IUBMB Enzyme Nomenclature


Accepted name: very-long-chain acyl-lipid ω-9 desaturase

Reaction: (1) 1-hexacosanoyl-2-acyl-[phosphoglycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = 1-[(17Z)-hexacos-17-enoyl]-2-acyl-[phosphoglycerolipid] + 2 ferricytochrome b5 + 2 H2O
(2) 1-tetracosanoyl-2-acyl-[phosphoglycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = 1-[(15Z)-tetracos-15-enoyl]-2-acyl-[phosphoglycerolipid] + 2 ferricytochrome b5 + 2 H2O

Other name(s): ADS2 (gene name)

Systematic name: very-long-chain acyl-[glycerolipid],ferrocytochrome b5:oxygen oxidoreductase (ω98-cis-dehydrogenating)

Comments: The enzyme, characterized from the plant Arabidopsis thaliana, acts on both 24:0 and 26:0 fatty acids, introducing a cis double bond at a position 9 carbons from the methyl end. These very-long-chain fatty acids are found as a minor component of seed lipids, but also in the membrane phosphatidylethanolamine and phosphatidylserine, in sphingolipids, as precursors and components of cuticular and epicuticular waxes, and in suberin.

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


1. Fukuchi-Mizutani, M., Tasaka, Y., Tanaka, Y., Ashikari, T., Kusumi, T. and Murata, N. Characterization of δA9 acyl-lipid desaturase homologues from Arabidopsis thaliana. Plant Cell Physiol 39 (1998) 247-253. [PMID: 9559566]

2. Smith, M.A., Dauk, M., Ramadan, H., Yang, H., Seamons, L.E., Haslam, R.P., Beaudoin, F., Ramirez-Erosa, I. and Forseille, L. Involvement of Arabidopsis acyl-coenzyme A desaturase-like2 (At2g31360) in the biosynthesis of the very-long-chain monounsaturated fatty acid components of membrane lipids. Plant Physiol. 161 (2013) 81-96. [PMID: 23175755]

[EC created 2018]

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