Title: A novel extracellular multicopper oxidase from Phanerochaete chrysosporium with ferroxidase activity
Author: Larrondo, Luis F.; Salas, Loreto; Melo, Francisco; Vicuna, Rafael; Cullen, Daniel;
Source: Applied and environmental microbiology. Vol. 69, no. 10 (Oct. 2003): Pages 6257-6263
Publication Series: Miscellaneous Publication
Description: Lignin degradation by the white rot basidiomycete Phanerochaete chrysosporium involves various extracellular oxidative enzymes, including lignin peroxidase, manganese peroxidase, and a peroxide-generating enzyme, glyoxal oxidase. Recent studies have suggested that laccases also may be produced by this fungus, but these conclusions have been controversial. We identified four sequences related to laccases and ferroxidases (Fet3) in a search of the publicly available P. chrysosporium database. One gene, designated mco1, has a typical eukaryotic secretion signal and is transcribed in defined media and in colonized wood. Structural analysis and multiple alignments identified residues common to laccase and Fet3 sequences. A recombinant MCO1 (rMCO1) protein expressed in Aspergillus nidulans had a molecular mass of 78 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the copper I-type center was confirmed by the UV-visible spectrum. rMCO1 oxidized various compounds, including 2,2’-azino(bis-3-ethylbenzthiazoline-6-sulfonate) (ABTS) and aromatic amines, although phenolic compounds were poor substrates. The best substrate was Fe 2+ , with a Km close to 2 µM. Collectively, these results suggest that the P. chrysosporium genome does not encode a typical laccase but rather encodes a unique extracellular multicopper oxidase with strong ferroxidase activity.
Keywords: Phanerochaete chrysosporium, white rot, lignin degradation, extracellular multicopper oxidase, ferroxidase activity
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
XML: View XML
Larrondo, Luis F.; Salas, Loreto; Melo, Francisco; Vicuna, Rafael; Cullen, Daniel 2003. A novel extracellular multicopper oxidase from Phanerochaete chrysosporium with ferroxidase activity. Applied and environmental microbiology. Vol. 69, no. 10 (Oct. 2003): Pages 6257-6263
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility