Allosteric Modulation of Neuronal Nicotinic Acetylcholine Receptors

描述（由申请人提供）：我们研究神经元烟碱乙酰胆碱受体（nAChR）的变构调节。这些配体门控离子通道是尼古丁成瘾的所在地，并与广泛的其他神经系统疾病有关。nAChR的变构调节越来越重要，因为它变得更好地理解，并作为新的化合物与这种药理学的配置文件被确定。一类模型调节化合物，相当具体的一个亚型的神经元乙酰胆碱受体的结合位点，是已知的，和一些分子的决定因素转导调制器结合信息到通道活性已被确定。在此之前的工作的基础上，我们现在建议进一步完善我们的理解的运动的一个子结构参与分子内信号转导和调节位点特异性的分子决定因素。此外，有关通道门控功效的问题将在最佳数量和安排的调制器网站相对于激动剂网站和疏水残基在细胞外结构域核心的作用。这些研究将通过宏观电压钳记录以及化学修饰分析，对具有点突变或串联亚基的表达受体进行药理学表征。该项目还包括一项针对新的调节剂类似物的结构-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，因为我们正在挑战的范式，通过占据两个激动剂结合位点的nAChRs的激活。我们正在研究一个最近确定的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。

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.