Isolation of a laccase with HIV-1 reverse transcriptase inhibitory activity from fresh fruiting bodies of the <i>Lentinus edodes</i> (Shiitake mushroom)<i></i>

Abstract

A laccase with a molecular mass of 67 kDa and inhibitory activity toward HIV-1 reverse transcriptase (IC₅₀ = 7.5 <img src='/image/spc_char/micro.gif' border=0> M) was isolated from fresh fruiting bodies of the <i>Lentinus edodes</i> (Shiitake mushroom). Its characteristics were compared with those of laccases from cultured mushroom mycelia reported earlier. The laccase was unadsorbed on DEAE-cellulose, Affi-gel blue gel and CM-cellulose, but was adsorbed on Con A-Sepharose. About 50-fold purification was achieved with a 19.2% yield of the enzyme. The activity of the enzyme increased steadily from 20°C to 70°C. The activity disappeared after exposure to the boiling temperature for 10 min. Its optimal pH was 4 and very little enzyme activity remained at and above pH 10. The laccase inhibited HIV-1 reverse transcriptase with an IC₅₀ of 7.5 <img src='/image/spc_char/micro.gif' border=0> M, but did not demonstrate any antifungal or anti-proliferative activity.