title: Purification and characterization of lipoxygenase from Pleurotus ostreatus.
abstract: Lipoxygenase was purified homogeneously from cups of Pleurotus ostreatus by Sephacryl S-400 HR gel filtration, Dyematrex Green A affinity, and DEAE-Toyopearl 650M ion-exchange chromatographies. The molecular weight of the enzyme was estimated to be 67,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 66,000 by gel filtration; the isoelectric point was pH 5.1. The optimum pH and temperature of the enzymatic activity were 8.0 and 25 degrees C, respectively. The enzyme contained non-heme iron, and a thiol group seemed to be involved in its activity. The K(m), V(max), and k(cat) values of the enzyme for linoleic acid were 0.13 mM, 23.4 micromol.min(-1).mg(-1), and 25.7 s(-1), respectively. The enzyme showed high specificity toward linoleic acid. When linoleic acid was incubated with the enzyme, 13-hydroperoxy-9Z,11E-octadecadienoic acid was found to be the main oxidative product.
authors.affiliation: Graduate School of Science and Technology and Faculty of Agriculture, Niigata University, Ikarashi 2-8050 Niigata, Niigata 950-2181, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuribayashi
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kaise
authors.forename: Chiharu
authors.initials: C
authors.lastname: Uno
authors.forename: Takashi
authors.initials: T
authors.lastname: Hara
authors.forename: Toshiro
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Joh
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D004795:Enzyme Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008084:Lipoxygenase / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D020076:Pleurotus / Q000201:enzymology*; D013816:Thermodynamics
chemical_list: D008084:Lipoxygenase