紫外-可见分光光度法和计时电流法测定酶催化2,6-二甲氧基苯酚氧化反应的米氏常数

Michaelis Constant Determination for Laccase Catalyzed Oxidation of 2,6-Dimethoxyphenol with UV-Vis Spectroscopy and Chronoamperometry

设计了一个使用不同方法测定酶催化反应动力学参数的综合性实验，即分别使用紫外一可见分光光度法和计时电流法测定固载在天然高分子衍生物包覆磁性纳米粒子上的漆酶催化酚类氧化反应的米氏常数KM。实验结果表明，2种方法测定所得的KM没有显著性差异，但计时电流法操作更简便、更迅速，测定结果具有更高的精密度。更重要的是，相对于紫外一可见分光光度法，计时电流法测定酚类浓度具有更为良好的重现性和更小的误差，是一种在线测定酚类含量的便捷方法。

Comprehensive experiment was introduced in this paper to propose different meth ods to measure kinetic parameter of enzymatic catalysis. Michaelis constant for catalytic oxidation of phenol-like compound induced by Laccase immobilization on the magnetic nano particle over lapped by derivative of natural polymer, was determined by UV-Vis spectroscopy and chrono amperometry, respectively. Results from experiments indicated no distinguished difference was observed for values of Michaelis constant measured by both methods while the latter showed such advantages as convenient operation, swift response and favorable precision. It was more impor- tant that superiority of better reproducibility and smaller error could be found in result of deter ruination in content of phenol for chronoamperometry in comparison to that for UV Vis spectros copy. All of these indicated chronoamperometry could be suitable for measurement of phenol con- tent on-line.