食品科学 ›› 2009, Vol. 30 ›› Issue (5): 60-63.doi: 10.7506/spkx1002-6630-200905012

• 基础研究 • 上一篇    下一篇

交变磁场对苹果多酚氧化酶反应动力学的影响研究

高梦祥,王雯蕙,严奉伟,张长峰   

  1. 长江大学生命科学学院
  • 收稿日期:2008-03-26 修回日期:2008-07-18 出版日期:2009-03-01 发布日期:2010-12-29
  • 通讯作者: 高梦祥 E-mail:mxgao0398@126.com;
  • 基金资助:

    湖北省科技攻关计划项目(2006AA201C36)

Effects of Alternating Magnetic Field on Reaction Kinetics of Apple Polyphenol-oxidase

GAO Meng-xiang,WANG Wen-hui,YAN Feng-wei,ZHANG Chang-feng   

  1. (College of Life Science, Yangtze University, Jingzhou 434025, China)
  • Received:2008-03-26 Revised:2008-07-18 Online:2009-03-01 Published:2010-12-29
  • Contact: GAO Meng-xiang, E-mail:mxgao0398@126.com;

摘要:

以邻苯二酚为底物,研究了交变磁场对苹果多酚氧化酶(PPO)反应动力学的影响。结果表明:苹果PPO褐变反应动力学符合米氏方程所描述的单底物酶促反应动力学。相应的动力学参数为Km=0.000687mol/L,Vmax=0.0477U/min。磁场强度小于0.87A/m 时,磁场处理的反应体系表现为促进作用。磁场强度为1.67A/m、处理时间小于3h 时,磁场处理表现为促进作用,处理时间大于3h 时,表现为抑制作用。磁场强度大于1.67A/m 时,磁场处理对反应体系都有抑制作用,而且随着磁场强度的增大,抑制作用增强。同一强度磁场在处理时间大于1h,随处理时间的增加,磁场处理的效果趋于平稳。以强度为4.22A/m 的磁场对多酚氧化酶反应体系的作用在出现促进作用后趋于稳定的抑制作用,0.5h 左右时促进作用最强,0.5h 之后开始呈现抑制作用,1h 左右抑制作用趋于平稳。以强度为4.22A/m 的磁场处理1h,其动力学参数Km 和 Vmax 分别变为0.0108mol/L 和0.0146U/min。表明交变磁场可抑制酶对底物的亲和力,并可使最大反应速度降低。

关键词: 苹果, 多酚氧化酶, 反应动力学, 交变磁场

Abstract:

With catechol as substrate, the change laws of reaction kinetics of apple polyphenol-oxidase (PPO) induced by alternating magnetic field were studied. The results indicated that the reaction kinetic of apple PPO browning is in accordance with Michaelis equation, and the Km and Vmax are 0.000687 mol/L and 0.0477 U/min, respectively. When the magnetic field strength is less than 0.87 A/m, the reaction system shows to be promoted; When the magnetic field strength is 1.67 A/m, the reaction system shows to be promoted by less 3-h treatment and to be inhibited by over 3-h treatment; When the magnetic field strength is more than 1.67 A/m, the reaction system is inbibited regardless of treatment time. Furthermore, the inhibitory effect of magnetic field increases with the increase of its strength. However, when the treatment time is over 1 h at the same strength, the effect of magnetic field tends to steady even if the treatment time extending. When the magnetic field strength is 4.22 A/m, it shows the strongest promotion effect on the PPO reaction system at 0.5 h and gradually presents the inhibitory effect after 0.5 h; Over 1 h, its inhibitory effect becomes steady with the Km of 0.0108 mol/L and Vmax of 0.0146 U/min. In conclusion, alternating magnetic field is able to inhibit the affinity of enzyme to substrate and decrease the maximum reaction velocity.

Key words: apple, polyphenol-oxidase (PPO), reaction kinetics, alternating magnetic field

中图分类号: