摘要
用高碘酸氧化法活化的右旋糖苷对大肠杆菌 L-天门冬酰胺酶进行化学修饰 ,修饰反应的酶活力回收率为 4 6 .8% ,修饰酶冻干品比活为 118.4 IU/ mg蛋白质。酶经修饰后 ,对底物的亲和力未发生变化 ,但抗胰蛋白酶水解能力明显提高 。
Escherichia coli L asparaginase Ⅱ was modified with oxidized dextran (MW 40 000D) using sodium metaperiodate as oxidizing agent. The resulting conjugate retained 46.8% catalytic activity of the original enzyme and a specific activity of 118.4/mg protein after freeze drying. The molecular weight of the modified enzyme was much higher than the native enzyme but the affinity of the modified enzyme to asparagine was the same as the native enzyme. The modified enzyme showed marked resistance to proteolysis and no cross reaction with antiasparaginase antibody in quantitative precipitation reaction.
出处
《药物生物技术》
CAS
CSCD
1997年第4期208-211,共4页
Pharmaceutical Biotechnology
