蛋白水解产物中多肽得率的测定方法研究

An Improved Method for Determination of the yield of Peptides via Protein Hydrolysis

在相同条件下对大豆分离蛋白和酪蛋白进行水解实验,并分别通过甲醛滴定法和TCA法测定水解度,结合SDS-PAGE图谱和GPC图谱可知,TCA法比甲醛滴定法更能准确地表达水解的真实情况。但是在工业化生产中,仅用TCA法测水解程度还存在一些不足,因为水解的主要目的是要得到具有更多功能特性的肽类,而不是游离氨基酸,而TCA可溶氮中还有一些氨基酸贡献的氮。针对这种问题,本文提出一种简单可行的辅助TCA法,不仅测定水解前后真蛋白含量得到TCA指数,而且测定水解前后粗蛋白含量、水溶蛋白含量、氨基氮含量来综合反映水解程度。并采用凝胶渗透色谱初步分析了水解产物中水溶蛋白的分子量分布。另外这种方法不需要特别的仪器,操作方便,尤其适用于工业生产中水解程度的测定与控制,值得广泛应用和推广。

Hydrolysis of soy protein isolate and casein were carried out under the same conditions and the degree of hydrolysis was determined by formaldehyde titration method and TCA method.SDS-PAGE electrophoregram and GPC analysis showed that TCA method was more accurate than the formaldehyde titration method in monitoring the hydrolysis reaction.But TCA method was more suitable for determination the DH value than the yield of the product peptides.To solve these problems,an improved TCA method was developed in this paper,with which the total protein,soluble protein,and amino nitrogen contents before and after the hydrolysis were determined.And GPC analysis was also used for the preliminary analysis of the distribution of molecular weight of the water soluble protein of the hydrolysates.Besides,this method is simple and particularly applicable to the analysis and control of DH in industry.