title: Peroxisomal oxidation of L-2-hydroxyphytanic acid in rat kidney cortex.
abstract: A previously unreported metabolite of mammalian phytanic acid catabolism, 2-oxophytanic acid, was identified by gas chromatography/mass spectrometry analysis. The formation of 2-oxophytanic acid was demonstrated to result from the oxidation of L-2-hydroxyphytanic acid, a reaction catalysed by a rat-kidney-cortex H2O2-generating oxidase. The pH optimum for the L-2-hydroxyphytanate oxidase activity was 8.5 and its apparent Km and Vm were about 0.15 mM and 0.35 mumol min-1 (g tissue)-1, respectively. L-2-Hydroxyisocaproate, a substrate of rat kidney L-alpha-hydroxyacid oxidase type B, inhibited the formation of 2-oxophytanate from L-2-hydroxyphytanic acid. Fractionation studies have indicated that 40% of L-2-hydroxyphytanate oxidase was associated with a particulate fraction and that the activity distribution of the oxidase closely paralleled that of catalase, a well known peroxisomal marker enzyme.
authors.affiliation: Laboratoire de Chimie Physiologique, Université de Louvain, Brussels, Belgium.
authors.forename: J P
authors.initials: JP
authors.lastname: Draye
authors.forename: F
authors.initials: F
authors.lastname: Van Hoof
authors.forename: E
authors.initials: E
authors.lastname: de Hoffmann
authors.forename: J
authors.initials: J
authors.lastname: Vamecq
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000818:Animals; D002849:Chromatography, Gas; D004537:Eicosanoic Acids / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D007672:Kidney Cortex / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D013058:Mass Spectrometry; D008830:Microbodies / Q000378:metabolism*; D009928:Organ Specificity; D010084:Oxidation-Reduction; D010831:Phytanic Acid / Q000031:analogs & derivatives / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004537:Eicosanoic Acids; D010831:Phytanic Acid; C002585:2-hydroxyphytanic acid; D000429:Alcohol Oxidoreductases; C021380:L-2-hydroxyacid oxidase