Isolation and characterization of a novel lectin from the wild mushroom Oudemansiella radicata (Relhan.: Fr.) sing

摘要

A novel lectin (ORL), with a molecular mass of 30 kDa and a unique amino acid sequence, was purified from dried fruiting bodies of the mushroom Oudemansiella radicata (Relhan.: Fr.) Sing. ORL is a dimer made of two 15-kDa subunits. The purification procedure encompassed ion exchange chromatography on DEAE-cellulose and QSepharose and fast protein liquid chromatography-gel filtration on Superdex 75. The hemagglutinating activity of ORL was stable at temperatures up to 70°C and between pH 2.0 ∼ 11.0, and was reduced at higher temperatures, and under acidic and alkaline conditions. The activity was activated by Cu2+, Al3+, Fe3+, and Pb2+ ions, and inhibited by Hg2+ and Fe2+ ions. ORL showed no specificity toward the carbohydrates tested. Unlike previously reported mushroom lectins, ORL had no inhibitory effect on HIV-1 reverse transcriptase and proliferation of hepatoma HepG2 cells, as well as breast cancer MCF7 cells, when tested up to 500 μM.