IUBMB Enzyme Nomenclature


Accepted name: acyl-CoA 6-desaturase

Reaction: (1) linoleoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = γ-linolenoyl-CoA + 2 ferricytochrome b5+ 2 H2O
(2) α-linolenoyl-CoA + 2 ferrocytochrome b5 + O2 + 2 H+ = stearidonoyl-CoA + 2 ferricytochrome b5+ 2 H2O

Other name(s): Δ6-desaturase; Δ6-fatty acyl-CoA desaturase; Δ6-acyl CoA desaturase; fatty acid Δ6-desaturase; fatty acid 6-desaturase; linoleate desaturase; linoleic desaturase; linoleic acid desaturase; linoleoyl CoA desaturase; linoleoyl-coenzyme A desaturase; long-chain fatty acid Δ6-desaturase; linoleoyl-CoA,hydrogen-donor:oxygen oxidoreductase; linoleoyl-CoA desaturase; FADS2 (gene name)

Systematic name: acyl-CoA,ferrocytochrome b5:oxygen oxidoreductase (6,7 cis-dehydrogenating)

Comments: An iron protein. The enzyme introduces a cis double bond at carbon 6 of acyl-CoAs. It is a front-end desaturase, introducing the new double bond between a pre-existing double bond and the carboxyl-end of the fatty acid. The human enzyme has a broad substrate range. It also acts on palmitoyl-CoA, generating sapienoyl-CoA [4], and on (9Z,12Z,15Z,18Z,21Z)-tetracosa-9,12,15,18,21-pentaenoyl-CoA, converting it to (6Z,9Z,12Z,15Z,18Z,21Z)-tetracosa-6,9,12,15,18,21-hexaenoyl-CoA as part of a pathway that produces docosahexaenoate [3]. The enzyme contains a cytochrome b5 domain that is assumed to act in vivo as the electron donor to the active site of the desaturase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9082-66-0


1. Okayasu, T., Nagao, M., Ishibashi, T. and Imai, Y. Purification and partial characterization of linoleoyl-CoA desaturase from rat liver microsomes. Arch. Biochem. Biophys. 206 (1981) 21-28. [PMID: 7212717]

2. Cho, H.P., Nakamura, M.T. and Clarke, S.D. Cloning, expression, and nutritional regulation of the mammalian Δ-6 desaturase. J. Biol. Chem. 274 (1999) 471-477. [PMID: 9867867]

3. Sprecher, H. Metabolism of highly unsaturated n-3 and n-6 fatty acids. Biochim. Biophys. Acta 1486 (2000) 219-231. [PMID: 10903473]

4. Ge, L., Gordon, J.S., Hsuan, C., Stenn, K. and Prouty, S.M. Identification of the Δ-6 desaturase of human sebaceous glands: expression and enzyme activity. J. Invest. Dermatol. 120 (2003) 707-714. [PMID: 12713571]

5. Domergue, F., Abbadi, A., Zähringer, U., Moreau, H. and Heinz, E. In vivo characterization of the first acyl-CoA Δ6-desaturase from a member of the plant kingdom, the microalga Ostreococcus tauri. Biochem. J. 389 (2005) 483-490. [PMID: 15769252]

[EC created 1986 as EC, transferred 2000 to EC, modified 2015]

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