Microcalorimetric studies on catalase reaction and inhibition of catalase by cyanide ion

Abstract

As Chance et al. [1–3] proposed, the decomposition of hydrogen peroxide catalyzed by catalase is an overall first-order reaction. In this paper, we have studied this enzyme-catalyzed reaction with a thermokinetic method. The rate constant and the molar reaction enthalpy of this reaction have been measured. At 310.15 K and pH=8.2, k cat=1.75×10 6 l mol −1 s −1, Δ r H m=88.99 kJ mol −1. Furthermore, we have studied the competitive inhibition of catalase by cyanide ion and reported some correlated parameters.