人 G类有机磷毒剂水解酶的性质(英文)

Characteristics of human G-type organophosphate hydrolyzing enzyme

观察了部分纯化的人肝 G类毒剂水解酶 ( G酶 )的一些生化性质 .二硫苏糖醇 ( 5mmol·L-1)使G酶活性在 37℃ ,30 min内抑制 35% ;对氯汞苯甲酸 ( 1 - 1 0 0 0 μmol· L-1)不影响 G酶活性 .说明二硫键对酶分子的三维结构至关重要 ,而没有游离巯基参与酶的催化反应 .人肝 G酶专一性地水解带P- F键的有机磷化合物梭曼 ,但不催化带 P- O,P- C或 P- S键的有机磷化合物的反应 .

The biochemical properties of a partially purified human liver G type organophosphate hydrolyzing enzyme (Gase) were examined. The enzyme activity was inhibited 35% by dithiothreitol (5 mmol·L -1 ) at 37℃ in 30 min, however no inhibitory effect was produced by p chloromercapto benzoic acid (1-1000 μmol·L -1 ). It suggests that the disulfide bond(s) be essential for the three dimentional structure of the Gase molecule, and there be no free sulfhydryl group taking part in the catalytic reaction. Human liver Gase specifically hydrolyzed organophosphorus compounds bearing P F bond (soman), however it did not catalyze the hydrolysis of compounds with P O, P C or P S bonding.