ARACHIDONATE 12-LIPOXYGENASE OF PORCINE LEUKOCYTE WITH ACTIVITY FOR 5-HYDROXYEICOSATETRAENOIC ACID

  • 1 January 1982
    • journal article
    • research article
    • Vol. 713  (3) , 638-646
Abstract
When arachidonic acid was incubated with porcine polymorphonuclear leukocytes, 12-hydroxy-5,8,10,14-eicosatetraenoic acid was produced as a major product. The production of this compound was not accounted for by contaminating platelets known to contain arachidonate 12-lipoxygenase. The enzyme sas found predominantly in a cytosol fraction of leukocytes, and the cytosolic enzyme was purified .apprx. 30-fold by ammonium sulfate fractionation and DEAE-Sephadex column chromatography. The partially purified enzyme transformed arachidonic acid to a compound which was identified as 12-hydroperoxy-5,8,10,14-eicosatetraenoic acid. 5-Hydroxy-6,8,11,14-eicosatetraenoic acid as substrate was .apprx. 40% as active as arachidonic acid and the reaction was inhibited by the addition of arachidonic acid. The reaction product which was further reduced by sodium borohydride was indistinguishable from authentic 5S,12S-dihydroxy-(E,Z,E,Z)-6,8,10,14-eicosatetraenoic acid.