The Enzyme Database

Your query returned 1 entry.    printer_iconPrintable version

Accepted name: sphingolipid 4-desaturase
Reaction: a dihydroceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4E)-sphing-4-enine ceramide + 2 ferricytochrome b5 + 2 H2O
Glossary: a dihydroceramide = an N-acylsphinganine
Other name(s): dehydroceramide desaturase
Systematic name: dihydroceramide,ferrocytochrome b5:oxygen oxidoreductase (4,5-dehydrogenating)
Comments: The enzyme, which has been characterized from plants, fungi, and mammals, generates a trans double bond at position 4 of sphinganine bases in sphingolipids [1]. The preferred substrate is dihydroceramide, but the enzyme is also active with dihydroglucosylceramide [2]. Unlike EC, sphingolipid 8-desaturase, this enzyme does not contain an integral cytochrome b5 domain [4] and requires an external cytochrome b5 [3]. The product serves as an important signalling molecules in mammals and is required for spermatide differentiation [5].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
1.  Stoffel, W., Assmann, G. and Bister, K. Metabolism of sphingosine bases. XVII. Stereospecificities in the introduction of the 4t-double bond into sphinganine yielding 4t-sphingenine (sphingosine). Hoppe-Seylers Z. Physiol. Chem. 352 (1971) 1531–1544. [PMID: 5140816]
2.  Michel, C., van Echten-Deckert, G., Rother, J., Sandhoff, K., Wang, E. and Merrill, A.H., Jr. Characterization of ceramide synthesis. A dihydroceramide desaturase introduces the 4,5-trans-double bond of sphingosine at the level of dihydroceramide. J. Biol. Chem. 272 (1997) 22432–22437. [PMID: 9312549]
3.  Causeret, C., Geeraert, L., Van der Hoeven, G., Mannaerts, G.P. and Van Veldhoven, P.P. Further characterization of rat dihydroceramide desaturase: tissue distribution, subcellular localization, and substrate specificity. Lipids 35 (2000) 1117–1125. [PMID: 11104018]
4.  Ternes, P., Franke, S., Zähringer, U., Sperling, P. and Heinz, E. Identification and characterization of a sphingolipid Δ4-desaturase family. J. Biol. Chem. 277 (2002) 25512–25518. [PMID: 11937514]
5.  Michaelson, L.V., Zäuner, S., Markham, J.E., Haslam, R.P., Desikan, R., Mugford, S., Albrecht, S., Warnecke, D., Sperling, P., Heinz, E. and Napier, J.A. Functional characterization of a higher plant sphingolipid Δ4-desaturase: defining the role of sphingosine and sphingosine-1-phosphate in Arabidopsis. Plant Physiol. 149 (2009) 487–498. [PMID: 18978071]
[EC created 2015]

Data © 2001–2017 IUBMB
Web site © 2005–2017 Andrew McDonald