Polyunsaturated fatty peroxidase

Kaplan E. and Ansari K. (1984). Reduction of polyunsaturated fatty acid hydroperoxides by human brain glutathione peroxidase. Lipids 19 784-789. 

As mentioned above, manganese peroxidase was unable to oxidize 2,7-dichloro-dibenzo-p-dioxin. Nevertheless, in the presence of polyunsaturated fatty acids, manganese peroxidase is able to form adducts with 2,7-dichlorodibenzo-p-dioxin [119]. 

Harazono K, Watanabe Y, Fukatsu T et al (2003) Trapping of 2, 7-dichlorodibenzo-p-dioxin in aqueous solution by enzymatic reaction of fungal manganese peroxidase in the presence of polyunsaturated fatty acids. Curr Microbiol 47 250-254... 

The eicosanoids are locally active hormones (autocoids) that are derived from precursor polyunsaturated fatty acids. The rate-limiting step in the synthesis of eicosanoids is the phospholipase-regulated release of arachidonic add from membranes. Arachi-donic acid metabolism may follow one of three possible pathways. In the first, the cydooxygenase- peroxidase pathway leads to the formation of the prostenoids - prostaglandins and thromboxanes. In the second, the lipoxygenase pathway yields the leuko-trienes and lipoxins. A third pathway, the cytochrome P-450 mono oxygenase pathway is also involved in the metabolism of arachidonic add. 

Yamauchi, K., Yada, K., Ohashi, T. and Pearson, A.M. (1984b) The interrelationship between polyunsaturated fatty acids, a-tocopherol and glutathione peroxidase in chicken and porcine skeletal muscles. Agric. Biol. Chem. 48, 2831-2832. 

Polyunsaturated fats from vegetable oils—A diet rich in polyunsaturated fatty acids (PUFA) but poor in vitamin E might raise the requirement for selenium because (1) PUFA may be readily converted to toxic peroxides by various metabolic processes unless there is sufficient vitamin E to prevent this conversion, and (2) selenium is needed to activate the enzyme (gluthathione peroxidase) which destroys the peroxides. 

Figure 5 The integrated antioxidant defense system comprises both endogenous and dietary-derived antioxidants. GR, glutathione reductase (EC1.6.4.2) GSH, reduced glutathione GSH-Px, glutathione peroxidase (EC1.11.1.9) GSSG, oxidized glutathione GST, glutathione-S-transferase (EC 2.5.1.18) MSR, methionine sulfoxide reductase (EC1.8.4.5) NADPH and, NADP, are, respectively, the reduced and oxidized forms of the co-factor nicotinamide adenine dinucleotide phosphate PUFA, polyunsaturated fatty acid S-AA, sulfur amino-adds SH, sulfydryl SOD, superoxide dismutase (EC1.15.1.1).

Ritov, V.B., Menshikova, E.V, Goldman, R. Kagan, VE. (1996) Direct oxidation of polyunsaturated cA-parinaric fatty acid by phenoxyl radicals generated by peroxidase/H2O2 in model systems and in HL-60 cells. Toxicol. Lett., 87, 121-129... 

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