INFLUENCE OF CELLOBIOSE OXIDASE ON PEROXIDASES FROM PHANEROCHAETE-CHRYSOSPORIUM

Reduction of H2O2-oxidized manganese peroxidase (MnP), lignin peroxida se and, to some extent, horseradish peroxidase, was studied in the pre sence of cellobiose oxidase (CbO) and cellobiose. It was found that th e reversion rates for MnP compound II and lignin peroxidase compound I I back to native enzymes increased significantly in the presence of Cb O and cellobiose. However, the reduction of cytochrome c by CbO plus c ellobiose was 40 times faster than the reduction of MnP compound II. A lso, the lag phase before reversion to the native states decreased for all three peroxidases in the presence of CbO and cellobiose. Active C bO 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 t heir catalytic cycles and function normally without interference from CbO. Without the presence of peroxidase substrates, active CbO reduced compound II of the above peroxidases.