Purification of lipoxygenase and hydroperoxide dehydrase in flaxseeds: interaction between these enzymatic activities

We have purified two enzymic activities from flaxseed acetone powder: a lipoxygenase and a hydroperoxide dehydrase. The lipoxygenase activity belongs to an iron-containing protein having a molecular weight of 130 kDa which, upon incubation with alpha-linolenic acid, forms 13-hydroperoxy-9(Z), 11(E), 15(Z)- octadecatrienoic acid. The hydroperoxide dehydrase (a 55 kDa protein) metabolizes this hydroperoxide to an allene oxide which in turn is spontaneously hydrolyzed to alpha- and gamma-ketols. Relationships between these two enzymes were studied and results suggest an inhibition of the lipoxygenase by hydroperoxide dehydrase.