IUBMB Enzyme Nomenclature


Accepted name: short-chain 2-methylacyl-CoA dehydrogenase

Reaction: 2-methylbutanoyl-CoA + electron-transfer flavoprotein = (E)-2-methylbut-2-enoyl-CoA + reduced electron-transfer flavoprotein + H+

Other name(s): ACADSB (gene name); 2-methylacyl-CoA dehydrogenase; branched-chain acyl-CoA dehydrogenase (ambiguous); 2-methyl branched chain acyl-CoA dehydrogenase; 2-methylbutanoyl-CoA:(acceptor) oxidoreductase; 2-methyl-branched-chain-acyl-CoA:electron-transfer flavoprotein 2-oxidoreductase; 2-methyl-branched-chain-enoyl-CoA reductase

Systematic name: short-chain 2-methylacyl-CoA:electron-transfer flavoprotein 2-oxidoreductase

Comments: A flavoprotein (FAD). The mammalian enzyme catalyses an oxidative reaction as a step in the mitochondrial β-oxidation of short-chain 2-methyl fatty acids and participates in isoleucine degradation. The enzyme from the parasitic helminth Ascaris suum catalyses a reductive reaction as part of a fermentation pathway, shuttling reducing power from the electron-transport chain to 2-methyl branched-chain enoyl CoA.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Ikeda, Y., Dabrowski, C. and Tanaka, K. Separation and properties of five distinct acyl-CoA dehydrogenases from rat liver mitochondria. Identification of a new 2-methyl branched chain acyl-CoA dehydrogenase. J. Biol. Chem. 258 (1983) 1066-1076. [PMID: 6401712]

2. Komuniecki, R., Fekete, S. and Thissen-Parra, J. Purification and characterization of the 2-methyl branched-chain acyl-CoA dehydrogenase, an enzyme involved in NADH-dependent enoyl-CoA reduction in anaerobic mitochondria of the nematode, Ascaris suum. J. Biol. Chem. 260 (1985) 4770-4777. [PMID: 3988734]

3. Komuniecki, R., McCrury, J., Thissen, J. and Rubin, N. Electron-transfer flavoprotein from anaerobic Ascaris suum mitochondria and its role in NADH-dependent 2-methyl branched-chain enoyl-CoA reduction. Biochim. Biophys. Acta 975 (1989) 127-131. [PMID: 2736251]

4. Vockley, J., Mohsen al,-W., A., Binzak, B., Willard, J. and Fauq, A. Mammalian branched-chain acyl-CoA dehydrogenases: molecular cloning and characterization of recombinant enzymes. Methods Enzymol. 324 (2000) 241-258. [PMID: 10989435]

5. Andresen, B.S., Christensen, E., Corydon, T.J., Bross, P., Pilgaard, B., Wanders, R.J., Ruiter, J.P., Simonsen, H., Winter, V., Knudsen, I., Schroeder, L.D., Gregersen, N. and Skovby, F. Isolated 2-methylbutyrylglycinuria caused by short/branched-chain acyl-CoA dehydrogenase deficiency: identification of a new enzyme defect, resolution of its molecular basis, and evidence for distinct acyl-CoA dehydrogenases in isoleucine and valine metabolism. Am. J. Hum. Genet. 67 (2000) 1095-1103. [PMID: 11013134]

[EC created 1992 as EC, transferred 2012 to EC (EC, created 1986, incorporated 2020), modified 2020]

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