The structural identification of the cationic channel of the acetylcholine nicotinic receptor involved its biochemical tagging by channel blockers, followed by site-directed mutagenesis analyses reported in two papers in 1988. The ion channel was demonstrated to be lined by the transmembrane segment MII, in which the binding sites of channel blockers are "framed" by anionic rings.

中文翻译：

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烟碱受体离子通道的结构鉴定

乙酰胆碱烟碱受体阳离子通道的结构鉴定涉及通道阻滞剂的生化标记，随后是 1988 年两篇论文中报道的定点诱变分析。 离子通道被证明由跨膜段 MII 排列，其中通道阻滞剂的结合位点被阴离子环“框住”。