Versatile peroxidases are a new class of ligninolytic enzymes secreted by fungi from the group of white-rot basidiomycetes. Versatile peroxidase (VP) is a structuml hybrid between lignin and manganese peroxidase. This hybrid combines the catalytic properties of the two above peroxidases being able to catalyze Mn(II)-dependent and Mn(lI)-independent reactions. A long-range electron transfer mechanism has been inferred for the oxidation of big substrate molecules starting from ah exposed tryptophan to the heme cofactor. A neutral tryptophan radical has been identified in VP from Bjerkandera adusta and Pleurotus eryngii, after H202 activation and assignr to a specific tryptophan residue using multifrequency electron paramagnetic resonance and electron-nuclear double resonance spectroscopy. Comparative density functional theory calculations were performed for tryptophan neutral and cation radical species, considering also the effect of the polar environment surrounding the radical. The functional role of the radicals is discussed in the context of mechanistic models for VP.

Pogni, R., C., T., F., L., Basosi, R. (2007). Tryptophan Radicals as Reaction Intermediates in Versatile Peroxidases: Combined Multifrequency EPR/ENDOR and Density Functional Theory Studies. APPLIED MAGNETIC RESONANCE, 31, 509-526.

Tryptophan Radicals as Reaction Intermediates in Versatile Peroxidases: Combined Multifrequency EPR/ENDOR and Density Functional Theory Studies

POGNI, REBECCA;BASOSI, RICCARDO
2007-01-01

Abstract

Versatile peroxidases are a new class of ligninolytic enzymes secreted by fungi from the group of white-rot basidiomycetes. Versatile peroxidase (VP) is a structuml hybrid between lignin and manganese peroxidase. This hybrid combines the catalytic properties of the two above peroxidases being able to catalyze Mn(II)-dependent and Mn(lI)-independent reactions. A long-range electron transfer mechanism has been inferred for the oxidation of big substrate molecules starting from ah exposed tryptophan to the heme cofactor. A neutral tryptophan radical has been identified in VP from Bjerkandera adusta and Pleurotus eryngii, after H202 activation and assignr to a specific tryptophan residue using multifrequency electron paramagnetic resonance and electron-nuclear double resonance spectroscopy. Comparative density functional theory calculations were performed for tryptophan neutral and cation radical species, considering also the effect of the polar environment surrounding the radical. The functional role of the radicals is discussed in the context of mechanistic models for VP.
2007
Pogni, R., C., T., F., L., Basosi, R. (2007). Tryptophan Radicals as Reaction Intermediates in Versatile Peroxidases: Combined Multifrequency EPR/ENDOR and Density Functional Theory Studies. APPLIED MAGNETIC RESONANCE, 31, 509-526.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/32831
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