Retinol isomerase

In enzymology, a retinol isomerase (EC 5.2.1.7) is an enzyme that catalyzes the chemical reaction

all-trans-retinol ${\displaystyle \rightleftharpoons }$ 11-cis-retinol

Hence, this enzyme has one substrate, all-trans-retinol, and one product, . These enzymes are alternatively referred to as retinoid isomerases.

This enzyme belongs to the family of isomerases, specifically cis-trans isomerases. The systematic name of this enzyme class is all-trans-retinol 11-cis-trans-isomerase. This enzyme is also called all-trans-retinol isomerase. This enzyme participates in retinol metabolism.

In vertebrates, RPE65 is the active retinol isomerase in the visual cycle. A lack of RPE65 function results in congenital blindness in children (specifically Leber congenital amaurosis). Emixustat, a partial inhibitor of RPE65, is currently in FDA clinical trials for the treatment of age-related macular degeneration.

References[]

• Bernstein PS, Law WC, Rando RR (1987). "Isomerization of all-trans-retinoids to 11-cis-retinoids in vitro". Proc. Natl. Acad. Sci. U.S.A. 84 (7): 1849–53. doi:10.1073/pnas.84.7.1849. PMC 304538. PMID 3494246.
• Bridges CD, Alvarez RA (1987). "The visual cycle operates via an isomerase acting on all-trans retinol in the pigment epithelium". Science. 236 (4809): 1678–80. doi:10.1126/science.3603006. PMID 3603006.