Branched-chain α-keto acid dehydrogenase complex (BCKDC)

The branched-chain α-keto acid dehydrogenase complex (BCKDC) is a large mitochondrial multienzyme complex responsible for the irreversible oxidative decarboxylation of branched-chain α-ketoacids, derived from the essential amino acids leucine, isoleucine, and valine. It consists of multiple copies of three catalytic subunits: E1 (branched-chain α-keto acid decarboxylase), E2 (dihydrolipoyl transacylase), and E3 (dihydrolipoamide dehydrogenase), and associated regulatory kinases and phosphatases. The complex is crucial for normal amino acid catabolism and energy production—defects cause maple syrup urine disease, a severe metabolic disorder. BCKDC is considered a potential therapeutic target for the management of metabolic disorders involving branched-chain amino acid catabolism[1][2][3][4][5].

Other names

Branched-chain α-ketoacid dehydrogenase complexBCKDH complexBCKDHcBranched-chain α-keto acid dehydrogenaseBranched-chain keto acid dehydrogenase complexBCKD enzyme complex

Thiamine as enzymatic cofactor facilitates decarboxylation; Inhibitors block enzyme activity or its regulatory kinase (potential research application; no approved BCKDC inhibitors for clinical use)