Photoreceptor rhodopsin: structural and conformational study of its chromophore 11-cis retinal in oriented membranes by deuterium solid state NMR. (ox.ac.uk)
Retinol is called vitamin A alcohol or, more often, simply vitamin A. Retinal can also be oxidized to retinoic acid: retinal + NAD+ + H2O → retinoic acid + NADH + H+ (catalyzed by RALDH) retinal + O2 + H2O → retinoic acid + H2O2 (catalyzed by retinal oxidase), catalyzed by retinal dehydrogenases also known as retinaldehyde dehydrogenases (RALDHs) as well as retinal oxidases. (wikipedia.org)
Retinal is a conjugated chromophore. (wikipedia.org)
The absorbance spectrum of the chromophore depends on its interactions with the opsin protein to which it is bound, so that different retinal-opsin complexes will absorb photons of different wavelengths (i.e., different colors of light). (wikipedia.org)
Retinal binds as chromophore at Lys296. (wikipedia.org)
Photoisomerization of the 11-cis-retinal chromophore of rod and cone visual pigments to an all-trans-configuration is the initiating event for vision in vertebrates. (johnshopkins.edu)
A nonvisual opsin known as retinal pigment epithelium (RPE)-retinal G-protein- coupled receptor (RGR) was previously shown to mediate visual chromophore regeneration in photic conditions, but conflicting results have cast doubt on its role as a photoisomerase. (johnshopkins.edu)
This activity was associated with RGR and enhanced by cellular retinaldehyde-binding protein (CRALBP), which binds the 11-cis-retinal produced by RGR and prevents its re-isomerization to all-trans-retinal. (johnshopkins.edu)
Light prevents exogenous 11-cis retinal from maintaining cone photoreceptors in chromophore-deficient mice. (musc.edu)
Polyene1
Analysis of the obtained 2H NMR spectra provided angles for the individual labelled chemical bond vectors leading to an overall picture for the three dimensional structure of the polyene chain of the chromophore in the protein binding pocket around the Schiff base attachment site. (ox.ac.uk)
Light1
These results provide key insights into the mechanisms of physiological retinoid photoisomerization and suggest a novel mechanism by which RGR, in concert with CRALBP, regenerates the visual chromophore in the RPE under sustained light conditions. (johnshopkins.edu)
We investigated human RPE65-LCA patients and mice with visual cycle abnormalities to determine the impact of chronic chromophore deprivation on cones. (nih.gov)
We hypothesized that the RPE65-emixustat crystal structure could help guide the design of retinaldehyde-sequestering agents with varying degrees of RPE65 inhibitory activity. (cornell.edu)
Functional studies are needed to define whether the substitution of aspartate impairs the folding of the tertiary RPE65 structure only and does not lead to the complete abolishment of chromophore production, thus explaining the less severe phenotype in adolescence. (bvsalud.org)