The G-Protein-Coupled Neuropeptide Y Receptor Type 2 is Highly Dynamic in Lipid Membranes as Revealed by Solid-State NMR Spectroscopy.
Related Articles The G-Protein-Coupled Neuropeptide Y Receptor Type 2 is Highly Dynamic in Lipid Membranes as Revealed by Solid-State NMR Spectroscopy.
Chemistry. 2014 Mar 13;
Authors: Schmidt P, Thomas L, Müller P, Scheidt HA, Huster D
Abstract
In spite of the recent success in crystallizing several G-protein-coupled receptors (GPCRs), a comprehensive biophysical characterization of these molecules under physiological conditions also requires the study of the molecular dynamics of these proteins. The molecular mobility of the human neuropeptide Y receptor type 2 reconstituted into dimyristoylphosphatidylcholine (DMPC) membranes was investigated by means of solid-state NMR spectroscopy. Static (15) N NMR spectra show that the receptor performs axially symmetric motions in the membrane, and several residues undergo large amplitude fluctuations. This was confirmed by quantitative measurements of the motional (1) H,(13) C order parameter of the CH, CH2 , and CH3 groups. In directly polarized (13) C NMR experiments, these order parameters showed astonishingly low values of SCH =0.55, S CH 2=0.33, and S CH 3=0.17, which corresponds to segmental amplitudes of approximately 50° in the backbone and approximately 50-60° in the side chain. At physiological temperature, (2) H NMR spectra of the deuterated receptor showed a narrow component that is indicative of molecular order parameters of S