流动注射法测定血红蛋白与过氧化物酶对H_(2)O_(2)/愈创木酚反应体系的动态催化性能

Determination of Dynamic Catalytic Activities of Hemoglobin and Peroxidase for H_(2)O_(2)/Guaiacol Reaction System by Flow Injection Analysis

辣根过氧化物酶(HRP)已被广泛应用于各个领域,但其价格昂贵且不易保存,所以寻找一种可替代HRP的模拟酶意义重大。本研究初步选择血红蛋白(Hb)作为模拟酶,利用流动注射光度系统(SP-FIA),在非平衡状态下对比了Hb与HRP对H_(2)O_(2)/愈创木酚(GA)反应的动态催化性能。结果表明:Hb在弱酸性及高温环境下其稳定性强于HRP;Hb对H_(2)O_(2)/GA反应体系的催化作用符合米氏方程,可作为一种过氧化物模拟酶使用;在动力学研究中发现,Hb对GA和H_(2)O_(2)的催化活性不及HRP,对GA的亲和力强于HRP,对H_(2)O_(2)的亲和力弱于HRP。干扰实验表明,Hb的催化性能可被Co^(2+)、Cu^(2+)、Pb^(2+)、Fe^(3+)、Zn^(2+)激活;EDTA和抗坏血酸可抑制Hb,柠檬酸的酸性环境利于Hb催化;EDTA、抗坏血酸及柠檬酸均能抑制HRP。

Horseradish peroxidase(HRP)has been widely used in various fields.But it is expensive and hard to preserve,so it will be important to search for an alternative mimetic enzyme.In this paper,taking hemoglobin(Hb)as a mimetic enzyme,dynamic catalytic properties of Hb and HRP to H_(2)O_(2)/guaiacol(GA)reaction under non-equilibrium state were compared by a special flow-injection photometric system(SP-FIA).The results showed that under weak acidity and high temperature environments,Hb was stronger than HRP in the stability;the catalysis of Hb to the H_(2)O_(2)/GA reaction conformed to Michaelis equation,this proved that it could be used as a simulation enzyme.In the study of dynamics,it was found that its catalytic activity to H_(2)O_(2)and GA was lower than HRP,the affinity of Hb to GA was stronger than that of HRP,and the affinity of Hb to H_(2)O_(2)was weaker than that of HRP.The interference tests showed that the catalytic activity of Hb could be activated by Co^(2+),Cu^(2+),Pb^(2+),Fe^(3+)and Zn^(2+);EDTA and ascorbic acid would lower the catalytic activity of Hb,but the acidity of citric acid was conducive to the Hb catalysis.