments leading to formation of so-called energy or charge sink. In these respects, the directly coupled (orthogonal and fused) porphyrin arrays without any linkers are ideal, because the conformational heterogeneity mainly arising from a dihedral angle distribution between the neighboring porphyrin moieties should be minimized. In addition, the electronic effect of the linker can be disregarded in design strategy of molecular photonic devices, because the linker can also be considered as a transmission element in electronic communication. Considering these features, these types (orthogonal vs fused) of porphyrin arrays would be one of the most suitable synthetic molecular modules for the realization of molecular photonic and electronic devices. To unveil the functionalities of various porphyrin arrays, starting from the dihedral angle dependence on the photophysical properties of the porphyrin dimers, we have extended our knowledge to longer orthogonal and fused porphyrin arrays. Overall, the regularly arranged porphyrin arrays with ample electronic interactions will be promising in the applications such as molecular wires, sensors, optical nonlinear materials, and so on. [References: 118] LG - English PT - Review SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physical Chemistry/Chemical Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Kim D Yonsei Univ, Natl Creat Res Initiat Ctr Ultrafast Opt Characte Seoul 120749 South Korea Yonsei Univ, Natl Creat Res Initiat Ctr Ultrafast Opt Characte Seoul 120749 South Korea Yonsei Univ, Dept Chem Seoul 120749 South Korea Kyoto Univ, Japan Sci & Technol Corp, Dept Chem Kyoto 6068502 Japan Kyoto Univ, Japan Sci & Technol Corp, CREST Kyoto 6068502 Japan <26> UI - 733FW-0004 DD - ISI Document Solution: 733FW AU - Tkachenko NV AU - Lemmetyinen H AU - Sonoda J AU - Ohkubo K AU - Sato T AU - Imahori H AU - Fukuzumi S MA - nikolai.tkachenko@tut.fi, helge.lemmetyinen@tut.fi, imahori@scl.kyoto-u.ac.jp, fukuzumi@ap.chem.eng.osaka-u.ac.jp RA - Tkachenko NV TI - Ultrafast photodynamics of exciplex formation and photoinduced electron transfer in porphyrin-fullerene dyads linked at close proximity SO - Journal of Physical Chemistry a Molecules. 107(42):8834-8844, 2003 Oct 23. AS - J. Phys. Chem. A 2003 Oct 23;107(42):8834-8844 PU - AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA. URL: http://pubs.acs.org IS - 1089-5639 MH - Picosecond laser photolysis MH - Charge-transfer complexes MH - Aromatic hydrocarbon complexes MH - Photosynthetic reaction-center MH - Synthetic dna hairpins MH - Excited singlet-state MH - Energy-transfer MH - Ion-pairs MH - Artificial photosynthesis MH - Solvent dependence. AB - The ultrafast photodynamics of porphyrin-fullerene dyads in which the distance between the porphyrin and C-60 moieties is varied systematically at close proximity has been examined using fluorescence up-conversion and pump-probe transient absorption techniques with time resolutions of ca. 100 fs. The porphyrin-fullerene dyads examined are MP-D-C-60 (M = Zn and 2H) in which the C-60 moiety is directly connected with the porphyrin ring at the meso position and MP-O-C-60, MP-M-C-60, and MP-P-C-60 in which the C-60 moiety is linked with porphyrin moieties through the benzene ring at the ortho, meta, and para positions, respectively. The charge transfer (CT) bands are observed for MP-D-C-60 and MP-O-C-60, whereas no CT band is seen for MP-M-C-60 and MP-P-C-60. Time-resolved absorption spectral measurements indicate that the photoexcitation of ZnP-D-C-60 in benzonitrile (PhCN) results in formation of the exciplex, which decays to the ground state without forming the charge-separated state. The strong interaction between the ZnP and the C-60 moieties due to the short linkage distance in ZnP-D-C-60 as indicated by the observation of the strongest CT band at the ground state results in formation of the exciplex. The energy of the exciplex is lower than that of the charge-separated state even in a polar solvent such as PhCN. In contrast, the photoexcitation of the dyad with longer linkage, ZnP-O-C-60, in PhCN results in formation of the charge-separated state via the exciplex formation, which is higher in energy than the charge-separated state. The photodynamics of exciplex formation of porphyrin-C-60-linked dyads with a short linkage is characterized by the extremely fast formation rate from the singlet excited states of porphyrins involving both the second and first excited states due to the interaction between the porphyrin and C-60 moieties, which are placed at close proximity. In the case of MP-D-C-60, the exciplex formation from the first singlet excited state of MP occurs at an ultrafast time scale with a time constant of 160 fs and that from the second singlet excited state occurs faster with a time constant less than 50 fs. [References: 73] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physical Chemistry/Chemical Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Tkachenko NV Tampere Univ Technol, Inst Mat Chem POB 541 FIN-33101 Tampere Finland Tampere Univ Technol, Inst Mat Chem FIN-33101 Tampere Finland Osaka Univ, CREST, Grad Sch Engn, Dept Mat & Life Sci Suita Osaka 5650871 Japan Sci & Technol Corp Suita Osaka 5650871 Japan Univ Tsukuba, Dept Chem Tsukuba Ibaraki 3058571 Japan Kyoto Univ, PRESTO, Grad Sch Engn, Dept Mol Engn,JST,Nishikyo Ku Kyoto 6158510 Japan Kyoto Univ, Fukui Inst Fundamental Chem, Sakyo Ku Kyoto 6068103 Japan <27> UI - 732FQ-0001 DD - ISI Document Solution: 732FQ AU - Arrigo KR AU - Robinson DH AU - Dunbar RB AU - Leventer AR AU - Lizotte MP MA - arrigo@pangea.stanford.edu RA - Arrigo KR TI - Physical control of chlorophyll a, POC, and TPN distributions in the pack ice of the Ross Sea, Antarctica - art. no. 3316 SO - Journal of Geophysical Research-Oceans. 108(C10):3316, 2003 Oct 10. AS - J. Geophys. Res.-Oceans 2003 Oct 10;108(C10):3316 PU - AMER GEOPHYSICAL UNION, 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA. URL: http://www.agu.org IS - 0148-0227 MH - Sea ice MH - Algae MH - Antarctic MH - Nutrients MH - Ecosystem. MH - Photosynthesis-irradiance relationships MH - Spring phytoplankton bloom MH - Dense microalgal bloom MH - Saroma-ko lagoon MH - Terra-nova bay MH - Mcmurdo-sound MH - Weddell-sea MH - Microbial communities MH - Thickness distribution MH - Phaeocystis-pouchetii. AB - The pack ice ecosystem of the Ross Sea was investigated along a 1470-km north-south transect during the spring 1998 oceanographic program Research on Ocean-Atmosphere Variability and Ecosystem Response in the Ross Sea (ROAVERRS). Snow and sea ice thickness along the transect varied latitudinally, with thinner snow and ice at the northern ice edge and thin new ice in the vicinity of the Ross Sea polynya. Relative to springtime observations in other sea ice regions, algal chlorophyll a (Chl a) concentrations were low. In contrast, particulate organic carbon (POC), total particulate nitrogen (TPN), and POC:Chl a were all high, indicating either that the ice contained substantial amounts of detritus or nonphotosynthetic organisms, or that the algae had a high POC: Chl a ratio. The abundance of Chl a, POC, and TPN in the sea ice was related to ice age and thickness, as well as to snow depth: older ice had thinner snow cover and contained higher algal biomass while new ice in the polynya had lower biomass. Older pack ice was dominated by diatoms (particularly Fragilariopsis cylindrus) and had vertical distributions of Chl a, POC, and TPN that were related to salinity, with higher biomass at the ice-water interface. Fluorescence-based measurements of photosynthetic competence (Fv/Fm) were higher at ice-water interfaces, and photosynthesis-irradiance characteristics measured for bottom ice algae were comparable to those measured in pack ice communities of other regions. Nutrient concentrations in extracted sea ice brines showed depletion of silicate and nitrate, depletion or regeneration of phosphate and nitrite, and production of ammonium when normalized to seawater salinity; however, concentrations of dissolved inorganic nitrogen, phosphorous, and silica were typically above levels likely to limit algal growth. In areas where pack ice and snow cover were thickest, light levels could be limiting to algal photosynthesis. Enrichment of delta(13) C-POC in the sea ice was correlated with the accumulation of POC, suggesting that carbon sources for photosynthesis might shift in response to decreasing CO2 supply. Comparisons between new ice and underlying waters showed similar algal species dominance (Phaeocystis antarctica) implying incorporation of phytoplankton, with substantially higher POC and TPN concentrations in the ice. [References: 93] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Earth Sciences in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Arrigo KR Stanford Univ, Dept Geophys Mitchell Bldg,Room 355 Stanford, CA 94305 USA Stanford Univ, Dept Geophys Stanford, CA 94305 USA San Francisco State Univ, Romberg Tiburon Ctr Tiburon, CA USA Colgate Univ, Dept Geol Hamilton, NY 13346 USA Univ Wisconsin, Dept Biol & Microbiol Oshkosh, WI 54901 USA <28> UI - 731BW-0026 DD - ISI Document Solution: 731BW AU - Borrelli R AU - Peluso A MA - apeluso@unisa.it RA - Borrelli R TI - Dynamics of radiationless transitions in large molecular systems: A Franck-Condon-based method accounting for displacements and rotations of all the normal coordinates SO - Journal of Chemical Physics. 