Purification and characterization of a laccase with inhibitory activity toward HIV-1 reverse transcriptase and tumor cells from an edible mushroom (pleurotus cornucopiae)

A 66-kda laccase,with an n-terminal sequence different from those of other mushroom laccases,was purified from fresh fruiting bodies of the edible mushroom pleurotus cornucopiae by using affinity chromatography on affi-gel blue gel,ion exchange chromatography on mono q and gel filtration on superdex 75. the procedure resulted in a 16-fold purification and a specific enzyme activity of 17.3 u mg-1. the optimum ph and temperature for the purified laccase were ph 4 and 40°c,respectively. this laccase inhibited proliferation of murine leukemia cell line l1210 and human hepatoma cell line hepg2,and reduced the activity of hiv-1 reverse transcriptase with an ic50 of 22 μm. there was neither mitogenic activity toward mouse splenocytes,nor hemagglutinating/hemolytic activity toward rabbit erythrocytes. this study yielded information about the potentially exploitable activities of p. cornucopiae laccase. © 2010 bentham science publishers ltd.