Purification and Properties of Laccase Produced from Pleurotus ostreatus

The laccase was purified from Pleurotus ostreatus 5.42 by ultrafiltration, DEAE- Cellulose 52 and SephadexA-50 chromatography, purification of about 18.1 fold was achieved with an overall yield of 36%. Single ribbon was obtained by PAGE. The molecular weight of the purified laccase was determined as about 61.4 kD by SDS-PAGE, but the molecular weight of the laccase purified by high performance liquid chromatography was tested for 60.5 kD by mass spectrometer. Its optimum pH and temperature for laccase activity were 5.0 and 40℃, respectively. Various metal ions have different effects on its activity: the activity was enhanced by K+, Mn2+, Cu2+and was strongly limited by Hg2+, Ag+, Ba2+ etc. The laccase mingling with pecticnase in optimum proportion play important role in coming unglaed nettle.