Solid-state 2H NMR relaxation illuminates functional dynamics of retinal cofactor in membrane activation of rhodopsin.
Proc Natl Acad Sci U S A. 2011 Apr 28;
Authors: Struts AV, Salgado GF, Brown MF
Rhodopsin is a canonical member of the family of G protein-coupled receptors, which transmit signals across cellular membranes and are linked to many drug interventions in humans. Here we show that solid-state (2)H NMR relaxation allows investigation of light-induced changes in local ps-ns time scale motions of retinal bound to rhodopsin. Site-specific (2)H labels were introduced into methyl groups of the retinal ligand that are essential to the activation process. We conducted solid-state (2)H NMR relaxation (spin-lattice, T(1Z), and quadrupolar-order, T(1Q)) experiments in the dark, Meta I, and Meta II states of the photoreceptor. Surprisingly, we find the retinylidene methyl groups exhibit site-specific differences in dynamics that change upon light excitation-even more striking, the C9-methyl group is a dynamical hotspot that corresponds to a crucial functional hotspot of rhodopsin. Following 11-cis to trans isomerization, the (2)H NMR data suggest the ?-ionone ring remains in its hydrophobic binding pocket in all three states of the protein. We propose a multiscale activation mechanism with a complex energy landscape, whereby the photonic energy is directed against the E2 loop by the C13-methyl group, and toward helices H3 and H5 by the C5-methyl of the ?-ionone ring. Changes in retinal structure and dynamics initiate activating fluctuations of transmembrane helices H5 and H6 in the Meta I-Meta II equilibrium of rhodopsin. Our proposals challenge the Standard Model whereby a single light-activated receptor conformation yields the visual response-rather an ensemble of substates is present, due to the entropy gain produced by photolysis of the inhibitory retinal lock.
PMID: 21527723 [PubMed - as supplied by publisher]
Molecular simulations and solid-state NMR investigate dynamical structure in rhodopsin activation.
Molecular simulations and solid-state NMR investigate dynamical structure in rhodopsin activation.
Molecular simulations and solid-state NMR investigate dynamical structure in rhodopsin activation.
Biochim Biophys Acta. 2011 Aug 8;
Authors: Mertz B, Struts AV, Feller SE, Brown MF
Abstract
Rhodopsin has served as the primary model for studying G protein-coupled receptors (GPCRs)-the largest group in the human genome, and consequently a primary target for pharmaceutical development. Understanding the functions and activation mechanisms of...
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08-20-2011 03:31 PM
Solid-State NMR of a Large Membrane Protein by Paramagnetic Relaxation Enhancement.
Solid-State NMR of a Large Membrane Protein by Paramagnetic Relaxation Enhancement.
Solid-State NMR of a Large Membrane Protein by Paramagnetic Relaxation Enhancement.
J Phys Chem Lett. 2011 Jul 21;2(14):1836-1841
Authors: Tang M, Berthold DA, Rienstra CM
Membrane proteins play an important role in many biological functions. Solid-state NMR spectroscopy is uniquely suited for studying structure and dynamics of membrane proteins in a membranous environment. The major challenge to obtain high quality solid-state NMR spectra of membrane proteins is...
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08-16-2011 01:19 PM
Solid-state 2H NMR relaxation illuminates functional dynamics of retinal cofactor in membrane activation of rhodopsin [Biophysics and Computational Biology]
Solid-state 2H NMR relaxation illuminates functional dynamics of retinal cofactor in membrane activation of rhodopsin
Struts, A. V., Salgado, G. F. J., Brown, M. F....
Date: 2011-05-17
Rhodopsin is a canonical member of the family of G protein-coupled receptors, which transmit signals across cellular membranes and are linked to many drug interventions in humans. Here we show that solid-state 2H NMR relaxation allows investigation of light-induced changes in local ps–ns time scale motions of retinal bound to rhodopsin. Site-specific 2H labels were introduced into methyl groups of the...
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05-17-2011 08:40 PM
Structure and dynamics of cationic membrane peptides and proteins: Insights from solid-state NMR.
Structure and dynamics of cationic membrane peptides and proteins: Insights from solid-state NMR.
Structure and dynamics of cationic membrane peptides and proteins: Insights from solid-state NMR.
Protein Sci. 2011 Feb 22;
Authors: Hong M, Su Y
Many membrane peptides and protein domains contain functionally important cationic Arg and Lys residues, whose insertion into the hydrophobic interior of the lipid bilayer encounters significant energy barriers. To understand how these cationic molecules overcome the free energy barrier to insert into the...
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02-24-2011 11:04 AM
[NMR paper] Deuterium NMR structure of retinal in the ground state of rhodopsin.
Deuterium NMR structure of retinal in the ground state of rhodopsin.
Related Articles Deuterium NMR structure of retinal in the ground state of rhodopsin.
Biochemistry. 2004 Oct 12;43(40):12819-28
Authors: Salgado GF, Struts AV, Tanaka K, Fujioka N, Nakanishi K, Brown MF
The conformation of retinal bound to the G protein-coupled receptor rhodopsin is intimately linked to its photochemistry, which initiates the visual process. Site-directed deuterium ((2)H) NMR spectroscopy was used to investigate the structure of retinal within the binding...
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11-24-2010 10:01 PM
[NMR paper] Solid-state NMR investigation of the dynamics of the soluble and membrane-bound colic
Solid-state NMR investigation of the dynamics of the soluble and membrane-bound colicin Ia channel-forming domain.
Related Articles Solid-state NMR investigation of the dynamics of the soluble and membrane-bound colicin Ia channel-forming domain.
Biochemistry. 2001 Jun 26;40(25):7662-74
Authors: Huster D, Xiao L, Hong M
Solid-state NMR spectroscopy was employed to study the molecular dynamics of the colicin Ia channel domain in the soluble and membrane-bound states. In the soluble state, the protein executes small-amplitude librations (with...
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11-19-2010 08:32 PM
[NMR paper] Membrane structure and dynamics as viewed by solid-state NMR spectroscopy.
Membrane structure and dynamics as viewed by solid-state NMR spectroscopy.
Related Articles Membrane structure and dynamics as viewed by solid-state NMR spectroscopy.
Biophys Chem. 1997 Oct;68(1-3):233-41
Authors: Auger M
The purpose of the present study is the investigation of the structure and dynamics of biological membranes using solid-state nuclear magnetic resonance (NMR) spectroscopy. Two approaches are used in our laboratory. The first involves the measurement of high-resolution 13C and 1H spectra obtained by the magic angle spinning...
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08-22-2010 05:08 PM
[NMR paper] NMR constraints on the location of the retinal chromophore in rhodopsin and bathorhod
NMR constraints on the location of the retinal chromophore in rhodopsin and bathorhodopsin.
Related Articles NMR constraints on the location of the retinal chromophore in rhodopsin and bathorhodopsin.
Biochemistry. 1995 Jan 31;34(4):1425-32
Authors: Han M, Smith SO
Rhodopsin is the photoreceptor in vertebrate rod cells responsible for vision at low light intensities. The photoreactive chromophore in rhodopsin is 11-cis-retinal bound to the protein via a protonated Schiff base with Glu113 as the counterion. We have used the observed 13C NMR...
Solid-state 2H NMR relaxation illuminates functional dynamics of retinal cofactor in membrane activation of rhodopsin.
Linear Mode
