Fatty acid desaturases

Fig. 4. Modification of plant metabolic pathways for the synthesis of poly(3HAMCL) in peroxisomes. The pathways created or enhanced by the expression of transgenes (P. aeruginosa PHA synthase and C. lanceolata decanoyl-ACP thioesterase) and of mutant alleles of plant fatty acid desaturase genes are highlighted by bold arrows and the enzymes involved underlined...

This enzyme [EC 1.14.99.5], also known as stearoyl-CoA desaturase, fatty acid desaturase, and A -desaturase, will catalyze the reaction of stearoyl-CoA with a hydrogen donor and dioxygen to produce oleoyl-CoA, water, and... 

CN197 Eder, K., and M. Kirchgessner. Activities of liver microsomal fatty acid desaturases in zinc-deficient rats force-fed diets with a coconut oil/safflower oil mixture of linseed oil. Biol Trace Elem Res 1995 48(3) 215-229. 

Other enzymes that are not obviously related to the dioxygenases have at least superficially similar metal sites. The fatty acid desaturase of the endoplasmic reticuluum is a nonheme iron protein and requires both oxygen and reducing equivalents for activity (Strittmatter and Enoch, 1978). It is not known whether this enzyme forms a nitroxyl complex, but rat liver microsomes containing the enzyme form an S = nitroxyl adduct when treated with nitrite and dithionite. 

NADH NADH-cyt bs reductase (fp), cyt. bs (Hp) NHI Liver microsomal fatty acid desaturase 33 — 35)... 

A group of related bacterial enzymes hydroxylate alkanes,507 toluene,508 phenol,509 and other substrates.5093 Eukaryotic fatty acid desaturases (Fig. 16-20B) belong to the same family.508 Some bacteria use cytochrome P450 or other oxygenase to add an oxygen atom to an alkene to form an epoxide. For example, propylene... 

Stukey J. E., McDonough V. M. and Martin C. E., (1990) The OLE1 gene of Saccharomyces cerevisiae encodes the A9 fatty acid desaturase and can be functionally replaced by the rat stearoyl-CoA desaturase gene. J. Biol. Chem. 265, 20144-20149. 

Wicker-Thomas C., Henriet C. and Dallerac R. (1997) Partial characterization of a fatty acid desaturase gene in Drosophila melanogaster. Insect Biochem. Molec. Biol. 27, 963-972. 

Figure 4.1 Cytogenetic localization of desaturase and elongase sequences in D. melanogaster. The four chromosomes are numbered with roman figures on the left. The arabic numbers on the chromosomes indicate the cytological positions. Arrows show the localizations of desaturases and elongases. Sixteen elongases and seven fatty acid desaturases are located on chromosome III. Three elongases, 1 sphingolipid deltas desaturase and two other putative desaturases are located on chromosome II.

Additionally, the study demonstrated that there are fatty acid metabolism genes that were positively associated with lovastatin production and tended to encode catabolic enzymes that are predicted to promote formation of the polyketide precursors acetyl-CoA and malonyl-CoA, whereas fatty acid metabolism genes that are negatively associated with secondary metabolite production encode anabolic enzymes, i.e., acyl-CoA oxidase, fatty acid desaturase, and fatty acid synthases. 

F26BP, fructose-2,6-bisphosphate FA, fatty acid FAD, fatty acid desaturase FADH2/FAD, reduced/oxidized flavin adenine dinucleotide F -ATPase, ATP synthetase F complex FGF, fibroblast growth factor FGF-RTK, fibroblast growth factor receptor tyrosine kinase Fmet, formylmethionine FMNH2/FMN, reduced/oxidized flavin mononucleotide... 

Infante JP (1999) A function for the vitaminE metabolite alpha-tocopherol quinone as an essential enzyme cofactor for the mitochondrial fatty acid desaturases. FEES letters 446, 1-5. 

In white winemaking, Saccharomyces cerevisiae must develop at low temperature, which reduces membrane fluidity. To maintain adequate fluidity in their membranes, yeasts increase the proportion of UFA in the phospholipids (Thurston et al. 1981 Torrija et al. 2003). Phospholipids with unsaturated fatty acids have a lower melting point and more flexibility than phospholipids with saturated acyl chains (Rodriguez et al. 2007). Such adaptation involves inducing the fatty acid desaturase OLEl which incorporate unsaturated bonds at defined positions in fatty acids (Nakagawa et al. 2002). 

Figure 1 Role of fatty acid desaturases in the biosynthesis of unsaturated fatty acids Typical fatty acids found as components of cell membranes and storage lipids (a) signaling agents (b) and plant-derived antifeedants (c).

Buist PH. Fatty acid desaturases selecting the dehydrogenation channel. Nat. Prod. Rep. 2004 21 249-262. 

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