Identity of D-3-aminoisobutyrate-pyruvate aminotransferase with alanine-glyoxylate aminotransferase 2.
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.
Kontani
Y
Y
Faculty of Nutrition, Kobe-Gakuin University, Japan.
Kaneko
M
M
Kikugawa
M
M
Fujimoto
S
S
Tamaki
N
N
D000409:Alanine / Q000378:metabolism; D000410:Alanine Transaminase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D005472:Fluorouracil / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D011233:Precipitin Tests; D051381:Rats; D000637:Transaminases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D014498:Uracil / Q000031:analogs & derivatives / Q000494:pharmacology; D015091:beta-Alanine / Q000378:metabolism
D015091:beta-Alanine; D014498:Uracil; D000637:Transaminases; D000410:Alanine Transaminase; C019685:D-3-aminoisobutyrate-pyruvate aminotransferase; C019635:Alanine-glyoxylate transaminase; C100248:azauracil; D000409:Alanine; D005472:Fluorouracil