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: 7276212
• 负责人: KELLY R CHRISTOPHERSON
• 金额: $ 2.71万
• 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/7276212
• 关键词: Adult; Affect; Affinity; Alcohol abuse; Alcohols; American; Aminobutyric Acid; Aminobutyric Acids; Anesthetics; Anxiety; Autoradiography; Azides; Barbiturates; Behavioral; Benzodiazepines; Binding; Binding Sites; Bos taurus; 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 Depression; Mental Health; Modeling; Molecular Weight; Pharmaceutical Preparations; Pharmacology; Play; Property; Protein Isoforms; Proteins; Relative (related person); Research; Role; Schizophrenia; Series; Societies; Steroids; Substance Addiction; Surface; Symptoms; Synaptic Transmission; Testing; Thinking; Work; alcohol effect; alcohol sensitivity; alcoholism/alcohol abuse; barbituric acid salt; chronic alcohol ingestion; cost; delta opioid receptor; drinking; gamma-Aminobutyric Acid; human gamma-aminobutyric acid A receptor delta; insight; 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）：A 型 γ-氨基丁酸 GABA (A) 受体介导大脑中大部分快速突触抑制，并且是许多抑制剂的靶点，例如苯二氮卓类药物、巴比妥类药物和酒精。最常见的受体亚型包含α、β和γ亚基。然而，含有 δ 亚基（而不是 γ 亚基）的 GABA (A) 受体对乙醇表现出独特的敏感性，并且可能在调节生理相关剂量的酒精行为效应中发挥关键作用。证据还表明，长期饮酒可能会导致大脑中受体亚型水平的永久性重新排列，这可能最终导致物质依赖性增加和受体药理学改变。酗酒和酗酒是严重问题，对身心健康以及家庭和生活方式产生严重影响。 1,380 万美国成年人有饮酒问题，其中 810 万是酗酒者。长期酗酒会对大脑造成严重损害，并出现其他需要广泛医疗护理的症状，每年总共给社会造成数十亿美元的损失。几个研究小组在研究含 GABA (A) δ 受体的乙醇敏感性时显示出相互矛盾的结果，并且乙醇敏感性可能取决于存在的亚基亚型。拟议的研究将使用 alpha4-beta2-delta 受体作为模型，通过确定其亚基化学计量来阐明并进一步表征包含 delta 的受体。将确定受体对低剂量乙醇的反应性，并绘制受体上推定的乙醇结合位点。目前临床上用于拮抗过量饮酒造成的行为影响的药物Ro15-4513，与含有δ的GABA（A）受体具有高亲和力，并被认为与酒精竞争相同的结合位点。 Ro15-4513 含有一个可光激活的叠氮基，可用于光标记含有 δ 的受体。然后将鉴定药物光掺入的特定亚基，并使用一系列蛋白水解消化缩小亚基的光标记区域范围。该项目的成功将有助于更好地了解 GABA (A) 受体如何介导酒精在大脑中的作用，并将提供有助于开发治疗慢性酒精滥用的许多症状的新型药物疗法的见解。需要更好的药物来治疗酗酒和酗酒。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结合的位置，从而有助于新药的开发。