Retinaldehyde isomerase

A microsomal retinol dehydrogenase catalyzes the oxidation of CRBP-hound all-trans-retinol to retinaldehyde it also acts as a 3a-hydroxysteroid dehydrogenase. A similar enzyme catalyzes the oxidation of 9-cis- and 11-ds-retinol, but not all-trans-retinol again, it has 3a-hydroxysteroid dehydrogenase activity. In the eye, the major product of this enzyme is 11-cts-retinaldehyde, whereas in other tissues it is 9-cts-retinaldehyde, which is then oxidized to 9-cis-retinoic acid (Section 2.3.2.1 Chen et al., 2000 Duester, 2000, 2001 Gamble et al., 2000 NapoU, 2001). Although there is known to be an isomerase in the eye for the formation of 11-cts-retinaldehyde as a... 

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