Structure of the GABA A Receptor Binding Sites

GABA A 受体结合位点的结构

• 批准号: 7156956
• 负责人: CYNTHIA M CZAJKOWSKI
• 金额: $ 31.47万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-12-01 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7156956
• 关键词: Address; Affect; Affinity; Agonist; Anesthetics; Barbiturates; Benzodiazepines; Binding; Binding Sites; Brain; Charge; Coupled; Coupling; Crosslinker; Cysteine; DNA Sequence Rearrangement; Disease; Distant; Disulfides; Drug effect disorder; Electrophysiology (science); Endopeptidases; Engineering; Epilepsy; Extracellular Domain; GABA A Receptor Binding; GABA Receptor; Gated Ion Channel; Glycine; Goals; Health; Kinetics; Length; Ligand Binding; Ligands; Link; Mediating; Membrane; Methods; Molecular Biology; Molecular Structure; Monitor; Movement; Mutagenesis; Mutate; Mutation; Pentobarbital; Peptide Hydrolases; Pliability; Positioning Attribute; Principal Investigator; Protein Chemistry; Publishing; Receptor Activation; Research; Site; Structural Models; Structure; Testing; Transmembrane Domain; Work; arginyllysine; barbituric acid salt; base; crosslink; desensitization; extracellular; gamma-Aminobutyric Acid; in vivo; interdisciplinary approach; mutant; patch clamp; prevent; programs; reaction rate; receptor; receptor function; research study; response; synaptic inhibition

DESCRIPTION (provided by applicant): Gamma-aminobutyric acid type A receptors (GABAARs) mediate the majority of synaptic inhibition in the brain and the actions of drugs such as benzodiazepines, barbiturates and anesthetics. Recently, mutations in the receptor have been linked to epilepsy. The long-term goal of our research program is to understand the function of the GABAAR in terms of its molecular structure. Work during the current project period significantly advanced our understanding of the structure of the GABA and benzodiazepine (BZD) binding sites. Experiments proposed herein build on this information to advance our understanding, on a structural level, of how GABA binding triggers channel activation and how BZD binding is coupled to receptor modulation. We propose to 1) identify local movements within the GABA binding site that couple binding to gating, 2) identify residues in the juxta-pore region that couple movements in the binding site to movements in the transmembrane domains and 3) identify residues that directly couple the GABA and BZD binding sites. The approach combines site-directed mutagenesis, disulfide crosslinking, mutant cycle analysis, substituted cysteine accessibility method, patch-clamping and kinetic analysis. The successful completion of these aims will not only increase our understanding of how GABAARs function in health and disease states but will also establish testable hypotheses for elucidating how other related ligand-gated ion channels function.

描述（由申请人提供）：γ-氨基丁酸A型受体（GABAAR）介导大脑中的大部分突触抑制以及药物（如苯二氮卓类、巴比妥类和麻醉剂）的作用。最近，受体的突变与癫痫有关。我们研究计划的长期目标是了解GABAAR分子结构的功能。在本项目期间的工作显着推进我们的GABA和苯二氮卓类（BZD）结合位点的结构的理解。本文提出的实验建立在这些信息的基础上，以推进我们的理解，在结构水平上，GABA结合如何触发通道激活和BZD结合如何耦合到受体调节。我们建议：1）确定GABA结合位点内将结合与门控偶联的局部运动，2）确定结合位点中将运动与跨膜结构域中的运动偶联的近孔区域中的残基，以及3）确定直接偶联GABA和BZD结合位点的残基。该方法结合了定点突变、二硫键交联、突变周期分析、取代半胱氨酸可及性方法、膜片钳和动力学分析。这些目标的成功完成不仅将增加我们对GABAARs在健康和疾病状态下如何发挥作用的理解，而且还将建立可验证的假说，以阐明其他相关配体门控离子通道的功能。