Yamamoto M, Hara S, Ikenaka T
J Biochem. 1983 Sep;94(3):849-63. doi: 10.1093/oxfordjournals.jbchem.a134427.
The trypsin inhibitor (WTI-1) purified from winged bean seeds is a Kunitz type protease inhibitor having a molecular weight of 19,200. WTI-1 inhibits bovine trypsin stoichiometrically, but not bovine alpha-chymotrypsin. The approximate Ki value for the trypsin-inhibitor complex is 2.5 X 10(-9) M. The complete amino acid sequence of WTI-1 was determined by conventional methods. Comparison of the sequence with that of soybean trypsin inhibitor (STI) indicated that the sequence of WTI-1 had 50% homology with that of STI. WTI-1 was separated into 2 homologous inhibitors, WTI-1A and WTI-1B, by isoelectric focusing. The isoelectric points of WTI-1A and WTI-1B were 8.5 and 9.4, respectively, and their sequences were presumed from their amino acid compositions.
从四棱豆种子中纯化得到的胰蛋白酶抑制剂（WTI-1）是一种分子量为19200的Kunitz型蛋白酶抑制剂。WTI-1能按化学计量比抑制牛胰蛋白酶，但不抑制牛α-糜蛋白酶。胰蛋白酶-抑制剂复合物的近似Ki值为2.5×10⁻⁹ M。通过传统方法确定了WTI-1的完整氨基酸序列。将该序列与大豆胰蛋白酶抑制剂（STI）的序列进行比较，结果表明WTI-1的序列与STI的序列具有50%的同源性。通过等电聚焦将WTI-1分离为两种同源抑制剂WTI-1A和WTI-1B。WTI-1A和WTI-1B的等电点分别为8.5和9.4，其序列根据氨基酸组成推测得出。
