A novel laccase with fair thermostability from the edible wild mushroom (Albatrella dispansus)

Abstract

A laccase with a novel N-terminal sequence was purified from fresh fruiting bodies of the edible wild mushroom Albatrella dispansus using a procedure that entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel and Con A–Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. In contrast to most of the previously reported laccases from mushroom mycelia, the laccase was unadsorbed on DEAE-cellulose. Although it was also unadsorbed on Affi-gel blue gel, it was adsorbed on Con A–Sepharose, indicating that it is a glycoprotein. It exhibited a molecular mass of 62 kDa in gel filtration and SDS–PAGE. The activity of the laccase increased with temperature from 20 to 70 °C, and notably remained high at 80 °C. The pH optimum for the enzyme was around 4. Enzyme activity was indiscernible at pH 8 and pH 9. The laccase did not exert any inhibitory activity toward HIV-1 reverse transcriptase at a concentration of 1 mg/ml, unlike some previously reported mushroom proteins.