食品科学 ›› 2007, Vol. 28 ›› Issue (6): 213-217.

• 生物工程 • 上一篇    下一篇

米曲霉蛋白酶动力学特性的研究

 张青, 许学书, 谢静莉, 梁晓声   

  1. 华东理工大学生物反应器工程国家重点实验室; 华东理工大学生物反应器工程国家重点实验室 上海200237; 上海200237;
  • 出版日期:2007-06-15 发布日期:2011-12-31

Study on Kinetic Behaviors of Aspergillus oryzae Protease

 ZHANG  Qing, XU  Xue-Shu, XIE  Jing-Li, LIANG  Xiao-Sheng   

  1. State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Online:2007-06-15 Published:2011-12-31

摘要: 研究了在不同底物浓度、温度和pH下米曲霉蛋白酶水解酪蛋白产生酪氨酸的动力学特性。在反应时间为10min时,最佳反应温度为50℃,最佳反应pH为9。实验表明米曲霉蛋白酶水解酪蛋白生成酪氨酸的反应符合米氏方程,根据实验数据回归得到温度为40℃时的速度方程为r=0.243CS/0.0282+CS,反应速度与氢离子浓度的关系为r=lgCH++3.14013/0.19759+0.05484(lgCH++3.14013)+(lgCH++3.14013)2。该蛋白酶在50℃下的失活规律符合双指数模型,相对酶活力与时间的关系为a=0.82531e(-0.02169t)+0.17469e(-0.41914t)。在4~50℃的范围内,蛋白酶水解反应的活化能Ea为30.67kJ。还研究了不同化学组分对蛋白酶活力的影响,发现10mmol/L的H3BO3和Mg2+对该蛋白酶有一定的激活作用,而EDTA、SDS、Zn2+、Mn2+和Sn2+对蛋白酶有明显的抑制作用,10mmol/L的H2O2对该蛋白酶的抑制作用不明显。

关键词: 米曲霉, 蛋白酶, 动力学

Abstract: The kinetic behaviors of casein hydrolysis by Aspergillus oryzae protease were studied under different substrate concentrations, temperatures and pHs. The optimal temperature and pH for 10 min-reactions are: 50 ℃ and pH 9 respectively. The experiment results showed that at 40 ℃, the kinetics of casein hydrolysis by the protease fit the Mchaelis-Menton equation which can be written as r=0.243CS/0.0282+CS and the relation between hydrolysis rate and hydrogen ion concentration is: r=lgCH++3.14013/0.19759+0.05484(lgCH++3.14013)+(lgCH++3.14013)2. The protease relative deactivity at 50 ℃ follows a= 0.82531e(-0.02169t)+0.17469e(-0.41914t). The energy of activation (Ea) under 50℃ is 30.67 kJ. The effects of different chemicals on protease activity were observed under the same condition as protease activity assay. The protease activity is enhanced by 10 mmol/L H3BO3 or Mg2+ and inhibited by EDTA, SDS, Zn2+, Mn2+ or Sn2+ obviously, however it is not affected by 10 mmol/L H2O2.

Key words: Aspergillus oryzae, protease, kinetic