(1)H and (13)C MAS NMR evidence for pronounced ligand-protein interactions involving the ionone ring of the retinylidene chromophore in rhodopsin.

ABSTRACT: Rhodopsin is a member of the superfamily of G-protein-coupled receptors. This seven alpha-helix transmembrane protein is the visual pigment of the vertebrate rod photoreceptor cells that mediate dim light vision. In the active binding site of this protein the ligand or chromophore, 11-cis-retinal, is covalently bound via a protonated Schiff base to lysine residue 296. Here we present the complete (1)H and (13)C assignments of the 11-cis-retinylidene chromophore in its ligand-binding site determined with ultra high field magic angle spinning NMR. Native bovine opsin was regenerated with 99% enriched uniformly (13)C-labeled 11-cis-retinal. From the labeled pigment, (13)C carbon chemical shifts could be obtained by using two-dimensional radio frequency-driven dipolar recoupling in a solid-sta

SUBMITTER: Creemers AF 

PROVIDER: S-EPMC123100 | biostudies-literature | 2002 Jul

REPOSITORIES: biostudies-literature