Oxidation of NADH by a peroxidase of a lignin-degrading Basidiomycete, Phanerochaete chrysosporium, and its involvement in the degradation of a lignin model compound.

A lignin-degrading Basidiomycete, Phanerochaete chrysosporium, produced peroxidases other than ligninperoxidase in a low nitrogen culture. One of the peroxidases was purified by DEAE-Sepharose column chromatography. The enzyme (NADH-peroxidase) oxidized NADH besides phenol red and other substrates for peroxidases. The product on NADH oxidation by the enzyme was H2O2. The reaction was stimulated by Mn2+ and inhibited by heme protein inhibitors. A diarylpropane compound, a lignin model, was degraded in the presence of both the NADH- and lignin-peroxidase with NADH. This reaction showed that NADH-peroxidase played a role as a H2O2 donor in the lignin-peroxidase reaction.