Molecular Characterization of Glutamine Synthetase from the Nitrogen-Fixing Phototrophic Bacterium Rhodopseudomonas palustris1
| Autor: | Hans-Joachim Horstmann, Walter G. Zumft, Kassem Alef, Hans-Joachim Burkardt |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
chemistry.chemical_classification
biology Ion chromatography biology.organism_classification General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Enzyme Dodecameric protein chemistry Biochemistry Glutamine synthetase Glutamate synthase biology.protein Nitrogen fixation Ammonium Rhodopseudomonas palustris |
| Zdroj: | Zeitschrift für Naturforschung C. 36:246-254 |
| ISSN: | 1865-7125 0939-5075 |
| DOI: | 10.1515/znc-1981-3-411 |
| Popis: | 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 of 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 55 800; that of the dodecamer 670 000. The amino acid composition of R. palustris glutamine synthetase was determined and compared by a statistical method with other known enzyme compositions from prokaryotic and eukaryotic origins |
| Databáze: | OpenAIRE |
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