应用化学 ›› 1994, Vol. 0 ›› Issue (4): 54-57.

• 研究论文 • 上一篇    下一篇

多酚氧化酶催化反应的抑制动力学及机理

孔龙, 霍瑞贞   

  1. 华南理工大学应用化学系 广州 510641
  • 收稿日期:1993-10-27 修回日期:1994-02-07 出版日期:1994-08-10 发布日期:1994-08-10

Kinetics and Mechanism of Inhibition of Polyphenoloxidase Catalyzed Oxidation

Kong Long, Huo Ruizhen   

  1. Department of Applied Chemistry, South China University fo Technology, Guanzhou 510641
  • Received:1993-10-27 Revised:1994-02-07 Published:1994-08-10 Online:1994-08-10

摘要: 用丙酮自香蕉皮中提取多酚氧化酶,用氧电极法测得酶促儿茶酚氧化反应的表现活化能为23.6kJ·mol-1,米氏常数为1.58×10-2mol/L,测试了9种化合物对酶活性的抑制效果。以苯甲酸为抑制剂研究了抑制动力学及机理,测出蕉皮酚酶中含有铜离子,它起着活化反应物的作用,抑制剂与铜离子的结合抑制了酶的催化活性。

关键词: 儿茶酚, 多酚氧化酶, 抑制剂, 反应动力学, 反应机理, 苯甲酸

Abstract: The polyphenoloxidase has been isolated from banana peel by extraction with cold acetone. The catechol oxidation reaction catalyzed by polyphenoloxidase is selected as a model to study the oxidase catalyzed oxidation by using an oxygen electrode,The activation energy of the reaction was calculated to be 23. 6kJ·mol-1,and the Michae's constant 1·58?10-2mol/L. Nine compounds were found to have inhibition effects on the activity of the oxidase,The inhibition kinetics and the mechanism of the catechol oxidation have been investigated by using benzoic acid as inhibitor. The results showed that the copper ions which was found in the polyphenoloxidase may activate the substrates and the combination of the copper ions with inhibitor results in the inhibition effect on the catalytic oxidation.

Key words: catechol, polyphenoloxidase, inhibition, kinetics, mechanism, benzoic acid