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.

项目概要 AMPA（¿-氨基-3-羟基-5-甲基-4-异恶唑丙酸）亚型离子型谷氨酸受体介导 AMPA 中中枢神经系统的大部分兴奋性神经传递改变。受体功能与包括阿尔茨海默病在内的许多破坏性神经系统疾病有关 AMPA 受体活性的调节是疾病、肌萎缩侧索硬化症、癫痫和缺血的关键。因此，AMPA 受体通过打开其离子通道以促进离子流动发挥作用。离子通道响应激动剂谷氨酸与受体结合的渗透阳离子。打开或激活门控通常伴随着较慢的脱敏过程。导致离子通道孔关闭，表现为 AMPA 受体减少 10-500 倍- 谷氨酸连续存在下介导的电流代表了一种自然的脱敏方式。抑制 AMPA 受体活性，保护神经元免受兴奋毒性钙超载的影响。因此，减弱脱敏是调节病理学中AMPA受体活性的有效途径。另一种具有治疗潜力的抑制 AMPA 受体活性的方法是使用离子。通道阻滞剂，堵塞通道孔的分子在分子水平上，脱敏和离子通道。块预计具有共同的特征，允许它们将离子通道锁定在封闭的区域中。我们计划结合使用结构和阻断来研究 AMPA 受体脱敏和阻断。功能方法并揭示这些过程的相似性和差异，因此，我们具体的。目标是：1) 获得脱敏状态下 AMPA 受体的高分辨率结构；2) 建立离子通道阻断的结构模型是结构-功能的一个具有挑战性的目标。研究，因为它代表了一种大尺寸的多聚体整合膜蛋白，通常具有较低的为了实现我们的目标，我们将结合使用结构和功能方法。包括现代晶体学技术、基于荧光的尺寸排阻色谱 (FSEC) 我们将使用不同的结晶方法和温度、筛选去污剂、脂质。和配体以获得脱敏和阻断剂结合状态下的全长 AMPA 受体结构。然后将把新生的结构信息与电生理记录和动力学模型结合起来弄清楚AMPA受体脱敏和阻断的机制将对实现我们的目标具有重大意义。对分子神经科学的影响并将产生 AMPA 受体的新结构/功能模型可以作为理论预测、计算机模拟和化学合成的动态模板可以在不同的神经系统疾病模型中进行测试并最终变得安全和可靠的化合物有效的药物。