Structure and Finction of AMPA subtype ionotropic glutamate receptors

AMPA 亚型离子型谷氨酸受体的结构和功能

基本信息

批准号：
8650439
负责人：
Alexander Sobolevsky
金额：
$ 34.72万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-30 至 2018-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8650439
关键词：
AMPA Receptors Acids Adamantane Agonist Alzheimer&apos s Disease Amyotrophic Lateral Sclerosis Binding Binding Sites Biochemical Calcium Cations Chemicals Clinical Complex Computer Simulation Crystallization Cysteine Data Detergents Down-Regulation Drug Design Electrophysiology (science)Engineering Entropy Epilepsy Fluorescence Glutamate Agonist Glutamate Receptor Glutamates Goals Integral Membrane Protein Ion Channel Ischemia Kinetics Knowledge Length Ligands Lipids Location Mediating Methods Modeling Modification Molecular Molecular Conformation Molecular Sieve Chromatography Mutation Neuraxis Neurons Neurosciences Patients Pharmaceutical Preparations Polyamines Primary Lateral Sclerosis Process Proteins Rattus Regulation Resolution Site-Directed Mutagenesis Structural Models Structure Surface Techniques Temperature Testing Therapeutic Toxin Work base chemical synthesis crosslink desensitization design electron density excitotoxicity improved ion channel blocker nervous system disorder neuron loss neurotransmission public health relevance receptor receptor function research study response

项目摘要

PROJECT SUMMARY AMPA (¿-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) subtype ionotropic glutamate receptors mediate the majority of excitatory neurotransmission in the central nervous system. Alteration in AMPA receptor function is associated with numerous devastating neurological diseases including Alzheimer's disease, amyotrophic lateral sclerosis, epilepsy and ischemia. Regulation of AMPA receptor activity is therefore an important clinical goal. AMPA receptors function by opening their ion channel for the flow of permeant cations in response to binding of agonist glutamate to the receptor. This process of ion channel opening or activation gating is accompanied by typically slower process of desensitization. Desensitization leads to the closure of the ion channel pore and appears as a 10-500 fold reduction of AMPA receptor- mediated currents in the continuous presence of glutamate. Desensitization represents a natural way of suppressing AMPA receptor activity that protects neurons from the excitotoxic calcium overload. Enhancing or weakening desensitization is therefore an effective way of regulating AMPA receptor activity in pathological conditions. An alternative way to suppress AMPA receptor activity that has therapeutic potential is to use ion channel blockers, molecules that plug the channel pore. At the molecular level, desensitization and ion channel block are expected to have common features that allow them to lock the ion channel in the closed conformation. We plan to study AMPA receptor desensitization and block using a combination of structural and functional approaches and to reveal similarities and differences in these processes. Accordingly, our specific aims are: 1) Obtaining a high-resolution structure of an AMPA receptor in the desensitized state and 2) Building a structural model of ion channel block. AMPA receptor is a challenging target for structure-functional studies because it represents a multimeric integral membrane protein of a large size with typically low expression level. To achieve our goals, we will use a combination of structural and functional approaches including modern crystallographic techniques, Fluorescence-based Size Exclusion Chromatography (FSEC) and electrophysiology. We will use different crystallization methods and temperatures, screen detergents, lipids and ligands to obtain full length AMPA receptor structures in the desensitized and blocker-bound states. We will then combine nascent structural information with electrophysiological recordings and kinetic modeling to figure out mechanisms of AMPA receptor desensitization and block. Achieving our aims will have a significant impact on molecular neuroscience and will result in a new structural/functional model of AMPA receptor that can serve as a dynamic template for theoretical prediction, in silico fitting and chemical synthesis of new compounds that can be tested in different models of neurological diseases and eventually become safe and effective medications.

项目摘要 AMPA（�-amino-3-羟基-5-甲基-4-异沙唑二唑替代丙酸）亚型离子型谷氨酸受体亚型 AMPA的改变。受体功能与包括阿尔茨海默氏症在内的许多毁灭性神经系统疾病有关疾病，肌萎缩性外侧病，癫痫和缺血。因此，一个重要的临床目标。对激动剂谷氨酸与受体的结合，呈per阳离子。打开或激活伴随着脱敏的过程通常会降低导致离子通道孔的闭合，并以10-500倍的AMPA受体的重新进行连续存在谷氨酸的电流。支持兴奋性钙超载神经元的AMPA感受活动。弱化的降低是一种有效的调节AMPA记录活性的方法条件。通道阻滞剂，插入通道孔的分子。预计块将具有共同的功能，以将离子通道锁定在闭合构象。我们计划使用结构和功能性方法并在这些过程中引起相似性和差异。目的是：1）在设计雕像中遵守AMPA受体的高分辨率结构和2）构建离子通道块的结构模型。研究是因为它代表了一个大尺寸的多聚体积分膜，通常很低表达水平。包含现代晶体学技术和电生理学。配体在脱敏和阻滞剂结合状态下获得全长AMPA受体结构将十个将新生的结构信息与电子杂质的记录和动力学结合在一起找出AMPA受体脱敏的机制，并实现我们的目标对分子神经科学的影响，将导致AMPA受体的新结构/功能模型，该模型可以用作理论预测的动态模板新的。可以在不同模型的神经系统疾病和最终的模型中测试的化合物变得安全，并且有效的药物。