A Novel Ribonuclease with HIV-1 Reverse Transcriptase Inhibitory Activity Purified from the Field Blewit Mushroom Lepista personata (Agaricomycetes)

A ribonuclease was purified from dry fruiting bodies of the wild edible mushroom Lepista personata (LPR) to 259-fold with a specific activity of 280 U/mg. The purification protocol involved ion-exchange chromatography on DEAE-cellulose, CM-cellulose and SP-sepharose, followed by size exclusion chromatography on Superdex 75. LPR is a homodimeric protein with a molecular weight of 27.8 kDa as determined by SDS-PAGE and by gel filtration. Three inner peptide sequences for LPR were obtained by LC-MS-MS analysis. It demonstrated the optimum pH of 4.0 and temperature optimum of 60°C. The specificity ribonuclease potencies order toward polyhomoribonucleotides was poly C > poly A > poly G > poly U. The ribonuclease inhibited HIV-1 reverse transcriptase with an IC50 of 0.53 μM.