A novel laccase with inhibitory activity towards HIV-I reverse transcriptase and antiproliferative effects on tumor cells from the fermentation broth of mushroom Pleurotus cornucopiae

A novel laccase with a molecular mass of 67 kDa was isolated from the fermentation broth of Pleurotus cornucopiae through ion exchange chromatography and gel filtration. The optimal pH and temperature for the laccase was pH 4.2 and 30 degrees C, respectively. The laccase activity was remarkably inhibited by Fe3+ and Hg2+, while it was stimulated by Cu2+ and Pb2+. It inhibited proliferation of the hepatoma cells HepG2 and the breast cancer cells MCF-7, and the activity of HIV-I reverse transcriptase with IC50 values of 3.9, 7.6 and 3.7 M, respectively. Copyright (c) 2013 John Wiley & Sons, Ltd.