碱性蛋白酶Alcalase凝固大豆分离蛋白的分子间作用力

Molecular forces involved in the enzymic coagulation of soybean protein isolate by an alkaline proteinase—Alcalase

为了进一步揭示蛋白酶凝固豆乳的机理,该文通过添加不同化学试剂研究碱性蛋白酶Alcalase凝固大豆分离蛋白(SPI)过程中的分子间作用力。结果发现凝固过程中的分子间作用力主要是氢键和疏水作用,而离子键和二硫键对凝固过程影响不大。大豆蛋白质分子间的交联主要由次级键起作用,同时需要克服由负电荷引起的静电斥力,这就解释了为什么与无机盐和酸相比,Alcalase得到的SPI凝固物强度低。根据以上结论,该文还对豆乳凝固酶当前的筛选策略进行了评价。

The molecular forces involved in the enzymatic coagulating process of soyabean protein isolate（SPI） by an alkaline proteinase Alcalase were investigated by adding different chemical reagents. Results indicate that non-covalent bonds, including hydrogen bond and hydrophobic reaction contribute most to the coagulating reaction, while ionic bond and disulfide bond have little effect on the coagulating process. Depending on secondary chemical bonds and having to resist to the repulsive interaction by the negative charges may explain why the coagulating strength of SPI coagulum induced by Alcalase is weaker than that induced by acid and saline coagulants. The current screening strategy for soymilk coagulating enzymes is also commented according to the results.