DETERMINING THE MOLECULAR ENVELOPE OF THE COMPLEX OF A G-PROTEIN AND ITS RECEPTO

确定 G 蛋白复合物及其受体的分子包膜

• 批准号: 8362362
• 负责人: William I Weis
• 金额: $ 0.74万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362362
• 关键词: Adrenergic Receptor; Agonist; Collaborations; Complex; Conflict (Psychology); Electron Microscopy; Funding; G-Protein-Coupled Receptors; G-substrate; GTP-Binding Proteins; Grant; Heterotrimeric GTP-Binding Proteins; Hormones; Individual; Ligands; Measurement; Mediating; Molecular; Molecular Conformation; Molecular Sieve Chromatography; National Center for Research Resources; Neurotransmitters; Nucleotides; Principal Investigator; Property; Proteins; Radiation; Research; Research Infrastructure; Resources; Shapes; Solutions; Source; Structure; United States National Institutes of Health; cost; receptor; receptor binding; response; sensory stimulus; stoichiometry; structural biology

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. G-protein coupled receptors are 7-transmembrane helix proteins that mediate the majority of cellular responses to hormones, neurotransmitters, and sensory stimuli. In collaboration with Dr. Brian Kobilka, we have been studying crystal structures of the beta2-adrenergic receptor, a well-characterized G-protein coupled receptor. These were the first structures of a ligand-activated G protein coupled receptor. Thus far all structures of this and related receptors have been of the inactive state, and there are no structures of the active complex of receptor and G protein. A key question is how activating ligands stabilize the conformation of the receptor that can interact with its cognate heterotrimeric G protein and trigger nucleotide exchange. We have recently succeeded in producing a stable complex of the receptor bound to an activating ligand and a G protein. The complex, approximately 150kDa, is monodisperse as determined by size exclusion chromatography and electron microscopy. We propose solution x-ray scattering measurements to assess if we can obtain information about the overall shape of the complex, since we have the crystal structures of the two individual components. The determination of the stoichiometry between the receptor and G protein would be of significant importance as there are a number of conflicting results on oligomerization property of the receptor in the complex. We would also like to apply solution scattering to study effects of ligand and antagonists/agonists in the overall structure of the complex.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 G 蛋白偶联受体是 7 次跨膜螺旋蛋白，介导大多数细胞对激素、神经递质和感觉刺激的反应。我们与 Brian Kobilka 博士合作，研究了 β2 肾上腺素受体（一种已充分表征的 G 蛋白偶联受体）的晶体结构。这些是配体激活的 G 蛋白偶联受体的第一个结构。迄今为止，该受体及相关受体的所有结构均处于非活性状态，并且没有受体与G蛋白的活性复合物的结构。一个关键问题是激活配体如何稳定受体的构象，从而与其同源异三聚体 G 蛋白相互作用并触发核苷酸交换。我们最近成功地生产了与激活配体和 G 蛋白结合的受体的稳定复合物。通过尺寸排阻色谱法和电子显微镜测定，该复合物大约为 150kDa，是单分散的。我们提出了溶液 X 射线散射测量来评估我们是否可以获得有关复合物整体形状的信息，因为我们拥有两个单独组件的晶体结构。受体和 G 蛋白之间化学计量的确定具有重要意义，因为复合物中受体寡聚化特性存在许多相互矛盾的结果。我们还想应用溶液散射来研究配体和拮抗剂/激动剂在复合物整体结构中的作用。