基于氨基酸偶合显色的丝胶蛋白定量分析

为了解决在蚕丝精练实际生产中监测练减率的问题,利用丝胶蛋白中氨基酸残基与重氮盐偶合显色的特征反应来推算练减率。文章首先绘制了氨基酸模拟丝胶蛋白偶合显色的吸光度—氨基酸浓度标准工作曲线,并且研究了重氮盐的稳定性、偶合反应pH值对偶合吸光度的影响,以及丝胶蛋白碱水解后的沉淀物成分。结果表明,在0℃时重氮盐能稳定保存,但温度升高会导致其不稳定;偶合反应pH值控制在10左右时,偶合效率较高。由于精练残液碱水解后与重氮盐偶合显色推导的练减率较实际练减率低3%～4%,丝胶蛋白碱水解沉淀物不含丝胶成分,因此加上实验误差,能够反映实际生产中蚕丝精练的脱胶情况。

Quantitative analysis of sericin based on amino acid coupling coloration

In order to realize monitoring degumming loss percentage in real production of silk refining,degumming loss percentage was reckoned based on the characteristic reaction of coupling coloration of amino acid residues in sericin with diazonium salt.In this study,the standard curve of absorbance-amino acid concentration of amino acid mimicking protein-coupled coloration was drawn first,and researches were conducted on stability of diazonium salt,effect of coupling reaction pH on coupled absorbance,and precipitation composition produced via sericin basic hydrolysis.The results show that diazonium salt can be stably stored at 0℃,but it will become instable as the temperature rises;coupling efficiency remains high as long as coupling reaction pH is controlled around 10.The degumming loss percentage reckoned after basic hydrolysis of bast liquor and coupling coloration of diazonium salt is lower than the real value by 3%to 4%,basic hydrolysis precipitation of sericin contains no glue-like component,and there exist experimental errors.In view of this,the results can reflect degumming of silk refining in actual production reliably.