Responses of subpopulation of muscarinic receptors

毒蕈碱受体亚群的反应

基本信息

批准号：
7320919
负责人：
JOHN ELLIS
金额：
$ 30.85万
依托单位：
PENNSYLVANIA STATE UNIV HERSHEY MED CTR
依托单位国家：
美国
项目类别：
财政年份：
1985
资助国家：
美国
起止时间：
1985-02-01 至 2012-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7320919
关键词：
Acetylcholine Affinity Agonist All Sites Allosteric Regulation Allosteric Site Alzheimer&apos s Disease Amino Acids Barbiturates Benzodiazepines Binding Binding Sites Biological Models Brain Central Nervous System Diseases Characteristics Chimera organism Cholinergic Agents Chromosome Pairing Class Collaborations Complex Condition Data Development Disease Drug effect disorder Enhancers Epitopes Facility Construction Funding Category Funding Future G-Protein-Coupled Receptors GABA Receptor GABA-A Receptor Gallamine Generations Investigation Ion Channel Knowledge Label Lead Ligands Location Maps Modeling Molecular Muscarinic Acetylcholine Receptor Muscarinics Mustard Mutagenesis Mutate Mutation Nature Neurotransmitters Numbers Pattern Peptide Fragments Pharmaceutical Preparations Pharmacology Predisposition Property Range Receptor Activation Research Research Personnel Rhodopsin Safety Selective Serotonin Reuptake Inhibitor Serotonin Site Structural Models Structure Study models Synapses Tacrine Testing Therapeutic Thinking Transmembrane Domain Work analog barbituric acid salt base cholinergic computerized data processing design desire extracellular functional group gamma-Aminobutyric Acid inhibitor/antagonist insight molecular modeling monomer mutant receptor research study response reuptake serotonin receptor spatiotemporal

项目摘要

DESCRIPTION (provided by applicant): The aims of this study are to define the structural features of allosteric sites on muscarinic acetylcholine receptors. These receptors have become a key model system for the molecular study of allosteric drug action at G protein-coupled receptors. Therefore, the knowledge to be gained from the proposed experiments is expected to have benefits ranging far beyond the advancement of muscarinic pharmacology. Allosteric drugs have inherent advantages of selectivity, efficacy, and safety. These advantages are especially important when the desired effect is to enhance the action of a neurotransmitter at a particular receptor in the brain. Allosteric enhancers are able to preserve the pattern of activity that is dictated by the very complex spatio-temporal motif of synaptic activity; by contrast, directly-acting agonists tend to disrupt these complex motifs that are the hallmark of synaptic activity in the brain. Previous studies in our lab have employed chimeric receptors, point-mutated receptor constructs, and molecular modeling to define a working model of the allosteric binding site. This site is predicted to lie within the extracellular loops and closely adjacent regions of the transmembrane domains of the receptor. An accurate model of the binding site is expected to be a key component of future attempts at rational design of therapeutic allosteric drugs. Therefore, in the requested funding period, we will investigate four different types of allosteric agonists, to refine the existing model so that it more accurately defines the specific sites and modes of binding of allosteric ligands that enhance the actions of acetylcholine. Additionally, we will independently test two major hypotheses of the current model: (1) the location of the binding site; and (2) that a single monomeric receptor represents the appropriate model. For (1), we will use new irreversible allosteric ligands that covalently label the site to unequivocally identify amino acid(s) involved in the binding site. For (2), receptors that have been purified in the monomeric or oligomeric state will allow us to evaluate "atypical" ligands that are known to bind cooperatively to multiple sites and to determine whether the multiple sites lie within one receptor or across an oligomeric complex. We expect these studies to lead to improvements in the cholinergic pharmacology of disorders of the central nervous system, including Alzheimer's Disease, and to contribute to an understanding of the potential for allosteric modulation of other G protein-coupled receptors.

描述（由申请人提供）：本研究的目的是确定毒蕈碱乙酰胆碱受体上变构位点的结构特征。这些受体已成为 G 蛋白偶联受体变构药物作用分子研究的关键模型系统。因此，从所提出的实验中获得的知识预计将带来远远超出毒蕈碱药理学进步的益处。变构药物具有选择性、有效性和安全性等固有优势。当所需效果是增强神经递质对大脑中特定受体的作用时，这些优点尤其重要。变构增强剂能够保留由突触活动的非常复杂的时空基序决定的活动模式；相比之下，直接作用的激动剂往往会破坏这些复杂的基序，而这些复杂的基序是大脑突触活动的标志。我们实验室之前的研究采用了嵌合受体、点突变受体结构和分子模型来定义变构结合位点的工作模型。预计该位点位于受体跨膜结构域的细胞外环和紧密相邻的区域内。结合位点的准确模型预计将成为未来合理设计治疗性变构药物的尝试的关键组成部分。因此，在所要求的资助期内，我们将研究四种不同类型的变构激动剂，以完善现有模型，使其更准确地定义增强乙酰胆碱作用的变构配体的具体位点和结合模式。此外，我们将独立测试当前模型的两个主要假设：（1）结合位点的位置； (2)单个单体受体代表适当的模型。对于（1），我们将使用新的不可逆变构配体共价标记该位点，以明确识别参与结合位点的氨基酸。对于（2），以单体或寡聚状态纯化的受体将允许我们评估已知协同结合多个位点的“非典型”配体，并确定多个位点是位于一个受体内还是跨寡聚复合物。我们期望这些研究能够改善中枢神经系统疾病（包括阿尔茨海默病）的胆碱能药理学，并有助于了解其他 G 蛋白偶联受体变构调节的潜力。