Several proteins from lily bulb for foodstuffs showed strong inhibitory activity toward bovine trypsin. A trypsin inhibitor (LTI-II-4) was purified from lily bulb by a method including column chromatographies on CM-Sepharose CL-6B and DEAE-Sepharose GL-6B and high-pressure liquid chromatography. Purified LTI-II-4 had a molecular weight of 21,000. The amino acid composition was characterized by high contents of glycine, aspartic acid and serine. The inhibitor contained 4 halfcystines in its constituent amino acids. The N-terminal 25 and the C-terminal 3 residues of LTI-II-4 were sequenced. The Inhibitor was stable in a wide pH range under 50℃ and was unstable at the higher temperatures than 80℃. The reactivesite amino acid of LTI-II-4 was assumed to be lysine. The inhibitor didn\u27t inhibit elastase and subtilisin. From these results, the inhibitor LTI-II-4 is assumed to belong to the Kunitz soybean trypsin inhibitor family
