[Kinetic study of the mechanisms of eliminating substrate inhibition of lactate dehydrogenase by anions and pH].
The dependence of lactate dehydrogenase inhibition at high pyruvate concentrations on pH and neutral salt anions was studied. It was shown that Cl- anions compete with the substrate within the ternary inhibitory complex, ENADpyr in equilibrium ENADCl-, as a result of which the pyruvate-induced inhibition is eliminated. The KD values for Cl- (50 mM) and I- (27 mM) were calculated from the substrate velocity curves at high concentrations of pyruvate. It was supposed that pyruvate inhibition elimination by OH- proceeds via the same kinetic mechanism. The pK value (7.1 +/- 0.1) calculated from this model corresponds to pKn of essential His-195. The additivity of OH- and Cl- function was demonstrated.
Saburova
E A
EA
Iagodina
L O
LO
D000818:Animals; D002712:Chlorides; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors*; D011773:Pyruvates / Q000494:pharmacology*; D019289:Pyruvic Acid; D013552:Swine
D002712:Chlorides; D006878:Hydroxides; D011773:Pyruvates; D019289:Pyruvic Acid; D007770:L-Lactate Dehydrogenase
Kineticheskie issledovaniia mekhanizma sniatiia substratnogo ingibirovaniia laktatdegidrogenazy anionami i pH.