Pyruvate dehydrogenase (E1) (PDH)

Pyruvate dehydrogenase (PDH) is the primary enzyme component (E1) of the mitochondrial pyruvate dehydrogenase complex (PDC), responsible for the rate-limiting step in the conversion of pyruvate to acetyl-CoA (UniProt P08559). By facilitating the oxidative decarboxylation of pyruvate, PDH serves as the critical metabolic bridge between glycolysis in the cytosol and the tricarboxylic acid (TCA) cycle in the mitochondria (StatPearls, 2023). This enzyme requires thiamine pyrophosphate (TPP) as a cofactor and is tightly regulated by phosphorylation and dephosphorylation via PDH kinases (PDKs) and phosphatases (PubMed PMID: 24743563). In many cancers, PDH activity is downregulated to promote the Warburg effect, shifting metabolism toward lactate production even in the presence of oxygen (PMC4129581). Therapeutic strategies often focus on reactivating PDH using inhibitors of its regulatory kinases, such as dichloroacetate, to restore oxidative phosphorylation and induce apoptosis in malignant cells (PubChem CID 260). Additionally, genetic mutations in the PDH E1 alpha subunit are the most common cause of PDH deficiency, leading to severe neurological symptoms and chronic lactic acidosis (NIH GARD).

Other names

Pyruvate decarboxylasePDHE1Pyruvate dehydrogenase (lipoamide)E1 component of the pyruvate dehydrogenase complexPDHA1

Catalyzes the thiamine pyrophosphate (TPP)-dependent oxidative decarboxylation of pyruvate to form a hydroxyethyl-TPP intermediate, followed by the transfer of the acetyl group to the lipoamide cofactor of the E2 subunit.