Positively charged retinoids are potent and selective inhibitors of the trans-cis isomerization in the retinoid (visual) cycle.

ABSTRACT: In vertebrate retinal photoreceptors, photoisomerization of opsin-bound visual chromophore 11-cis-retinal to all-trans-retinal triggers phototransduction events. Regeneration of the chromophore is a critical step in restoring photoreceptors to their dark-adapted state. This regeneration process, called the retinoid cycle, takes place in the photoreceptor outer segments and in the retinal pigmented epithelium (RPE). We have suggested that the regeneration of the chromophore might occur through a retinyl carbocation intermediate. Here, we provide evidence that isomerization is inhibited by positively charged retinoids, which could act as transition state analogs of the isomerization process. We demonstrate that retinylamine (Ret-NH2) potently and selectively inhibits the isomerization step o

SUBMITTER: Golczak M 

PROVIDER: S-EPMC1149451 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature