甲基毒死蜱对红细胞膜乙酰胆碱酯酶的抑制作用及其与膜脂相互关系

Relationship between Membrane Lipids and the Inhibition of Acetylcholinesterase on Human Erythrocyte by Chlorpyrifos-Methyl

以人红细胞膜为材料,研究了甲基毒死蜱与膜上乙酰胆碱酯酶(AChE)的相互作用及其与膜脂的关系。结果显示,甲基毒死蜱对人红细胞膜AChE有明显的抑制作用,与膜温育30min,其半数抑制浓度约为0.10 mmol/L。动力学分析表明,其抑制作用为非竞争性。0.2％Triton X-100并不改变AChE对甲基毒死蜱的敏感性,亦即AChE上甲基毒死蜱的作用部位与其所处的脂质微环境无关。

Relationship between the inhibition of acetylcholinesterase on human erythrocyte (ACHE) by Chlorpyrifos-Methyl (CPM) and membrane lipids was studied. The results showed that CPM is the potent inhibitor of ACHE. The inhibition is concentration-dependent and IC_(50) is approximately 0.10 mmol/L after 30min of incubation. Enzymatic kinetics analysis indicated that the inhibition is noncompetitive. Theenzyme in nonionic detergent Triton X-100 solutions exhibits full catalytic activity and nonchanged kinetics. Furthcrmore, in both conditions the AChE possesses the same susceptibility to the inhibition by CPM, i.e. the action site of CPM on AChE molecules is independent on the hydrophobic surrounding of the membrane.