Extracellular laccase (benzenediol:oxygen oxidoreductase EC 126.96.36.199) from the lignin‐degrading fungus, Phlebia radiata, was shown to contain a novel combination of electron carriers as its prosthetic groups. In addition to two copper atoms per enzyme molecule, one molecule of PQQ was included as a cofactor. The EPR spectrum exhibits features of type 1 and type 2 copper atoms. In the enzymatic reaction 4 molecules of lignin model compound, coniferyl alcohol, are oxidized per molecule of oxygen reduced to water. During the reaction coniferyl alcohol is transformed to dilignols.
Karhunen, E., Niku-Paavola, M-L., Viikari, L., Haltia, T., Meer, R. V. D., & Duine, J. (1990). A novel combination of prosthetic groups in a fungal laccase, PQQ and two copper atoms. FEBS Letters, 267(1), 6-8. https://doi.org/10.1016/0014-5793(90)80273-L