119(16):8437-8448, 2003 Oct 22. AS - J. Chem. Phys 2003 Oct 22;119(16):8437-8448 PU - AMER INST PHYSICS, CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA. URL: http://www.aip.org IS - 0021-9606 MH - Photosynthetic reaction centers MH - Potential-energy surfaces MH - Valence-bond approach MH - S1-s2 conical intersection MH - Assisted electron-transfer MH - Induced structural-changes MH - Polyatomic-molecules MH - Proton-transfer MH - Excited-state MH - Rhodopseudomonas-sphaeroides. AB - An efficient method to study the dynamics of radiationless transition in large molecular systems is proposed. It is based on the use of the whole set of normal coordinates of vibration and allows for taking properly into account both the displacements and the mix of the normal modes upon transition between two electronic states. The Hamiltonian matrix elements are written in terms of generalized Franck-Condon integrals and are analytically evaluated by recursion formulas. Applications to the S-2-->S-1 internal conversion in pyrazine and to long-range electron transfer between quinones in photosynthetic reaction centers are given. (C) 2003 American Institute of Physics. [References: 86] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physical Chemistry/Chemical Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Borrelli R Univ Salerno, Dipartimento Chim I-84081 Baronissi Salerno Italy Univ Salerno, Dipartimento Chim I-84081 Baronissi Salerno Italy <29> UI - 730TX-0026 DD - ISI Document Solution: 730TX AU - Rodionov DA AU - Vitreschak AG AU - Mironov AA AU - Gelfand MS MA - rodionov@genetika.ru RA - Rodionov DA TI - Comparative Genomics of the vitamin B-12 metabolism and regulation in prokaryotes SO - Journal of Biological Chemistry. 278(42):41148-41159, 2003 Oct 17. AS - J. Biol. Chem 2003 Oct 17;278(42):41148-41159 PU - AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA. URL: http://www.asbmb.org IS - 0021-9258 MH - Salmonella-typhimurium MH - Escherichia-coli MH - Cobalamin vitamin-b-12 MH - Pseudomonas-denitrificans MH - Acid a,c-diamide MH - Porphyromonas-gingivalis MH - Rhodobacter-capsulatus MH - Hemoglobin receptor MH - Messenger-rna MH - Biosynthesis. AB - Using comparative analysis of genes, operons, and regulatory elements, we describe the cobalamin ( vitamin B-12) biosynthetic pathway in available prokaryotic genomes. Here we found a highly conserved RNA secondary structure, the regulatory B-12 element, which is widely distributed in the upstream regions of cobalamin biosynthetic/transport genes in eubacteria. In addition, the binding signal (CBL-box) for a hypothetical B-12 regulator was identified in some archaea. A search for B-12 elements and CBL-boxes and positional analysis identified a large number of new candidate B-12-regulated genes in various prokaryotes. Among newly assigned functions associated with the cobalamin biosynthesis, there are several new types of cobalt transporters, ChlI and ChlD subunits of the CobN-dependent cobaltochelatase complex, cobalt reductase BluB, adenosyltransferase PduO, several new proteins linked to the lower ligand assembly pathway, L-threonine kinase PduX, and a large number of other hypothetical proteins. Most missing genes detected within the cobalamin biosynthetic pathways of various bacteria were identified as nonorthologous substitutes. The variable parts of the cobalamin metabolism appear to be the cobalt transport and insertion, the CobG/CbiG- and CobF/CbiD-catalyzed reactions, and the lower ligand synthesis pathway. The most interesting result of analysis of B-12 elements is that B-12-independent isozymes of the methionine synthase and ribonucleotide reductase are regulated by B-12 elements in bacteria that have both B-12-dependent and B-12-independent isozymes. Moreover, B-12 regulons of various bacteria are thought to include enzymes from known B-12-dependent or alternative pathways. [References: 50] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Rodionov DA State Sci Ctr GosNIIGenetika Moscow 113545 Russia State Sci Ctr GosNIIGenetika Moscow 113545 Russia Russian Acad Sci, Inst Problems Informat Transmiss Moscow 101447 Russia Integrated Genom Moscow Moscow 117333 Russia <30> UI - 730TX-0133 DD - ISI Document Solution: 730TX AU - Hihi AK AU - Kebir H AU - Hekimi S MA - siegfried.hekimi@mcgill.ca RA - Hekimi S TI - Sensitivity of Caenorhabditis elegans clk-1 mutants to ubiquinone side-chain length reveals multiple ubiquinone-dependent processes SO - Journal of Biological Chemistry. 278(42):41013-41018, 2003 Oct 17. AS - J. Biol. Chem 2003 Oct 17;278(42):41013-41018 PU - AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA. URL: http://www.asbmb.org IS - 0021-9258 MH - Lived clk-1 mutants MH - Coenzyme-q MH - Saccharomyces-cerevisiae MH - Carboxylate proteins MH - Alternative oxidase MH - Genetic-evidence MH - Active-site MH - Elegans MH - Mitochondrial MH - Biosynthesis. AB - Ubiquinone ( coenzyme Q, or Q) is a membrane constituent, whose head group is capable of accepting and donating electrons and whose lipidic side chain is composed of a variable number of isoprene subunits. A possible role for Q as a dietary antioxidant for treating conditions that involve altered cellular redox states is being intensely studied. Mutations in the clk-1 gene of the nematode Caenorhabditis elegans affect numerous physiological rates including behavioral rates, developmental rates, reproduction, and life span. clk-1 encodes a protein associated with the inner mitochondrial membrane that is necessary for Q biosynthesis in C. elegans. clk-1 mutants do not synthesize Q but accumulate demethoxyubiquinone, a Q synthesis intermediate that is able to partially sustain mitochondrial respiration in worms as well as in mammals. Recently, we and others have found that exogenous Q is necessary for the fertility and development of clk-1 mutants. Here, we take advantage of the clk-1 genetic model to identify structural features of Q that are functionally important in vivo. We show that clk-1 mutants are exquisitely sensitive to the length of the side chain of the Q they consume. We also identified differential sensitivity to Q side-chain length between null alleles of clk-1 (qm30 and qm51) and the weaker allele e2519. This allows us to propose a model where we distinguish several types of Q-dependent processes in vivo: processes that are very sensitive to Q side-chain length and processes that are permissive to Q with shorter chains. [References: 30] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Hekimi S McGill Univ, Dept Biol 1205 Dr Penfield Montreal PQ H3A 1B1 Canada McGill Univ, Dept Biol Montreal PQ H3A 1B1 Canada <31> UI - 733FP-0107 DD - ISI Document Solution: 733FP AU - Garofano A AU - Zwicker K AU - Kerscher S AU - Okun P AU - Brandt U MA - brandt@zbc.kgu.de RA - Brandt U TI - Two aspartic acid residues in the PSST-homologous NUKM subunit of complex I from Yarrowia lipolytica are essential for catalytic activity SO - Journal of Biological Chemistry. 278(43):42435-42440, 2003 Oct 24. AS - J. Biol. Chem 2003 Oct 24;278(43):42435-42440 PU - AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA. URL: http://www.asbmb.org IS - 0021-9258 MH - Nadh-ubiquinone oxidoreductase MH - Sulfur cluster n2 MH - Site-directed mutagenesis MH - Mitochondrial nadh MH - Escherichia-coli MH - 49-kda subunit MH - Core MH - Hydrogenases MH - Tyky. AB - Mitochondrial proton-translocating NADH: ubiquinone oxidoreductase ( complex I) couples the transfer of two electrons from NADH to ubiquinone to the translocation of four protons across the mitochondrial inner membrane. Subunit PSST is the most likely carrier of iron-sulfur cluster N2, which has been proposed to play a crucial role in ubiquinone reduction and proton pumping. To explore the function of this subunit we have generated site-directed mutants of all eight highly conserved acidic residues in the Yarrowia lipolytica homologue, the NUKM protein. Mutants D99N and D115N had only 5 and 8% of the wild type catalytic activity, respectively. In both cases complex I was stably assembled but electron paramagnetic resonance spectra of the purified enzyme showed a reduced N2 signal (about 50%). In terms of complex I catalytic activity, almost identical results were obtained when the aspartates were individually changed to glutamates or to glycines. Mutations of other conserved acidic residues had less dramatic effects on catalytic activity and did not prevent assembly of iron-sulfur cluster N2. This excludes all conserved acidic residues in the PSST subunit as fourth ligands of this redox center. The results are discussed in the light of the structural similarities to the homologous small subunit of water-soluble [NiFe] hydrogenases. [References: 29] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Brandt U Univ Frankfurt, Fachbereich Med, Inst Biochem 1, Gustav Embden Zentrum Biol Chem Theodor Stern Kai 7,Haus 25B D-60590 Frankfurt Germany Univ Frankfurt, Fachbereich Med, Inst Biochem 1, Gustav Embden Zentrum Biol Chem D-60590 Frankfurt Germany <32> UI - 731NB-0004 DD - ISI Document Solution: 731NB AU - Muller AM AU - Wasmund N MA - annamariamueller@surfeu.de RA - Muller AM TI - Photophysiology of surface phytoplankton communities in a transect from the mouth of the Peene-Strom to the Arkona Sea (Baltic) SO - International Review of Hydrobiology. 