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

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 G蛋白偶联受体是介导大多数细胞对激素、神经递质和感觉刺激的反应的7跨膜螺旋蛋白。与Brian Kobilka博士合作，我们一直在研究β 2-肾上腺素能受体的晶体结构，这是一种具有良好特征的G蛋白偶联受体。到目前为止，这种受体和相关受体的所有结构都处于非活性状态。一个关键的问题是如何激活配体稳定的受体，可以与它的同源异源三聚体G蛋白和触发核苷酸交换的构象。我们最近已经成功地生产了一个稳定的复合物的受体结合到一个激活配体和G蛋白。该复合物，约150 kDa，是单分散的，通过尺寸排阻色谱法和电子显微镜测定。我们想进行初步的SAXS测量，以评估我们是否可以获得有关复杂的整体形状的信息，因为我们知道两个单独组件的结构。

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. 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. Thus far all structures of this and related receptors have been of the inactive state. 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 would like to carry out preliminary SAXS measurements to assess if we can obtain information about the overall shape of the complex, since we know the structures of the two individual components.