In enzymology, a branched-chain-2-oxoacid decarboxylase (EC 4.1.1.72) is an enzyme that catalyzes the chemical reaction
- (3S)-3-methyl-2-oxopentanoate 2-methylbutanal + CO2
Hence, this enzyme has one substrate, (3S)-3-methyl-2-oxopentanoate, and two products, 2-methylbutanal and CO2.
This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is (3S)-3-methyl-2-oxopentanoate carboxy-lyase (2-methylbutanal-forming). Other names in common use include branched-chain oxo acid decarboxylase, branched-chain alpha-keto acid decarboxylase, branched-chain keto acid decarboxylase, BCKA, and (3S)-3-methyl-2-oxopentanoate carboxy-lyase.