Determination of the kinetic parameters for the ''suicide substrate'' inactivation of bovine liver catalase by hydrogen peroxide

The kinetics of the bovine liver catalase inactivation by its suicide substrate, H2O2 was investigated in sodium phosphate buffer, 50 mM pH 7.0, at 27 degrees C. By combination of the rate equations of two concurrent reactions, decomposition of H2O2 by catalase and suicide inactivation of catalase by H2O2, simple, semiempirical kinetic equations were defined and used for the determination of the inactivation rate constant and the partition ratio which were found to be 6.86 +/- 0.19 M(-1) min(-1) and 1.82 x 10(7) +/- 5.0 x 10(5), respectively. A close match was found between the experimental data and the equations.