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

As Chance et al. [1-3] proposed, the decomposition of hydrogen peroxide cat alyzed by catalase is an overall first-order reaction. In this paper, we ha ve studied this enzyme-catalyzed reaction with a thermokinetic method. The rate constant and the molar reaction enthalpy of this reaction have been me asured. At 310.15 K and pH=8.2, k(cat)=1.75x10(6) l mol(-1) s(-1) Delta(r)H (m)=88.99 kJ mol(-1). Furthermore, we have studied the competitive inhibiti on of catalase by cyanide ion and reported some correlated parameters. (C) 2000 Elsevier Science B.V. All rights reserved.