A　novel　protease　inhibitor,　designated　mungoin,　with　both　antifungal　and　antibacterial　activities,　and　exhibiting　a　molecular　mass　of　10　kDa　in　SDS-polyacrylamide　gel　electrophoresis,　was　isolated　from　mung　bean　(Phaseolus　mungo)　seeds.　The　isolation　procedure　involved　a　combination　of　extraction,　ammonium　sulfate　precipitation,　ion　exchange　chromatography　on　CM-Sephadex,　and　high-performance　liquid　chromatography　(HPLC)　on　SP-Toyopearl.　Its　isoelectric　point　was　estimated　to　be　9.8　by　isoelectric　focusing.　Its　N-terminal　amino　acid　sequence　was　determined　to　be　EMPGKPACLDTDDFCYKP,　demonstrating　some　resemblance　to　the　C-terminal　sequences　of　other　protease　inhibitors　and　inhibitor　precursors　from　leguminous　plants.　It　exerted　a　potent　inhibitory　action　toward　a　variety　of　fungal　species　including　Physalospora　piricola,　Mycosphaerella　arachidicola,　Botrytis　cinerea,　Pythium　aphanidermatum,　Sclerotium　rolfsii　and　Fusarium　oxysporum,　as　well　as　an　antibacterial　action　against　Staphylococcus　aureus.　In　addition,　this　novel　plant　protease　inhibitor　displayed　anti-proliferative　activity　toward　tumor　cells.　(c)　2006　Published　by　Elsevier　Inc.