α-ketoglutarate dehydrogenase

α-ke·to·glu·ta·rate de·hy·dro·gen·ase (ke″to-glooґtə-rāt de-hiґdro-jən-ās) an enzyme of the oxidoreductase class that is a component of the multienzyme α-ketoglutarate dehydrogenase complex (q.v.). The enzyme catalyzes the decarboxylation and oxidation of α-ketoglutarate, forming succinyl bound to the cofactor thiamine pyrophosphate; the succinyl is subsequently transferred to the lipoamide linked to the side chain of a lysine residue of the enzyme dihydrolipoyllysine-residue succinyltransferase, which is also part of the complex. Called oxoglutarate dehydrogenase (succinyl-transferring) in EC nomenclature.