Purification and characterization of a growth-regulating laccase from Pleurotus florida

Pleurotus florida produces two laccase enzymes (L-1 and L-2) within which L -2 is associated with the vegetative growth of the fungus. In the present i nvestigation the L-2 has been purified to homogeneity and characterized. Th e molecular mass of the enzyme has been determined to be 73 kDa and 70 kDa by gel filtration chromatography and SDS-PAGE, respectively. The purified e nzyme shows a pI value of 4.2. The optimum reaction temperature is 50 degre esC. Spectroscopic analysis reveals that L-2 has two copper atoms, a type I copper and a type II copper. The K-m and some other kinetic parameters of L-2 has been determined.