联苯胺对碱性磷酸酶抑制作用及其动力学研究  

Inhibition Effect of Benzidine on Alkaline Phosphatase and Its Kinetics Study

作　　者：刘斌[1] 周培疆[1] 吴新国[1] 宋立荣[2] 

机构地区：[1]武汉大学资源与环境科学学院,武汉430079 [2]中科院水生生物研究所,武汉430072

出　　处：《环境科学与技术》2005年第3期6-8,共3页Environmental Science & Technology

基　　金：国家高技术研究发展计划(863)项目(2001AA641030);国家自然科学基金项目(20177018)

摘　　要：联苯胺作为一种危害严重对环境污染物,对小牛肠碱性磷酸酶的酶活力有明显的抑制作用。这种抑制随着联苯胺浓度的增加而增强,当联苯胺浓度>1.0μg/L时,其抑制程度趋于恒定。运用酶活力研究的动力学模型,在不同的酶底物浓度及不同的抑制剂浓度下,用分光光度法监测酶底物水解产物浓度随时间变化的过程,研究了抑制剂联苯胺对小牛肠碱性磷酸酶活性的抑制动力学,结果表明,联苯胺对小牛肠碱性磷酸酶的抑制是可逆抑制,属于可逆抑制中的竞争性抑制类型;求得其抑制剂常数Ki为1.28×10-7mol/L。Spectrophotometry was used to study activity of alkaline phosphatase in the presence and absence of benzidine. Relative activity of alkaline phosphatase was calculated according to the absorbance variation. Results showed the activity of alkaline phosphatase was obviously inhibited by benzidine.The inhibition type and inhibition constant of benzidine on alkaline phosphatase were determined by using double reciprocal plot.The kinetics of substrate reaction with different concentrations of substrate p-notrophenylphostrate (PNPP) and inactivator benzidine suggested a competitive complex mechanism for inactivation by benzidine, which is a competitive inhibitor of alkaline phosphatase,with inhibition constant of 1.28×10^(-7)mol/L.

关 键 词：碱性磷酸酶 联苯胺 抑制作用 动力学 

分 类 号：X132[环境科学与工程—环境科学]