INTERACTIONS OF A NOVEL LIGAND WITH A MODEL CHANNEL

新型配体与模型通道的相互作用

• 批准号: 6386549
• 负责人: KI-JOON SHON
• 金额: $ 10.86万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6386549
• 关键词: Gastropoda; Torpedo; acetylcholine; animal tissue; chemical binding; chemical models; chemical synthesis; crosslink; fish electric organ; high performance liquid chromatography; ligands; lipid bilayer membrane; membrane channels; membrane proteins; membrane structure; method development; neurotoxins; nicotinic receptors; nuclear magnetic resonance spectroscopy; protein structure; radiotracer; receptor binding

Membrane associated receptors and ion channels serve as the molecular basis for electrical signaling, selective information transfer between excitable cells, and controlling the activity of the nervous system. Contrary to their biological significance, very little is known about how these proteins recognize neurotransmitters and ligands at the molecular level. The PI is interested in developing a novel methodology for revealing molecular features governing ligand-receptor recognition using modern high- field NMR spectroscopy. The methodology focuses on 1) designing relatively small model systems for ligand-receptor complexes, 2) developing a chemical strategy for synthesizing such models in the case of ion channels, the ability to transport ions is retained, and 3) applying both solution and solid-state NMR techniques to free ligands in aqueous solution, model channels in detergent micelles, and ligand-receptor complexes in lipids. Conotoxins, peptide neurotoxins from Conus snails, are ideal molecules for providing a model system for studying ligand-receptor interactions. They bind these membrane proteins with dissociation constants in nanomolar range, and there are potentially tens of thousands of these peptide ligands. The proposed project is based on exploiting their extraordinary specificity in developing model systems suitable for structural studies by NMR methods. A novel ligand (psi-conotoxin), which is a non-competitive inhibitor of the nicotinic acetylcholine receptor, has been recently discovered by the PI. The present experimental evidence strongly suggests that the binding region is at the carboxyl ends of the second transmembrane domains (M2). Such model channel has been chemically synthesized, and structure determination of the channel and its ligand bound complex will be the main focus of this proposal. Successful execution of the research will provide leads for rational drug design as well as for engineering subtype specific ligands targeted to specific receptors and ion channels.

膜相关受体和离子通道作为分子基础 对于电信号，在可激发的 细胞，并控制神经系统的活动。 违反 它们的生物学意义，很少有人知道这些 蛋白质在分子水平上识别神经递质和配体。 PI有兴趣开发一种新的方法来揭示 分子特征控制配体受体识别使用现代高， 场核磁共振波谱学 方法论的重点是1）设计相对 配体-受体复合物的小模型系统，2）开发化学 在离子通道的情况下，合成这种模型的策略， 保持传输离子的能力，以及3）施加溶液和 固态核磁共振技术在水溶液中游离配体，模型 洗涤剂胶束中的通道和脂质中的配体-受体复合物。 芋螺毒素是一种来自芋螺的肽类神经毒素， 为研究配体-受体相互作用提供了一个模型系统。 他们 以纳摩尔的解离常数结合这些膜蛋白 可能有数以万计的这种肽 配体。 该项目是基于利用其非凡的 开发适合结构研究的模型系统的特异性， NMR方法。 一种新的配体（psi-芋螺毒素），它是一种非竞争性抑制剂， 烟碱乙酰胆碱受体，最近已被PI发现。 目前的实验证据有力地表明， 位于第二跨膜结构域（M2）的羧基末端。 等 化学合成了模型通道，并进行了结构测定 通道及其配体结合的复合物将是本研究的主要焦点。 提议 研究的成功执行将为以下方面提供线索： 合理的药物设计以及工程亚型特异性配体 靶向特定受体和离子通道。