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'Rhodopseudomonas palustris' in keywords
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1983 (1)
1981 (1)
1Author    Michaela Preuß, Jobst-H Einrich KlemmeRequires cookie*
 Title    Purification and Characterization of a Dissimilatory Nitrite Reductase from the Phototrophic Bacterium Rhodopseudomonas palustris  
 Abstract    A dissimilatory nitrite reductase from the facultatively phototrophic bacterium , Rhodopseudo­ monas palustris strain la l was studied. A basic level o f the enzyme (1 0 -5 0 m U /m g protein) was measured in dark, aerated and anaerobic, photosynthetic cultures. A m arked derepression of enzyme synthesis occurred under conditions of oxygen lim itation (2 0 0 -3 0 0 m U /m g protein). The addition of nitrite (or nitrate) to the culture m edium had only a slight effect on the maximal nitrite reductase titer o f cells. The enzyme was purified from photosynthetically grown cells by precipitation with am m onium sulfate, gel filtration through Sepharose 6 B and repeated chromatography on DE 52-cellulose. As estimated by gel filtration, the nitrite reductase had a molecular weight o f about 120 000 + 12 000 and yielded only one band (mol. wt. o f about 68 000 + 7000) in SDS-gel electrophoresis. The isoelectric point o f the enzyme was at pH 5.1. Nitric oxide (NO) was identified as the reaction product of nitrite reduction. The enzyme also exhibited cytochrome c-oxidase activity and was active with chemically reduced viologen dyes, FMN and cytochrome c as electron donors. Highly purified nitrite reductase preparations con­ tained 10mol% of a c-type cytochrome. Trace metal analyses indicated the presence o f Cu in the enzyme. Consistent with the detection of Cu was the finding that the C u-chelator, diethyl-dithiocarbamate, strongly inhibited the nitrite reductase. 
  Reference    Z. Naturforsch. 38c, 933—938 (1983); received July 11/Septem ber 8 1983 
  Published    1983 
  Keywords    N itrite Reductase, N itrite D issimilation, Phototrophic Bacterium, Rhodopseudomonas palustris 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0933.pdf 
 Identifier    ZNC-1983-38c-0933 
 Volume    38 
2Author    Kassem Alef, Hans-Joachim Burkardt, Hans-Joachim Horstmann, WalterG. ZumftRequires cookie*
 Title    Molecular Characterization of Glutamine Synthetase from the Nitrogen-Fixing Phototrophic Bacterium Rhodopseudomonas palustris1  
 Abstract    The phototrophic bacterium Rhodopseudomonas palustris assimilated ammonium via glutamine synthetase and glutamate synthase. Diazotrophic and ammonium-grown cells had high levels of both enzymes, whereas enzymes o f alternative assimilatory pathways were absent or had only low activities. Glutamine synthetase was purified to electrophoretic homogeneity within three steps by dye-ligand and ion exchange chromatography. Electron microscopy revealed a dodecameric molecular entity which was in accordance with parameters derived from electrophoretic techniques. The molecular weight of the enzyme monomer was 55800; that o f the dodecamer 670000. The amino acid composition o f R. palustris glutamine synthetase was determined and compared by a statistical method with other known enzyme compositions from prokaryotic and eukaryotic origins. 
  Reference    Z. Naturforsch. 36c, 246—254 (1981); received December 231980 
  Published    1981 
  Keywords    Rhodopseudomonas palustris, Glutamine Synthetase, Dye-Ligand Chromatography, Nitrogen Fixation, Ammonium Assimilation 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0246.pdf 
 Identifier    ZNC-1981-36c-0246 
 Volume    36