SuccinylCoAacetoacetate

succinylCoAacetoacetate refers to the metabolic reaction in which succinyl‑CoA transfers its coenzyme‑A moiety to the ketone body acetoacetate to form succinate and acetoacetyl‑CoA. The enzyme catalyzing this conversion is commonly called succinyl‑CoA:acetoacetate CoA transferase or simply succinyl‑CoA acetoacetimate transferase. It belongs to the family of CoA transferases, which facilitate the reversible transfer of coenzyme‑A between different acyl carriers.

The reaction proceeds with succinyl‑CoA donating CoA to acetoacetate, producing succinate—a Krebs cycle intermediate—and acetoacetyl‑CoA, which can undergo subsequent β‑oxidation or condensation to form the ketone body acetone. This enzymatic activity links the citric acid cycle to ketogenesis and ketogenic amino acid catabolism. In organisms that rely heavily on fatty acid oxidation, such as during extended fasting or in diabetes, succinyl‑CoA acetoacetate transferase can play a role in maintaining energy homeostasis by regulating the balance between acetyl‑CoA production and acetate utilization.

The transferase is encoded by genes such as atoDA and is expressed in tissues with high metabolic activity, including liver, kidney, and brain. Mutations or deficiencies affecting this enzyme may impair ketone body utilization and have been associated with metabolic disorders in animal models. Because the product acetoacetyl‑CoA can enter the ketone body synthesis pathway, the activity of succinyl‑CoA acetoacetate transferase is considered a point of metabolic control in the regulation of ketogenesis versus anaplerotic input into the citric acid cycle.

In summary, succinylCoAacetoacetate describes a key enzymatic step that couples the tricarboxylic acid cycle with ketone body metabolism, facilitating cellular energy balance under varying nutritional states.