Allosteric Modulation of Neuronal Nicotinic Acetylcholine Receptors

描述（由申请人提供）：我们研究神经烟碱乙酰胆碱受体（nAChRs）的变构调节。这些配体门控离子通道是尼古丁成瘾的基础，并与许多其他神经系统疾病有关。nachr的变构调节越来越重要，因为人们对它有了更好的了解，并且发现了具有这种药理特征的新化合物。一类模型调节化合物的结合位点是已知的，对神经元nAChR的一种亚型具有特异性，并且已经确定了将调节剂结合信息转导为通道活性的一些分子决定因素。在先前工作的基础上，我们现在建议进一步完善我们对参与分子内信号转导的一个子结构的运动和调节位点特异性的分子决定因素的理解。此外，关于通道门控效应的问题将在相对于激动剂位点的调节位点的最佳数量和排列以及疏水残基在细胞外结构域核心中的作用方面得到解决。这些研究将通过宏观电压钳记录以及化学修饰分析，对点突变或连接亚基的表达受体进行药理学表征。该项目还包括针对新的调制器类似物的结构-活性关系研究。在某些情况下，为了支持这些主要目标，我们将通过单通道记录进一步探索调制机制。我们的工作是创新的，因为我们通过占据两个激动剂结合位点来挑战nachr激活的范式。我们正在研究最近发现的nAChR配体结合位点，我们提出的工作将大大加强合理设计nAChR变构调节剂的基础，这是一种可能具有临床应用的药物类别。

DESCRIPTION (provided by applicant): We study allosteric modulation of neuronal nicotinic acetylcholine receptors (nAChRs). These ligand-gated ion channels are the seat of nicotine addiction and are implicated in a wide range of other neurological disorders. Allosteric modulation of nAChRs is growing in importance as it becomes better understood and as novel compounds with this pharmacological profile are identified. The binding sites for a class of model modulatory compounds, quite specific for one subtype of neuronal nAChR, are known, and some molecular determinants of transducing modulator binding information into channel activity have been identified. Building on this previous work, we now propose to further refine our understanding of the movement of one sub- structure involved in intra-molecular signal transduction and of the molecular determinants of modulator site specificity. In addition, questions about channel gating efficacy will be addressed in terms of the optimal number and arrangement of modulator sites relative to agonist sites and the role of hydrophobic residues in the extracellular domain core. These studies will employ pharmacological characterization of expressed receptors with point mutations or concatenated subunits by macroscopic voltage-clamp recordings, as well as chemical modification analyses. The project also includes a targeted structure-activity relationship study with new modulator analogues. In some cases, to support these primary aims, we will explore the modulation mechanisms further by single-channel recordings. Our work is innovative because we are challenging the paradigm of activation of nAChRs by occupying two agonist binding sites. We are studying a recently identified nAChR ligand binding site, and the work we propose stands to substantially strengthen the foundation for rational design of nAChR allosteric modulators, a drug class with possible clinical applications.