A peptide with potent antifungal and antiproliferative activities from Nepalese large red beans

An antifungal defensin-like peptide with a molecular mass of 7.1 kDa was isolated from dried Nepalese large red beans (Phaseolus angularis). The purification protocol employed included ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on SP-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The antifungal peptide was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and SP-Sepharose. The antifungal peptide inhibited mycelial growth in Fusarium oxysprorum and Mycosphaerella arachidicola with an IC50 value of 1.4 and 1.8 mu M, respectively. It did not inhibit HIV-1 reverse transcriptase when tested up to 200 mu M. It exerted an antiproliferative action on L1210 leukemia cells and MBL2 lymphoma cells with an IC50 of 15 and 60 mu M, respectively. (C) 2009 Elsevier Inc. All rights reserved.