|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 1.14.19.m
In Pathway: phospholipid desaturation
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: acyl-lipid ω-3 desaturase (cytochrome b5)
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): -73.37747 [Latendresse13]
Enzyme Commission Summary:
This microsomal enzyme introduces a cis double bond three carbons from the methyl end of a fatty acid incorporated into a glycerlipid. The distance from the carboxylic acid end of the molecule does not have an effect. The plant enzyme acts on carbon 15 of linoleoyl groups incorporated into both the sn,/i>-1 and sn-2 positions of the glycerol backbone of phosphatidylcholine and other phospholipids, converting them into α-linolenoyl groups. The enzyme from the fungus Mortierella alpina acts on γ-linolenoyl and arachidonoyl groups, converting them into stearidonoyl and icosapentaenoyl groups, respectively [Sakuradani05]. cf. EC 1.14.19.j, sn-2 acyl-lipid ω-3 desaturase (ferredoxin).
Browse93: Browse J, McConn M, James D, Miquel M (1993). "Mutants of Arabidopsis deficient in the synthesis of alpha-linolenate. Biochemical and genetic characterization of the endoplasmic reticulum linoleoyl desaturase." J Biol Chem 1993;268(22);16345-51. PMID: 8102138
Sakuradani05: Sakuradani E, Abe T, Iguchi K, Shimizu S (2005). "A novel fungal omega3-desaturase with wide substrate specificity from arachidonic acid-producing Mortierella alpina 1S-4." Appl Microbiol Biotechnol 66(6);648-54. PMID: 15538555
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