米渣浓缩蛋白酶法增溶机理初探

Study on Mechanism of Solubilization of Rice Dreg Protein Concentrates

从酶反应动力学的角度讨论了不溶性的米渣浓缩蛋白(RDPC)增溶机理,包括:一部分溶解的蛋白酶与不溶性米渣浓缩蛋白(RDPC)吸附,使不溶性蛋白增溶,另一部分溶解的蛋白酶用来断裂由不溶性蛋白增溶后,溶解于溶液中的片段;反应产物对酶活力的抑制;补加底物的增溶说明了反应体系中有大量溶解的游离态酶没有得到充分利用,同时提示可以用固定化酶的方法来减少产物(低分子量肽段)对酶活力的抑制;动力学反应的初速率方程式为:V0=k2X1mK1[E]0[S]0/1+K1[E]0+K1[S]0X1m=0.8859×[E]0[S]0V0/1+6.3027[E]0+0.03590[S]0水解产物的凝胶过滤显示,碱性蛋白酶(Alcalase)降解不溶性组分(Pr)有可能符合“ZipperReaction”模型。

From the kinetics point of view, the mechanism of solubilization of rice dreg protein concentrates （RDPC） was discussed and would include： enzyme interacted with RDPC suspensions partly by rapid adsorption into RDPC particles, increasing solubilization of insoluble proteins, and partly due to protein fragments proteolysis cleaved by the adsorbed enzyme already dissolved in the liquor. The product inhibited the enzyme activity. Experiment of addition of substrate in a batch reaction showed fresh substrate can increased the extent of solubilization and better utilization of the enzyme. It also suggested that the immobilized-enzyme recycle system can decrease the product inhibition of enzyme activity. The initial reaction velocity equation is established as follows：V0=k2X1mK1[E]0[S]0/1＋K1[E]0＋K1[S]0X1m=0.8859×[E]0[S]0/1＋6.3027[E]0＋0.03590[S]0 Gel filtration of hydrolysate showed that the hydrolysis of insoluble fraction of Pr is possibly fit for ＂Zipper Reaction＂ model.