Activities | Families | Sequences | Fold types | References | Help
B6db references: 85131114

type Journal Article
authors Yonaha, K.; Suzuki, K.; Toyama, S.
title Streptomyces beta-alanine:alpha-ketoglutarate aminotransferase, a novel omega-amino acid transaminase. Purification, crystallization, and enzymologic properties
journal J Biol Chem
ui 85131114
year (1985)
volume 260
number 6
pages 3265-8.
keywords 4-Aminobutyrate Transaminase/*isolation & purification
abstract An enzyme which catalyzes the transamination of beta-alanine with alpha- ketoglutarate was purified to homogeneity from Streptomyces griseus IFO 3102 and crystallized. Molecular weight of the enzyme was found to be 185,000 +/- 10,000 by a gel-filtration method. The enzyme consists of four subunits identical in molecular weight (51,000 +/- 1,000). The transaminase is composed of 483 amino acids/subunit containing 7 and 8 residues of half-cystine and methionine, respectively. The enzyme exhibits absorption maxima at 278 and 415 nm. The pyridoxal 5'- phosphate content was determined to be 4 mol/mol of enzyme. The enzyme catalyzes transamination of omega-amino acids including taurine and hypotaurine. beta-Alanine and DL-beta-aminoisobutyrate served as a good amino donor; the Michaelis constants are 8.0 and 12.5 mM, respectively. alpha-Ketoglutarate is the only amino acceptor (Km = 4.0 mM); pyruvate and oxalacetate are inactive. Based on the substrate specificity, the terminology of beta-alanine:alpha-ketoglutarate transaminase is proposed for the enzyme. Carbonyl reagents, HgCl2,DL-gabaculine, and alpha-fluoro-beta-alanine strongly inhibited the enzyme.
last changed 2002/11/04 17:41

B6db references