A general model for analysis of linear and hyperbolic enzyme inhibition mechanisms

Abstract

The mechanisms of reversible inhibitors with a single binding site on enzymes are usually divided into basic groups: linear and hyperbolic, also called partial. Each of them subdivided into types: competitive, non-competitive and mixed. These six mechanisms are often considered separate identities. Here, prompted by the characterization of the inhibition of the wild-type and mutant {beta}-glucosidase Sf{beta}gly by Imidazole and Tris (2-amino-2-(hydroxymethyl)-1,3-propanediol) we developed a unifying enzyme kinetic model that integrates these six basic inhibition mechanism onto a single one. From this model we deduced a general enzyme kinetic equation that through modulation of simple parameters, i.e. the relative inhibitor affinity for two binding sites and the reactivity of the enzyme-substrate-inhibitor complex, is converted into the particular kinetic equation of each of those six inhibition mechanism. In short, we conclude that six fundamental inhibition mechanisms, linear and hyperbolic, are not isolate compartments, but actually facets of the same general model here presented.