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 Pseudomonas 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 sucrose and Tris buffer salts

一、贮存

应充氩气密封于0℃以下（粉末）和4℃（悬浮液）保存。