Abstract
To examine the molecular details of ligand activation of G-protein coupled receptors (GPCRs), emphasis has been placed on structure determination of these receptors with stabilizing ligands. Here we present the methodology for receptor dynamics characterization of the GPCR human beta(2) adrenergic receptor bound to the inverse agonist carazolol using the technique of amide hydrogen/deuterium exchange coupled with mass spectrometry (HDX MS). The HDX MS profile of receptor bound to carazolol is consistent with thermal parameter observations in the crystal structure and provides additional information in highly dynamic regions of the receptor and chemical modifications demonstrating the highly complementary nature of the techniques. After optimization of HDX experimental conditions for this membrane protein, better than 89% sequence coverage was obtained for the receptor. The methodology presented paves the way for future analysis of beta(2)AR bound to pharmacologically distinct ligands as well as analysis of other GPCR family members.