Oxidation of NADH by a Peroxidase of a Lignin-degrading Basidiomycete, Phanerochaete chrysosporium, and Its Involvement in the Degradation of a Lignin Model Compound

Abstract

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.