Properties of the soluble arachidonic acid 15-lipoxygenase and 15-hydroperoxide isomerase from the oomycete Saprolegnia parasitica.
The soluble hydroperoxide isomerase and 15-lipoxygenase activities were partially purified from the oomycete Saprolegnia parasitica and some of their properties characterized. Both enzymes co-eluted with a molecular weight of 145,000-150,000 on Sephacryl S-300 chromatography. The enzyme activities also co-eluted on DEAE Sephadex ion exchange chromatography and hydroxylapatite chromatography. Both activities showed similar responses to pH and temperature. Both enzymes showed parallel inhibition by p-hydroxymercuribenzoate and eicosatetraynoic acid. The partially purified hydroperoxide isomerase showed an apparent km of 166 microM and a Vmax of 5.3 mumol/min/mg protein for exogenous 15-HPETE. It was not stimulated by calcium. These results suggest that the soluble hydroperoxide isomerase and 15-lipoxygenase activities from S. parasitica are both contained on the same protein or protein complex.
Department of Biology, New Mexico State University, Las Cruces 88003.
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D001093:Arachidonate 15-Lipoxygenase / Q000302:isolation & purification*; D001091:Arachidonate Lipoxygenases / Q000302:isolation & purification*; D002845:Chromatography / Q000379:methods; D008411:Chytridiomycota / Q000201:enzymology*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D019746:Intramolecular Oxidoreductases; D007535:Isomerases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D016859:Lipoxygenase Inhibitors; D009868:Oomycetes / Q000201:enzymology*
D016859:Lipoxygenase Inhibitors; D001091:Arachidonate Lipoxygenases; D001093:Arachidonate 15-Lipoxygenase; D007535:Isomerases; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase