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

As Chance et al. 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, kcat=1.75×106 l mol−1 s−1, ΔrHm=88.99 kJ mol−1. Furthermore, we have studied the competitive inhibition of catalase by cyanide ion and reported some correlated parameters.