Kinetic Aspects of the Irreversible Thermal Inactivation of Enzymes

The methods for the kinetic description and the mechanisms of the thermal inactivation of proteins (enzymes) in various media (aqueous solutions, inverted surfactant micelles, and microsomal membranes) are examined critically. The effective kinetic constants calculated from a first order equation and by approximate methods in conformity with an associative-dissociative mechanism are compared. The temperature dependence of the effective inactivation rate constants is analysed for enzymes and the causes of its deviation from the Arrhenius equation are discussed. The influence of polyols and detergents on the stability of enzymes and their modified forms is analysed and the thermodynamic activation parameters (ΔH*, ΔS*, and ΔG*) for the thermal inactivation of different enzymes in various media are compared and discussed. Recommendations are given concerning the quantitative description of the thermal stability of proteins (enzymes) under the real conditions of their application.
The bibliography includes 138 references.