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

Pleurotus florida produces two laccase enzymes (L1 and L2) within which L2 is associated with the vegetative growth of the fungus. In the present investigation the L2 has been purified to homogeneity and characterized. The 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 enzyme shows a pI value of 4.2. The optimum reaction temperature is 50 degrees C. Spectroscopic analysis reveals that L2 has two copper atoms, a type I copper and a type II copper. The Km and some other kinetic parameters of L2 has been determined.