Spectroscopic Investigations of Glutamate Receptor

谷氨酸受体的光谱研究

• 批准号: 7099158
• 负责人: Vasanthi Jayaraman
• 金额: $ 23.66万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-04-10 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7099158
• 关键词: chemical kinetics; conformation; electrophysiology; fluorescence resonance energy transfer; gene mutation; glutamate receptor; glutamates; intermolecular interaction; ion transport; ligands; protein structure function; receptor binding; receptor sensitivity; stimulant /agonist; chemical kinetics; conformation; electrophysiology; fluorescence resonance energy transfer; gene mutation; glutamate receptor; glutamates; intermolecular interaction; ion transport; ligands; protein structure function; receptor binding; receptor sensitivity; stimulant /agonist

DESCRIPTION (provided by applicant): The specific molecular interactions between glutamate and the glutamate receptor are central to the allosteric regulation of function in this membrane bound protein, which is main excitatory neurotransmitter receptor in the mammalian central nervous system. Recent spectroscopic investigations of the isolated ligand-binding domain of the glutamate receptor in the apo and ligand bound forms provide a first view of such interactions. What is now needed is a more detailed understanding of the role of these chemical interactions in mediating the sequence of conformational changes that ultimately regulate ion flow. We propose to address this goal using two strategies. First, using a panel of mutants that exhibit a wide range of activities we will identify changes in specific ligand protein interactions using vibrational spectroscopy and correlate these to changes in the cleft closure conformational change in the ligand binding domain using fluorescence resonance energy transfer measurements. The changes thus identified in the ligand binding domain will then be contextualized in terms of changes in receptor function that will be studied by electrophysiological measurements. Secondly, we will monitor the kinetic events in the ligand binding domain and correlate these to the functional consequences in the receptor, i.e., activation and desensitization. For such a correlation, a panel of mutants that are known to alter one or more of the kinetic steps in the ligand binding domain will be used and the specific effects on the structural changes in the ligand binding domain as well as corresponding changes in function will be investigated. These equilibrium and kinetic investigations will provide comprehensive understanding of the changes at the molecular level that drive the changes in the large conformational changes in the ligand binding domain and eventually control the functional changes of the ion channel. More importantly, such correlations will aid in bridging the gap between studies on the isolated ligand-binding domain and the behavior of the intact receptor, and provide a basis for rational design of drugs aimed at modulating the function of this important protein which is known to play an important role in diverse neuropathologies, including epilepsy and ischemia.

描述（由申请人提供）：谷氨酸和谷氨酸受体之间的特定分子相互作用对于该膜结合蛋白的功能变构调节至关重要，该膜结合蛋白是哺乳动物中枢神经系统中的主要兴奋性神经递质受体。对Apo和配体结合形式中谷氨酸受体分离的配体结合结构域的最新光谱研究提供了这种相互作用的第一视图。现在所需要的是对这些化学相互作用在介导最终调节离子流的构象变化序列中的作用的更详细理解。我们建议使用两种策略来解决这一目标。首先，使用表现出广泛活性的突变体的面板，我们将使用振动光谱法确定特定配体蛋白相互作用的变化，并将这些变化与使用荧光共振能量转移测量值的配体结合结构域中的裂口闭合构象变化相关。然后，在配体结合结构域中确定的变化将通过受体功能的变化来进行上下文，这将通过电生理测量研究。其次，我们将监测配体结合结构域中的动力学事件，并将其与受体中的功能后果相关联，即激活和脱敏。对于这种相关性，将使用一组已知会改变配体结合结构域的动力学步骤的突变体，并将研究对配体结合结构域的结构变化以及功能上相应变化的特定影响。这些平衡和动力学研究将提供对分子水平上的变化的全面理解，这些变化驱动了配体结合域中大构象变化的变化，并最终控制了离子通道的功能变化。更重要的是，这种相关性将有助于弥合有关孤立的配体结合结构域的研究和完整受体的行为之间的差距，并为旨在调节这种重要蛋白质功能的药物的合理设计提供了基础，该药物在包括癫痫病在内的多种神经病理学中起着重要作用，包括癫痫病和iSchemia。