An antiproliferative ribonuclease from fruiting bodies of the wild mushroom Russula delica.

Zhao, Shuang; Zhao, Yongchang; Li, Shuhong; Zhang, Guoqing; Wang, Hexiang; Ng, Tzi Bun

An antiproliferative ribonuclease with a new N-terminal sequence was purified from fruiting bodies of the edible wild mushroom Russula delica in this study. This novel ribonuclease was unadsorbed on DEAE-cellulose, but absorbed on SP-Sepharose and Q-Sepharose. It had a molecular mass of 14 kDa as judged by fast protein liquid chromatography on Superdex 75 and SDS-polyacrylamide gel electrophoresis. Its optimal pH and optimal temperature were pH 5 and 60 degrees , respectively. The ranking of its activity toward various polyhomoribonucleotides was poly C > poly G > poly A > poly U. It could inhibit proliferation of HepG2 and MCF-7 cancer cells with an IC50 value of 8.6 microM and 7.2 microM, respectively. It was devoid of antifungal and HIV-1 reverse transcriptase inhibitory activity.