Influence of cellobiose oxidase on peroxidases from Phanerochaete chrysosporium.

Reduction of H2O2-oxidized manganese peroxidase (MnP), lignin peroxidase and, to some extent, horseradish peroxidase, was studied in the presence of cellobiose oxidase (CbO) and cellobiose. It was found that the reversion rates for MnP compound II and lignin peroxidase compound II back to native enzymes increased significantly in the presence of CbO and cellobiose. However, the reduction of cytochrome c by CbO plus cellobiose was 40 times faster than the reduction of MnP compound II. Also, the lag phase before reversion to the native states decreased for all three peroxidases in the presence of CbO and cellobiose. Active CbO did not repress formation of compounds I or II of the peroxidases, and Mn2+/veratryl alcohol reduced compound II of the peroxidases much more rapidly than did active CbO. This indicates that, in the presence of Mn2+ or veratryl alcohol, MnP and lignin peroxidase can complete their catalytic cycles and function normally without interference from CbO. Without the presence of peroxidase substrates, active CbO reduced compound II of the above peroxidases.