88(5):482-497, 2003. AS - Int. Rev. Hydrobiol 2003;88(5):482-497 PU - WILEY-V C H VERLAG GMBH, PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY. URL: http://www.wiley-vch.de IS - 1434-2944 MH - Phytoplankton MH - Photoinhibition MH - Fluorescence MH - Algal class composition MH - Estuary MH - Open baltic. MH - Chlorophyll fluorescence MH - Xanthophyll cycle MH - Ozone depletion MH - Marine photosynthesis MH - Ultraviolet-radiation MH - Induction kinetics MH - Photosystem-ii MH - North-atlantic MH - Quantum yield MH - In-vivo. AB - The potential of surface phytoplankton to withstand photostress was investigated in August 1998 along a transect from the mouth of the Peene-Strom (Pomeranian Bight) to the open Arkona Sea (Baltic). Photosynthetic efficiency, algal class composition and pigment pattern were determined. Algae were photoinhibited by artificial illumination and the kinetics of recovery were recorded. Under photoinhibitory treatment, algae from the estuary showed a low effective quantum yield but a high potential to recover their maximum photosynthetic efficiency. Contrary to this, the relatively high effective quantum yield of open sea algae under photoinhibitory treatment is accompanied by a low final recovery of maximum photosynthetic efficiency. These phenomena are discussed with respect to nutrient supply, algal class composition and to different strategies of algae to react to light stress. Literature data of summer primary productivity of open sea and coastal algae are compared with our data on electron transport rates. This revealed a low influence of photoinhibitory effects on productivity. [References: 57] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2003 week 45 IN - Reprint available from: Muller AM Balt Sea Res Inst Seestr 15 D-18119 Rostock Germany Balt Sea Res Inst D-18119 Rostock Germany <33> UI - 732QY-0023 DD - ISI Document Solution: 732QY AU - Jakobisiak M AU - Golab J MA - mjakobis@ib.amwaw.edu.pl RA - Jakobisiak M TI - Potential antitumor effects of statins (Review) [Review] SO - International Journal of Oncology. 23(4):1055-1069, 2003 Oct. AS - Int. J. Oncol 2003 Oct;23(4):1055-1069 PU - PROFESSOR D A SPANDIDOS, 1, S MERKOURI ST, EDITORIAL OFFICE,, ATHENS 116 35, GREECE IS - 1019-6439 MH - Statins MH - Antitumor activity MH - Combination therapy. MH - Hmg-coa reductase MH - Endothelial growth-factor MH - Lovastatin-induced apoptosis MH - Coronary-heart-disease MH - Coenzyme-a reductase MH - Smooth-muscle-cells MH - Scandinavian simvastatin survival MH - Nf-kappa-b MH - Vascular-permeability factor MH - Signal-transduction pathway. AB - Statins, which have been introduced to the clinic for the treatment of hypercholesterolemia, are competitive inhibitors of 3-hydroxy-3-methyglutaryl-coenzyme A (HMG-CoA) reductase, the major rate-limiting enzyme that controls the conversion of HMG-CoA to mevalonic acid (MA). MA is the precursor in the biosynthesis of isoprenoid compounds including cholesterol, dolichol and ubiquinone. Furthermore, mevalonate-derived prenyl groups enable precise cellular localization and function of many proteins such as Ras and Rho proteins. Therefore, besides lowering cholesterol level, statins exert pleiotropic effects on many essential cellular functions including cell proliferation, differentiation, and survival but also participate in the regulation of cell shape and motility. Statins have been shown to inhibit proliferation and to induce apoptosis in a variety of tumor cells. They have also been found to display antitumor effects against melanoma, mammary carcinoma, pancreatic adenocarcinoma, fibrosarcoma, glioma. neuroblastoma, and lymphoma in animal tumor models resulting in retardation of tumor growth, and/or inhibition of the metastatic process. In preclinical studies statins have also been demonstrated to potentiate the antitumor effects of some cytokines and chemotherapeutics. The molecular mechanisms underlying antitumor activity of statins have not been fully elucidated but interference with the function of Ras and Rho family GTPases, inhibition of the activity of certain cyclin-dependent kinases (CDK), and activation of CDK inhibitors, all seem to participate in this activity. The results of several clinical studies of statins in cancer patients including phase I, phase I/II, and phase II trials have been published. Although evaluation of the therapeutic efficacy is not the purpose of early clinical trials and all conclusions might be premature at this stage, some preliminary conclusions have already been drawn. The results of these studies do not show any significant therapeutic effects of statins in cancer patients. However, the results of one of these studies suggest that statins could effectively strengthen the therapeutic activity of some chemotherapeutics. This observation seems to agree with the results of preclinical studies. However, as toxic side effects of statins have been particularly evident in their combination with some other drugs great caution should be advised while planning clinical trials based on combination therapy including statins in cancer patients. [References: 230] LG - English PT - Review SB - Current Contents(R)/Life Sciences CC - Oncogenesis & Cancer Research in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Jakobisiak M Med Univ Warsaw, Dept Immunol, Ctr Biostrust Chalubinskiego 5 PL-02004 Warsaw Poland Med Univ Warsaw, Dept Immunol, Ctr Biostrust PL-02004 Warsaw Poland <34> UI - 733TH-0009 DD - ISI Document Solution: 733TH AU - Hase CC MA - claudia.hase@science.orst.edu RA - Hase CC TI - Ion motive force dependence of protease secretion and phage tranduction in Vibrio cholerae and Pseudomonas aeruginosa SO - FEMS Microbiology Letters. 227(1):65-71, 2003 Oct 10. AS - FEMS Microbiol. Lett 2003 Oct 10;227(1):65-71 PU - ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. URL: http://www.elsevier.nl IS - 0378-1097 MH - Membrane energetics MH - Sodium motive force MH - Zinc-metalloprotease MH - Ctxphi bacteriophage. MH - Virulence gene-expression MH - Escherichia-coli MH - Outer-membrane MH - Sodium bioenergetics MH - Molecular machine MH - Suicide vector MH - Translocation MH - Na+ MH - Requirement MH - Energetics. AB - Vibrio cholerae is known to secrete a large number of proteins into the extracellular milieu, including the important virulence factor cholera toxin (CT). However. one of the most abundant proteins found in V cholerae supernatants is the zinc-metalloprotease HA/protease (HAP). Whereas efficient protein secretion in Escherichia coli requires ATP hydrolysis and the proton motive force (pmf), little is known about the energy requirements for protein secretion in V cholerae. To analyze some of the energy requirements for protein secretion in V cholerae, HAP accumulation in culture supernatants following growth in the presence of various ionophores was assayed. Extracellular production of HAP was strongly reduced in the presence of monensin, an artificial Na+/H+ antiporter that collapses the DeltapNa(+) across the membrane without affecting Deltapsi, whereas the protonophore CCCP had no significant effect on the extracellular accumulation of HAP. In contrast, extracellular protease production in Pseudomonas aeruginosa was affected by CCCP, but not monensin. Furthermore, extracellular protease production of V. cholerae, but not P. aeruginosa, was increased in increasing amounts of NaCl in the culture medium. Together these results indicate that the V. cholerae HAP requires an intact sodium motive force (smf) for its efficient translocation across the membranes, whereas extracellular protease production by P. aeruginosa requires only pmf. As the entry of some bacteriophage genomes has been reported to require pmf, the effects of ionophores on the efficiency of tranduction of V. cholerae by the CTXPhi phase were analyzed. CTXPhi transduction was strongly affected by CCCP, but not monensin, suggesting that phage entry requires pmf but not smf. Understanding the energy requirements for these potentially important virulence aspects of pathogens might lead to novel intervention strategies. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved. [References: 40] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Microbiology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Hase CC Oregon State Univ, Dept Microbiol 220 Nash Hall Corvallis, OR 97331 USA Oregon State Univ, Dept Microbiol Corvallis, OR 97331 USA <35> UI - 732DG-0003 DD - ISI Document Solution: 732DG AU - Hurtado O AU - De Cristobal J AU - Sanchez V AU - Lizasoain I AU - Cardenas A AU - Pereira MP AU - Colado MI AU - Leza JC AU - Lorenzo P AU - Moro MA MA - neurona@med.ucm.es RA - Moro MA TI - Inhibition of glutamate release by delaying ATP fall accounts for neuroprotective effects of antioxidants in experimental stroke SO - FASEB Journal. 