Browsing by Author "Vicuña, Rafael"
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- ItemA novel extracellular multicopper oxidase from Phanerochaete chrysosporium with ferroxidase activity(2003) Larrondo Castro, Luis Fernando; Salas, L.; Melo Ledermann, Francisco Javier; Vicuña, Rafael; Cullen, D.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 Fe2+, 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.
- ItemAssesment of Various Commercial Enzymes in the Bleaching of Radiata Pine Kraft Pulps(1995) Vicuña, Rafael
- ItemAstronomy meets biology: EFOC2 and the chirality of life.(2010) Vicuña, Rafael
- ItemBiotechnology in Chile(1994) Vicuña, Rafael
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- ItemLoss of Filamentous Multicellularity in Cyanobacteria: the Extremophile Gloeocapsopsis sp. Strain UTEX B3054 Retained Multicellular Features at the Genomic and Behavioral Levels(2020) Urrejola Santa Maria, Catalina; Dassow, Peter von; van den Engh, G.; Salas, L.; Mullineaux, C. W.; Vicuña, Rafael; Sánchez-Baracaldo, P.
- ItemPredicting the minimal genome.(2008) Vicuña, Rafael