Determination of the Kinetic Parameters for the “Suicide Substrate” Inactivation of Bovine Liver Catalase by Hydrogen Peroxide

Abstract

The kinetics of the bovine liver catalase inactivation by its suicide substrate, H₂0₂ was investigated in sodium phosphate buffer, 50 mM pH 7.0, at 27°C. By combination of the rate equations of two concurrent reactions, decomposition of H₂0₂ by catalase and suicide inactivation of catalase by H₂0₂ 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 × 10⁷± 5.0 × 10⁵, respectively. A close match was found between the experimental data and the equations.

Key Words: :

• Enzymes inactivation
• suicide substrate
• catalase
• kinetic equations