DLD (Dihydrolipoamide dehydrogenase), also known as GCSL (glycine cleavage system L protein), is a component of the glycine cleavage system as well as of the alpha ketoacid dehydrogenase complexes. DLD is a flavin-dependent oxidoreductase and functions as a component of the α-keto acid dehydrogenase, the pyruvate dehydrogenase, the α-ketoglutarate dehydrogenase, the branched-chain α-keto acid dehydrogenase and as the L protein in the mitochondrial glycine cleavage system.