17(12):NIL_36-NIL_52, 2003 Sep. AS - Faseb J 2003 Sep;17(12):NIL_36-NIL_52 PU - FEDERATION AMER SOC EXP BIOL, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA. URL: http://www.faseb.org IS - 0892-6638 MH - Cerebral infarct MH - Mcao MH - Reactive oxygen species. MH - Mitochondrial respiratory-chain MH - Oxygen-glucose deprivation MH - Focal cerebral-ischemia MH - Rat forebrain slices MH - Hippocampal slices MH - Brain ischemia MH - Hydrogen-peroxide MH - Free-radicals MH - Gerbil brain MH - Nitric-oxide. AB - Excitotoxic neuronal injury related to excessive glutamate release is believed to play a key role in the pathogenesis of focal cerebral ischemia. Reversal of neuronal glutamate transporters caused by ATP fall and subsequent imbalance of membrane ionic gradients accounts for most glutamate release after cerebral ischemia. ATP synthesis from oxidative phosphorylation derives from the coupled functioning of the mitochondrial respiratory chain (MRC) and the ATP synthase; interestingly, the MRC is one of the main sites of cellular reactive oxygen species (ROS) generation even in physiological circumstances. Hence, we have studied the effect of the antioxidants glutathione, superoxide dismutase, and alpha-tocopherol on infarct outcome, brain ATP, and glutamate levels after permanent middle cerebral artery occlusion (MCAO) in Fischer rats; we have also characterized the actions of antioxidants on MRC complexes. Our results show that intraperitoneal administration of antioxidants 2 h before MCAO enhances ATP synthesis and causes a neuroprotective effect concomitant to inhibition of ischemia-induced increase in brain glutamate. Antioxidants also increased mitochondrial ATP and MRC complex I-III activity and respiration, suggesting that these actions are due to removal of the inhibition caused by endogenous ROS on MRC. These findings may possess important therapeutic repercussions in the management of ischemic stroke. [References: 56] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Experimental Biology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Moro MA Univ Complutense Madrid, Fac Med, Dept Farmacol E-28040 Madrid Spain Univ Complutense Madrid, Fac Med, Dept Farmacol E-28040 Madrid Spain <36> UI - 731XJ-0006 DD - ISI Document Solution: 731XJ AU - Motterlini R AU - Mann BE AU - Johnson TR AU - Clark JE AU - Foresti R AU - Green CJ MA - r.motterlini@imperial.ac.uk RA - Motterlini R TI - Bioactivity and pharmacological actions of carbon monoxide-releasing molecules [Review] SO - Current Pharmaceutical Design. 9(30):2525-2539, 2003. AS - Curr. Pharm. Design 2003;9(30):2525-2539 PU - BENTHAM SCIENCE PUBL LTD, PO BOX 1673, 1200 BR HILVERSUM, NETHERLANDS. URL: http://www.bentham.org IS - 1381-6128 MH - Transition metal carbonyls MH - Carbon monoxide-releasing molecules (co-rms) MH - Heme oxygenase MH - Nitric oxide (no). MH - Heme oxygenase-1 induction MH - Metal-metal bond MH - Vascular endothelial-cells MH - Soluble guanylyl cyclase MH - Protein-kinase pathway MH - X-ray-structure MH - Nitric-oxide MH - Rhodospirillum-rubrum MH - Smooth-muscle MH - Cyclic-gmp. AB - Carbon monoxide (CO) is a resourceful gas as recent advances in the area of cell signaling are revealing an unexpected physiological role for CO in the cardiovascular, immune and nervous systems. Transition metal carbonyls have been lately discovered to function as CO-releasing molecules (CO-RMs) and elicit distinct pharmacological activities in biological systems. Studies currently ongoing in our laboratories are investigating both the chemical and bioactive features of a series of water-soluble CO-RMs and their specific utilization as vasoactive mediators, anti-inflammatory agents and inhibitors of cellular and tissue damage. The data presented in this review corroborate the notion that transition metal carbonyls could be used as carriers to deliver CO in mammals and highlight the bioactivity and potential therapeutic features of CO-RMs in the mitigation of cellular and organ dysfunction. [References: 134] LG - English PT - Review SB - Current Contents(R)/Life Sciences CC - Pharmacology & Toxicology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Motterlini R Northwick Pk Inst Med Res, Dept Surg Res, Vasc Biol Unit Harrow HA1 3UJ Middx England Northwick Pk Inst Med Res, Dept Surg Res, Vasc Biol Unit Harrow HA1 3UJ Middx England Univ Sheffield, Dept Chem Sheffield S3 7HF S Yorkshire England <37> UI - 732LR-0011 DD - ISI Document Solution: 732LR AU - Lohrenz SE AU - Carroll CL AU - Weidemann AD AU - Tuel M MA - steven.lohrenz@usm.edu RA - Lohrenz SE TI - Variations in phytoplankton pigments, size structure and community composition related to wind forcing and water mass properties on the North Carolina inner shelf SO - Continental Shelf Research. 23(14-15):1447-1464, 2003 Sep-Oct. AS - Cont. Shelf Res 2003 Sep-Oct;23(14-15):1447-1464 PU - PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND. URL: http://www.elsevier.nl IS - 0278-4343 MH - Phytoplankton MH - Size structure MH - Pigments MH - Estuarine plumes MH - Inner shelf MH - Chesapeake bay. MH - Middle atlantic bight MH - Chesapeake bay plume MH - Gulf-stream water MH - Cape-hatteras MH - Photosynthetic pigments MH - Hplc measurements MH - Class abundances MH - Chlorophyll-a MH - Coastal MH - Diversity. AB - Variations in phytoplankton pigments, size structure and community composition were examined in inner shelf waters off North Carolina in relationship to water mass properties subject to the influence of low salinity outflow from the Chesapeake Bay, alternations in wind forcing and interactions with shelf water masses. Observations were made aboard the R/V Edwin Link during May 1997. Episodes of upwelling-favorable conditions were accompanied by detachment of the low salinity outflow plume from the coast, and enhanced dispersion and mixing with shelf waters. Distinct water masses were identified using cluster analysis of temperature-salinity (T-S) properties. Two major clusters, distinguished on the basis of relatively high and low salinities, were identified as ambient coastal water (A) and modified bay water (B). Each of these could be further separated into two water mass types characterized by relatively high and low temperatures. The pigment and taxonomic composition of these water masses were examined. The carotenoid fucoxanthin was generally the most abundant accessory pigment. Zeaxanthin and chlorophyll b were also relatively abundant at most stations. Ratios to chlorophyll a of 19'-hexanoyloxyfucoxanthin and peridinin were higher for the high salinity clusters. A shift to downwelling-favorable conditions toward the latter part of the cruise gave rise to a narrow, southward flowing jet of low salinity Chesapeake Bay water corresponding to the low salinity, relatively high temperature water mass identified by cluster analysis. Fucoxanthin dominated the accessory pigments in this low salinity feature. Proportions of chlorophyll a associated with different phytoplankton classes, as estimated using CHEMTAX software (Mar. Ecol. Prog. Ser. 144 (1996) 265), varied among groups in a manner consistent with pigment composition. A diverse assemblage of diatoms, cyanobacteria, cryptophytes and prasinophytes accounted for the majority of chlorophyll a at most stations. Haptophytes and dinoflagellates were relatively more abundant in warmer, higher salinity stations. The low salinity jet exhibited high biomass and low diversity compared to other water masses. Its phytoplankton population was dominated by diatoms larger than 8 mum in diameter. The results demonstrate that phytoplankton community composition varies substantially among the different water masses in this coastal region and is subject to event scale (i.e., days to weeks) changes in relation to wind forcing and shelf circulation processes. (C) 2003 Elsevier Ltd. All rights reserved. [References: 53] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Aquatic Sciences in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2003 week 45 IN - Reprint available from: Lohrenz SE Univ So Mississippi, Dept Marine Sci 1020 Balch Blvd Stennis Space Ctr, MS 39529 USA Univ So Mississippi, Dept Marine Sci Stennis Space Ctr, MS 39529 USA Naval Oceanog Off Stennis Space Ctr, MS 39522 USA USN, Res Lab Stennis Space Ctr, MS 39529 USA <38> UI - 731UJ-0009 DD - ISI Document Solution: 731UJ AU - Yang GC AU - Wang L AU - Yang GZ MA - wangli@aphy.iphy.ac.cn RA - Yang GC TI - Excitonic level structures of LH1 and LH2 of purple photosynthetic bacteria using an analytical approach SO - Chinese Physics. 12(10):1096-1104, 2003 Oct. AS - Chin. Phys 2003 Oct;12(10):1096-1104 PU - CHINESE PHYSICAL SOC, P O BOX 603, BEIJING 100080, PEOPLES R CHINA IS - 1009-1963 MH - Excitonic level MH - Photosynthesis MH - Lh1 MH - Lh2. MH - Light-harvesting complex MH - Antenna complex MH - Rhodopseudomonas-acidophila MH - Spectroscopic properties MH - Energy-transfer MH - Rhodospirillum-molischianum MH - Stark spectroscopy MH - Crystal-structure MH - Reaction centers MH - Bacteriochlorophyll. AB - The excitonic level structure of a ring-like chain of dimers is discussed analytically in order to aid the understanding of the possible spectral properties of LH1 and LH2 of purple photosynthetic bacteria. Under the approximation of dipole-dipole interaction between Bchls, the excitonic levels, bandwidths and energy gap between two Davydov subbands are expressed analytically in terms of interaction energies and configurational parameters of dipoles. Our model includes all the interactions between pigment molecules in the system. The oscillator strengths and circular dichroism (CD) for the excitonic states are also presented analytically. The simulated absorption and CD spectra of LH1 and LH2 complexes reproduce the main features of the measured results. [References: 24] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Yang GC Chinese Acad Sci, Inst Phys, Lab Opt Phys POB 603 Beijing 100080 Peoples R China Chinese Acad Sci, Inst Phys, Lab Opt Phys Beijing 100080 Peoples R China <39> UI - 731UJ-0019 DD - ISI Document Solution: 731UJ AU - Ren ZY AU - Xu XM AU - Wang SC AU - Xin YY AU - He JF AU - Hou X MA - rzy@nwu.edu.cn RA - Ren ZY TI - Research on the ultrafast fluorescence property of thylakoid membranes of the wild-type and mutant rice SO - Chinese Physics. 