title: Mn(2+) is dispensable for the production of active MnP2 by Pleurotus ostreatus.
abstract: The regulation mechanism for expression of versatile peroxidase MnP2 by the basidiomycete fungus Pleurotus ostreatus was examined using chemically defined synthetic media. Expression of MnP2 was down-regulated at the transcription level by nutrient nitrogen, e.g., NH(4)(+), arginine or urea. As is often the case with other fungal manganese peroxidases, active MnP2 was not detected when Mn(2+) was omitted from the culture, while mnp2 transcription was barely affected by Mn(2+). However, Mn(2+) can be substituted by an MnP2 substrate, Poly R-478, since active MnP2 was detected extracellularly when the compound was added to the culture without Mn(2+). Enzyme stability assays with the purified MnP2 indicated an indispensable requirement for a substrate that can be used to complete the catalytic cycle, and avoid inactivation resulting from an excess H(2)O(2). This report is the first of the Mn(2+)-independent production of an active versatile peroxidase by P. ostreatus.
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan.
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Kamitsuji
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Honda
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kuwahara
mesh_terms: D002384:Catalysis; D002413:Cations, Divalent; D003470:Culture Media; D015536:Down-Regulation; D004795:Enzyme Stability; D006861:Hydrogen Peroxide / Q000378:metabolism; D008345:Manganese / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism*; D020076:Pleurotus / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D002413:Cations, Divalent; D003470:Culture Media; D008345:Manganese; D006861:Hydrogen Peroxide; D010544:Peroxidases; C051129:manganese peroxidase; D009584:Nitrogen