White-rot fungal peroxidases

Compared with plant and other peroxidases, white-rot fungal peroxidases are characterized by their high redox potential, related to the architecture of the heme environment (see Chap. 4). This is required to perform their role in nature, namely the oxidative biodegradation of the recalcitrant lignin polymer present in the cell wall of all vascular plants [30-32], By contrast, one of the roles of plant peroxidases... 

An additional characteristic of white-rot fungal peroxidases is their wide-substrate specificity allowing them to oxidize substrates that shares structural characteristics with lignin units [38]. Among others, these enzymes are able to oxidize phenolic and nonphenolic pollutants [39], pesticides [40], polycyclic aromatic hydrocarbons [41] and industrial dyes [42]. These properties expand the range of applications also to the environmental sector. 

Extracellnlar H2O2 is required for the activity of peroxidases in white-rot fungi, and this can be prodnced by several fungal reactions ... 

Hofrichter, M., and Fritsche, W., Depolymerization of Low-Rank Coal by Extracellular Fungal Enzyme Systems. 3. In Vitro Depolymerization of Coal Humic Acids by a Crude Preparation of Manganese Peroxidase From the White-Rot Fungus Nematoloma Frowardii B19. Applied Microbiology and Biotechnology, 1997. 47(5) pp. 566-571. 

Because the three-dimensional structures of the peroxidase, its reductant cytochrome c, and the complex of the two (Fig. 16-9) are known, cytochrome c peroxidase is the subject of much experimental study. Other fungal peroxidases, some of which contain manganese rather than iron, act to degrade lignin (Chapter 25).218 A lignin peroxidase from the white wood-rot fungus Phanerochaete chrysosporium has a surface tryptophan with a specifically hydroxylated C(3 carbon atom which may have a functional role in catalysis.2183 0... 

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