IUBMB Enzyme Nomenclature


Accepted name: acyl-lipid Δ12-acetylenase

Reaction: linoleoyl-[glycerolipid] + 2 ferrocytochrome b5 + O2 + 2 H+ = crepenynyl-[glycerolipid] + 2 ferricytochrome b5 + 2 H2O

Glossary: crepenynate = (9Z)-octadec-9-en-12-ynoate

Systematic name: Δ12 acyl-lipid,ferrocytochrome-b5:oxygen oxidoreductase (12,13 dehydrogenating)

Comments: The enzyme, characterized from the plant Crepis alpina, converts the double bond at position 12 of linoleate into a triple bond. The product is the main fatty acid found in triacylglycerols in the seed oil of Crepis alpina.

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


1. Banas, A., Bafor, M., Wiberg, E., Lenman, M., Staahl, U. and Stymne, S. Biosynthesis of an acetylenic fatty acid in microsomal preparations from developing seeds Crepis alpina. Physiol. Biochem. Mol. Biol. Plant. [Proc. Int. Symp. Plant Lipids] 12th (1997) 57-59.

2. Lee, M., Lenman, M., Banas, A., Bafor, M., Singh, S., Schweizer, M., Nilsson, R., Liljenberg, C., Dahlqvist, A., Gummeson, P.O., Sjodahl, S., Green, A. and Stymne, S. Identification of non-heme di-iron proteins that catalyze triple bond and epoxy group formation. Science 280 (1998) 915-918. [PMID: 9572738]

3. Nam, J.W. and Kappock, T.J. Cloning and transcriptional analysis of Crepis alpina fatty acid desaturases affecting the biosynthesis of crepenynic acid. J. Exp. Bot. 58 (2007) 1421-1432. [PMID: 17329262]

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