G蛋白偶联受体纯化方法的改进产生了光稳定的视紫红质晶体。
Improvements in G protein-coupled receptor purification yield light stable rhodopsin crystals.
作者信息
Salom David, Le Trong Isolde, Pohl Ehmke, Ballesteros Juan A, Stenkamp Ronald E, Palczewski Krzysztof, Lodowski David T
机构信息
Novasite Pharmaceuticals, Inc., San Diego, CA 92121, USA.
出版信息
J Struct Biol. 2006 Dec;156(3):497-504. doi: 10.1016/j.jsb.2006.05.003. Epub 2006 Jun 2.
G protein-coupled receptors (GPCRs) represent the largest family of transmembrane signaling proteins and are the target of approximately half of all therapeutic agents. Agonist ligands bind their cognate GPCRs stabilizing the active conformation that is competent to bind G proteins, thus initiating a cascade of intracellular signaling events leading to modification of the cell activity. Despite their biomedical importance, the only known GPCR crystal structures are those of inactive rhodopsin forms. In order to understand how GPCRs are able to transduce extracellular signals across the plasma membrane, it is critical to determine the structure of these receptors in their ligand-bound, active state. Here, we report a novel combination of purification procedures that allowed the crystallization of rhodopsin in two new crystal forms and can be applicable to the purification and crystallization of other membrane proteins. Importantly, these new crystals are stable upon photoactivation and the preliminary X-ray diffraction analysis of both photoactivated and ground state rhodopsin crystals are also reported.
G蛋白偶联受体(GPCRs)是最大的跨膜信号蛋白家族,约占所有治疗药物靶点的一半。激动剂配体与其同源GPCRs结合,稳定能够结合G蛋白的活性构象,从而引发一系列细胞内信号事件,导致细胞活性改变。尽管它们在生物医学上具有重要意义,但目前已知的GPCR晶体结构仅为无活性视紫红质形式。为了了解GPCRs如何能够跨质膜转导细胞外信号,确定这些受体在其配体结合的活性状态下的结构至关重要。在此,我们报告了一种新的纯化程序组合,该组合使得视紫红质以两种新的晶体形式结晶,并且可应用于其他膜蛋白的纯化和结晶。重要的是,这些新晶体在光激活后是稳定的,并且还报告了光激活和基态视紫红质晶体的初步X射线衍射分析。