EC - Dihydrolipoyl dehydrogenase

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IntEnz Enzyme Nomenclature


Accepted name:
dihydrolipoyl dehydrogenase
Other names:
dehydrolipoate dehydrogenase
dihydrolipoamide dehydrogenase
dihydrolipoamide:NAD+ oxidoreductase
dihydrolipoic dehydrogenase
dihydrothioctic dehydrogenase
lipoamide dehydrogenase (NADH)
lipoamide oxidoreductase (NADH)
lipoamide reductase
lipoamide reductase (NADH)
lipoate dehydrogenase
lipoic acid dehydrogenase
lipoyl dehydrogenase
E3 component of α-ketoacid dehydrogenase complexes
glycine-cleavage system L-protein
protein-6-N-(dihydrolipoyl)lysine:NAD+ oxidoreductase
Systematic name:
protein-N6-(dihydrolipoyl)lysine:NAD+ oxidoreductase




A flavoprotein (FAD). A component of the multienzyme 2-oxo-acid dehydrogenase complexes. In the pyruvate dehydrogenase complex, it binds to the core of EC, dihydrolipoyllysine-residue acetyltransferase, and catalyses oxidation of its dihydrolipoyl groups. It plays a similar role in the oxoglutarate and 3-methyl-2-oxobutanoate dehydrogenase complexes. Another substrate is the dihydrolipoyl group in the H-protein of the glycine-cleavage system, in which it acts, together with EC, glycine dehydrogenase (decarboxylating), and EC, aminomethyltransferase, to break down glycine. It can also use free dihydrolipoate, dihydrolipoamide or dihydrolipoyllysine as substrate. This enzyme was first shown to catalyse the oxidation of NADH by methylene blue; this activity was called diaphorase. The glycine cleavage system is composed of four components that only loosely associate: the P protein (EC, the T protein (EC, the L protein (EC and the lipoyl-bearing H protein [6].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , DIAGRAM , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , NIST 74 , UniPathway
Protein domains and families: PROSITE:PDOC00073
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004148
CAS Registry Number: 9001-18-7
UniProtKB/Swiss-Prot: (81) [show] [UniProt]


  1. Massey, V.
    Lipoyl dehydrogenase.
    In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.) The Enzymes , 2nd ed. vol. 7 , Academic Press , New York , 1963 , 275-306
  2. Massey, V., Gibson, Q.H. and Veeger, C.
    Intermediates in the catalytic action of lipoyl dehydrogenase (diaphorase).
    Biochem. J. 77 : 341-351 (1960). [PMID: 13767908]
  3. Savage, N.
    Preparation and properties of highly purified diaphorase.
    Biochem. J. 67 : 146-155 (1957). [PMID: 13471525]
  4. Straub, F.B.
    Isolation and properties of a flavoprotein from heart muscle tissue.
    Biochem. J. 33 : 787-792 (1939).
  5. Perham, R.N.
    Swinging arms and swinging domains in multifunctional enzymes: catalytic machines for multistep reactions.
    Annu. Rev. Biochem. 69 : 961-1004 (2000). [PMID: 10966480]
  6. Nesbitt, N.M., Baleanu-Gogonea, C., Cicchillo, R.M., Goodson, K., Iwig, D.F., Broadwater, J.A., Haas, J.A., Fox, B.G. and Booker, S.J.
    Expression, purification, and physical characterization of Escherichia coli lipoyl(octanoyl)transferase.
    Protein Expr. Purif. 39 : 269-282 (2005). [PMID: 15642479]

[EC created 1961 as EC, modified 1976, transferred 1983 to EC, modified 2003, modified 2006]