摘要
以聚苯胺固定失活的尿酸酶形成酶电极,用酶电极研究尿酸酶的失活过程,在双硫腙存在下,固定的尿酸酶被激活,实验结果表明:尿酸酶的失活是由于 E+SES 反应的米氏常数下降而导致的。即失活的酶与底物形成的络合物的稳定性比活性酶与底物形成的络合物的稳定性高;双硫腙使尿酸酶激活是通过降低活化能而实现的.在双硫腙存在下,酶电极的响应电流随溶液的 pH 值、电位与温度的升高而增大;当底物浓度小于0.8 mmol·dm^(-3)时,响应电流与底物浓度呈线性关系.
An inactive uricase is immobilized in the polyaniline film to form an enzyme electrode,which is used for marking a study of the process for lose of enzymatic activity.The results show that the decrease in the Michaelis-Menten constant of the reaction E+SES,i.e. the stability of the complex formed from inactive uricase and uric acid is stronger than that formed from active uricase and uric acid,results in the lose of activity of uricase.Uricase is acti- vated by dithizone via lowering the activation energy.The response current of the enzyme elec- trode in the presence of dithizone increases with increasing pH values of the solution,potential and temperature,and increases linearly with increasing the concentration of uric acid in the range below 0.8 mmol·dm^(-3).
基金
江苏省教委自然科学基金
