Purification and functional reconstitution of monomeric mu-opioid receptors: allosteric modulation of agonist binding by Gi2.

ABSTRACT: Despite extensive characterization of the mu-opioid receptor (MOR), the biochemical properties of the isolated receptor remain unclear. In light of recent reports, we proposed that the monomeric form of MOR can activate G proteins and be subject to allosteric regulation. A mu-opioid receptor fused to yellow fluorescent protein (YMOR) was constructed and expressed in insect cells. YMOR binds ligands with high affinity, displays agonist-stimulated [(35)S]guanosine 5'-(gamma-thio)triphosphate binding to Galpha(i), and is allosterically regulated by coupled G(i) protein heterotrimer both in insect cell membranes and as purified protein reconstituted into a phospholipid bilayer in the form of high density lipoprotein particles. Single-particle imaging of fluorescently labeled receptor indicates

SUBMITTER: Kuszak AJ 

PROVIDER: S-EPMC2785361 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature