title: Biochemical and immunochemical evidences for the presence of lipoxygenase in plant mitochondria.
abstract: In this paper, both biochemical and immunochemical evidence for the presence of lipoxygenase (LOX) in plant mitochondria is presented. Highly purified pea (Pisum sativum L., cv. Alaska) mitochondria show LOX activity, evaluated as conjugated diene formation, oxygen consumption, and hydroperoxide formation. Both 9- and 13-hydroperoxy-octadecadienoic acids are produced by the oxidation of linoleic acid. LOX activity is particularly evident in swollen mitochondria; it is inhibited by nordihydroguaiaretic acid, a pea anti-LOX B antibody, and has two pH optima (6.0 and 7.5). A mitochondrial protein of approximately 97 kDa cross-reacts with a pea seed anti-LOX B antibody. This reaction is detectable in both soluble (matrix fraction) and membrane-bound (submitochondrial particles) proteins. Considering that pea mitochondria were extracted from actively growing stems that were differentiating tube elements, it is suggested that the presence of LOX in these organelles may be related to their degradation linked to xylem differentiation.
authors.affiliation: Section of Plant Biology, Department of Biology and Agro-industrial Economics, University of Udine, via Cotonificio 108, I-33100 Udine, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Braidot
authors.forename: Elisa
authors.initials: E
authors.lastname: Petrussa
authors.forename: Stefano
authors.initials: S
authors.lastname: Micolini
authors.forename: Franco
authors.initials: F
authors.lastname: Tubaro
authors.forename: Angelo
authors.initials: A
authors.lastname: Vianello
authors.forename: Francesco
authors.initials: F
authors.lastname: Macrì
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes; D008084:Lipoxygenase / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000201:enzymology*; D018532:Pisum sativum / Q000201:enzymology*; D013997:Time Factors
chemical_list: D007527:Isoenzymes; D008084:Lipoxygenase