title: Production and induction of manganese peroxidase isozymes in a white-rot fungus Pleurotus ostreatus.
abstract: The production of MnP by Pleurotus ostreatus in different liquid cultures was investigated. The highest level of activity was observed after 8 days of culture in peptone-glucose-yeast extract medium (PGY), whereas maximal activity was achieved after 30 days in glucose-yeast extract medium (GY). MnP was purified to homogeneity from PGY (designated MnP-PGY) and GY (MnP-GY). The isoelectric points of MnP-PGY and MnP-GY were 3.77 and 4.06, respectively. The molecular mass of both enzymes was 42 kDa. Analysis of the N-terminal amino acid sequence of purified MnPs and nucleotide sequence of cloned mnp indicated that MnP-GY has VTCATGQTTANE at the N-terminus, whereas MnP-PGY has ATCADGRTTANA. A putative exposed tryptophan residue (W170) was found in MnP-GY. Both isozymes oxidized veratryl alcohol, although the K(m) of MnP-GY was lower than that of MnP-PGY. Thus, the presence of peptone in the medium affected the production of MnP isozymes. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that the synthesis of MnP isozymes is controlled by culture conditions at the transcriptional level.
authors.affiliation: Laboratory of Biomass Conversion, Kyoto University, Wood Research Institute, Gokasho Uji Kyoto 611-0011, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kamitsuji
authors.forename: Y
authors.initials: Y
authors.lastname: Honda
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Kuwahara
mesh_terms: D000595:Amino Acid Sequence; D003470:Culture Media; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D010461:Peptones; D010544:Peroxidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020076:Pleurotus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
chemical_list: D003470:Culture Media; D007527:Isoenzymes; D010461:Peptones; D010544:Peroxidases; C051129:manganese peroxidase