Mapping the Putative Ethanol Binding Site on alpha4-beta2-delta GABA(A) Receptors

绘制 alpha4-beta2-delta GABA(A) 受体上假定的乙醇结合位点

• 批准号: 7651397
• 负责人: KELLY R CHRISTOPHERSON
• 金额: $ 2.73万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7651397
• 关键词: Adult; Affect; Affinity; Alcohol abuse; Alcoholism; Alcohols; American; Aminobutyric Acids; Anesthetics; Anxiety; Autoradiography; Azides; Barbiturates; Behavioral; Benzodiazepines; Binding; Binding Sites; Brain; Bungarotoxins; Caring; Cattle; Cells; Chloride Channels; Chronic; Conflict (Psychology); DNA Sequence Rearrangement; Development; Digestion; Dose; Epilepsy; Epitopes; Ethanol; Exhibits; Family; GABA Receptor; GABA-A Receptor; Gated Ion Channel; Goals; Heavy Drinking; Individual; Label; Life Style; Ligands; Link; Location; Maps; Mediating; Medical; Mental Health; Modeling; Molecular Weight; Pharmaceutical Preparations; Pharmacology; Play; Property; Protein Isoforms; Proteins; Relative (related person); Research; Role; Schizophrenia; Series; Societies; Substance Addiction; Surface; Symptoms; Synaptic Transmission; Testing; Work; alcohol effect; alcohol sensitivity; barbituric acid salt; chronic alcohol ingestion; cost; delta opioid receptor; depression; drinking; gamma-Aminobutyric Acid; human gamma-aminobutyric acid A receptor delta; insight; neurosteroids; novel; problem drinker; receptor; receptor function; research study; stoichiometry; success; synaptic inhibition

DESCRIPTION (provided by applicant): The gamma-aminobutyric acid type A, GABA (A), receptor mediates the majority of fast synaptic inhibition in the brain and is a target of many depressants, such as the benzodiazipines, barbiturates, and alcohol.The most prevalent receptor subtype contains alpha, beta, and gamma subunits. However, GABA (A) receptors containing the delta subunit, instead of gamma, display a unique sensitivity to ethanol and may play a key role in mediating the behavioral effects of alcohol at physiologically relevant doses. Evidence also indicates that chronic use of alcohol may cause a permanent rearrangement of receptor subtype levels in the brain, which may ultimately result in increased substance dependence and altered receptor pharmacology. Alcoholism and alcohol abuse are serious problems that have severe repercussions on physical and mental health as well as family and lifestyle. 13.8 million American adults have problems with drinking, 8.1 million of which are alcoholic. Chronic alcohol abuse causes major damage to the brain as well as other symptoms requiring extensive medical care that in total costs society billions of dollars each year. Several research groups have shown conflicting results when investigating ethanol sensitivity of GABA (A) delta-containing receptors, and ethanol sensitivity may be dependent on the subunit isoforms present. The proposed research will clarify and further characterize delta-containing receptors by determining their subunit stoichiometry, using alpha4-beta2-delta receptors as a model. The responsiveness of the receptors to low doses of ethanol will be established and the putative ethanol binding site on the receptors will be mapped. The drug Ro15-4513, which is currently used clinically to antagonize the behavioral effects of excessive alcohol consumption, binds with high affinity to delta-containing GABA (A) receptors and is thought to compete for the same binding site as alcohol. Ro15-4513 contains a photo-activatable azido group that will be used to photolabel delta-containing receptors. The specific subunit into which the drug photoincorporates will then be identified and the photolabeled region of the subunit will be narrowed down using a series of proteolytic digestions. The success of this project will provide a better understanding of how GABA (A) receptors mediate the effects of alcohol in the brain and will provide insight that will aid in the development of novel pharmacotherapeutics for the treatment of many symptoms of chronic alcohol abuse. Better drugs are needed to treat alcoholism and alcohol abuse. Alcohol affects the brain by binding to specific proteins called GABA (A) receptors. The proposed research will help identify where alcohol is binding to these receptors and thus will aid in the development of new drugs.

描述（由申请人提供）：γ-氨基丁酸A型，GABA（A），受体介导了大脑中的大多数快速突触抑制作用，并且是许多抑郁剂的靶标，例如苯甲二氮嗪，巴比妥酸盐和酒精。但是，包含三角洲亚基的GABA（A）受体，而不是伽马表现出对乙醇的独特敏感性，并且可能在介导酒精对生理相关剂量的行为影响方面起关键作用。证据还表明，长期使用酒精可能会导致大脑中受体亚型水平的永久重排，这最终可能导致物质依赖性增加和受体药理学改变。酒精中毒和酗酒是严重的问题，对身心健康以及家庭和生活方式产生了严重影响。 1380万美国成年人的饮酒问题，其中810万是酗酒者。慢性酒精滥用会对大脑以及其他症状造成重大损害，这些症状需要大量的医疗服务，总计每年成本数十亿美元。在研究GABA（A）含Delta的受体的乙醇敏感性时，几个研究组显示出矛盾的结果，并且乙醇敏感性可能取决于存在的亚基同工型。拟议的研究将通过使用Alpha4-Beta2-Delta受体作为模型来确定其亚基化学计量法，从而阐明并进一步表征含Delta的受体。将建立受体对低剂量乙醇的反应，并将映射受体上假定的乙醇结合位点。目前在临床上用于拮抗过度饮酒的行为影响的药物RO15-4513与含Delta的GABA（a）受体具有高亲和力结合，被认为与酒精相同的结合位点竞争。 RO15-4513包含一个可光活化的偶氮群，该基团将用于光片含三角洲的受体。然后，将使用一系列蛋白水解消化范围缩小鉴定药物企业的特定亚基，并将其光标记区域缩小。该项目的成功将更好地了解GABA（A）受体如何介导酒精在大脑中的影响，并提供洞察力，这将有助于开发新型药物治疗药，以治疗许多慢性酒精滥用症状。需要更好的药物来治疗酒精中毒和酗酒。酒精通过与称为GABA（A）受体的特定蛋白质结合来影响大脑。拟议的研究将有助于确定酒精与这些受体的结合位置，从而有助于开发新药。