PURIFICATION AND CHARACTERIZATION OF LACCASE FROM MONOCILLIUM-INDICUM SAXENA

An ascomycete Monocillium indicum Saxena producing extracellular laccase was isolated. The culture filtrate on native polyacrylamide gel electrophoresis (PAGE) revealed four bands of activity, one of which was a major one. The major laccase band, a glycoprotein, was purified and characterized. Gel filtration chromatography showed that the relative molecular weight (M(r)) of laccase was 100000. On sodium dodecyl sulphate (SDS)-PAGE the major laccase band further resolved into three proteins Of M(r) 72000, 56000 and 24000. The enzyme had a pH optimum of 3.0 and was active on a number of o-phenols and aromatic acids. The 72000 M(r) protein was found to share common immunological properties with laccases of Coriolus versicolor, Agaricus bisporus and lignin peroxidase of Phanerochaete chrysosporium.