Arachidonate 12-lipoxygenase

Arachidonate 12-lipoxygenase (EC 1.13.11.31) is an enzyme that catalyzes the chemical reaction

arachidonate + O₂ (5Z,8Z,10E,14Z)-(12S)-12-hydroperoxyicosa-5,8,10,14-tetraenoate

Thus, the two substrates of this enzyme are arachidonate and oxygen, whereas its product is (5Z,8Z,10E,14Z)-(12S)-12-hydroperoxyicosa-5,8,10,14-tetraenoate.

This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O₂ as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O₂. The systematic name of this enzyme class is arachidonate:oxygen 12-oxidoreductase. Other names in common use include Delta12-lipoxygenase, 12-lipoxygenase, 12Delta-lipoxygenase, C-12 lipoxygenase, 12S-lipoxygenase, leukotriene A4 synthase, and LTA4 synthase. This enzyme participates in arachidonic acid metabolism. At least one compound, 3-methoxytropolone is known to inhibit this enzyme.

References

• Hamberg M, Samuelsson B (1974). "Prostaglandin endoperoxides. Novel transformations of arachidonic acid in human platelets". Proc. Natl. Acad. Sci. U.S.A. 71 (9): 3400–4. doi:10.1073/pnas.71.9.3400. PMC 433780. PMID 4215079. 
• Nugteren DH (1975). "Arachidonate lipoxygenase in blood platelets". Biochim. Biophys. Acta 380 (2): 299–307. doi:10.1016/0005-2760(75)90016-8. PMID 804329. 
• Wallach DP, Brown VR (1981). "A novel preparation of human platelet lipoxygenase. Characteristics and inhibition by a variety of phenyl hydrazones and comparisons with other lipoxygenases". Biochim. Biophys. Acta 663 (2): 361–72. doi:10.1016/0005-2760(81)90165-x. PMID 6783111.