摘要
为探讨有机磷及氨基甲酸酯类农药对麦麸酯酶的抑制作用,以酶活抑制率为指标,通过测定酶动力学常数(Ki、Ka、K2)及半数抑制浓度(IC50)揭示麦麸酯酶的动力学特性。结果显示:麦麸酯酶对3种有机磷农药的敏感性大小顺序依次为:敌敌畏>甲基对硫磷>乐果,其对麦麸酯酶的IC50分别为0.176、1.754、2.583 mg/L;对3种氨基甲酸酯类农药的敏感性大小依次为:叶蝉散>西维因>丁硫克百威,其对麦麸酯酶的IC50分别为0.489、0.799、2.035 mg/L;各农药抑制麦麸酯酶的动力学常数(Ki、Ka、K2)及IC50值表明,不同农药对麦麸酯酶的抑制作用存在不同程度的选择性,农药与麦麸酯酶的亲和力强弱是导致麦麸酯酶对农药敏感性差异的主要原因;运用该方法检测蔬菜和水果中农药残留,得出莴笋叶、四季豆和葡萄中含有农药,且确定葡萄中为乐果残留。该研究可为麦麸酯酶应用于农药检测提供一定的理论基础。
The enzyme kinetic constants(K i,K a,K 2)and half inhibitory concentration(IC 50)were determined to reveal the kinetic characteristics of wheat bran esterase with the index of enzyme activity inhibition rate.Results showed that,the sensitivity order of wheat bran esterase to three organophosphorus pesticides was as follows:dichlorvos>methyl parathion>dimethoate,and that to carbamate pesticides was:isoprocarb>carbaryl>carbosulfan.In addition,the corresponding IC 50 values for the six pesticides were 0.176,1.754,2.583,0.489,0.799,2.035 mg/L,respectively.The conclusion that the inhibitory effects of pesticides on wheat bran esterase were selective in different degrees was obtained by comparing the kinetic constants(K i,K a,K 2)of wheat bran esterase and IC 50 values of the six pesticides.And the main reason for the difference of the sensitivity to pesticides was the affinity of wheat bran esterase and pesticides.Actually,lettuce,green beans and grapes were detected to contain pesticides by using this method,and the pesticide residues in grape were confirmed to be dimethoate.The method could provide a theoretical basis for the application of wheat bran esterase in pesticide detection.
作者
侯晓艳
姜露
叶麟
申光辉
黎杉珊
罗擎英
吴贺君
张志清
HOU Xiao-yan;JIANG Lu;YE Lin;SHEN Guang-hui;LI Shan-shan;LUO Qing-ying;WU He-jun;ZHANG Zhi-qing(College of Food Science,Sichuan Agricultural University,Ya an 625014,China;Luzhou Product Quality Supervision and Inspection Institute,Luzhou 646000,China)
出处
《分析测试学报》
CAS
CSCD
北大核心
2018年第3期324-330,共7页
Journal of Instrumental Analysis
基金
四川省科技计划项目(2016JY0118)
四川农业大学学科双支计划(03572107)
关键词
麦麸酯酶
酶动力学
农药残留
敏感性
有机磷
氨基甲酸酯
wheat bran esterase
enzyme dynamics
pesticide residue
sensitivity
organophosphorus
carbamate
