Oxalate oxidase from Ceriporiopsis subvermispora: Biochemical and cytochemical studies

Aguilar C.; Urzua, U; Vicuna, R; Koenig, C

Keywords: substrate, acid, electron, proteins, inhibition, enzyme, purification, activation, protein, plant, cell, metabolism, fungi, fungal, oxidoreductases, oxidoreductase, basidiomycetes, article, fractions, analysis, activity, focusing, felis, priority, nonhuman, journal, isoelectric, Microscopy,, catus, Basidiomycota, Ceriporiopsis, subvermispora, Histocytochemistry, Subcellular, oxalic, Polyporaceae

Abstract

The enzyme oxalate oxidase was identified in mycelial extracts of the basidiomycete Ceriporiopsis subvermispora and thereafter purified to homogeneity. The purification procedure included only three steps: Q- Sepharose chromatography, precipitation at pH 3.0, and phosphocellulose chromatography. The enzyme is a 400-kDa homohexamer, as determined by gel permeation in Sephadex G-200 and SDS-polyacrylamide gel electrophoresis. Isoelectrofocusing revealed a pI of 4.2. Optimal activity was obtained at pH 3.5 and at 45°C. The purified enzyme has K(m) and k(cat) values of 0.1 mM and 88 s -1, respectively. It is highly specific for oxalate, although it is inhibited at concentrations of this substrate above 2.5 mM. Hystochemistry studies conducted over mycelium slices showed reactions products in both endocellular and periplasmic associated elements. A possible connection between the intracellular metabolism of oxalate and the extracellular ligninolytic activity of the fungus is proposed.

Más información

Título de la Revista: Archives of Biochemistry and Biophysics
Volumen: 366
Número: 2
Editorial: Elsevier Science Inc.
Fecha de publicación: 1999
Página de inicio: 275
Página final: 282
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-0033563869&partnerID=q2rCbXpz