摘要
为掌握碱性蛋白酶对荞麦蛋白的酶解特性,实现对荞麦蛋白的深加工利用及生物活性肽的开发。采用pH-stat法,系统分析了底物浓度、酶浓度、pH及温度对荞麦蛋白水解度的影响,并运用对数函数对水解动力学过程进行描述和拟合。结果表明:在碱性蛋白酶水解荞麦蛋白的过程中,水解度随水解时间的变化呈现对数函数关系,可用公式h=(1/b)ln(1+abt)对其水解动力学过程进行描述;底物具有促进水解反应速度和抑制酶活性的双重作用,在低底物浓度条件下,荞麦蛋白的水解度较高;当底物浓度增加到6%时,蛋白水解度与底物浓度的关系曲线出现转折,水解度较低且趋于平缓;在酶浓度为0.002 g/mL时,水解反应的临界底物浓度为12.27%;在pH 9.8、水解温度为50℃、水解时间30 min的条件下,碱性蛋白酶催化水解荞麦蛋白的动力学方程为h=1.218 2 ln(1+12.6([E][S]+0.58)t)
The hydrolysis kinetic model of buckwheat protein catalyzed with alkaline protease was studied using the pH - stat method in order to grasp the enzymatic hydrolysis characteristics, realize deep processing and utilization of buck- wheat protein and develop biological active peptide products. The effects of substrate concentration, enzyme concentration, pH and temperature on the hydrolysis degree of buckwheat protein were systematically analyzed, and the hydrolysis kinetic process was described and fitted using logarithmic function. Results show： During the process of buckwheat protein hydrolysis with alkaline protease, the change between hydrolysis degree and time presents logarithmic function relationship, and its hydrolytic kinetic process can be described using the formula of h = （1/b） In（ 1 ＋ abt）. The substrate concentration possesses dual function of accelerating hydrolysis reaction rate and depressing enzyme activation, and the hydrolysis degree of buckwheat protein is higher under lower substrate concentration condition; as the substrate concentration increases to 6%, the relationship curve between protein hydrolysis degree and substrate concentration presents a transition, the hydrolysis degree becomes lower and tends to flat; in the enzyme concentration of 0. 002 g/mL, the critical substrate concentration is 12.27%. Under the condition of pH 9.8 and temperature 50 ℃, the first 30 min kinetic equation of hydrolysis of buck-wheat protein catalyzed by alkaline protease can be expressed as h=1.2182ln（1＋12.6（[E][S]＋0.58）t）.
出处
《中国粮油学报》
EI
CAS
CSCD
北大核心
2009年第6期41-46,共6页
Journal of the Chinese Cereals and Oils Association
基金
陕西省科技攻关项目(2008G01-02)
关键词
荞麦蛋白
碱性蛋白酶
水解
动力学
buckwheat protein, alkaline protease, hydrolysis, kinetics
