燐光寿命法研究变性剂对大肠杆菌碱性磷酸酶构象的影响  

Study on Effects of Denaturants on the Conformation of Escherichia coli Alkaline Phosphatase by Phosphorescence Lifetime

作　　者：张海容[1] 晋卫军[2] 刘长松[2] 

机构地区：[1]忻州师范学院化学系,忻州034000 [2]山西大学化学系,太原030006

出　　处：《化学学报》2003年第3期312-315,共4页Acta Chimica Sinica

基　　金：国家自然科学基金 (Nos.2 95752 0 4 ;2 98750 1 6)资助项目

摘　　要：色氨酸残基光寿命监测了大肠杆菌碱性磷酸酶在不同变性剂中展开过程的构象变化 .结果表明 :不同变性剂加入蛋白质溶液中 ,色氨酸残基的微环境发生了较大的变化 ,光发射减弱 ,寿命缩短 ,预示了色氨酸残基从刚性的疏水内芯转移到蛋白质表面 ;通过Arrhenius关系式获得的热动力学参数如活化能 (Ea)、活化熵 (ΔS°)、活化焓 (ΔH°)The conformational change of Escherichia coli alkaline phosphatase in different denaturants during unfolding is monitored by phosphorescence lifetime of tryptophan (Trp) residue. The results suggest that addition of different denaturants to solution of protein results in a major change of microenvironment near Trp residues, causing a decrease of the phosphorescence emission and a corresponding shortening of the phosphorescence lifetimes. The results predict that the Trp residues are transferred from rigid hydrophobic core to the surface of protein. The data of thermodynamic parameters such as activation energy, activation entropy (ΔS°) and activation enthalpy (ΔH°) are obtained by the Arrhenius plots of AP, which further confirm that there is a stable intermediate state between the folding and unfolding conformation in AP solution.

关 键 词：Lin光寿命法 变性剂 大肠杆菌 碱性磷酸酶 色氨酸残基 蛋白质 构象 

分 类 号：Q936[生物学—微生物学]