6-s-cis Conformation and polar binding pocket of the retinal chromophore in the photoactivated state of rhodopsin.

ABSTRACT: The visual pigment rhodopsin is unique among the G protein-coupled receptors in having an 11-cis retinal chromophore covalently bound to the protein through a protonated Schiff base linkage. The chromophore locks the visual receptor in an inactive conformation through specific steric and electrostatic interactions. This efficient inverse agonist is rapidly converted to an agonist, the unprotonated Schiff base of all-trans retinal, upon light activation. Here, we use magic angle spinning NMR spectroscopy to obtain the (13)C chemical shifts (C5-C20) of the all-trans retinylidene chromophore and the (15)N chemical shift of the Schiff base nitrogen in the active metarhodopsin II intermediate. The retinal chemical shifts are sensitive to the conformation of the chromophore and its molecular int

SUBMITTER: Ahuja S 

PROVIDER: S-EPMC2783296 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature