扫描电化学显微镜研究辣根过氧化物酶催化反应的动力学

Investigation of the Kinetics of Horseradish Peroxidase Catalytic Reaction by Scanning Electrochemical Microscopy

本文通过β-环糊精与环氧氯丙烷反应,合成了交联预聚物,进而在酸性条件下与戊二醛和辣根过氧化物酶反应,从而把辣根过氧化物酶固定在所形成的聚合物绝缘体基底上。应用扫描电化学显微镜的反馈模式,研究了辣根过氧化物酶的催化反应动力学。通过对扫描电化学显微镜在酶点上的反馈曲线与理论曲线的拟合,测得了一级反应速率常数,并用此方法研究了pH对反应速率常数的影响。在pH=7.0时,辣根过氧化物酶的活性最高,与文献报道一致,结果满意。

The homeradish peroxidases （HRP） molecules were immobilized on an insulator substrate with the crosslinked polymer of β-cyclodextrin prepolymer and glutaraldhyde. The kinetics of catalytic reaction of hydrnquinone （HQ） to p-benzoquinone （BQ） on the surface of immobilized HRP was studied by the scanning electrochemical microscopy with the feedback mode. The one-order enzyme-mediator kinetics was established. The apparent heterogeneous rate constant depended on pH. At pH 7.0, the heterogeneous rate constants had a maximmn value of 1.8×10^ -2cm/s.