12(10):1159-1165, 2003 Oct. AS - Chin. Phys 2003 Oct;12(10):1159-1165 PU - CHINESE PHYSICAL SOC, P O BOX 603, BEIJING 100080, PEOPLES R CHINA IS - 1009-1963 MH - Rice MH - Photosynthesis MH - Ultrafast process MH - Time constant MH - Exciting energy transfer. MH - B-deficient mutants MH - Chlorophyll-b MH - Photosystem-ii MH - Barley MH - Proteins MH - Stress MH - Leaves. AB - A high yielding rice variety mutant (Oryza sativa L., Zhenhui 249) with low chlorophyll b (Chl b) has been discovered in natural fields. It has a quality character controlled by a pair of recessive genes (nuclear gene). The partial loss of Chl b in content affects the efficiency of light harvest in a light harvest complex (LHC), thus producing the difference of the exciting energy transfer and the efficiency of photochemistry conversion between the mutant and wild-type rice in photosynthetic unit. The efficiency of utilizing light energy is higher in the mutant than that in the wildtype rice relatively. For further discussion of the above-mentioned difference and learning about the mechanism of the increase in the photochemical efficiency of the mutant, the pico-second resolution fluorescence spectrum measurement with delay-frame-scanning single photon counting technique is adopted. Thylakoid membranes of the mutant and the wild-type rice are excited by an Ar+ laser with a pulse width of 120 ps, repetition rate of 4 MHz and wavelength of 514 nm. Compared with the time and spectrum property of exciting fluorescence, conclusions of those ultrafast dynamic experiments are: 1) The speeds of the exciting energy transferred in photo-system I are faster than that in photo-system II in both samples. 2) The speeds of the exciting energy transfer of mutant sample are faster than those of the wildtype. This might be one of the major reasons why the efficiency of photosynthesis is higher in mutant than that in the wild-type rice. [References: 18] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Ren ZY NW Univ Xian, Inst Photon & Photo Technol Xian 710068 Peoples R China NW Univ Xian, Inst Photon & Photo Technol Xian 710068 Peoples R China Nanjing Agr Univ, Lab Photosynth Res Nanjing 210095 Peoples R China Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transience Opt Technol Xian 710068 Peoples R China Chinese Acad Sci, Inst Bot, Lab Photosynth Beijing 100093 Peoples R China <40> UI - 732XJ-0015 DD - ISI Document Solution: 732XJ AU - Plekhanov SE AU - Chemeris YK MA - irinaoplekhanova@mail.ru RA - Plekhanov SE TI - Early toxic effects of zinc, cobalt, and cadmium on photosynthetic activity of the green alga Chlorella pyrenoidosa Chick S-39 SO - Biology Bulletin. 30(5):506-511, 2003 Sep-Oct. AS - Biol. Bull 2003 Sep-Oct;30(5):506-511 PU - MAIK NAUKA/INTERPERIODICA, C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA. URL: http://www.maik.rssi.ru IS - 1062-3590 MH - Chlorophyll fluorescence MH - Light MH - Leaves MH - Plants. AB - Early toxic effects of heavy metals (HMs) Zn, Co, and Cd at concentrations from 0.01 to 100 mM on photosynthetic activity of the green alga Chlorella pyrenoidosa Chick S-39 were studied. The early effect of HMs was manifested as a rapid (within 0.5-2 h) reduction of photoinduced oxygen release by the algal cells. The suppressed relative yield of variable chlorophyll fluorescence (F-v/F-m) by HMs as well as its dynamics in C. pyrenoidosa provided evidence for rapid inactivation of photosystem II (PS II). Analysis of the induction curve of delayed chlorophyll fluorescence in Chlorella cells suggested that the early toxic effects of Zn, Co, and Cd at the above concentrations manifested itself not only in inhibited electron transport in PS II, but also in reduced energization of photosynthetic membranes. Hence, the early toxic effect of Zn, Co, and Cd was primarily related to the decreased efficiency of the light reactions of photosynthesis, which subsequently resulted in reduced productivity of the alga. [References: 26] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Biology in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2003 week 45 IN - Reprint available from: Plekhanov SE Moscow MV Lomonosov State Univ, Fac Biol Moscow 119892 Russia Moscow MV Lomonosov State Univ, Fac Biol Moscow 119892 Russia <41> UI - 733GF-0003 DD - ISI Document Solution: 733GF AU - Pishchalnikov RY AU - Moskalenko AA AU - Razjivin AP MA - andrey-mos@issp.serpukhov.su, razjivin@belozersky.msu.ru RA - Pishchalnikov RY TI - Hypothesis on origin of three bands in absorption spectrum of new type LH2 complex (B800-830-850) from Thiorhodospira sibirica [Russian] SO - Biologicheskie Membrany. 20(5):386-394, 2003 Sep-Oct. AS - Biol. Membr 2003 Sep-Oct;20(5):386-394 PU - MEZHDUNARODNAYA KNIGA, 39 DIMITROVA UL., 113095 MOSCOW, RUSSIA. URL: http://www.maik.rssi.ru IS - 0233-4755 MH - Light-harvesting antenna MH - Photosynthetic purple bacteria MH - Selective picosecond spectroscopy MH - Rhodospirillum-rubrum MH - Crystal-structure MH - Chromatophores MH - Mechanism MH - B800-850 MH - Dynamics. AB - A model of spatial arrangement and mutual orientation of bacteriochlorophyll (BChl) molecules in peripheral light-harvesting complex LH2 from purple bacterium Thiorhodospira sibirica is proposed. Absorption and circular dichroism spectra were calculated on the basis of LH2 structure in two other bacteria, known from X-ray data, and exciton theory for circular aggregates of BChls. It was assumed that BChl molecules in LH2 complex from Tsr. sibirica form trimers, which include two adjacent BChl molecules of the B850 ring (Bchl850) and one close BChl molecule of the B800 ring (BChl800). The expected orientation of BChl molecules within the trimer provides lower interaction between the adjacent BChl850 molecules rather than between BChl800 molecule and each of two BChl850 molecules. According to calculations the short-wavelength band with a peak at 800 nm occurs mainly due to interaction between BChl850alpha and BChl800 molecules, the long-wavelength band at 860 nm, due to interaction between BChl850beta and BChl800 molecules, and the band at 830 nm, due to interaction of BChl800 molecules and BChl850alpha with BChl850beta. Three-peak absorption spectra are available for confined set of spatial arrangements and mutual orientations of BChl molecules. [References: 18] LG - Russian PT - Article SB - Current Contents(R)/Life Sciences CC - Cell & Developmental Biology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Pishchalnikov RY Moscow MV Lomonosov State Univ, Belozersky Inst Physicochem Biol Moscow 119890 Russia Moscow MV Lomonosov State Univ, Belozersky Inst Physicochem Biol Moscow 119890 Russia Russian Acad Sci, Inst Fundamental Problems Biol Pushchino 142290 Moscow Region Russia <42> UI - 733GX-0002 DD - ISI Document Solution: 733GX AU - Nedbal L AU - Brezina V AU - Adamec F AU - Stys D AU - Oja V AU - Laisk A AU - Govindjee MA - nedbal@greentech.cz RA - Nedbal L TI - Negative feedback regulation is responsible for the non-linear modulation of photosynthetic activity in plants dynamic light and cyanobacteria exposed to a environment SO - Biochimica et Biophysica Acta - Bioenergetics. 1607(1):5-17, 2003 Oct 17. AS - Biochim. Biophys. Acta-Bioenerg 2003 Oct 17;1607(1):5-17 PU - ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. URL: http://www.elsevier.nl IS - 0005-2728 MH - Calvin-benson cycle MH - Forced oscillation MH - Intermittent light MH - Phycobilisome MH - State transition MH - Systems analysis. MH - Chlorophyll fluorescence MH - Electron-transport MH - Chlorella-pyrenoidosa MH - Mathematical-model MH - Quantum yield MH - Oscillations MH - Leaves MH - Photosystem-1 MH - Cycle. AB - Photosynthetic organisms exposed to a dynamic light environment exhibit complex transients of photosynthetic activities that are strongly dependent on the temporal pattern of the incident irradiance. In a harmonically modulated light of intensity I approximate to const. + sin(omegat), chlorophyll fluorescence response consists of a steady-state component, a component modulated with the angular frequency of the irradiance omega and several upper harmonic components (2omega, 3omega and higher). Our earlier reverse engineering analysis suggests that the non-linear response can be caused by a negative feedback regulation of photosynthesis. Here, we present experimental evidence that the negative feedback regulation of the energetic coupling between phycobilisome and Photosystem II (PSII) in the cyanobacterium, Synechocystis sp. PCC6803 indeed results in the appearance of upper harmonic modes in the chlorophyll fluorescence emission. Dynamic changes in the coupling of the phycobilisome to PSII are not accompanied by corresponding antiparallel changes in the Photosystem I (PSI) excitation, suggesting a regulation limited to PSII. Strong upper harmonic modes were also found in the kinetics of the non-photochemical quenching (NPQ) of chlorophyll fluorescence, of the P700 redox state and of the CO2 assimilation in tobacco (Nicotiana tabaccum) exposed to harmonically modulated light. They are ascribed to negative feedback regulation of the reactions of