摘要
酪氨酸在辣根过氧化物酶催化下被H2O2氧化为强荧光物质(产物S),姜黄素对其荧光产生猝灭作用,根据Stern-Volmer方程和荧光寿命法研究了姜黄素对产物S的荧光猝灭为静态猝灭。姜黄素与产物S的形成常数K=9.51×108L/mol(25℃),结合点数n=1.94。探讨了产物S与姜黄素的反应机理,该反应的热力学参数△G=-56.11 kJ.mol-1,△H=57.37 kJ.mol-1,△S=365.9 J.K-1.mol-1,说明该反应是自发进行的吸热过程。
Because of catalysis of horseradish peroxidase, tyrosine reacted with H2 O2 to form the product S which was a strong fluorescent substance. Curcumin acted as a quencher to the product. The static quenching process was confirmed by the measurement of fluorescence lifetime and on the basis of Stern- Volmer plot. The binding constant, K=9.51×108 L·mol ^-1 and the number of binding sitesn=1. 94, were obtained. The reaction mechanism between product S and curcumin was also studied. The thermodynamic parameters, △H=57.37 kJ·mo1^-1 , △S=365.9 J·mo1^-1·K^-1 and the mean value △G =-56.11 kJ·mol^-1, were estimated. The thermodynamic parameters showed that the reaction was an endothermic and spontaneousvan process.
出处
《分析科学学报》
CAS
CSCD
北大核心
2009年第4期451-454,共4页
Journal of Analytical Science
基金
山东省自然科学基金(No.Y2006B31)
关键词
酪氨酸
酶催化
荧光猝灭
姜黄素
热力学参数
Tyrosine
Enzyme-catalyzed
Fluorescence quenching
Curcumin
Thermodynamic parameters
