The Energy of Activation of Protein Denaturations

Abstract

The abnormally large values of the energy and the entropy of activation encountered in protein denaturations and enzyme destructions are illusory, since the customary method of calculating these quantities by the comparison of rates at constant p_H alone is fallacious. This procedure includes, in addition to the true energy of activation, the heat of dissociation of all acidic equilibria involved in preparing the initial molecules for the kinetic step of activation. Steinhardt has shown by a simple and concrete mechanism that the kinetics of pepsin destruction obey the simple laws of chemical kinetics when correction is made for the preliminary acidic dissociation equilibria which are not part of the activation process.