GENERAL ANESTHETIC SITES ON LIGAND GATED ION CHANNELS

每年约有2500万名患者接受全身麻醉。 美国使用治疗指数非常低的药物。分子 全身麻醉的机制仍不清楚，阻碍了设计 改进后的代理。全身麻醉药被认为可以调节这种功能 突触后配体门控离子通道的同源超家族。 本PPG主要研究对抑制性GABA/A受体的增强作用 (GABAAR)和对兴奋性尼古丁受体的抑制作用， NAcChor.总的假设是全麻药与一种 这些受体上的位置和亲和力 随着麻醉剂的结构和受体的构象而变化， 两个同源受体之间存在相似之处。整体而言 PPG的目的是：(I)定位GABA/A和 NACCHO受体，以及(Ii)定义它们的功能意义。焦点 位于受体的三个区域：细胞外部分， 尤其是在第一个跨膜螺旋之前，第二个 跨膜螺旋和脂蛋白界面。两个互补性 技术将被用来检测位点，光亲和标记 (项目I、II和IV)和现场定向突变(项目III和IV)。 项目二将确定挥发性物质、酒精和类固醇 麻醉剂光标记nAcChoR和Project的平衡状态 IV将使用类似的技术以及定点突变来 找到GABAAR上的地点。项目I将确定哪些站点禁止 NAcChoR的开放频道使用了时间分辨照片标签。项目III 将使用快速灌流膜片钳动态地确定机制 野生型和突变受体的技术，结合了照片- 标记结果以指导突变和解释。工程项目I及II 将研究胆固醇位点在调节变构中的作用 麻醉部位与类固醇麻醉作用之间的相互作用 分别进行了分析。合成和蛋白质化学核心对于 新型光亲和全身麻醉药的研制及定位 照片合并的地点分别为。

Some 25 million patients are given general anesthesia each year in the USA using agents with very low therapeutic indices. The molecular mechanisms of general anesthesia remain unknown, hampering the design of improved agents. General anesthetics are believed to modulate the function of a homologous super-family of postsynaptic ligand-gated ion channels. This PPG focuses on the enhancing action on the inhibitory GABA/A receptor (GABAAR) and the inhibitory action on the excitatory nicotinic receptor, nAcChoR. The overall hypothesis is that general anesthetics bind to a number of sites on these receptors, that their location and affinity varies with the anesthetic's structure and the receptor's conformation, and that parallels exist between the two homologous receptors. The overall aims of the PPG are to: (i) locate anesthetics sites on the GABA/A and nAcCho receptors, and (ii) define their functional significance. The focus is on three regions of the receptors: the extracellular portion, particularly just before the fist transmembrane helix, the second transmembrane helix, and the lipid protein interface. Two complementary techniques will be employed to detect sites, photoaffinity labeling (Projects I, II & IV) and site directed mutagenesis (Projects III and IV). Project II will locate the sites where volatile, alcohol and steroid anesthetics photo-label the equilibrium states of the nAcChoR, and Project IV will use similar techniques, as well as site directed mutagenesis, to locate sites on the GABAAR. Project I will determine which sites inhibit the nAcChoR's open channel using time resolved photo-labeling. Project III will define mechanisms kinetically using rapid perfusion patch clamp techniques in wild type and mutated receptors, incorporating the photo- labeling results to guide mutagenesis and interpretation. Projects I & II will investigate the role of cholesterol sites in modulating allosteric interactions between anesthetic sites and steroid anesthetic action, respectively. Synthetic and Protein Chemistry Cores are essential for developing novel photoaffinity general anesthetics and for locating the sites of photo-incorporation, respectively.