Pyruvate dehydrogenase complex and Alpha-ketoglutarate dehydrogenase complex (PDC, PDHc, OGDC, α-KGDHC)

Pyruvate dehydrogenase complex (PDC/PDHc) and Alpha-ketoglutarate dehydrogenase complex (OGDC/α-KGDHC) are large mitochondrial multi-enzyme complexes critical for central carbohydrate metabolism. PDC converts pyruvate to acetyl-CoA, linking glycolysis to the citric acid cycle, while OGDC catalyzes the conversion of alpha-ketoglutarate to succinyl-CoA within the citric acid cycle. Both complexes produce NADH, fueling mitochondrial respiration and ATP synthesis. Structurally, they are composed of three main enzymatic subunits (E1, E2, E3), utilize several cofactors (thiamine pyrophosphate, lipoic acid, FAD, NAD^+, CoA), and serve as regulatory hubs in metabolism. Dysfunction in either complex results in energy deficits and contributes to diverse diseases, including metabolic, neurodegenerative, and neoplastic conditions.

Other names

PDCPDH complexE1-E2-E3 (component names)OGDCOGDH complexα-KGDHC2-oxoglutarate dehydrogenase complexα-keto acid dehydrogenase complexes

Activation: Small molecules or cofactors (such as thiamine or dichloroacetate) enhance enzyme activity directly or through kinases/phosphatases regulation. Inhibition: Inhibitors (e.g., phosphorylation by PDH kinases for PDHc, product inhibition by NADH/succinyl-CoA) decrease activity; toxins can block catalytic functions.