FUNCTIONAL MAPPING OF NICOTINIC RECEPTOR BINDING SITES

描述(改编自申请人的描述)：本报告的目的 建议开发一个尼古丁的动态结构模型 结合乙酰胆碱受体激动剂结合部位 通过功能和生化分析对受体进行诱变。 分子生物学技术在青枯病研究中的应用 尼古丁受体已导致在 对受体结构与功能关系的认识 功能。例如，受体的区域负责 乙酰胆碱结合和形成离子通道本身的区域 已经被确认了。现在的任务是了解这些地区是如何 相互作用以产生功能性反应。具体在哪里？ 乙酰胆碱和结合域之间的接触点？何谓 蛋白质结合时发生的物理变化 最终导致离子通道的打开？通过使用一个面板 用于化学修饰的基因修饰受体 已经在整个结合结构域中引入了，作用于 将对个别残留物进行检查。生化分析将产生 关于残基的可及性和二级结构的信息 结合部位。还将监测蛋白质构象的变化 通过检查乙酰胆碱依赖的化学成分的差异 修改。总体而言，这项工作的目标是增进认识 乙酰胆碱作用的具体机制，并提供 适用于其他配体活化离子研究的信息 频道。

DESCRIPTION (adapted from applicant's description): The aim of this proposal is to develop a dynamic structural model of the nicotinic acetylcholine receptor (AChR) agonist binding site by combining mutagenesis of the receptor with functional and biochemical analysis. The application of molecular biological techniques to studies of the nicotinic receptor has resulted in significant advances in the understanding of the relationship between receptor structure and function. For example, the regions of the receptor responsible for acetylcholine binding and the region which forms the ion channel proper have been identified. The task now is to understand how these regions interact to generate the functional response. Where are the specific contact points between acetylcholine and the binding domain? What are the physical changes in the protein that occur upon binding which ultimately lead to the opening of the ion channel? By using a panel of genetically modified receptors in which sites for chemical modification have been introduced throughout the binding domain, the roles of individual residues will be examined. Biochemical analysis will yield information on the accessibility of residues and secondary structure of the binding site. Protein conformational changes will also be monitored by examining acetylcholine-dependent differences in chemical modification. Overall the goal of this work is to enhance understanding of the specific mechanisms of acetylcholine action and to provide information applicable to studies of other ligand-activated ion channels.