日本野生大豆中的一个Kunitz型胰蛋白酶抑制剂变异的纯化与活性测定(英文)

Purification and Activity Characterization of a Kunitz Trypsin Inhibitor Variant in Wild Soybean (Glycine soja) in Japan

大豆Kunitz型胰蛋白酶抑制剂现已报告有6个电冰形态,Tia、Tib、Tic、Tia-s、Tib-f和一个最慢的电泳移动度形态。Tia、Tib、Tic的活性已被报道。Tia和Tic有相似的活性,Tib的活性低于前两者。本文使用DEAE-cellulose层析纯化了Tia和Tia-s蛋白和测定比较了这两个形态的活性。测定结果表明,Tia-s形态比Tia有较高的活性,即使在尿素存在的条件下,Tia-s也表现较高的活性。

The soybean Kunitz trypsin inhibitor (SKTI) has been reported to have several elec- trophoretic types Tia, Tib, Tic, Tia-s, Tib-f and the slowest form. Tia and Tic have a similar inhibitory activity, higher than that of Tib. Here we purified the Tia-s variant protein through DEAR-cellulose chro- matography and examined its trypsin inhibitory activity. The results indicated that the inhibitory activity of the Tia-s was higher than that of the Tia. In the presence of urea, the decreasing degree of trypsin in hibitory activity of the Tia-s was lower than that of the Tia, showing that the Tia-s had stronger resis tance to denaturing agent urea.