Acetyl-CoA acetyltransferase (ACAT (commonly used for the gene family and enzyme), sometimes specified as ACAT1 for the mitochondrial isoform)

Acetyl-CoA acetyltransferase (ACAT) is an essential enzyme that catalyzes the reversible condensation of two acetyl-CoA molecules to form acetoacetyl-CoA and coenzyme A. This reaction is pivotal in the metabolic pathways for ketone body synthesis, fatty acid β-oxidation, and cholesterol/isoprenoid biosynthesis. The enzyme exists in multiple isoforms, including mitochondrial and cytosolic, encoded in humans by the ACAT1 and ACAT2 genes. Dysfunction or inherited deficiency leads to metabolic disorders such as beta-ketothiolase deficiency. As an acyltransferase, it operates at a key junction in cellular energy and lipid metabolism and is a prospective target in diseases involving metabolic dysregulation.

Other names

Acetoacetyl-CoA thiolaseAcetyl-CoA C-acetyltransferaseAcetyl coenzyme A acetyltransferaseAcetyl-CoA:acetyl-CoA C-acetyltransferaseThiolase IIBeta-acetoacetyl-CoA thiolaseACAT (gene/protein)ACAT1 (mitochondrial human isoform)

Competitive or allosteric inhibition/blockade of enzyme active site, preventing Claisen condensation or thiolytic cleavage of acetyl-CoA or acetoacetyl-CoA. Substrate analogs that block enzyme turnover.