Retinol Dehydrogenase

Retinol Dehydrogenase

In enzymology, a retinol dehydrogenase (RDH) (EC 1.1.1.105) is an enzyme that catalyzes the chemical reaction

retinol + NAD+ retinal + NADH + H+

Sometimes, in addition to or along with NAD+, NADP+ can act as a preferred cofactor in the reaction as well. The substrate of the enzyme can be all-trans- or -cis- retinol. There are at least over 20 different isolated enzymes with RDH activity to date. Thus, the two substrates of this enzyme are retinol and NAD+, whereas its 3 products are retinal, NADH (or NADPH in the case where NADP+ is a cofactor), and H+.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is retinol:NAD+ oxidoreductase. Other names in common use include retinol (vitamin A1) dehydrogenase, MDR, microsomal retinol dehydrogenase, all-trans retinol dehydrogenase, retinal reductase, and retinene reductase. This enzyme participates in retinol metabolism. Occasionally, the literature refers to retinol dehydrogenase as an enzyme that oxidizes retinol in general, such as class IV alcohol dehydrogenase (ADH4), which reportedly is the most efficient retinol oxidation in the human alcohol dehydrogenase (ADH) family.