PHOTORECEPTOR RHODOPSIN - STRUCTURAL AND CONFORMATIONAL STUDY OF ITS CHROMOPHORE 11-CIS RETINAL IN ORIENTED MEMBRANES BY DEUTERIUM SOLID-STATE NMR

Rhodopsin is the retinal photoreceptor responsible for visual signal t ransduction. To determine the orientation and conformation of retinal within the binding pocket of this membrane bound receptor, an ab initi o solid state H-2 NMR approach was used. Bovine rhodopsin containing I l-cis retinal, specifically deuterated at its methyl groups at the C-1 9 or C-20 position, was uniaxially oriented in DMPC bilayers. Integrit y of the membranes and quality of alignment were monitored by P-31 NMR . Analysis of the obtained H-2 NMR spectra provided angles for the ind ividual labelled chemical bond vectors leading to an overall picture f or the three dimensional structure of the polyene chain of the chromop hore in the protein binding pocket around the Schiff base attachment s ite. (C) 1998 Federation of European Biochemical Societies.