NAD(P)H-hydrate epimerase (EC 5.1.99.6, NAD(P)HX epimerase) is an enzyme with systematic name (6R)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide 6-epimerase.^[1] This enzyme catalyses the following chemical reaction

(1) (6R)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide ${\displaystyle \rightleftharpoons }$ (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide

(2) (6R)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate ${\displaystyle \rightleftharpoons }$ (6S)-6beta-hydroxy-1,4,5,6-tetrahydronicotinamide-adenine dinucleotide phosphate

The enzyme can use either (R)-NADH-hydrate or (R)-NADPH-hydrate as a substrate.

• NAD(P)H-hydrate+epimerase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)