摘要
采用量子化学的CNDO/2法,探讨了胆碱酯酶活性部位的组氨酸、丝氨酸等残基问氢键的形成和氢迁移问题,从理论上阐明了酸催化乙酸胆碱反应中何者作为亲核基团向底物进攻。考虑到氧化对酶生物活性的丧失有较大影响,对组氨酸残基氧化前后的氢键构成和催化机理进行了理论比较。为研究酶催化过程提供了有用的信息。
The formation of hydrogen bonding between histidine and serine residues and the hydrogen migration on the active sites of cholinesterase ester were studied by the quantum chemistry calculation (CNDO/2). From the theoretical point of view, what nucleophilic groups that attacked the substrate in the catalytic hydrolysis of acetylcholine was discussed. In consideration of the great effect of oxidation on the deactivation of the enzyme, a theoretical comparison was made between the hydrogen bondings before and after the oxidation of histidine residues. Some useful information about the enzyme catalysis was provided.
