Lignin peroxidase secretion

Lignin peroxidase, secreted by the white-rot fungus Phanerochaete chrysosporium in response to nutrient deprivation, catalyzes the H202-dependent oxidation of non-phenolic aromatic substrates. The present report summarizes the kinetic and structural characteristics of lignin peroxidase isozymes. Our results indicate that the active site of lignin peroxidase is more electron deficient than other peroxidases. As a result, the redox potential of the heme active site is higher, the heme active site is more reactive and the oxycomplex is more stable than that of other peroxidases. Also discussed is the heme-linked ionization of lignin peroxidase. 

Among the most studied fungi, Phanerochaete chrysosporium secretes at least two lignolytic peroxidases, namely, lignin peroxidase (LiP) and Mn peroxidase (MnP) [50]. Both LiP and MnP contain a heme iron center at their active site and both function according to the following simplified scheme (where P represents porphyrin) [50,51],... 

The white rot basidiomycete Phanerochaete chrysosporium secretes two soluble H202-requiring peroxidases which are Involved in lignin degradation. Both lignin peroxidase (LIP) and manganese peroxidase (MnP) form the oxidized intermediates compound 1 and compound II. 

Lignin (LiP) and manganese dependent (MnP) peroxidases of R chrysosporium are secreted in conjunction with a number of other enzymes and chemicals under nutrient deficient conditions (3, 33, 44-47, 86, 92, 93). The peroxidases are known to catalyze a number of free radical reactions. Research on these enzymes has been extensively reviewed recently (5, 49, 85). The resting enzyme (ferric-heme protein) is initially oxidized by two electrons in a reaction with hydrogen peroxide (Fig. 6). The resulting intermediate, com-... 

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