MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.
Trends Biochem Sci. 2012 Sep;37(9):343-52. doi: 10.1016/j.tibs.2012.06.003. Epub 2012 Jul 10.
G-protein-coupled receptors (GPCRs) are medically important membrane proteins that are targeted by over 30% of small molecule drugs. At the time of writing, 15 unique GPCR structures have been determined, with 77 structures deposited in the PDB database, which offers new opportunities for drug development and for understanding the molecular mechanisms of GPCR activation. Many different factors have contributed to this success, but if there is one single factor that can be singled out as the foundation for producing well-diffracting GPCR crystals, it is the stabilisation of the detergent-solubilised receptor-ligand complex. This review will focus predominantly on one of the successful strategies for the stabilisation of GPCRs, namely the thermostabilisation of GPCRs using systematic mutagenesis coupled with thermostability assays. Structures of thermostabilised GPCRs bound to a wide variety of ligands have been determined, which has led to an understanding of ligand specificity; why some ligands act as agonists as opposed to partial or inverse agonists; and the structural basis for receptor activation.
G 蛋白偶联受体（GPCRs）是医学上重要的膜蛋白，超过 30%的小分子药物以其作为靶点。截至撰写本文时，已经确定了 15 种独特的 GPCR 结构，其中 77 种结构已存入 PDB 数据库，这为药物开发和理解 GPCR 激活的分子机制提供了新的机会。许多不同的因素促成了这一成功，但如果有一个单一的因素可以被挑出来作为产生具有良好衍射能力的 GPCR 晶体的基础，那就是稳定去污剂溶解的受体-配体复合物。本文综述主要集中在稳定 GPCR 的成功策略之一，即使用系统诱变结合热稳定性测定来稳定 GPCR。已经确定了与各种配体结合的热稳定 GPCR 的结构，这使得人们对配体特异性有了更深入的了解；解释了为什么有些配体作为激动剂，而有些则作为部分激动剂或反向激动剂；以及受体激活的结构基础。
