脱卤酶化学修饰的研究

脱卤酶是催化α-卤酸转化为α-羟基酸的酶。本文用各种化学修饰剂对脱卤酶YL、109和H-2进行化学修饰。实验结果表明作用于丝氨酸、赖氨酸、色氨酸残基的试剂对酶活无明显影响，而作用于组氨酸、精氨酸和带羧基氨基酸残基的试剂使酶活降低。底物对化学修饰剂有保护作用。组氨酸、精氨酸和带羧基氨基酸(答氨酸或天冬氨酸)残基为脱卤酶活力所必需。

Chemical Modification of Dehalogenase

Dehalogenase is an enzyme which catalyzes a-haloacid to a-hydroxyl acid. Chemical modification reactions of dehalogenase YL, 109 and H-2 were carried out by various reagents. The experimental results showed that the activity was not significantly altered by seryl lysyl and trpyl reagent but decreased by hisyl, arginyl and carboxyl reagent. Substitute could protect the active centre to chemical modification. It was indicated that hisyl, arginyl and carboxyl (glu or asp) residue would be essential for the acti vity of dehalogenase.