linoleoyl-CoA desaturase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: (9Z,12Z)-octadecadienoyl-CoA + 2 Fe(II)-[cytochrome b5] + 2 H+ + O2 = (6Z,9Z,12Z)-octadecatrienoyl-CoA + 2 Fe(III)-[cytochrome b5] + 2 H2O. Can also use a substrate with 3 double bonds (a (9Z,12Z,15Z)-octadecatrienoyl-CoA and add a fourth double bond (a (6Z,9Z,12Z,15Z)-octadecatetraenoyl-CoA). [PMID:12713571, PMID:7212717, RHEA:47140, RHEA:47144]

Linoleoyl-CoA desaturase activity is a key enzyme in the biosynthesis of polyunsaturated fatty acids (PUFAs), specifically the conversion of linoleic acid (18:2) to gamma-linolenic acid (18:3). This enzymatic activity is catalyzed by a family of enzymes called fatty acid desaturases, which are integral membrane proteins found in the endoplasmic reticulum. The desaturase reaction involves the introduction of a double bond between the 12th and 13th carbon atoms in the fatty acid chain, with the cis configuration being the preferred outcome. The mechanism of this reaction involves the transfer of electrons from NADH or NADPH to a heme group within the desaturase enzyme. These electrons are subsequently used to activate oxygen molecules, which then oxidize the substrate (linoleoyl-CoA) at the targeted carbon atoms. The desaturation reaction is a complex process that requires several cofactors, including iron, cytochrome b5, and molecular oxygen. The activity of linoleoyl-CoA desaturase is highly regulated and influenced by factors such as dietary intake of PUFAs, hormonal signaling, and the availability of reducing equivalents. The end product of this enzymatic activity, gamma-linolenic acid, is a precursor for the biosynthesis of other important PUFAs, including arachidonic acid, which plays a crucial role in inflammation, cell signaling, and the production of eicosanoids. Linoleoyl-CoA desaturase activity is essential for maintaining lipid homeostasis, cell membrane fluidity, and various physiological functions.'
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Proteins (3)

Compounds (3)