title: GPCR stabilization using the bicelle-like architecture of mixed sterol-detergent micelles.
abstract: The biophysical characterization of purified membrane proteins typically requires detergent mediated extraction from native lipid membrane environments. In the case of human G protein-coupled receptors (GPCRs), this process has been complicated by their conformational heterogeneity and the general lack of understanding the composition and interactions within the diverse human cellular membrane environment. Several successful GPCR structure determination efforts have shown that the addition of cholesterol analogs is often critical for maintaining protein stability. We have identified sterols that substantially increase the stability of the NOP receptor (ORL-1), a member of the opioid GPCR family, in a mixed micelle environment. Using dynamic light scattering and small-angle X-ray scattering, we have determined that the most thermal stabilizing sterol, cholesteryl hemisuccinate, induces the formation of a bicelle-like micelle architecture when mixed with dodecyl maltoside detergent. Together with mutagenesis studies and recent GPCR structures, our results provide indications that stabilization is attained through a combination of specific sterol binding to GPCRs and modulation of micelle morphology.
authors: Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors: Aaron A
authors: AA
authors: Thompson
authors: Jeffrey J
authors: JJ
authors: Liu
authors: Eugene
authors: E
authors: Chun
authors: Daniel
authors: D
authors: Wacker
authors: Huixian
authors: H
authors: Wu
authors: Vadim
authors: V
authors: Cherezov
authors: Raymond C
authors: RC
authors: Stevens
mesh_terms: D000465:Algorithms; D002788:Cholesterol Esters / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry*; D006801:Humans; D008027:Light; D008823:Micelles; D008958:Models, Molecular; D008968:Molecular Conformation; D010316:Particle Size; D055550:Protein Stability; D011957:Receptors, Opioid / Q000096:biosynthesis* / Q000737:chemistry; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000737:chemistry; D012542:Scattering, Radiation; D053838:Scattering, Small Angle; D044366:Transition Temperature; D014961:X-Ray Diffraction; D000094942:Nociceptin Receptor
chemical_list: D002788:Cholesterol Esters; D005960:Glucosides; D008823:Micelles; D011957:Receptors, Opioid; D011993:Recombinant Fusion Proteins; C040358:dodecyl maltoside; C013440:cholesteryl succinate; D000094942:Nociceptin Receptor; C000722283:OPRL1 protein, human