Enzymic hydrolysis of biopolymers via single-scission attack pathways: a unified kinetic model

Abstract

A unified analytical model is suggested for describing single-scission attack pathways for enzymic hydrolysis of polymers. This model encompasses the preferred attack degradation, as well as the endo- and exo-type ones. The model is based on kinetic and statistic considerations. It was developed to account for a variety of reaction characteristics, including cases in which the kinetic constants depend upon the chain length of the polymeric substrate. The analytical model provides a dynamic description of the enzymic degradation process, including the overall reaction rate, the time course of the reaction and the array of products obtained throughout the process. These characteristics are shown to be affected, to a large extent, by even minor changes in the probabilities for bond cleavage. The model developed also provides the quantitative evidence for the view that the endo- and exo-type degradation pathways are but particular cases of the general, preferred attack one.