家蝇AChE检测毒死蜱残留的最佳条件研究

以纯化的家蝇(Museadomestica)乙酰胆碱酯酶(AChE)为试验材料,研究了缓冲液pH值、底物(ATCh)浓度、温度三个因素对酶活性的影响。结果表明:在pH值为8.5￣9.0,温度为30℃,底物浓度为2.5mmol/L的条件下,该酶具有最大活性。在此基础上,测定了不同pH值的缓冲反应体系和不同抑制时间条件下毒死蜱(Chiorpyifos)对AChE活性的抑制,发现pH值为8.0时AChE对毒死蜱最为敏感,而且对毒死蜱具有良好的线性响应关系(R2=0.9973),半抑制浓度仅为39.1μg/(L抑制时间为20min),检测下限为4.4μg/L。随着抑制时间的延长,毒死蜱对AChE的抑制程度逐渐增强,检测限可进一步降低。可见家蝇AChE是指示环境中毒死蜱污染程度的良好材料。

Optimum Condition for Detection of Chiorpyifos Residue by Using Acetylcholinesterase of Musea domestica

The effect of pH value of buffer solution,concentration of substrate(ATCh)and temperature on activity of acetylchloinesterase(AChE)of Musea domestica was studied.Results showed that optimum conditions were pH value of 8.5 to 9.0,concentration of substrate 2.5mmol/L and temperature of 30℃.The inhibition of AChE of Musea domestica by chiorpyifos at different pH of buffer solution and inhibition time was studied.It was found AChE of Musea domestica to chiorpyifos was most sensitive in buffer solution of pH 8.0,and there was a good linearity between percent inhibition of AChE activity and concentration of chiorpyifos.In addition,39.1 μg/L of chiorpyifos was sufficient enough to inhibit 50% of AChE mobility of Musea domestica inhibited for 20min,and the percent inhibition of AChE activity rose with lasting inhibition time.AChE from Musea domestica was considered to be excellent indicator of monitoring chiorpyifos.