Oxygenation of phosphatidylcholine by human polymorphonuclear leukocyte 15-lipoxygenase

A cell-free human polymorphonuclear leukocyte preparation containing both 15- and 5-lipoxygenase activities was found to oxygenate phosphatidylcholine at carbon-15 of the arachidonic acid moiety. No oxygenation at carbon-5 was found. Under similar incubation conditions, soybean and rabbit reticulocyte 15-lipoxygenases also oxygenated phosphatidylcholine, whereas rat basophilic leukemia cell 5-lipoxygenase, rabbit platelet 12-lipoxygenase and rat liver cytochrome P-450 preparations did not. Our results suggest that the oxygenation of phospholipids may be a unique property of the 15-lipoxygenases.