Abstract

Carbonic anhydrase (CA, EC 4.2.1.1) plays crucial physiological roles in many different organisms, such as in pH regulation, ion transport, and metabolic processes. CA was isolated from the European bee Apis mellifera (AmCA) spermatheca and inhibitory effects of pesticides belonging to various classes, such as carbamates, thiophosphates, and pyrethroids, were investigated herein. The inhibitory effects of methomyl, oxamyl, deltamethrin, cypermethrin, dichlorodiphenyltrichloroethane (DDT) and diazinon on AmCA were analysed. These pesticides showed effective in vitro inhibition of the enzyme, at sub-micromolar levels. The IC₅₀ values for these pesticides ranged between of 0.0023 and 0.0385 μM. The CA inhibition mechanism with these compounds is unknown at the moment, but most of them contain ester functionalities which may be hydrolysed by the enzyme with the formation of intermediates that can either react with amino acid residues or bid to the zinc ion from the active site.

摘要

碳酸酐酶（CA，EC 4.2.1.1）在许多不同的生物中起着至关重要的生理作用，例如在pH调节，离子迁移和代谢过程中。CA是从欧洲蜜蜂Apis mellifera（AmCA）spermatheca分离得到的，本文研究了各种农药（如氨基甲酸酯，硫代磷酸盐和拟除虫菊酯）的抑制作用。分析了灭多威，乙酰胺，溴氰菊酯，氯氰菊酯，二氯二苯基三氯乙烷（DDT）和二嗪农对AmCA的抑制作用。这些农药在亚微摩尔水平上显示出对酶的有效体外抑制作用。IC ₅₀这些农药的值介于0.0023和0.0385μM之间。目前尚不清楚这些化合物的CA抑制机制，但其中大多数都含有酯官能团，该酯官能团可能会被酶水解并形成中间体，该中间体可与氨基酸残基反应或从活性位点与锌离子结合。