School of Life Science, Shanxi University, No. 92, Wucheng Road, Taiyuan, 030006, China.
Department of Food Science and Agricultural Chemistry, McGill University (Macdonald Campus), Ste-Anne-de-Bellevue, Québec, H9X 3V9, Canada.
Protein Expr Purif. 2020 Jul;171:105614. doi: 10.1016/j.pep.2020.105614. Epub 2020 Feb 28.
The inhibitory activities of buckwheat trypsin inhibitor (rBTI) towards trypsin were compared with soybean trypsin inhibitor (SBTI) in terms of their sensitivities to temperature, pH, salt ions and organic solvents. Both rBTI and SBTI were stable over a broad pH range of 2.0-12.0. rBTI exhibited higher thermal stability than SBTI. The inhibitory activity of rBTI was decreased by Zinc ions (Zn), KSCN, vitamin C and urea, while that of SBTI remained unchanged. However, HO, Mg and Cu ions had no significant effects on the inhibitory activities of rBTI and SBTI. Acetonitrile enhanced the inhibitory activity of rBTI, but had no effect on SBTI, while dimethylacetamide (DMAC) increased the inhibitory effect of both rBTI and SBTI. On the contrary, the inhibitory activities of rBTI and SBTI were reduced by isopropyl alcohol and methanol. The inhibition constants K of rBTI and SBTI were calculated to be 7.41 × 10 M and 6.52 × 10 M, respectively.
荞麦胰蛋白酶抑制剂（rBTI）对胰蛋白酶的抑制活性与大豆胰蛋白酶抑制剂（SBTI）在温度、pH 值、盐离子和有机溶剂方面的敏感性进行了比较。rBTI 和 SBTI 在 2.0-12.0 的宽 pH 范围内均稳定。rBTI 的热稳定性高于 SBTI。Zn 离子（Zn）、KSCN、维生素 C 和尿素降低了 rBTI 的抑制活性，而 SBTI 的抑制活性保持不变。然而，HO、Mg 和 Cu 离子对 rBTI 和 SBTI 的抑制活性没有显著影响。乙腈增强了 rBTI 的抑制活性，但对 SBTI 没有影响，而二甲基乙酰胺（DMAC）则增加了 rBTI 和 SBTI 的抑制效果。相反，异丙醇和甲醇降低了 rBTI 和 SBTI 的抑制活性。rBTI 和 SBTI 的抑制常数 K 分别计算为 7.41×10^-7 M 和 6.52×10^-7 M。
