all known visual pigments consists of 11-cis-retinal (derived from either vitamin A1 or A2)
or a hydroxylated derivative, bound to a protein (opsin) via a Schiff base.
RPE65 is a member of the carotenoid oxygenase family and is expressed
in the retinal pigment epithelium bound to endoplasmic reticulum.
It is a Fe2+-dependent isomerase enzyme that catalyzes the hydrolysis
of all-trans-retinyl ester and the isomerization of all-trans-retinol
to 11-cis-retinol (2).
RPE65是類胡蘿蔔素加氧酶家族的成員,在與內質網結合的視網膜色素上皮中表達。
它是一種Fe2+依賴性異構酶,催化全反式視黃醇酯的水解和全反式視黃醇向11-順式視黃醇的異構化(2)。
Figure 1.
11-順式視黃醇(11-cis retinol)經由視黃醇脫氫酶retinol dehydrogenase 14
變成 11-順式視黃醛(11-cis-retinal)
然後才變成11-順式視黃醛視蛋白(11-cis-retinal opsin)