3-hydroxybutyrate dehydrogenase

3-Hydroxybutyrate dehydrogenase is an enzyme that catalyzes the oxidation of 3-hydroxybutyrate, a type of ketone body, to acetoacetate. This reaction is a key step in the metabolic pathway of ketone bodies, which are important energy sources for the body, particularly during periods of fasting or intense exercise.

Function

The primary function of 3-hydroxybutyrate dehydrogenase is to convert 3-hydroxybutyrate to acetoacetate in the mitochondria of liver cells. This reaction is reversible, meaning that the enzyme can also catalyze the reduction of acetoacetate to 3-hydroxybutyrate. The direction of the reaction depends on the relative concentrations of the reactants and products.

Structure

3-Hydroxybutyrate dehydrogenase is a dimeric enzyme, meaning it is composed of two identical subunits. Each subunit contains a catalytic site where the reaction takes place, as well as a binding site for NAD+, a coenzyme that is necessary for the reaction to occur.

Clinical significance

Deficiencies in 3-hydroxybutyrate dehydrogenase can lead to a buildup of 3-hydroxybutyrate in the body, which can result in a condition known as ketosis. This can cause a variety of symptoms, including nausea, fatigue, and in severe cases, coma or death.

See also

• Ketone bodies
• Ketosis
• Metabolism