Studies on pH-activity profiles of an immobilized two-enzyme system

Abstract

1. 1.|The pH-activity profile of a two-enzyme system, with both enzymes immobilized together by CNBr coupling to a neutral support (Sepharose), has been studied and compared with that of an analogous system consisting of the two enzymes unbound and in solution. 2. 2.|The enzymes studied were amylo-α-1,4-α-1,6-glucosidase and glucose oxidase (β-d-glucose:O2 oxidoreductase, EC 1.1.3.4). All measurements were carried out in a buffer solution of high ionic strength so that the influence of charged products could be neglected. 3. 3.|Immobilization of the enzymes together does not change the pH optimum for either enzyme. 4. 4.|The pH optimum for the sequential two-enzyme reaction could be displaced towards the alkaline side in one case by a factor of about 0.75 pH unit compared to the system in solution. Such a displacement is a function of the ratio of the bound enzymic activities. © 1972.