Linked Life Data

15461454

Source:http://linkedlifedata.com/resource/pubmed/id/15461454

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
2004-10-5
pubmed:abstractText
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 pocket of bovine rhodopsin. Aligned recombinant membranes were studied containing rhodopsin that was regenerated with retinal (2)H-labeled at the C(5), C(9), or C(13) methyl groups by total synthesis. Studies were conducted at temperatures below the gel to liquid-crystalline phase transition of the membrane lipid bilayer, where rotational and translational diffusion of rhodopsin is effectively quenched. The experimental tilt series of (2)H NMR spectra were fit to a theoretical line shape analysis [Nevzorov, A. A., Moltke, S., Heyn, M. P., and Brown, M. F. (1999) J. Am. Chem. Soc. 121, 7636-7643] giving the retinylidene bond orientations with respect to the membrane normal in the dark state. Moreover, the relative orientations of pairs of methyl groups were used to calculate effective torsional angles between different planes of unsaturation of the retinal chromophore. Our results are consistent with significant conformational distortion of retinal, and they have important implications for quantum mechanical calculations of its electronic spectral properties. In particular, we find that the beta-ionone ring has a twisted 6-s-cis conformation, whereas the polyene chain is twisted 12-s-trans. The conformational strain of retinal as revealed by solid-state (2)H NMR is significant for explaining the quantum yields and mechanism of its ultrafast photoisomerization in visual pigments. This work provides a consensus view of the retinal conformation in rhodopsin as seen by X-ray diffraction, solid-state NMR spectroscopy, and quantum chemical calculations.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12819-28
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Deuterium NMR structure of retinal in the ground state of rhodopsin.
pubmed:affiliation
Departments of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, Arizona 85721, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't