In enzymology, a 3-hydroxybutyrate dehydrogenase (EC 220.127.116.11) is an enzyme that catalyzes the chemical reaction
- (R)-3-hydroxybutanoate + NAD+ acetoacetate + NADH + H+
Thus, the two substrates of this enzyme are (R)-3-hydroxybutanoate and NAD+, whereas its three products are acetoacetate, NADH, and H+.
This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (R)-3-hydroxybutanoate:NAD+ oxidoreductase. Other names in common use include NAD+-beta-hydroxybutyrate dehydrogenase, hydroxybutyrate oxidoreductase, beta-hydroxybutyrate dehydrogenase, D-beta-hydroxybutyrate dehydrogenase, D-3-hydroxybutyrate dehydrogenase, D-(–)-3-hydroxybutyrate dehydrogenase, beta-hydroxybutyric acid dehydrogenase, 3-D-hydroxybutyrate dehydrogenase, and beta-hydroxybutyric dehydrogenase. This enzyme participates in synthesis and degradation of ketone bodies and butanoate metabolism.
As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1WMB and 1X1T.