KINETICS OF INACTIVATION OF LDH DURING IRREVERSIBLE MODIFICATION BY OPTA
OPTA对乳酸脱氢酶的抑制动力学

Kinetics of inactivation of LDH by OPTA has been studied by following the substrate reaction in the presence of the inactivator. The microscopic constants for the reaction of the inactivator with the free-enzyme and with the enzyme - substrate complexes were determined. Results showed that with respect to substrate, NADH, the inactivator, OPTA, is competitive. The formation of the enzyme -substrate complex protects against the inactivation by OPTA. The inactivation kinetics is monophasic with OPTA. and the results also suggested that OPTA is a noncomplexing inhibiton for LDH. The present paper proves that the theory of the kinetics of substrate reaction during irreversible modification of enzyme activity can also be applied to enzyme reactions involving two substrates forming a ternary complex by an ordered sequence.