Bisfunction of propionic acid on purified rat liver beta-ureidopropionase.
Propionic acid and isobutyric acid, which are structural analogues of N-carbamoyl-beta-alanine and N-carbamoyl-beta-aminoisobutyric acid, respectively, acted as an allosteric activator as well as a competitive inhibitor of purified rat liver beta-ureidopropionase. Propionic acid and isobutyric acid had a Ki value of approx. 0.3 mM at pH 7.0. The Hill coefficient for N-carbamoyl-beta-alanine was 2.0, but the cooperatively decreased to 1.0 in the presence of 1 mM propionic acid. The K1/2 value towards N-carbamoyl-beta-alanine was calculated to be 0.17 mM from Hill plots and the Km value was determined to be 0.06 mM from replots of the apparent Km vs propionic acid.
Kikugawa
M
M
Faculty of Nutrition, Kobe-Gakuin University, Japan.
Fujimoto
S
S
Mizota
C
C
Tamaki
N
N
D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D002264:Carboxylic Acids / Q000494:pharmacology; D004789:Enzyme Activation; D058610:Isobutyrates; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D011422:Propionates / Q000494:pharmacology*; D051381:Rats
D002087:Butyrates; D002264:Carboxylic Acids; D058610:Isobutyrates; D011422:Propionates; C020380:isobutyric acid; D000581:Amidohydrolases; C021590:beta-ureidopropionase; C029658:propionic acid