竹笋胰蛋白酶抑制剂的分离纯化及其性质

Purification and character of trypsin inhibitor from bamboo shoots

为寻找天然胰蛋白酶抑制剂,经过葡聚糖凝胶G25、G50柱、二乙二胺乙基纤维素-葡聚糖凝胶A50分离纯化从竹笋中获得了竹笋胰蛋白酶抑制剂(BSTI),纯化后浓度比粗提物提高了1 200倍,SDS-PAGE显示纯化胰蛋白酶抑制剂为单一条带。其性质研究表明:经100℃热变性15 min后,BSTI仍保持50%的抑制活性,表明BSTI有较强的热稳定性;BSTI的等电点为4.4左右;BSTI在CoCl_2溶液中还有94.7%的活性,但是在FeSO_4溶液中活性却完全被压制;BSTI在氧化剂中活性不高;几种还原剂对其活性有一定的抑制,但是维生素C不仅不会抑制其活性反而能够提高它的活力;螯合剂KCN能大幅提高BSTI的活性,EDTA和喔星会抑制其活性。

For seeking natural trypsin inhibitor, bamboo shoots trypsin inhibitor （BSTI） was purified and characterized from bamboo shoots, using sephadex G25 column, sephadex G50 column, ethylene diamine ethyl cellulose-Sephadex A50. After purifying, the concentration of the bamboo shoots trypsin inhibitor was 1 200 times higher than that of crud extract. And there was a single band in SDS-PAGE. Studying the properties of BSTI indicated flow. BSTI has good thermal stability, which held 50% inhibitory activity at 100 ℃ for 15min.The isoelectric point of BSTI was about 4.4. There was 94.7% inhibitory activity in COCl2 solution. But the activity in FeSO4 solution was completely suppressed. The activity of BSTI in the oxidant is not high. Several reducing agents have some inhibition on its activity. However, vitamin C did not inhibit its activity, but can improve its vitality. KCN which was a chelating agent can significantly improve the activity of BSTI, EDTA and oxine can inhibit its activity.