Solution NMR Spectroscopy of the Human Vasopressin V2 Receptor,A G Protein-Coupled Receptor

摘要

The human genome encodes at least 800 unique G protein-coupled receptors (GPCRs),which share a common membrane topology of seven transmembrane segments.GPCRs serve as the primary sensors for human olfaction,taste,and vision,play a host of critical roles in human physiology,and are the targets for a substantial fraction of all known drugs.Despite their importance,only a single high-resolution structure of a GPCR has been determined,that of the dark (signaling-off) state of the bovine photoreceptor,rhodopsin,first solved by X-ray crystallographic methods in 2000.While solution NMR spectroscopy is now established as a method for determining the structures of polytopic membrane proteins,the feasibility of approaching the structures of GPCRs by this method has not been clear.Previous solution NMR applications to GPCRs have been limited to (i) characterization of GPCR fragments and isolated extramembrane domains,(ii) examination of ligands bound to GPCRs,and (iii) probes of selectively labeled rhodopsin to address specific structural,dynamic,and mechanistic issues (see also refs 22 and 23).Here,results are presented for a uniformly isotopically labeled GPCR that indicate a promising outlook for application of solution NMR methods to structural studies of intact receptors.