A heme peroxidase different from other microbial, plant, and animal peroxidases, termed VP has recently been discovered in Pleurotus and Bjerkandera species (Camarero et al. 1999; Mester and Field 1998; Ruiz-Duenas et al. 1999; 2001). The VP is characterized by catalytic properties of MnP and LIP. The enzyme exhibits high affinity for Mn2+, hydroquinones, and dyes, and also oxidizes VA, dimethoxybenzene, and lignin dimers (Ruiz-Duenas et al. 2001). Molecular models show a Mn2+-binding site formed by three acidic residues near the heme internal propionate accounting for the ability of VP to oxidize Mn2+ (Ruiz-Duenas et al. 1999). Concerning aromatic substrate oxidation, VP shows a putative long-range electron transfer pathway from an exposed trytophan to heme, similar to that postulated in LIP (Ruiz-Duenas et al. 2001). Mutagenesis and chemical modification of this tryptophan and the acidic residues forming the Mn2+-binding site confirmed their role in catalysis.
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