牦牛肉组织蛋白酶L酶学特性的研究

Study on enzymatic characteristics of cathepsin L from yak meat

摘要: 以牦牛背最长肌为原料,从中提取组织蛋白酶L并对其酶学性质进行研究。结果表明,该酶水解专一性荧光底物Z-Phe-Arg-AMC的最适反应pH和温度分别为5.5和40℃,在pH5.0～6.0、40～50℃条件下酶活稳定性最高。最适酶促反应时间和底物浓度分别为30min和25μmol/L。金属离子Ca2+、Cu2+、Mn2+、K+、Fe3+、Fe2+、Zn2+均能抑制酶活。EDTA和EGTA对酶有一定的抑制作用,L-Cys和β-ME对酶起激活作用。

Abstract: Cathepsin L was extracted from Longissimusdorsi of yak and studied on its enzymatic characteristics.Results indicated that optimum pH and temperature of the enzyme for hydrolysis of substrate specificity Z-Phe-Arg-AMC were pH5.5 and 40℃.It was high stable at pH5.0 ～ 6.0 and 40 ～ 50℃.The appropriate reaction time and substrate concentration were 30min and 25μmol/L, respectively.Metal ions including Ca2+、Cu2+、Mn2+、K+、Fe2+、Fe3+and Zn2+inhibited the enzyme in various degree.The enzyme was partially inhibited by EDTA and EGTA while L-Cys and β-ME could increase the activity of the protease.