Krupka R M
Biochim Biophys Acta. 1975 Nov 20;410(1):115-9. doi: 10.1016/0005-2744(75)90211-9.
The effects of various agents that could be expected to perturb enzyme structure in a non-specific and reversible manner (alcohols, dimethylsulfoxide, dimethylformamide, dinitrobenzene, urea and guanidine - HCl) have been determined on reaction of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) with a substrate, p-nitrophenyl acetate, and two irreversible inhibitors, diisopropylphosphorofluoridate and methanesulfonyl fluoride. In all three of these reactions an acyl group (acetyl, phosphoryl or sulfonyl respectively) bonds covalently with the active center of the enzyme. As expected, the reactions of p-nitrophenyl acetate and diisopropylphosphorofluoridate were severely retarded by most of these agents. By contrast, reaction of methanesulfonyl fluoride was usually depressed to a far smaller degree, and in two cases was faster. These findings are of interest in connection with: (1) differing requirements for the integrity of tha active center in catalysis with various substrate analogs, and (2) the mechanism by which cationic substrate analogs accelerate reaction of the enzyme with methanesulfonyl fluoride.
研究了各种有望以非特异性且可逆的方式扰乱酶结构的试剂（醇类、二甲基亚砜、二甲基甲酰胺、二硝基苯、尿素和盐酸胍）对乙酰胆碱酯酶（乙酰胆碱水解酶，EC 3.1.1.7）与底物对硝基苯乙酸酯以及两种不可逆抑制剂二异丙基氟磷酸酯和甲磺酰氟反应的影响。在所有这三种反应中，一个酰基（分别为乙酰基、磷酰基或磺酰基）与酶的活性中心共价结合。正如预期的那样，对硝基苯乙酸酯和二异丙基氟磷酸酯的反应受到大多数这些试剂的严重阻碍。相比之下，甲磺酰氟的反应通常受到的抑制程度要小得多，并且在两种情况下反应更快。这些发现与以下方面相关：（1）催化各种底物类似物时对活性中心完整性的不同要求，以及（2）阳离子底物类似物加速酶与甲磺酰氟反应的机制。
