COVALENT IMMOBILIZATION OF GLUCOSE-OXIDASE ON CATION-EXCHANGE AND ANION-EXCHANGE RESINS

Glucose oxidase (GOD) was immobilized on the cation- and anion-exchang e resins having carboxyl groups and amino groups, respectively. The co valent immobilization of GOD was carried out by use of a condensing ag ent; ca. 50 mu g of GOD was immobilized on 1 g of each resin. Specific activities of GODs immobilized on cation- and anion-exchange resins w ere 290 and 44 U/mg, respectively. The pi-I-activity profile of GOD im mobilized on anion-exchange resins showed a shift of optimum pH from 7 to 6. It was considered that the functional groups on the resins affe cted the molecular structure of immobilized GOD to cause the change of enzyme activity and the shift of optimum pH. The properties of immobi lized GOD were investigated on the basis of the glucose oxidation kine tics. The Michaelis constant of GOD immobilized on each exchange resin , calculated from Lineweaver-Burk plots, was smaller than that of nati ve GOD, which suggested the enhanced interaction between the immobiliz ed GOD and glucose.