Irreversible inhibition of D-3-aminoisobutyrate-pyruvate aminotransferase by gabaculine.
Gabaculine, 5-amino-1,3-cyclohexadienylcarboxylate, is an analogue of GABA and a potent irreversible inhibitor of GABA aminotransferase. However, D-3-aminoisobutyrate-pyruvate aminotransferase for which GABA was neither a substrate nor an inhibitor was also inactivated by gabaculine. The Ki for D-3-aminoisobutyrate-pyruvate aminotransferase was 8.3 x 10(-6) M, and the Kcat for its turnover was 0.31 min-1 at 25 degrees C. beta-Alanine protected the enzyme from inactivation by gabaculine, but GABA did so to much a lesser extent.
Kaneko
M
M
Faculty of Nutrition, Kobe-Gakuin University, Japan.
Fujimoto
S
S
Kikugawa
M
M
Tamaki
N
N
D000612:4-Aminobutyrate Transaminase / Q000037:antagonists & inhibitors; D000410:Alanine Transaminase / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D000818:Animals; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D011551:Pseudomonas fluorescens / Q000201:enzymology; D051381:Rats; D000637:Transaminases / Q000037:antagonists & inhibitors*; D015091:beta-Alanine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D003509:Cyclohexanecarboxylic Acids; D007527:Isoenzymes; D015091:beta-Alanine; C012987:gabaculine; D005680:gamma-Aminobutyric Acid; D000637:Transaminases; D000612:4-Aminobutyrate Transaminase; D000410:Alanine Transaminase; C019685:D-3-aminoisobutyrate-pyruvate aminotransferase