萌发绿豆中水解大豆胰蛋白酶抑制子蛋白酶的纯化及固定化

大豆是豆类植物中最早发现存在蛋白酶抑制子的 ,由于其存在影响了豆类的利用价值 ,因此研究人员一直在寻找着解决办法。采用加热处理方法不能彻底钝化豆类蛋白的蛋白酶抑制子活性 ,且豆类蛋白的含硫氨基酸主要存在于各类蛋白酶抑制子中 ,从豆类蛋白中除去抑制子蛋白将大大降低其营养效价。本研究的目的是试图寻找一种可在常温下降解豆类胰蛋白酶抑制子的蛋白酶 ,从而钝化豆类的胰蛋白酶抑制活性。在前期工作中 ,我们发现枯草杆菌蛋白酶 (Ｓｕｂ ｔｉｌｉｓｉｎ)可在在常温下降解花生及大豆胰蛋白酶抑制剂1] ,近期我们的研究表明 ,Ａｌｃａ…

Purification and Immobilization of the Proteinase from Mung Bean Burgeon Inactivating Soybean Trypsin Inhibitor

By 30%-60% s(NH4)2SO4 fractional precipitation, anion-exchange chromatographs on DEAE-Sepharose CL-6B, gel filtration on Sephacryl S-200 and anion-exchange chromatographs on Waters AP-1 column(ProteinTm-Pak DEAE 15HR), a proteinase which can inactivated STI was purified from mung bean(Phaseolus aureus) burgeon. It was stable at temperatures lower than 50 degrees C and pH7.5-8.5, and the Km and Vmax of the proteinase for STI was 769.2 alpha-N-benzoyl-L-arginine ethyl ester(BAEE)/mL and 115.3BAEE/min/mL respectively. The molecular weight of the proteinase was estimated to be 29.8kD by SDS-PAGE. The proteinase immobilized by polyacrylamide was stable at temperatures lower than 60 degrees C and pH7.0-9.0, and the apparent Km* and Vmax* of the immobilized proteinase for STI was 1303.8 (BAEE)/mL and 94.34(BAEE)/min/mL respectively. The half-life of the immobilized proteinase was about 12 days at 4 degrees C.