Purification and characterization of a novel valine dehydrogenase from Streptomyces aureofaciens
Language English Country Netherlands Media print
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
7669808
DOI
10.1016/0167-4838(95)00095-c
PII: 0167-4838(95)00095-C
Knihovny.cz E-resources
- MeSH
- Hydrogen-Ion Concentration MeSH
- Amino Acid Oxidoreductases antagonists & inhibitors chemistry isolation & purification MeSH
- Streptomyces aureofaciens enzymology MeSH
- Substrate Specificity MeSH
- Temperature MeSH
- Valine Dehydrogenase (NADP+) MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Amino Acid Oxidoreductases MeSH
- Valine Dehydrogenase (NADP+) MeSH
- valine dehydrogenase (NAD+) MeSH Browser
The first valine dehydrogenase of S. aureofaciens had been described (Vancurová, I., Vancura, A., Volc, J., Neuzil, J., Flieger, M., Basarová, G. and Bĕhal, V. (1988) J. Bacteriol. 170, 5192-5196). In the present work, a second valine dehydrogenase was detected and purified by hydrophobic and fast protein liquid chromatographies. The enzyme has a relative molecular mass (M(r)) of 240,000 and is composed of 6 identical subunits, each of M(r) 41,000. In the presence of NAD, the enzyme catalyzes the reversible deamination of several branched- and straight-chain amino acids. The enzyme activities with L-2-aminobutyrate and deamino-NAD+ are markedly higher than those with L-valine and NAD+, respectively. The enzyme synthesis is significantly induced by L-valine but severely repressed by ammonia. Molecular and catalytic properties of the enzyme distinguish it from the other described valine dehydrogenases. The results directly demonstrate the presence of two valine dehydrogenases in a single Streptomyces species.
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