丝素蛋白膜作为葡萄糖氧化酶载体的研究

采用戊二醛共价交联法将葡萄糖氧化酶（GOD）固定在丝素膜上，探讨了酶的固定化方法，研究了固定化酶膜的动力学性质，并与包埋法制备的酶膜进行了比较。共价法可获得高活力的酶膜（534u／cm2），固定化过程中使用甲醇或戊二醛处理对酶活力有轻微影响。固定化GOD最适pH值向中性偏移（pH7．0），最适温度为50℃，热稳定性提高，表观米氏常数比溶液酶降低，酶膜的贮存稳定性良好。

STUDIES ON GLUCOSE OXIDASE IMMOBILIZATION WITH SILK FIBROIN MEMBRANES

Bombyx mori silk fibroin was utilized to prepare enzyme membranes. Glucose oxidase (GOD) was covalented on the silk fibroin membrane by treatment with glutaraldehyde (GA), which had very little effect on the activity of enzyme. The kinetic properties of the immobilized GOD were extensively studied. The immobilized enzpoe activity was characterized with apparent Michaelis constant Km~(app), which was lower than that of the free enzyme. Optimum pH for the activity of the immobilized GOD shifted to around neutrality and the optimum temperature changed to 50℃ from 35℃. Its thermal stability was scarely lost even incubated at 60℃ for 30min while the free enzyme lost about 52% of the original activity.Thus, the stability of the enzyme vs. pH and heat was well improved by the immobilization with silk fibroin. In addition. The enzyme-membrane characteristics prepared with colavent - crossing method were compared with that of entrapped method.