测定鸡血清丁酰胆碱酯酶(butyrylcholinesterase,BChE)对农药的敏感性,为农药残留快速检测提供新的敏感酶源。本文以马血清丁酰胆碱酯酶为对照,以碘化硫代丁酰胆碱为底物,采用Ellman法,研究了鸡血清丁酰胆碱酯酶的酶学性质及其对有机磷和氨基甲酸酯类农药的敏感性,计算相关半抑制浓度(half-inhibitory concentration,IC50)。结果表明,两种BChE在35℃、pH 8.0时达到最佳的反应活性,无底物抑制效应,对毒扁豆碱敏感,对盐酸多奈哌齐相对不敏感;鸡血清BChE对敌百虫、克百威、灭多威、速灭威、敌敌畏的IC50值分别为0.77、31.99、1.14、5.49、0.95μmol/L;马血清BChE对这五种农药的IC50值分别为3.88、1.22、22.58、24.18、5.46μmol/L。除克百威外,鸡血清BChE对供试农药的敏感性均高于马血清BChE。因此,鸡血清BChE具有较好的农药敏感性,可以作为农药残留快速检测的候选酶源。
The inhibition effect of butyrylcholinesterase(BChE) in the chicken serum to pesticide was investigated,and new sensitive enzyme source to the quick examination of pesticide were provided.Taking the horse serum BChE for comparison,enzymology properties of the chicken serum BChE and its sensitivity to pesticides were studied by the colorimetric method of Ellman's,and then the half inhibitory concentration value(IC50) was calculated.The results showed that both BChE reached their best reactivity at 35 ℃ and pH 8.0,no substrate inhibition effect was observed,and both were sensitive to physostigmine but relatively insensitive to donepezil HCL.The IC50 value for trichlorfon,carbofuran,methomyl,metolcarb,dichlorvos to the chicken serum BChE were 0.77,31.99,1.14,5.49,0.95 μmol/L,respectively,while the IC50 value for those five pesticides to horse serum BChE were 3.88,1.22,22.58,24.18,5.46 μmol/L,respectively.Thus,the chicken serum BChE has good sensitivity to pesticides and could be used as a candidate enzyme source for rapid detection of pesticide residues.