Kinetics of the course of inactivation of yeast alcohol dehydrogenase by 4-(2-pyridylazo)-resorcinol.

Abstract

The kinetic theory of the substrate reaction during modification of enzyme activity previously described by Wang and Tsou has been applied to a study on the kinetics of the course of inactivation of alcohol dehydrogenase by 4-(2-pyridylazo)-resorcinol (PAR). The results showed that the inhibition of this enzyme by PAR was irreversible. A plot of 1n([P] infinity -[P]) versus give a straight line, suggesting that the inactivation kinetic course is monophasic. The kinetic analysis of the substrate reaction with different concentrations of the substrate and the inactivator has shown that the inactivation of yeast alcohol dehydrogenase by PAR involves complex formation, and that the substrate ethanol competes with PAR at the active site of the enzyme. The dissociation constants between the substrates and the enzyme as well as the microscopic rate constants for the inactivation of the enzyme have been determined.