Aijafari A A
Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia.
Biochem Mol Biol Int. 1995 Aug;36(6):1243-53.
Kinetic analysis of the interaction of mercuric chloride with human erythrocyte acetylcholinesterase was investigated in the present study. It was found that mercuric chloride reversibly inhibited the AChE activity in a concentration dependent manner, the IC50 being 16 microM while the IC100 was 47 microM. The Km for the hydrolysis of acetylthiocholine iodide by AChE was found to be 97 microM in the control system, and the value increased by 16-144% in the mercuric chloride treated systems. The Vmax was 1.72 mumol/min/mg protein for the control as well as the mercuric chloride treated systems. Dixon as well as Lineweaver-Burke plots and their secondary replots indicated that the nature of the inhibition is of the reversible competitive type. The K(i) value was estimated as 6.26 microM. The K(i) value increased with an increase in substrate concentration.
本研究对氯化汞与人体红细胞乙酰胆碱酯酶相互作用进行了动力学分析。结果发现，氯化汞以浓度依赖性方式可逆地抑制乙酰胆碱酯酶活性，IC50为16微摩尔，IC100为47微摩尔。在对照体系中，乙酰胆碱酯酶水解碘化硫代乙酰胆碱的Km值为97微摩尔，在经氯化汞处理的体系中该值增加了16%至144%。对照体系和经氯化汞处理的体系的Vmax均为1.72微摩尔/分钟/毫克蛋白质。Dixon图以及Lineweaver-Burke图及其二级重绘图表明，抑制作用的性质为可逆竞争性类型。K(i)值估计为6.26微摩尔。K(i)值随底物浓度增加而增加。
