3-hydroxy-3-methylglutaryl-CoA -->
beta-hydroxy-beta-methylglutaryl-CoA
medical dictionary

-OOCCH2C(OH)(CH3)CH2COS-CoA;a key intermediate in the synthesis of ketone bodies and of steroids.

Synonyms: 3-hydroxy-3-methylglutaryl-CoA.

Beta-hydroxy-beta-methylglutaryl-lyase, an enzyme, found primarily in liver and rumen epithelium that catalyses the formation of acetyl-CoA and acetoacetate from beta-hydroxy-beta-methylglutaryl-CoA; a key step in ketogenesis; a deficiency of this enzyme leads to episodes of severe metabolic acidosis without ketosis.

Beta-hydroxy-beta-methylglutaryl-reductase, an enzyme that catalyses the rate-limiting step of cholesterol biosynthesis, beta-hydroxy-beta-methylglutaryl-CoA + 2NADPH + 2H+ → mevalonate + 2NADP+ + coenzyme A.

Beta-hydroxy-beta-methylglutaryl-synthase, an enzyme in mitochondria that catalyses the reaction of acetyl-CoA with acetoacetyl-CoA and water to form beta-hydroxy-beta-methylglutaryl-CoA and coenzyme A, a step required for both ketogenesis and steroidogenesis to occur.

Abbreviation: HMG-CoA

(05 Mar 2000)