title: Functional dynamics of deuterated β2 -adrenergic receptor in lipid bilayers revealed by NMR spectroscopy.
abstract: G-protein-coupled receptors (GPCRs) exist in conformational equilibrium between active and inactive states, and the former population determines the efficacy of signaling. However, the conformational equilibrium of GPCRs in lipid bilayers is unknown owing to the low sensitivities of their NMR signals. To increase the signal intensities, a deuteration method was developed for GPCRs expressed in an insect cell/baculovirus expression system. The NMR sensitivities of the methionine methyl resonances from the β2 -adrenergic receptor (β2 AR) in lipid bilayers of reconstituted high-density lipoprotein (rHDL) increased by approximately 5-fold upon deuteration. NMR analyses revealed that the exchange rates for the conformational equilibrium of β2 AR in rHDLs were remarkably different from those measured in detergents. The timescales of GPCR signaling, calculated from the exchange rates, are faster than those of receptor tyrosine kinases and thus enable rapid neurotransmission and sensory perception.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan).
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kofuku
authors.forename: Takumi
authors.initials: T
authors.lastname: Ueda
authors.forename: Junya
authors.initials: J
authors.lastname: Okude
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Keita
authors.initials: K
authors.lastname: Kondo
authors.forename: Takuya
authors.initials: T
authors.lastname: Mizumura
authors.forename: Shiho
authors.initials: S
authors.lastname: Suzuki
authors.forename: Ichio
authors.initials: I
authors.lastname: Shimada
mesh_terms: D000818:Animals; D002460:Cell Line; D008051:Lipid Bilayers / Q000737:chemistry*; D008075:Lipoproteins, HDL / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D018343:Receptors, Adrenergic, beta-2 / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D008075:Lipoproteins, HDL; D018343:Receptors, Adrenergic, beta-2
keywords: G-protein-coupled receptors; NMR spectroscopy; isotopic labeling; lipid bilayers; membrane proteins