A　novel　chitinase　with　antifungal　activity　was　isolated　from　fava　bean　(Vicia　faba)　seeds.　The　protein　exhibited　a　molecular　mass　of　21.5　kDa　in　reduced　condition　while　25.5　kDa　in　oxidized　condition　on　SDS-PAGE,　indicating　that　there　are　disulfide　bonds　inside　the　molecule.　Its　N-terminal　amino　acid　sequence　was　determined　to　be　D-D-V-G-S-V-I-S-A-S-L-F-E-Q-L-L-K-H,　showing　homologous　to　those　of　chitinase　and　chitinase　precursors　from　leguminous　plants.　The　optimum　pH　and　the　optimum　temperature　for　activity　toward　N-acetyl-D-glucosamine　were　5.4　and　50　degrees　C,　respectively.　The　pl　was　determined　to　be　8.7　by　isoelectric　focusing　electrophoresis.　The　chitinase　was　thermostable　up　to　58　degrees　C　in　both　enzymatic　reaction　and　antifungal　activity.　It　showed　chitin-binding　activity,　suggesting　that　the　catalytic　domain　is　involved　in　the　binding　of　chitinase　to　a　certain　extent.　In　addition,　it　exerted　potent　antifungal　action　toward　a　variety　of　fungal　species　including　Pythium　aphanidermatum,　Fusarium　solani,　Physalospora　piricola,　Alternaria　alternate,　Botrytis　cinerea,　and　Fusarium　oxysporum　f.　sp.　melonis.　The　present　findings　demonstrated　a　novel　chitinase　with　disulfide　bonds　inside　the　molecule　and　show　antifungal　significance　in　agriculture.　(C)　2011　Elsevier　Ltd.　All　rights　reserved.