title: Visible spectrophotometric assay, purification, and molecular properties of a lipoxygenase from eggplant (Solanum melongena Linne) fruits.
abstract: We purified a lipoxygenase to homogeneity from eggplant (Solanum melongena Linne) fruits employing the established visible spectrophotometric assay, in which the products of the lipoxygenase-catalyzed reaction, hydroperoxyfatty acids, oxidizes 2,2'-azino-di-[3-ethylbenzothiazoline-(6)-sulfonic acid] diammonium salt in the presence of a catalyst cytochrome c to yield chromophores in the visible region. This allowed for the rapid detection of the lipoxygenase activity and was helpful in accomplishing the efficient purification of the lipoxygenase. The purified lipoxygenase was a monomeric enzyme with a molecular weight of 95,000, s20,w of 5.3 S, and an isoelectric point of 4.4. The specific activity and Km value for the linoleate oxygenation were 7.8 mumol min-1 mg-1 and 0.8 mM, respectively, at 25 degrees C and pH 7.0. The enzyme contained 1.3 g-atom of nonheme iron per enzyme.
authors.affiliation: Department of Nutritional Physiology, Faculty of Nutrition, Kobe Gakuin University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakayama
authors.forename: Y
authors.initials: Y
authors.lastname: Takeura
authors.forename: T
authors.initials: T
authors.lastname: Ueda
mesh_terms: D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D007202:Indicators and Reagents; D007501:Iron / Q000032:analysis; D007525:Isoelectric Focusing; D007700:Kinetics; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008084:Lipoxygenase / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D013053:Spectrophotometry / Q000379:methods; D014675:Vegetables / Q000201:enzymology*
chemical_list: D007202:Indicators and Reagents; D008041:Linoleic Acids; D019787:Linoleic Acid; D007501:Iron; D008084:Lipoxygenase