beta-Hydroxybutyrate Dehydrogenase from Rhodopseudomonas sphaeroides

Application

Suitable for the determination of acetoacetate and D(-)-3-hydroxybutyrate by the method of Williamson, D. H., and Mellanby, J., Methods of Enzymatic Analysis, Bergmeyer, H., ed., 2nd edition, 4, 1836 (1974).

Biochem/physiol Actions

In mammalian systems, β-hydroxybutyrate dehydrogenase is localized on the inner mitochondrial membrane and requires phosphatidyl choline for activity. In contrast, the enzyme from Rhodopseudomonas is a soluble cytosolic enzyme that does not require a phospholipid allosteric activator. The enzyme is required for the utilization of ketone bodies as a source of metabolic energy. It catalyzes the oxidation of 3-hydroxybutyrate to acetoacetate, the first step in the conversion of ketone bodies to citric acid, which is then further metabolized via the tricarboxylic acid cycle (Krebs cycle).

Unit Definition

One unit will oxidize 1.0 μmole of D-β-hydroxybutyrate to acetoacetate per min at pH 7.8 at 37 °C.

Physical form

Lyophilized powder containing Tris buffer salts