蛋白酶对大豆分离蛋白的降解模式研究

COMPARATIVE DIGESTIBILITY OF SPI BY SEVERAL COMMERCIAL PROTEINASE

采用十二烷基酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE)方法,分析了几种商品蛋白酶(包括枯草杆菌蛋白酶、胰蛋白酶、胰凝乳蛋白酶、木瓜蛋白酶和细菌碱性蛋白酶)对大豆分离蛋白(SPI)的降解模式。结果表明,大豆球蛋白酸性亚基的Ax多肽链最容易被水解,所有的酶对其均有作用,而碱性亚基和大豆伴球蛋白的β亚基最难被水解。木瓜蛋白酶对大豆分离蛋白的水解最迅速、彻底,由于大豆蛋白中含有胰蛋白酶抑制因子,胰蛋白酶和胰凝乳蛋白酶对大豆蛋白水解能力较差。

SPI hydrolysates induced by several commercial proteinases （subtilisin, protease, chymotrypsin, trypsin, papain, and Protex） were analyzed by the SDS-PAGE. The results indicate that Ax peptides of the acid subunit of soybean glycinin was most susceptible, and the β bands of β -conglyeinin and basic subunit of glycinin was most resistant to digestion. The native SPI was rapidly hydrolyzed by papain, while was markedly resistant to the trypsin and chvmotrvnsin because of the trypsin inhibitor.