A hemoprotein. The enzyme from white rot basidiomycetes is involved in the oxidative degradation of lignin. The enzyme oxidizes a bound Mn2+ ion to Mn3+ in the presence of hydrogen peroxide. The product, Mn3+, is released from the active site in the presence of a chelator (mostly oxalate and malate) that stabilizes it against disproportionation to Mn2+ and insoluble Mn4+ . The complexed Mn3+ ion can diffuse into the lignified cell wall, where it oxidizes phenolic components of lignin and other organic substrates . It is inactive with veratryl alcohol or nonphenolic substrates.
Glenn, J.K., Akileswaran, L. and Gold, M.H. Mn(II) oxidation is the principal function of the extracellular Mn-peroxidase from Phanerochaete chrysosporium. Arch. Biochem. Biophys.251 (1986) 688–696. [PMID: 3800395]
Paszczynski, A., Huynh, V.-B. and Crawford, R. Comparison of ligninase-I and peroxidase-M2 from the white-rot fungus Phanerochaete chrysosporium. Arch. Biochem. Biophys.244 (1986) 750–765. [PMID: 3080953]
Wariishi, H., Akileswaran, L. and Gold, M.H. Manganese peroxidase from the basidiomycete Phanerochaete chrysosporium: spectral characterization of the oxidized states and the catalytic cycle. Biochemistry27 (1988) 5365–5370. [PMID: 3167051]
Kuan, I.C. and Tien, M. Stimulation of Mn peroxidase activity: a possible role for oxalate in lignin biodegradation. Proc. Natl. Acad. Sci. USA90 (1993) 1242–1246. [PMID: 8433984]