福林酚试剂法与缩二脲试剂法测定饲用蛋白酶活力的比较分析

Comparison of the Folinphenol reagent method and the Biuret reagent method for determination of feed protease activity

本试验采用福林酚试剂法和缩二脲试剂法分别测定10种饲用蛋白酶活力,并比较两种方法测得牛血清蛋白(BSA)和酪氨酸(Tyr)标准曲线的线性相关性和两种方法测定蛋白酶活力的准确性、灵敏度及变异度。结果表明,两种方法测得的两种标准曲线的线性相关性均较好,同时两种方法测得蛋白酶活力的精确度及变异度也均较好;相对于缩二脲试剂法,福林酚试剂法测定蛋白酶活力的灵敏度较高,检测限较低,同时福林酚试剂法测定中性或碱性蛋白酶活力准确性较高,但测定酸性蛋白酶活力准确性较低。普通氨基酸含量的测定可以选用福林酚试剂法,而双缩脲试剂法可以很好地测定饲料中蛋白质含量,故在实际工作中应根据需要选择合适的方法。

In this study,the protolytic activity of 10 feed proteases was measured by the Folinphenol reagent method and the Biuret reagent method respectively.Then,the linear correlation of standard curves of BSA and Tyr,and the accuracy,sensibility and variation of two methods were compared.The results showed that there were satisfactory linear correlations between the activity and the absorbance read using the two methods.The precision and variation of the enzyme preparations by the two methods were also acceptable.Compared with the Biuret reagent method,the Folinphenol reagent method produced the higher sensibility and lower detectability of enzyme activity,and more accurate measurement of neutral or alkaline proteases activities.However,the measurement of acid protease activity was less accurate using the Folinphenol reagent method.The content of amino acids could be measured by the flinol reagent method,while the content of protein in feedstuff could be measured by the biuret reagent method.The present study implied that we should select the appropriate method to measure the activity of proteases according to specific need in practical work.