|
type |
Journal Article |
authors |
Kontani, Y.; Kaneko, M.; Kikugawa, M.; Fujimoto, S.; Tamaki, N. |
title |
Identity of D-3-aminoisobutyrate-pyruvate aminotransferase with alanine- glyoxylate aminotransferase 2 |
journal |
Biochim Biophys Acta |
Activity |
2.6.1.40 |
sel |
selected |
ui |
8427875 |
year |
(1993) |
volume |
1156 |
number |
2 |
pages |
161-6 |
| |
keywords |
Alanine/metabolism |
abstract |
D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40) and alanine-glyoxylate aminotransferase 2 (EC 2.6.1.44) were co-purified from rat liver as a single protein. The ratio of the two activities remained constant after Sephacryl S-200 chromatography and chromatofocussing. The Km value for beta-alanine as a substrate with 1 mM glyloxylate as amino group acceptor was 1.4 mM. The activity was inhibited by (S)-alanine with Ki = 2.2 mM. The Km for (S)-alanine as substrate with 1 mM glyoxylate as amino group was 6 mM. This activity was inhibited competitively by beta-alanine with Ki = 0.7 mM. (R)-3- aminoisobutyric acid, 5-aminolevulinic acid, NG,NG'-dimethyl-(S)- arginine, and (S)-2-aminobutyric acid were active competitively with respect to beta-alanine with Km of 0.12 mM, 2.1 mM, 6.4 mM and 11.3 mM, respectively. Antiserum to rat liver D-3-aminoisobutyrate-pyruvate aminotransferase inhibited alanine-glyoxylate aminotransferase activity in rat liver in the same way as that of D-3-aminoisobutyrate-pyruvate aminotransferase. Alanine-glyoxylate aminotransferase activity and D-3- aminoisobutyrate-pyruvate aminotransferase activities were inactivated competitively with respect to beta-alanine by 5-fluorouracil and 6- azauracil, which are chemotherapeutic reagents used to cancer. These experiments indicate that D-3-aminoisobutyrate-pyruvate aminotransferase is identical with alanine-glyoxylate aminotransferase 2, aminolevulinate aminotransferase, 2-aminobutyrate aminotransferase and dimetylarginine-pyruvate aminotransferase. |
last changed |
2009/05/04 17:42 |
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