STRUCTURE OF A GLUTAMATE RECEPTOR BINDING DOMAIN

谷氨酸受体结合域的结构

• 批准号: 8171500
• 负责人: ROBERT E OSWALD
• 金额: $ 0.71万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8171500
• 关键词: Agonist; Amyotrophic Lateral Sclerosis; Binding; Binding Sites; Brain; Cations; Cell membrane; Collaborations; Computer Retrieval of Information on Scientific Projects Database; Crystallization; Disease; Drug Delivery Systems; Electron Spin Resonance Spectroscopy; Epilepsy; Extracellular Domain; Funding; GluR2 subunit AMPA receptor; Glutamate Receptor; Glutamates; Grant; Institution; Ion Channel; Ions; Ischemic Brain Injury; Laboratories; Length; Ligand Binding; Ligand Binding Domain; Ligands; Link; Lobe; Measurement; Measures; Motion; NMR Spectroscopy; Neuraxis; Neurons; Neurotransmitter Receptor; Proteins; Research; Research Personnel; Resolution; Resources; Source; Structure; Time; United States National Institutes of Health; Work; X-Ray Crystallography; extracellular; flexibility; protein function; receptor binding

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Glutamate receptors are the major excitatory neurotransmitter receptors in vertebrate brain and are involved in a variety of normal and pathological neuronal functions. These proteins function by binding glutamate in an extracellular domain and opening an intrinsic ion channel that allows cations to flow in and out of the neuron. Drugs targeted to glutamate receptors may have considerable potential for treating such diverse disorders as epilepsy, amyotrophic lateral sclerosis, and ischemic brain damage. We are studying two important glutamate receptors (GluR2 and GluR3), using X-ray crystallography and NMR and ESR spectroscopy to understand the structure and dynamics and to compare the results with the function of the protein measured using single channel recording (measurement of ion conductance across the cell membrane). The structural work is done on the extracellular ligand-binding domains of the proteins (GluR2 S1S2 and GluR3 S1S2), which are a soluble constructs derived from the full-length proteins. The proteins have a bilobed structure with the binding site for glutamate and derivatives at the interface between the two lobes. For GluR2, previous work has suggested that the degree to which the lobes close upon binding of ligand may relate to the function of the protein. Our initial work with NMR spectroscopy and our recent crystal structures, suggest that the relationship between structure and function may be more complicated, involving protein flexibility. Obtaining additional structures, under conditions that reveal the range of possible motions, is essential for understanding the functional consequences of agonist binding. In collaboration with the Sondermann laboratory, we have obtained the structures of GluR2 S1S2 bound to several new ligands (1.5 to 1.7 angstrom resolution). The time requested in this cycle will be used to determine structures of GluR2 S1S2 with three new ligands under two crystallization conditions that we suspect will provide an indication of the range of possible motions of the protein. We also have crystals for GluR3 S1S2, the structure of which has not yet been determined. This protein is also available bound to at three different ligands. In addition the importance of understanding its crucial function in the central nervous system, the rationale for expanding these studies to the GluR3 subtype is that our functional studies of GluR3 have advanced considerably in recent years, and the hope of understanding in detail the link between structural changes in the binding domain to the conductance of ions through the cell membrane is very promising with this subtype. We have determined the conditions and have grown all of the crystals to be used in these studies. As noted above, the crystals that we have obtained from GluR2 diffract to high resolution (1.5 to 1.7 angstroms), and we anticipate similar results from the new crystals that we have obtained.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 谷氨酸受体是脊椎动物脑中主要的兴奋性神经递质受体，参与多种正常和病理神经元功能。这些蛋白质通过在细胞外结构域中结合谷氨酸并打开允许阳离子流入和流出神经元的内在离子通道来发挥作用。针对谷氨酸受体的药物可能具有治疗癫痫、肌萎缩侧索硬化症和缺血性脑损伤等多种疾病的巨大潜力。我们正在研究两种重要的谷氨酸受体（GluR2 和 GluR3），使用 X 射线晶体学以及 NMR 和 ESR 光谱来了解结构和动力学，并将结果与​​使用单通道记录测量的蛋白质功能进行比较（离子电导测量）穿过细胞膜）。结构工作是在蛋白质（GluR2 S1S2 和 GluR3 S1S2）的胞外配体结合域上完成的，它们是衍生自全长蛋白质的可溶性构建体。这些蛋白质具有双叶结构，谷氨酸及其衍生物的结合位点位于两个叶之间的界面处。对于 GluR2，先前的工作表明，配体结合时叶关闭的程度可能与蛋白质的功能有关。我们对核磁共振波谱的初步研究和最近的晶体结构表明，结构和功能之间的关系可能更加复杂，涉及蛋白质的灵活性。在揭示可能运动范围的条件下获得额外的结构对于理解激动剂结合的功能后果至关重要。 我们与 Sondermann 实验室合作，获得了与几种新配体结合的 GluR2 S1S2 的结构（分辨率为 1.5 至 1.7 埃）。该循环中要求的时间将用于确定在两种结晶条件下具有三种新配体的 GluR2 S1S2 的结构，我们怀疑这将提供蛋白质可能运动范围的指示。我们还有 GluR3 S1S2 晶体，其结构尚未确定。该蛋白质还可与三种不同的配体结合。除了了解其在中枢神经系统中的关键功能的重要性之外，将这些研究扩展到 GluR3 亚型的理由是我们对 GluR3 的功能研究近年来取得了相当大的进展，并且希望详细了解结构之间的联系对于这种亚型，结合域与离子通过细胞膜的电导的变化非常有希望。 我们已经确定了条件并生长了用于这些研究的所有晶体。如上所述，我们从 GluR2 获得的晶体衍射至高分辨率（1.5 至 1.7 埃），并且我们预计我们获得的新晶体也会出现类似的结果。