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.
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]
[EC created 2000 as EC, transferred 2015 to EC]
Transferred entry: Δ12-fatty acid dehydrogenase. Now EC, acyl-lipid Δ12-acetylenase
[EC created 2000, deleted 2015]