Chemnitius J M, Haselmeyer K H, Zech R
Biochem Pharmacol. 1983 Jun 1;32(11):1693-9. doi: 10.1016/0006-2952(83)90111-9.
Cholinesterases in hen brain were characterized with respect to inhibition kinetics and substrate specificity. Three organophosphorus inhibitors were used: diethyl p-nitrophenyl phosphate (Paraoxon, E 600), di-isopropylphosphorofluoridate (DFP), and N,N'-di-isopropylphosphorodiamidic fluoride (Mipafox). The kinetics of irreversible cholinesterase inhibition were studied using two substrates, acetylthiocholine and butyrylthiocholine. The inhibition curves were analysed by the method of iterative elimination of exponential functions. Final classification of the different enzymes was done by combining two inhibitors in sequential inhibition expts. Six cholinesterases were shown to hydrolyse choline esters in hen brain, one was identified as acetylcholinesterase (EC 3.1.1.7) and one as cholinesterase (EC 3.1.1.8). Four enzymes can be classified as intermediate type cholinesterases according to their substrate specificity and to their inhibition constants. The possible role of different brain cholinesterases for the development of atypical symptoms following organophosphate intoxication is discussed.
对母鸡大脑中的胆碱酯酶进行了抑制动力学和底物特异性方面的表征。使用了三种有机磷抑制剂：对硝基苯基磷酸二乙酯（对氧磷，E 600）、二异丙基氟磷酸酯（DFP）和N，N'-二异丙基磷二酰胺氟化物（米帕明）。使用两种底物乙酰硫代胆碱和丁酰硫代胆碱研究了不可逆胆碱酯酶抑制的动力学。通过迭代消除指数函数的方法分析抑制曲线。通过在连续抑制实验中组合两种抑制剂对不同的酶进行最终分类。结果表明，母鸡大脑中有六种胆碱酯酶可水解胆碱酯，一种被鉴定为乙酰胆碱酯酶（EC 3.1.1.7），一种为胆碱酯酶（EC 3.1.1.8）。根据它们的底物特异性和抑制常数，四种酶可归类为中间型胆碱酯酶。讨论了不同脑胆碱酯酶在有机磷中毒后非典型症状发展中的可能作用。
