Allosteric Potentiation of Neuronal Nicotinic Receptors

描述(申请人提供)：我们研究神经元烟碱型乙酰胆碱受体(NAChRs)的正变构调节。这些配基门控离子通道是尼古丁成瘾的场所，并与广泛的其他神经疾病有关。随着人们对nAChRs的更好的理解和具有这种药理特征的新化合物的发现，nAChRs的变构调节变得越来越重要。在以前的工作中，我们阐明了化合物莫兰特的作用机制，我们确定莫兰特尔结合在不同于结合激动剂的亚基界面上。作为这项工作的延伸，我们现在建议确定调节剂结合部位与激动剂结合部位和通道门直接通信的分子决定因素，并确定Morantel位点特异性的分子决定因素。这些研究将使用宏观电压钳记录，结合突变和化学修饰分析。为了支持这些主要目标，我们还建议通过单通道记录和数学建模来进一步探索增强机制。我们的工作是创新的，因为我们正在通过占据两个激动剂结合位点来挑战nAChRs的激活范式：我们正在研究一个以前未知的nAChR配体结合位点，我们提出的工作将大大加强nAChR正性变构调节剂的合理设计基础，这类药物具有可能的临床应用。 公共卫生相关性：我们研究尼古丁型乙酰胆碱受体，这是大脑中负责尼古丁成瘾的蛋白质家族，与各种其他神经病理有关。利用分子生物学和电生理学技术，我们将进一步阐明某一类药物(变构调节剂)上调这些蛋白质功能的分子药理机制。

DESCRIPTION (provided by applicant): We study positive 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. In previous work, we elucidated the mechanism of action for the compound morantel and we determined that morantel binds at subunit interfaces distinct from those that bind agonist. As an extension of this work, we now propose to identify the molecular determinants through which the modulator binding site communicates with the agonist binding site and with the channel gate directly, and to identify the molecular determinants of morantel site specificity. These studies will employ macroscopic voltage-clamp recordings combined with mutational and chemical modification analyses. To support these primary aims, we also propose to explore further the potentiation mechanism by single-channel recordings and mathematical modeling. Our work is innovative because we are challenging the paradigm of activation of nAChRs by occupying two agonist binding sites: We are studying a previously unknown nAChR ligand binding site, and the work we propose stands to substantially strengthen the foundation for rational design of nAChR positive allosteric modulators, a drug class with possible clinical applications. PUBLIC HEALTH RELEVANCE: We study nicotinic acetylcholine receptors, the family of proteins in the brain responsible for addiction to nicotine and implicated in a variety of other neuropathologies. Using molecular biology and electrophysiology techniques in the proposed work, we will further elucidate the molecular pharmacological mechanisms by which a certain drug class (allosteric modulators) can up-regulate the function of these proteins.