Defining Alcohol Binding Sites in Ligand-Gated Ion Channels

定义配体门控离子通道中的醇结合位点

• 批准号: 8877373
• 负责人: JAMES Robert TRUDELL
• 金额: $ 30.34万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8877373
• 关键词: 3-Dimensional; Acetylcholine; Address; Affect; Alcohol abuse; Alcohol dependence; Alcoholism; Alcohols; Algorithms; Amino Acids; Binding; Binding Sites; Bioinformatics; Chloride Channels; Computational Biology; Computer Simulation; Conflict (Psychology); Cysteine; Data; Disulfides; Docking; Ethanol; Future; GABA Receptor; Gated Ion Channel; Glutamates; Glycine; Goals; Health; Homologous Gene; Homology Modeling; Imagery; Ion Channel; Ion Channel Protein; Ions; Knowledge; Laboratories; Ligand Binding; Ligands; Location; Maps; Measures; Mediating; Methods; Modeling; Molecular Biology; Molecular Models; Mutate; Mutation; National Institute on Alcohol Abuse and Alcoholism; Nervous system structure; Neurons; Oocytes; Pathway interactions; Pharmaceutical Preparations; Positioning Attribute; Property; Protons; Publications; Reagent; Research; Research Personnel; Resources; Roentgen Rays; Series; Serotonin Receptors 5-HT-3; Site; Solutions; Structure; Sulfhydryl Compounds; Synapses; Synaptic Receptors; System; Techniques; Testing; Texas; United States National Institutes of Health; Universities; addiction; alcohol abuse therapy; alcohol effect; alcohol research; alcohol sensitivity; alpha helix; analog; austin; base; computational neuroscience; cost; craving; design; improved; innovation; methanethiosulfonate; model building; molecular modeling; novel; pharmacophore; programs; receptor; relating to nervous system; screening; success; three-dimensional modeling

DESCRIPTION (provided by applicant): Alcohol abuse and alcoholism are significant health problems that affect over 17 million people and cost nearly $200 billion annually. It is likely tha a solution to these problems will result from a better understanding of alcohol effects on neuronal ion channels and the proteins that modulate them. The goal of the proposed research will be a significant step towards understanding the properties of alcohol-binding sites at an atomic level. We believe this knowledge will be essential for future design and selection of drugs that could reduce craving or addiction induced by alcohol. Specifically, we will study the sites fo alcohol binding in ligand- gated ion channels (LGICs), which include GABAaRs and GlyRs. Our homology modeling and experimental methods will provide 3-dimensional visualization of GABAaRs to increase our understanding of alcohol's action. This innovative approach combines cutting-edge computational and neuroscience techniques with molecular biology. We expect our results will have a significant impact on the broader class of alcohol- binding sites in other important receptors of the nervous system. Our Approach focuses on three aspects of alcohol-binding sites via three Specific Aims: Where are alcohol-binding sites; intra-subunit versus inter- subunit in LGICs (Aim 1), which specific residues or segments in LGICs mediate the effect of alcohol binding at these sites (Aims 1 and 2), and how do these sites modulate ligand binding (Aims 2 and 3). In Aim 1, Trudell and Bertaccini will build computational models of alcohol-binding sites in GABA receptors and design site-directed mutations to test the models. Harris and Howard, under a subcontract to the University of Texas, Austin, will test the function of these mutated receptors. We will iteratively refine the models the Trudell group will use the models to predict the effects of mutations; the Harris group will test if the models are consistent with experimental data; and the Trudell group will then modify the models to fit the new data. They will address this controversial question: What is the most important alcohol effect site in GABAaR? Is it Intra-subunit or Inter-subunit? They will also test the hypothesis that the GABAaR TM3 helix must rotate during activation in order to incorporate all recent experimental data. In Aim 2, the Trudell and Harris laboratories will recreate the alcohol-binding site from GABAaRs in the homologous but natively EtOH insensitive ion channel, GLIC, by determining which residues are specific to EtOH binding in GABAR and mutating these into their corresponding homologous positions within GLIC. In Aim 3, Trudell and Bertaccini will use three docking programs to investigate binding of alcohol analogs. Our investigators have proven accomplishment in alcohol research and possess the resources necessary to accomplish our Aims. Our proposal is responsive to both the NIAAA initiative in computational neuroscience and the NIH Roadmap: Bioinformatics and Computational Biology. These significant studies will provide essential knowledge needed to design alcohol-binding antagonists which could revolutionize treatment for alcohol abuse and dependence.

描述（由申请人提供）：酗酒和酗酒是严重的健康问题，影响超过 1700 万人，每年造成近 2000 亿美元的损失。更好地了解酒精对神经元离子通道和调节它们的蛋白质的影响可能会解决这些问题。拟议研究的目标将是在原子水平上了解酒精结合位点特性的重要一步。我们相信，这些知识对于未来设计和选择可以减少酒精引起的渴望或成瘾的药物至关重要。具体来说，我们将研究配体门控离子通道 (LGIC) 中酒精结合的位点，其中包括 GABAaR 和 GlyR。我们的同源建模和实验方法将提供 GABAaR 的 3 维可视化，以增进我们对酒精作用的理解。这种创新方法将尖端计算和神经科学技术与分子生物学相结合。我们预计我们的结果将对神经系统其他重要受体中更广泛的酒精结合位点产生重大影响。我们的方法通过三个具体目标重点关注酒精结合位点的三个方面：酒精结合位点在哪里；亚基内与亚基间 LGIC 中的亚基（目标 1），LGIC 中的哪些特定残基或片段介导这些位点处的醇结合作用（目标 1 和 2），以及这些位点如何调节配体结合（目标 2 和 3）。 在目标 1 中，Trudell 和 Bertaccini 将建立 GABA 受体中酒精结合位点的计算模型，并设计定点突变来测试模型。哈里斯和霍华德根据德克萨斯大学奥斯汀分校的分包合同，将测试这些突变受体的功能。我们将迭代地完善模型，Trudell 小组将使用这些模型来预测突变的影响；哈里斯小组将测试模型是否一致 有实验数据；然后特鲁德尔小组将修改模型以适应新数据。他们将解决这个有争议的问题：GABAaR 中最重要的酒精作用位点是什么？是亚基内还是亚基间？他们还将测试 GABAaR TM3 螺旋在激活过程中必须旋转的假设，以便合并所有最新的实验数据。在目标 2 中，Trudell 和 Harris 实验室将通过确定 GABAR 中哪些残基对 EtOH 结合具有特异性，并将这些残基突变到其相应的同源位置，在同源但天然对乙醇不敏感的离子通道 GLIC 中重建 GABAaR 的酒精结合位点。 GLIC。在目标 3 中，Trudell 和 Bertaccini 将使用三个对接程序来研究酒精类似物的结合。我们的研究人员在酒精研究方面已取得了公认的成就，并拥有实现我们目标所需的资源。我们的提案响应了 NIAAA 计算神经科学倡议和 NIH 路线图：生物信息学和计算生物学。这些重要的研究将提供设计酒精结合拮抗剂所需的基本知识，从而彻底改变酒精滥用和酒精依赖的治疗方法。