|
type |
Journal Article |
authors |
Rhee, H.; Murata, K.; Kimura, A. |
title |
L-alanine: 4,5-dioxovalerate aminotransferase from Pseudomonas riboflavina: purification and inactivation by methylglyoxal |
journal |
J Biochem (Tokyo) |
Activity |
2.6.1.43 |
ui |
89008191 |
year |
(1988) |
volume |
103 |
number |
6 |
pages |
1045-9. |
| |
keywords |
Aldehydes/*pharmacology |
abstract |
L-Alanine:4,5-dioxovalerate aminotransferase, which catalyzes transamination between L-alanine and 4,5-dioxovalerate to yield delta- aminolevulinate and pyruvate, has been purified from Pseudomonas riboflavina IFO 3140. The enzyme had a molecular weight of 190,000 and consisted of four identical subunits. It was crystallized as pale yellow needles. The enzyme used L-alanine (relative activity 100), beta- alanine (39), and L-ornithine (14) as amino donors. gamma-aminobutyrate (55) and epsilon-aminocaproate (34) were also effective as amino donors. The reaction proceeded according to a ping-pong mechanism and the Km values for L-alanine and 4,5-dioxovalerate were 1.7 and 0.75 mM, respectively. The activity of the enzyme is strongly inhibited by pyruvate, hemin, and methylglyoxal. Methylglyoxal interacted with the enzyme and brought about a complete inactivation. |
last changed |
2002/11/12 16:17 |
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