由于天然酶其异源蛋白的抗原性、易受蛋白酶水解、酶活性较低、稳定性差等原因，严重影响胰蛋白酶的应用范围和效果。为了获取理化性质更稳定的胰蛋白酶，研究了右旋糖苷修饰胰蛋白酶的反应条件和胰蛋白酶修饰前后的酶学性质。结果表明右旋糖苷修饰胰蛋白酶的最优反应条件为：右旋糖苷与胰蛋白酶的摩尔比为1∶2，修饰反应最适pH 为8.0，最适反应温度为35 ℃，最佳修饰时间为4 h，胰蛋白酶保留酶活力56.1%，修饰率为49.2%。修饰后的胰蛋白酶适合温度、pH 值范围变大，热稳定性和酸碱稳定性明显的提高。因而右旋糖苷修饰胰蛋白酶能够增强胰蛋白酶的热稳定性和酸碱稳定性，为胰蛋白酶的修饰提供理论参考并扩展蛋
白酶的工业应用价值。

The application of wild trypsin is severely limited due to the antigenicity of heterologous protein, degradation by protease, low activity and poor stability. In order to obtain a trypsin with stable physical and chemical properties, the modification conditions of the trypsin by dextran and its enzymatic characteristics before and after modification were studied in this paper. The results showed that the optimal modification conditions of the trypsin by dextran were as follows: the molar ratio of dextran and trypsin 1∶2, pH 8.0, temperature 35 ℃, reaction time 4 h. Under the optimized conditions, the trypsin retained 56.1% of its activity. The range of optimum temperature and pH of the modified trypsin became wider and the heat stability and acid stability were significantly improved. These results indicated that thermal stability and pH stability of the trypsin modified by dextran can be improved, which provides theoretical basis for the modification of trypsin and expands its industrial application.