作　　者： ; ; ; ;

机构地区： 华南理工大学轻工与食品学院

出　　处： 《云南农业大学学报》 2006年第2期142-149,共8页

摘　　要： 研究了大豆分离蛋白的枯草杆菌蛋白酶水解产物的聚集行为。加入枯草杆菌蛋白酶后,大豆蛋白分离物被迅速降解为分子量小于6.5 kDa小分子组分,这些组分相互作用形成大的聚集物。水解液的浊度变化趋势呈S型,底物浓度大于3.2%(酶浓度为750 U/mL)时蛋白质的浓度对聚集过程的影响更明显,此临界浓度主要取决于酶浓度。适当的预热处理有利于酶促聚集。由于聚集物能溶于SDS和尿素,说明非共价键(主要是疏水相互作用、氢键和离子键)对聚集物的形成有特别重要的作用。最后并提出了酶促聚集的机理。 The behavior of aggregation of soy protein isolate （SPI） induced by Subtilisin protease was vestigated. Once incubated with Subtilisin protease, the SPI proteins were rapidly digested to small fragments （ 〈6.5 kDa）, which were the major fragments involved in the aggregates. The process of the aggregation was monitored using a turbidity method. The development of the turbidity followed a kind of S-curve because of the digestion of protein and the aggregation of hydrolysates. Higher[ SPI]0 in the range from 1% to 8% favored the aggregation, the influence of the concentration of SPI on the aggregation became more outstanding at the higher concentration of SPI （ 〉 3.2 % ） with 750 U/mL enzyme. The critical concentration was dependent strongly on the concentration of enzyme （ [ E ] 0 ）. Proper thermal pretreatment favored the enzyme-induced aggregation, the velocity of aggregation of the preheated SPI induced by Subtilisin protease was 100 times as fast as that of the native SPI. As the ag- gregates were solubilized in SDS and urea, it was proposed that noncovalent interactions, mainly electrostatic, hydrophobic and hydrogen bindings, are major interaction forces, and the disulfide bonds contribute little or not at all to the formation of aggregates induced by Subtilisin protease .

关 键 词： 大豆分离蛋白 枯草杆菌蛋白酶 聚集 相互作用力

领　　域： [生物学]