the Calvin-Benson cycle limiting the photosynthetic electron transport. We propose that the observed non-linear response of photosynthesis may also be relevant in a natural light environment that is modulated, e.g., by ocean waves, moving canopy or by varying cloud cover. Under controlled laboratory conditions, the non-linear photosynthetic response provides a new insight into dynamics of the regulatory processes. (C) 2003 Elsevier B.V. All rights reserved. [References: 40] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Nedbal L Univ S Bohemia, Inst Landscape Ecol, Lab Appl Photobiol & Bio Imaging, CAS Zamek 136 CZ-37333 Nove Hrady Czech Republic Univ S Bohemia, Inst Landscape Ecol, Lab Appl Photobiol & Bio Imaging, CAS CZ-37333 Nove Hrady Czech Republic Univ S Bohemia, Inst Phys Biol CZ-37333 Nove Hrady Czech Republic Univ Tartu, Inst Mol & Cell Biol, Dept Plant Physiol EE-51010 Tartu Estonia Univ Illinois, Dept Biochem Urbana, IL 61801 USA Univ Illinois, Dept Plant Biol Urbana, IL 61801 USA <43> UI - 733GX-0003 DD - ISI Document Solution: 733GX AU - Braun P AU - Vegh AP AU - von Jan A AU - Strohmann B AU - Hunter CN AU - Robert B AU - Scheer H MA - braun@botanik.biologie.uni-muenchen.de RA - Braun P TI - Identification of intramembrane hydrogen bonding between 13(1) keto group of bacteriochlorophyll and serine residue alpha 27 in the LH2 light-harvesting complex SO - Biochimica et Biophysica Acta - Bioenergetics. 1607(1):19-26, 2003 Oct 17. AS - Biochim. Biophys. Acta-Bioenerg 2003 Oct 17;1607(1):19-26 PU - ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. URL: http://www.elsevier.nl IS - 0005-2728 MH - Intramembrane h-bonding MH - Raman resonance spectroscopy MH - Antenna complex MH - Photosystem i MH - Chlorophyll binding pocket MH - Heat denaturation. MH - Primary electron-donor MH - Rhodobacter-sphaeroides MH - Purple bacteria MH - Photosystem-i MH - Binding-site MH - Membrane-proteins MH - Pigment binding MH - Heterologous expression MH - Transmembrane helices MH - Reaction centers. AB - Intramembrane hydrogen bonding and its effect on the structural integrity of purple bacterial light-harvesting complex 2, LH2, have been assessed in the native membrane environment. A novel hydrogen bond has been identified by Raman resonance spectroscopy between a serine residue of the membrane-spanning region of LH2 alpha-subunit, and the C-13(1) keto carbonyl of bacteriochlorophyll (BChl) B850 bound to the p-subunit. Replacement of the serine by alanine disrupts this strong hydrogen bond, but this neither alters the strongly red-shifted absorption nor the structural arrangement of the BChls, as judged from circular dichroism. It also decreases only slightly the thermal stability of the mutated LH2 in the native membrane environment. The possibility is discussed that weak H-bonding between the C-13(1) keto carbonyl and a methyl hydrogen of the alanine replacing serine(- 4) or the imidazole group of the nearby histidine maintains structural integrity in this very stable bacterial light-harvesting complex. A more widespread occurrence of H-bonding to C-13(1) not only in BChl, but also in chlorophyll proteins, is indicated by a theoretical analysis of chlorophyll/polypeptide contacts at < 3.5 Angstrom in the high-resolution structure of Photosystem I. Nearly half of the 96 chlorophylls have aa residues suitable as hydrogen bond donors to their keto groups. (C) 2003 Elsevier B.V. All rights reserved. [References: 51] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Braun P Univ Munich, Dept Biol 1, Sect Bot Menzinger Str 67 D-80638 Munich Germany Univ Munich, Dept Biol 1, Sect Bot D-80638 Munich Germany CEA, DBJC, Sect Biophys Fonct Membranaires F-91191 Gif Sur Yvette France CNRS, URA 2096, CE Saclay F-91191 Gif Sur Yvette France Semmelweis Univ Med, Fac Med, Inst Biophys & Radiat Biol H-1088 Budapest Hungary Univ Sheffield, Dept Mol Biol & Biotechnol Sheffield S10 2TN S Yorkshire England <44> UI - 733GX-0006 DD - ISI Document Solution: 733GX AU - Andrasson U AU - Carlsson T AU - Andreasson LE MA - lars-erik.andreasson@bcbp.gu.se RA - Andreasson LE TI - Spectroscopic characterization of a semi-stable, charge-separated state in Cu2+-substituted reaction centers from Rhodobacter sphaeroides SO - Biochimica et Biophysica Acta - Bioenergetics. 1607(1):45-52, 2003 Oct 17. AS - Biochim. Biophys. Acta-Bioenerg 2003 Oct 17;1607(1):45-52 PU - ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. URL: http://www.elsevier.nl IS - 0005-2728 MH - Bacterial photosynthesis MH - Conformational change MH - Reaction center MH - Stabilized charge-separated state MH - Copper substitution. MH - Photosynthetic reaction centers MH - Bacterial reaction centers MH - Induced structural-changes MH - Rhodopseudomonas-spheroides MH - Cryogenic temperatures MH - Electron-transfer MH - Protein MH - Acceptor MH - R-26. AB - In reaction centers from Rhodobacter sphaeroides exposed to continuous illumination in the presence of an inhibitor of the Q(A)(-) to Q(B) electron transfer, a semi-stable, charge-separated state was formed with halftimes of formation and decay of several minutes. When the non-heme iron was replaced by Cu2+, the decay of the semi-stable, charge-separated state became much slower than in centers with bound Fe 21 with about the same rate constant for formation. In Cu2+ substituted reaction centers, the semi-stable state was associated with an EPR signal, significantly different from that observed after chemical reduction of the acceptor-side quinone or after illumination at low temperature, but similar to that of an isolated Cu2+ in the absence of magnetic interaction. The EPR results, obtained with Cu2+ substituted reaction centers, suggest that the slow kinetics of formation and decay of the charge-separated, semi-stable state is associated with a structural rearrangement of the acceptor side and the immediate environment of the metal-binding site. (C) 2003 Elsevier B.V. All rights reserved. [References: 24] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Andreasson LE Univ Gothenburg, Dept Biochem & Biophys Med Aregatan 9E S-41390 Gothenburg Sweden Univ Gothenburg, Dept Biochem & Biophys S-41390 Gothenburg Sweden <45> UI - 733GX-0007 DD - ISI Document Solution: 733GX AU - Wakeham MC AU - Frolov D AU - Fyfe PK AU - van Grondelle R AU - Jones MR MA - m.r.jones@bristol.ac.uk RA - Jones MR TI - Acquisition of photosynthetic capacity by a reaction centre that lacks the Q(A) ubiquinone; possible insights into the evolution of reaction centres? SO - Biochimica et Biophysica Acta - Bioenergetics. 1607(1):53-63, 2003 Oct 17. AS - Biochim. Biophys. Acta-Bioenerg 2003 Oct 17;1607(1):53-63 PU - ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. URL: http://www.elsevier.nl IS - 0005-2728 MH - Reaction centre MH - Rhodobacter sphaeroides MH - Ubiquinone. MH - Bacterial reaction centers MH - Evolving photosystem-ii MH - Bound reaction centers MH - Rhodobacter-sphaeroides MH - Rhodopseudomonas-sphaeroides MH - Photochemical reaction MH - Angstrom resolution MH - Crystal-structure MH - Electron-transfer MH - Proton delivery. AB - A photosynthetically impaired strain of Rhodobacter sphaeroides containing reaction centres with an alanine to tryptophan mutation at residue 260 of the M-polypeptide (AM260W) was incubated under photosynthetic growth conditions. This incubation produced photosynthetically competent strains containing suppressor mutations that changed residue M260 to glycine or cysteine. Spectroscopic analysis demonstrated that the loss of the Q(A) ubiquinone seen in the original AM260W mutant was reversed in the suppressor mutants. In the mutant where Tip M260 was replaced by Cys, the rate of reduction of the Q(A) ubiquinone by the adjacent (HA) bacteriopheophytin was reduced by three-fold. The findings of the experiment are discussed in light of the X-ray crystal structures of the wild-type and AM260W reaction centres, and the possible implications for the evolution of reaction centres as bioenergetic complexes are considered. (C) 2003 Elsevier B.V. All rights reserved. [References: 55] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Jones MR Univ Bristol, Sch Med Sci, Dept Biochem Univ Walk Bristol BS8 1TD Avon England Univ Bristol, Sch Med Sci, Dept Biochem Bristol BS8 1TD Avon England Free Univ Amsterdam, Dept Phys & Astron NL-1081 HV Amsterdam Netherlands <46> UI - 733NH-0017 DD - ISI Document Solution: 733NH AU - Fronzes R AU - Chaignepain S AU - Bathany K AU - Giraud MF AU - Arselin G AU - Schmitter JM AU - Dautant A AU - Velours J AU - Brethes D MA - daniet.brethes@ibgc.u-bordeaux2.fr RA - Brethes D TI - Topological and functional study of subunit h of the F1Fo ATP synthase complex in yeast Saccharomyces cerevisiae SO - Biochemistry. 