One year after detection of lignin peroxidase, Kuwahara et al. (1984) reported the isolation of another enzyme fraction from P. chrysosporium strain ME 446. This fraction showed Mn(II), H2O2 and lactate dependency and stimulation by increased protein concentration in reaction mixtures. The enzyme can oxidize a variety of dyes, including phenol red, o-dianisidine, and Poly R. Purification and characterization of this manganese dependent peroxi-dase was subsequently carried out (Glenn and Gold 1985).
A similar enzyme, tentatively named vanillylacetone peroxidase was purified from P. chrysosporium strain BKM-1767 (Paszczynski et al. 1985). This enzyme oxidized various low-molecular weight phenols and an aromatic amine in the presence of Mn(II) and H2O2. It did not oxidize phenol red and was not activated by lactate. The enzyme oxidized NADPH and reduced glutathione (GSH) thereby, possibly, indicating a link with xenobiotic metabolism. Hydrogen peroxide was formed in this reaction. Generation of hydrogen peroxide from GSH occurs with a manganese dependent peroxidase from Lentinus edodes (Forrester et al. 1988).
Manganese accumulation in the decayed residue of wood (Blanchette 1984) supported the hypothesis that manganese dependent peroxidases participated in lignin degradation (Paszczynski et al. 1985) via oxidation to a higher oxidation state (Glenn et al. 1986; Paszczynski et al. 1986). Manganese dependent peroxidase oxidation of Mn(II) to Mn(III) was subsequently demonstrated (Glenn et al. 1986).
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