Tryptophanase from a marine bacterium, Vibrio K-7 synthesis, purification, and some chemical catalytic properties
| Autor: | Dixie D. Whitt, R. D. DeMoss, Michael J. Klug |
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| Rok vydání: | 1979 |
| Předmět: |
Brachyura
Tryptophanase activity Lyases Sodium Chloride Biochemistry Microbiology Cofactor Substrate Specificity Serine chemistry.chemical_compound Genetics Animals Seawater Molecular Biology Pyridoxal Vibrio Indole test biology Tryptophanase Tryptophan General Medicine Hydrogen-Ion Concentration Molecular Weight chemistry Enzyme Induction biology.protein Enzyme Repression Water Microbiology Cysteine |
| Zdroj: | Archives of Microbiology. 122:169-175 |
| ISSN: | 1432-072X 0302-8933 |
| Popis: | The conditions for synthesis, purification, and properties of tryptophanase by a marine organism (Vibrio K-7) were studied. Tryptophanase was induced by tryptophan and its analogs, and partially repressed by 0.5% glucose or glycerol. NaCl (0.4 M) was required for optimal growth and tryptophanase activity in whole cells. The enzyme was purified to 92% homogeneity by heat treatment, hydroxyapatite chromatography and fractionation with ammonium sulfate. This tryptophanase has been found to have kinetic properties similar to the tryptophanase from other microorganisms. It carries out both alpha, beta-elimination reactions (using tryptophan, serine, cysteine and S-methylcysteine as substrates) and beta-replacement reactions (forming tryptophan from indole and serine, cysteine or S-methyl-cysteine). The enzyme has a sedimentation coefficient of 9.2S and requires pyridoxal 5'-phosphate as a cofactor. The optimal pH for the tryptophanase reaction is pH 8.0. |
| Databáze: | OpenAIRE |
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