Relation between ligand binding and activation gating in nicotinic acetylcholine receptors

烟碱乙酰胆碱受体是配体门控离子通道，属于cys环受体家族。它们在神经元和非神经元细胞类型中均有表达，并在胆碱能突触的传递中起重要作用。它们通过乙酰胆碱与细胞外结合位点的结合而被激活。已知三种不同的激活状态：开放、封闭和脱敏。为了阐明配体结合和受体激活之间的关系，我们将同时研究这两个过程。为此，将应用共聚焦膜片钳荧光测定法，这是一种结合电生理膜片钳技术和使用荧光标记配体的光学技术的方法。同时记录的电流和结合数据将用于讨论已发表的模型，并创建描述分子门控行为的替代模型。通过这种方法，对烟碱乙酰胆碱受体和相关cys-loop受体的激活门控有了新的认识。关于状态依赖性结合和解结合行为的详细知识为药理学用途的激动剂和拮抗剂的系统开发提供了基础。

Nicotinic acetylcholine receptors are ligand-gated ion channels and belong to the cys-loop receptor family. They are expressed in both neuronal and non-neuronal cell types and play an important role in the transmission at cholinergic synapses. They are activated by the binding of acetylcholine to extracellular binding sites. Three distinct activation states are known: open, closed and desensitized. To shed light into the relation between ligand binding and receptor activation, these two processes will be studied simultaneously. To this end the confocal patch-clamp fluorometry will be applied, a method combining electrophysiological patch-clamp techniques and optical techniques using a fluorescently labelled ligand. The simultaneously recorded current and binding data will be used to discuss published models and to create alternative models describing the molecular gating behaviour. With this approach new insights into to activation gating of nicotinic acetylcholine receptors and related cys-loop receptors are expected. The detailed knowledge about the state-dependent binding and unbinding behaviour provide a base for a systematic development of agonists and antagonists for the pharmacological use.