D-Beta-Hydroxybutyrate Dehydrogenase Mitochondrial (BDH) is a member of the short-chain dehydrogenases/reductases (SDR) family. BDH is localized in the mitochondrion matrix. BDH forms a homotetrameric lipid-requiring enzyme of the mitochondrial membrane and has a specific necessity for phosphatidylcholine for optimal enzymatic activity. BDH catalyzes the interconversion of acetoacetate and (R)-3-hydroxybutyrate, the 2 main ketone bodies formed during fatty acid catabolism.