42(41):12038-12049, 2003 Oct 21. AS - Biochemistry 2003 Oct 21;42(41):12038-12049 PU - AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA. URL: http://pubs.acs.org IS - 0006-2960 MH - Stalk region MH - Linking MH - F-0 MH - Mitochondria MH - Proteins MH - Membrane MH - Mutagenesis MH - Topography MH - Transport MH - Sector. AB - Subunit h, a 92-residue-long, hydrophilic, acidic protein, is a component of the yeast mitochondrial F1Fo ATP synthase. This subunit, homologous to the mammalian factor F6, is essential for the correct assembly and/or functioning of this enzyme since yeast cells lacking it are not able to grow on nonfermentable carbon sources. Chemical cross-links between subunit h and subunit 4 have previously been shown, suggesting that subunit It is a component of the peripheral stalk of the F1Fo ATP synthase. The construction of cysteine-containing subunit h mutants and the use of bismaleimide reagents provided insights into its environment. Cross-links were obtained between subunit h and subunits alpha, f, d, and 4. These results and secondary structure predictions allowed us to build a structural model and to propose that this subunit occupies a central place in the peripheral stalk between the F1 sector and the membrane. In addition, subunit h was found to have a stoichiometry of one in the F1Fo ATP synthase complex and to be in close proximity to another subunit h belonging to another F1Fo ATP synthase in the inner mitochondrial membrane. Finally, functional characterization of mitochondria from mutants expressing different C-terminal shortened subunit h suggested that its C-terminal part is not essential for the assembly of a functional F1Fo ATP synthase. [References: 32] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Brethes D Univ Bordeaux 2, CNRS, Inst Biochim & Genet Cellulaires, UMR5095 1 Rue Camille St Saens F-33077 Bordeaux France Univ Bordeaux 2, CNRS, Inst Biochim & Genet Cellulaires, UMR5095 F-33077 Bordeaux France Inst Europeen Chim & Biol, CNRS, FRE 2247 F-33607 Pessac France <47> UI - 733RV-0015 DD - ISI Document Solution: 733RV AU - Wilkinson JA AU - Jacob R MA - ron.jacob@kcl.ac.uk RA - Jacob R TI - Agonist-induced calcium and oxidative stress responses in endothelial cells SO - Biochemical Society Transactions. 31(Part 5):960-962, 2003 Oct. AS - Biochem. Soc. Trans 2003 Oct;31(Part 5):960-962 PU - PORTLAND PRESS, 59 PORTLAND PLACE, LONDON W1N 3AJ, ENGLAND. URL: http://www.portlandpress.co.uk IS - 0300-5127 MH - Atp MH - Calcium MH - Carboxy-2 ',7 '-dichlorofluorescein MH - Endothelium MH - Mitochondria MH - Oxidative stress. AB - [Ca2+](i) (Cytosolic [Ca2+]) and OS (oxidative stress) were measured simultaneously in calf pulmonary artery endothelial cells using fura-2 and carboxy-2',7'-dichlorodihydrofluorescein. ATP stimulated a [Ca2+](i) increase that was followed a few seconds later by an increase in OS. Pre-exposure to 5 muM H2O2 potentiated these responses to ATP. Elevating or removing extracellular Ca2+ increased or reduced the [Ca2+](i) response to ATP and caused parallel changes in the OS response, suggesting that this response was a consequence of the [Ca2+](i) response. inhibition of mitochondria with rotenone or antimycin A affected the responses but not in a manner that allowed a simple interpretation of the role of mitochondria. These data show an initimate connection between [Ca2+](i) and OS that can be modulated by low levels of exogenously applied OS, allowing the possibility of positive feedback. [References: 2] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Jacob R Univ London Kings Coll, Ctr Cardiovasc Biol & Med London SE1 1UL England Univ London Kings Coll, Ctr Cardiovasc Biol & Med London SE1 1UL England <48> UI - 733UY-0012 DD - ISI Document Solution: 733UY AU - Takahashi S AU - Nishino T AU - Koyama T MA - koyama@tagen.tohoku.ac.jp RA - Koyama T TI - Isolation and expression of Paracoccus denitrificans decaprenyl diphosphate synthase gene for production of ubiquinone-10 in Escherichia coli SO - Biochemical Engineering Journal. 16(2):183-190, 2003 Nov. AS - Biochem. Eng. J 2003 Nov;16(2):183-190 PU - ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND. URL: http://www.elsevier.nl IS - 1369-703X MH - Prenyltransferase MH - Ubiquinone-10 MH - Decaprenyl diphosphate MH - Enzyme activity MH - Recombinant dna MH - Paracoccus denitrificans. MH - Molecular-cloning MH - Pyrophosphate synthetase MH - Caenorhabditis-elegans MH - Micrococcus-luteus MH - Clk-1 mutants MH - Coenzyme-q MH - System MH - Chain MH - Prenyltransferase MH - Biosynthesis. AB - Ubiquinones (coenzyme Q) play important roles as an electron carrier in the mitochondrial respiratory chain and have been successfully used as an orally administrated prophylaxis and therapy for various diseases. The number of isoprene unit in the prenyl side chain of ubiquinone varies depending on the organism. This organism-dependency of the isoprene unit number is determined by the availability of the prenyl diphosphate in the cell. Paracoccus denitrificans has (all-E)-decaprenyl diphosphate (DecPP) synthase catalyzing condensation of seven molecules of isopentenyl diphosphate with (all-E)-farnesyl diphosphate to afford DecPP (C-50), the precursor of the prenyl side chain of coenzyme Q-10. To understand structure-activity relationship of prenyl chain elongating enzymes in molecular level as well as to establish a manipulation system of ubiquinone-10 in Escherichia coli cells, the structural gene encoding DecPP synthase was cloned from Paracoccus denitrificans. An overproducing system of this enzyme was constructed, and the prenyltransferase assay of the cell-free system of the transformant indicated that the recombinant protein overexpressed in E. coli cells showed distinct DecPP synthase activity. Moreover, the level of ubiquinone-10 in the transformed cells was greater than that of ubiquinone-8, which is intrinsic in wild type E. coli host cells. (C) 2003 Elsevier Science B.V. All rights reserved. [References: 31] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences CC - Biotechnology & Applied Microbiology in Current Contents(R)/Agricultural, Biology & Environmental Sciences. EW - 2003 week 45 IN - Reprint available from: Koyama T Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Aoba Ku Katahira 2-1-1 Sendai Miyagi 9808577 Japan Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Aoba Ku Sendai Miyagi 9808577 Japan Tohoku Univ, Dept Biochem & Engn, Aoba Ku Sendai Miyagi 9808579 Japan <49> UI - 731UF-0053 DD - ISI Document Solution: 731UF AU - Shimizu M AU - Kazutoshi K AU - Morii H AU - Mitsui K AU - Knoll W AU - Nagamune T MA - nagamune@bio.t.u-tokyo.ac.jp RA - Nagamune T TI - Secondary structure analyses of protein films on gold surfaces by circular dichroism SO - Biochemical & Biophysical Research Communications. 310(2):606-611, 2003 Oct 17. AS - Biochem. Biophys. Res. Commun 2003 Oct 17;310(2):606-611 PU - ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA. URL: http://www.apnet.com IS - 0006-291X MH - Ultra-thin protein film MH - Circular dichroism MH - Secondary structure MH - Self-assembly. MH - Self-assembled monolayer MH - Photosynthetic reaction centers MH - Escherichia-coli MH - Cytochrome b(562) MH - Electron-transfer MH - Plasmon resonance MH - Orientation MH - Resolution MH - Adsorption MH - Particles. AB - In order to analyze the secondary structures of protein molecules adsorbed on gold surfaces, circular dichroism (CD) spectra were measured and the secondary structure contents of protein ultra-thin films were estimated quantitatively. A disulfide group was introduced to cytochrome h(562) (cyt.b562), which is a water-soluble b-type heme protein. The cyt.b562 molecules self-assembled to form an ultra-thin protein film both on a gold substrate modified with 2,2'-dithiodiacetic acid and on a bare gold surface. CD measurements were carried out both in solution and in air, and these results were compared. The protein denaturation was partially prevented, not only in solution but also in air, by both the modification of the substrate and the introduction of the anchor group to the protein molecule. The secondary structure contents of ultra-thin protein films on flat gold surfaces were observed for the first time both in solution and in air by CD spectra. (C) 2003 Elsevier Inc. All rights reserved. [References: 41] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Nagamune T Univ Tokyo, Sch Engn, Dept Biochem & Chem, Bunkyo Ku 7-3-1 Hongo Tokyo 2238522 Japan Univ Tokyo, Sch Engn, Dept Biochem & Chem, Bunkyo Ku Tokyo 2238522 Japan Hitachi Chem Co Ltd, Ctr Res & Dev, Analyt Sci Lab Ibaraki 3088421 Japan Natl Inst Adv Ind Sci & Technol Tsukuba Ibaraki 3068566 Japan Tokyo Inst Technol, Interdisciplinary Grad Sch Sci & Engn, Dept Informat Proc, Midori Ku Yokohama Kanagawa 2268502 Japan Max Planck Inst Polymer Res D-55128 Mainz Germany <50> UI - 733GK-0022 DD - ISI Document Solution: 733GK AU - Chen YH AU - Wu HL AU - Chen CK AU - Huang YH AU - Yang BC AU - Wu LW MA - liwhawu@mail.ncku.edu.tw RA - Wu LW TI - Angiostatin antagonizes the action of VEGF-A in human endothelial cells via two distinct pathways SO - Biochemical & Biophysical Research Communications. 