Eldefrawi M E, Mansour N A, Eldefrawi A T
Adv Exp Med Biol. 1977;84:449-63. doi: 10.1007/978-1-4684-3279-4_20.
Micromolar concentrations of methylmercury and several organic mercury fungicides were found to block binding of [3H]acetylcholine (ACh) to the ACh-receptor of the electric organ of the electric ray, Torpedo ocellata. The same compounds had little or no effect on the catalytic activity of ACh-esterase of the same tissue. [14C]Methyl-mercury bound to the purified ACh-receptor with high affinity (Kd=7micrometer) and there were 6.5 +/- 0.5 binding sites for each ACh-binding site. Binding of methylmercury was highly cooperative with a Hill coefficient of 2.6. This binding was irreversible by redialysis in methylmercury - free medium, however, the bound [14C]methylmercury was easily displaced from the receptor protein with micrometer concentrations of BAL or penicillamine. Methylmercury also blocked binding of [3H] nicotine and [3H]pilocarpine to the nicotinic and muscarinic ACh-receptors of the rat brain, respectively. The data suggest that the ACh-receptor may be a target for methylmercury and other organic mercury compounds.
已发现微摩尔浓度的甲基汞和几种有机汞杀菌剂会阻断[3H]乙酰胆碱（ACh）与电鳐（Torpedo ocellata）电器官的ACh受体的结合。相同的化合物对同一组织的ACh酯酶的催化活性几乎没有影响或没有影响。[14C]甲基汞以高亲和力（Kd = 7微米）与纯化的ACh受体结合，每个ACh结合位点有6.5±0.5个结合位点。甲基汞的结合具有高度协同性，希尔系数为2.6。在无甲基汞的培养基中通过再透析，这种结合是不可逆的，然而，用微摩尔浓度的二巯丙醇（BAL）或青霉胺很容易将结合的[14C]甲基汞从受体蛋白上置换下来。甲基汞还分别阻断了[3H]尼古丁和[3H]毛果芸香碱与大鼠脑烟碱型和毒蕈碱型ACh受体的结合。数据表明，ACh受体可能是甲基汞和其他有机汞化合物的作用靶点。
