From the seeds of the shelf bean, an antifungal peptide with a molecular mass of 6.5 kDa was isolated. The isolation procedure comprised affinity chromatography on Affi-gel blue gel, ion exchange chromatography on Mono S, and gel filtration on Superdex 75. The peptide was adsorbed on Affi-gel blue gel and Mono S. It potently suppressed mycelial growth in Botrytis cinerea, Fusarium oxysporum, and Mycosphaerella arachidicola with an IC50 of 2.9, 2.1, and 0.34 mu M, respectively. It exerted antibacterial activity toward several bacterial species with an IC50 approximating 100 mu M. [Methyl-H-3]-thymidine incorporation into isolated mouse splenocytes was stimulated. [Methyl-H-3]-thymidine incorporation into M1 (myeloma) and L1210 (leukemia) cells was inhibited. The peptide reduced the activity of HIV-1 reverse transcriptase and also inhibited translation in a cell-free rabbit reticulocyte lysate system. Copyright (c) 2005 European Peptide Society and John Wiley & Sons, Ltd.