310(3):804-810, 2003 Oct 24. AS - Biochem. Biophys. Res. Commun 2003 Oct 24;310(3):804-810 PU - ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA. URL: http://www.apnet.com IS - 0006-291X MH - Angiogenesis MH - Endothelial cells MH - Angiostatin MH - Fasl MH - P53. MH - Cytochrome-c release MH - Growth-factor vegf MH - Tumor-growth MH - Atp synthase MH - In-vivo MH - Apoptosis MH - Angiogenesis MH - Inhibition MH - Surface MH - Mitochondria. AB - Angiostatin consisting of the first four-kringle domains of the plasminogen potently inhibits angiogenesis in vitro and in vivo. However, the molecular mechanism of action whereby angiostatin mediates its inhibitory effect on proliferating endothelial cells remains elusive. We therefore used the proliferating cultured human umbilical vein endothelial cells (HUVECs) promoted by vascular endothelial growth factor A to identify the endogenous signaling elements that mediate the antiangiogenic effect of angiostatin. Treatment of HUVEC with angiostatin at a concentration known to inhibit cell proliferation and induce apoptosis resulted in induction of p53-, Bax-, and tBid-mediated release of cytochrome c into the cytosol. In addition, angiostatin also activated the Fas-mediated apoptotic pathway in part via Up-regulation of FasL mRNA, down-regulation of c-Flip, and activation of caspase 3. These results suggest that the anti-angiogenic action of angiostatin is likely mediated by two distinct signaling pathways, one intrinsic mediated by p53 while the other extrinsic involved in FasL engagement and mitochondria dysfunction. (C) 2003 Elsevier Inc. All rights reserved. [References: 42] LG - English PT - Article SB - Current Contents(R)/Life Sciences CC - Biochemistry & Biophysics in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Wu LW Natl Cheng Kung Univ, Coll Med, Inst Mol Med Tainan 70101 Taiwan Natl Cheng Kung Univ, Coll Med, Inst Mol Med Tainan 70101 Taiwan Natl Cheng Kung Univ, Coll Med, Inst Basic Med Sci Tainan 70101 Taiwan Natl Cheng Kung Univ, Coll Med, Dept Biochem Tainan 70101 Taiwan Natl Cheng Kung Univ, Coll Med, Dept Microbiol & Immunol Tainan 70101 Taiwan <51> UI - 733ED-0002 DD - ISI Document Solution: 733ED AU - Sciare J AU - Cachier H AU - Oikonomou K AU - Ausset P AU - Sarda-Esteve R AU - Mihalopoulos N MA - sciare@lsce.saclay.cea.fr RA - Sciare J TI - Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July-August 2001: a multi-analytical approach SO - Atmospheric Chemistry & Physics. 3:1743-1757, 2003 Oct 16. AS - Atmos. Chem. Phys 2003 Oct 16;3:1743-1757 PU - EUROPEAN GEOPHYSICAL SOC, MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY. URL: http://www.copernicus.org/EGU/EGU.html IS - 1680-7324 MH - Black carbon MH - Atmospheric aerosols MH - Chemical-composition MH - Light-absorption MH - Diesel exhaust MH - Particles MH - Emissions MH - Monoxide MH - Summer MH - Size. AB - During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T > 550degreesC) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) mass concentrations were on average respectively 1.19 +/- 0.56 and 3.62 +/- 1.08 mugC/m(3) for the IMPROVE temperature program, and 1.09 +/- 0.36 and 3.75 +/- 1.24 mugC/m(3) for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope = 1.00, r(2) = 0.93, n = 56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33 +/- 22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these two methods for determining BC brings here new insights on the origin of carbonaceous aerosols in a complex mixture of different sources. It brings also to our attention that important deviations in BC levels are observed using three widely used EGA's techniques and most probably none of the EGA tested here are well adapted to fully characterize this aerosol mixture. Spherical, smooth and silico-aluminated fly-ash observed by an Analytical Scanning Electron Microscope (ASEM) confirm the influence of coal combustion on the carbonaceous aerosol load throughout the campaign. A rough calculation based on a BC/nss-SO4 mass ratio suggests that biomass burning could be responsible for half of the BC concentration recorded during the MINOS campaign. From the plot of BC as a function of TC, two linear correlations were observed corresponding to 2 times series (before and after 12 August). Such good correlations suggest, from a first look, that both BC and OC have similar origin and atmospheric transport. On the other hand, the plot of BC as a function of TC obtained from the 2-step thermal method applied to DEKATI Low Pressure Cascade Impactor samples does not show a similar correlation and points out a non conservative distribution of this ratio with 2 super micron modes enriched in OC, correlated with sea salt aerosols and probably originating from gas-to-particle conversion. [References: 49] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Earth Sciences in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Sciare J Max Planck Inst Chem, Dept Biogeochem Mainz Germany Max Planck Inst Chem, Dept Biogeochem Mainz Germany LSCE Gif Sur Yvette France Univ Crete, Dept Chem Iraklion Crete Greece LISA Creteil France <52> UI - 732UU-0003 DD - ISI Document Solution: 732UU AU - Geoffroy L AU - Dewez D AU - Vernet G AU - Popovic R MA - popovic.radovan@uqam.ca RA - Popovic R TI - Oxyfluorfen toxic effect on S-obliquus evaluated by different photosynthetic and enzymatic biomarkers SO - Archives of Environmental Contamination & Toxicology. 45(4):445-452, 2003 Nov. AS - Arch. Environ. Contam. Toxicol 2003 Nov;45(4):445-452 PU - SPRINGER-VERLAG, 175 FIFTH AVE, NEW YORK, NY 10010 USA. URL: http://www.springer-ny.com IS - 0090-4341 MH - Photosystem-ii MH - Chlorophyll fluorescence MH - Antioxidative enzymes MH - Scenedesmus-obliquus MH - Oxidative stress MH - Soybean cells MH - Peroxidation MH - Chloroplasts MH - Herbicides MH - Induction. AB - The effect of oxyfluorfen was investigated when alga Scenedesmus obliquus has been exposed to different concentrations (7.5, 15, and 22.5 mug.L-1) at 12, 24, and 48 hours of exposure. Toxicity test was done by using 13 biomarkers concerning growth rate, chlorophyll content and indicators of photosynthetic and antioxidant enzyme activities. The change of the 13 parameters showed a great variation of sensitivity indicating differences in parameters' suitability to be used as biomarkers when alga culture was exposed to oxyfluorfen toxicity. The order of sensitivity between those biomarkers was: Antenna size (ABS/RC) > Chlorophyll content > Catalase (CAT) > Operational PSII quantum yield (PhiS(PSII)) > Glutathione S-transferase (GST) > Functional plastoquinone pool (Q(PQ)) > Glutathione reductase (GR) > Growth rate > Nonphotochemical quenching (Q(N)) > Proton gradient quenching (Q(Emax)) > Ascorbate peroxidase (APX) > Photochemical quenching (Q(P)) > Maximum PSII quantum yield (Phi(PSII)). The effect of oxyfluorfen on the changes of those parameters was interpreted as a result of herbicide mode of action at molecular level of alga cellular system. This study indicated for some photosynthetic and enzymatic biomarkers to be useful indicators of toxicity effect induced in non-target alga species. Determination of biomarkers' sensitivity order may facilitate their selection to be used in environmental risk assessment of polluted water. [References: 48] LG - English PT - Article SB - Current Contents(R)/Agriculture, Biology & Environmental Sciences Current Contents(R)/Life Sciences CC - Environment/Ecology in Current Contents(R)/Agricultural, Biology & Environmental Sciences. Pharmacology & Toxicology in Current Contents(R)/Life Sciences. EW - 2003 week 45 IN - Reprint available from: Popovic R Univ Reims, UPRES EA 2069, Unite Rech Vignes & Vins Champagne, Lab Ecotoxicol BP 1039 F-51687 Reims 2 France Univ Reims, UPRES EA 2069, Unite Rech Vignes & Vins Champagne, Lab Ecotoxicol F-51687 Reims 2 France Univ Quebec, Dept Chim, TOXEN Montreal PQ H3C 3P8 Canada <53> UI - 732KL-0004 DD - ISI Document Solution: 732KL AU - Crooker SA AU - Barrick T AU - Hollingsworth JA AU - Klimov VI RA - Crooker SA TI - Ultrafast coherent terahertz spectroscopy in high magnetic fields and directed energy flows in quantum dot assemblies SO - Acta Physica Polonica A. 104(2):113-122, 2003 Aug. AS - Acta Phys. Pol. A 2003 Aug;104(2):113-122 PU - POLISH ACAD SCIENCES INST PHYSICS, AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND. URL: http://info.ifpan.edu.pl IS - 0587-4246 MH - Time-domain spectroscopy MH - Semiconductors MH - Antennas MH - Exciton MH - Beams MH - Dark. AB - We describe the design, construction, and use of fiber-coupled terahertz antennas for performing ultrafast coherent THz spectroscopy directly in the cryogenic bore of high-field magnets. With an aim towards measuring the high-frequency (100 GHz to 2000 GHz) complex conductivity of correlated electron materials in the regime of low temperatures and high magnetic fields, these miniature THz emitters and receivers are demonstrated to work down to 1.5 K and up to 18 T, for eventual use in higher-field magnets. Results from a variety of semiconducting and superconducting samples are presented. This paper also describes a separate effort towards achieving coupling between colloidal semiconductor nanocrystal quantum dots, wherein we realize and study inter-dot communication via resonant (Foster) energy transfer. We present studies of the dynamics of resonant energy transfer in monodisperse and energy gradient (layered) assemblies of CdSe nanocrystal quantum dots. Time- and spectrally-resolved photoluminescence data directly reveal the energy-dependent transfer rate of excitons from smaller to larger dots. Results from layered nanocrystal quantum dot assemblies demonstrate unidirectional energy flows, a first step towards artificial light-harvesting structures. Lastly, time-resolved studies at millikelvin temperatures elucidate the nature of ground-state "dark" excitons in these quantum dots. [References: 11] LG - English PT - Article SB - Current Contents(R)/Physical, Chemical & Earth Sciences CC - Physics in Current Contents(R)/Physical, Chemical & Earth Sciences. EW - 2003 week 45 IN - Reprint available from: Crooker SA Natl High Magnet Field Lab Los Alamos, NM 87545 USA Natl High Magnet Field Lab Los Alamos, NM 87545 USA Div Chem Los Alamos, NM 87545 USA