Ligninase-mediated phenoxy radical formation and polymerization unaffected by cellobiose: quinone oxidoreductase

Single electron transfer by an extracellular laccase from the white-rot fungus Pleurotus ostreatus

“…protons). It was very similar to the EPR spectrum obtained from Phanerochaete chyosporium lignin peroxidase except that the latter showed extra peaks due to a secondary radical signal (Odier et al, 1988). The phenoxy radical from laccase I-catalysed oxidation of 3,5-dimethoxy-5-hydroxyacetophenone may be formed via …”

Enzymology and Molecular Biology of Lignin Degradation

“…This explains both the depolymerization of lignin (Tien and Kirk 1983) and also the repolymerization of phenolic lignin fragments in vitro (Haemmerli et al 1986;Odier et al 1988). Dilute lignin dispersions and low steady-state H2O2 concentrations are thought to be important in minimizing bimolecular coupling of phenoxy radicals that would lead to polymerization in vitro (Hammel and Moen 1991).…”

Evidence that cellobiose oxidase from Phanerochaete chrysosporium is primarily an Fe(III) reductas

“…The use of such an acid pH can be justified by comparison with other studies of enzymes released from P . chrysosporium, including work with cellobiose: quinone oxidoreductase (Deshpande et al, 1978;Odier et al, 1988;Kirk et al, 1990). Morpeth (1985) presented evidence for superoxide as the product of O2 reduction by cellobiose oxidase, leading to HzOz as a result of dismutation.…”