从不同的动物组织中筛选胆碱酯酶,研究胆碱酯酶的酶学性质和检测有机磷农药残留的条件。实验结果表明:驴血清胆碱酯酶活力较高,确定驴血清为检测有机磷农药的最佳酶源。胆碱酯酶最适反应温度为35℃,最适pH值为7.5～8.0,底物碘化硫代丁酰胆碱对驴血清胆碱酯酶没有过量底物抑制现象,最适浓度为5mmol/L;该酶热稳定性较好,在35℃保温60 min,酶活力基本不变。以有机磷农药—敌敌畏检测为例,对胆碱酯酶的半抑制浓度IC50为0.124 mg/mL,抑制时间为15 min。

Cholinesterase was screened from different animal tissues,and the characteristics of cholinesterase and the detecting conditions of organophosphorus pesticides were studied in this paper.The results showed that cholinesterase activity from donkey serum was high.Cholinesterase from donkey serum was chosen for the detection of organophosphorus pesticides.It is observed that the optimum temperature of enzymatic reaction was 35 ℃,and the optimum pH value range from7.5 to 8.0.The enzyme activity was not inhibited by excess butyryl thiocholineiodide,and the optimal concentration of substrate was 5 mmol/L.The enzyme activity was unchanged at 35℃ for 60 min,which showed the good thermal stability of the enzyme.IC50 of dichlorvos was 0.124 mg/mL and its inhibition time was 15 min.