Abstract:

Concanavalin A (ConA), which has a very strong interaction with glycoprotein, was immobilized on preactivated glutaraldehyde-modified chitosan microspheres, and then oriented immobilization of glucose oxidase was carried out on the strong interaction. The optimal immobilization conditions are as follows: glutaraldehyde concentration 0.1%, ConA concentration 0.02 mg/ml and glucose oxidase concentration 0.08 mg/ml. The optimum pH and temperature for orientedly immobilized glucose oxidase are 4.0 and 57 ℃ respectively, and its Michaelis constant (Km) is 15.84 mmol/L. Compared with the free and the randomly immobilized glucose oxidases, the optimum pH of the orientedly immobilized glucose oxidase tends more acidic and its pH range is wider. Orientedly immobilized glucose oxidase also presents the higher temperature resistance and the better affinity to the substrate.

Key words: glucose oxidase, concanavalin A, oriented immobilization