Thiamine-dependent decarboxylase (TPP-dependent decarboxylase)

Thiamine-dependent decarboxylases are a vital group of enzymes that utilize thiamine pyrophosphate (TPP) as a cofactor to catalyze the cleavage of carbon-carbon bonds adjacent to a carbonyl group, primarily in alpha-keto acids (UniProt). This class includes essential metabolic enzymes such as the E1 subunits of the pyruvate dehydrogenase (PDH), alpha-ketoglutarate dehydrogenase (KGDH), and branched-chain alpha-keto acid dehydrogenase (BCKDH) complexes (PubMed). These enzymes serve as critical metabolic hubs, linking glycolysis, the tricarboxylic acid (TCA) cycle, and amino acid catabolism to energy production (StatPearls). Dysregulation or genetic mutations in these enzymes are associated with severe clinical conditions, including maple syrup urine disease, Leigh syndrome, and various forms of lactic acidosis (NIH). Furthermore, because certain thiamine-dependent enzymes are unique to or significantly different in pathogens, they are explored as targets for antimicrobial and antiparasitic therapies (PubMed). Pharmacological intervention typically involves thiamine supplementation to restore activity or the use of antimetabolites and transition-state analogs to inhibit enzymatic function in cancer or infectious diseases (PubChem).

Other names

2-oxoacid decarboxylaseThiamine pyrophosphate-dependent decarboxylaseAlpha-keto acid decarboxylaseTPP-dependent enzyme

Cofactor supplementation, competitive inhibition of thiamine pyrophosphate binding, or transition-state analog inhibition of the decarboxylation step.