Do the extracellular enzymes cellobiose dehydrogenase and manganese peroxidase form a pathway in lignin biodegradation?

FEBS Letters

Johansson, Gunnar³  Li, Jiebing¹  Pettersson, Göran³  Hildén, Lars¹  Henriksson, Gunnar¹  Ljungquist, Pierre² 

[1] Department of Pulp and Paper Chemistry and Technology, Royal Institute of Technology, Drottning Kristinas väg 53, SE-100 44 Stockholm, Sweden;STFI (Swedish Pulp and Paper Research Institute), P.O. Box 5604, SE-114 86 Stockholm, Sweden;Department of Biochemistry, Uppsala University, Biomedical Centre, P.O. Box 576, SE-751 23 Uppsala, Sweden

关键词: Lignin biodegradation;    Cellobiose dehydrogenase;    Hydroxyl radical;    Manganese peroxidase;    Phanerochaete chrysosporium;    CDH;    cellobiose dehydrogenase;    GC;    gas chromatography;    GC–MS;    gas chromatography connected to mass spectroscopy;    LP;    lignin peroxidase;    MnP;    manganese peroxidase;    MS;    mass spectroscopy;    MSA;    α-methylsyringylalcohol;    NIST;    National Institute of Standards and Technology;    RP-HPLC;    reverse-phase high-pressure liquid chromatography;    SDS-PAGE;    sodium dodecyl sulphate–polyacrylamide gel electrophoresis;    VG;    veratryl glycol;   

DOI  :  10.1016/S0014-5793(00)01757-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The extracellular enzyme manganese peroxidase is believed to degrade lignin by a hydrogen peroxide-dependent oxidation of Mn(II) to the reactive species Mn(III) that attacks the lignin. However, Mn(III) is not able to directly oxidise the non-phenolic lignin structures that predominate in native lignin. We show here that pretreatment of a non-phenolic lignin model compound with another extracellular fungal enzyme, cellobiose dehydrogenase, allows the manganese peroxidase system to oxidise this molecule. The mechanism behind this effect is demethoxylation and/or hydroxylation, i.e. conversion of a non-phenolic structure to a phenolic one, mediated by hydroxyl radicals generated by cellobiose dehydrogenase. This suggests that cellobiose dehydrogenase and manganese peroxidase may act in an extracellular pathway in fungal lignin biodegradation. Analytical techniques used in this paper are reverse-phase high-pressure liquid chromatography, gas chromatography connected to mass spectroscopy and UV-visible spectroscopy.

【 授权许可】

Unknown