槐定碱与溶菌酶相互作用的荧光法研究  

Studies on the Interaction of Sophordine with Lysozyme by Fluorescence Spectroscopy

作　　者：张国文[1] 赵楠[1] 李蔚博[1] 胡兴[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《南昌大学学报（理科版）》2009年第4期350-353,共4页Journal of Nanchang University(Natural Science)

基　　金：科技部国家重点实验室基金资助项目(SKLF-MB-200807);江西省教育厅科技计划基金资助项目(GJJ08025);江西省自然科学基金资助项目(2007GZH1924)

摘　　要：应用荧光和紫外-可见光谱法,研究了生理酸度(pH 7.4)条件下槐定碱与溶菌酶(LYS)相互作用的光谱特性。荧光猝灭光谱、共振瑞利散射光谱和紫外吸收光谱实验显示,槐定碱与溶菌酶相互作用生成新的复合物引起的静态猝灭是导致溶菌酶内源荧光猝灭的主要原因;求得不同温度下槐定碱与溶菌酶作用的结合常数和结合位点数;由van’tHoff方程式计算出槐定碱与溶菌酶反应的热力学参数:焓变ΔH和熵变ΔS值分别为-73.19 kJ.mol-1和-130.86 J.mol-1.K-1,表明槐定碱与溶菌酶之间的作用力以氢键和范德华力为主。同步荧光光谱显示,槐定碱与溶菌酶结合并不影响溶菌酶的构象;金属离子的存在对槐定碱与溶菌酶作用的结合常数产生一定的影响。The spectroscopic character between sophordine and lysozyme （LYS） was studied using fluorescence and UV - vis absorption spectra under the simulative physiological condition. The experimental results showed that there was a strong fluorescence quenching of lysozyme by sophordine. of lysozyme by sophordine was a static quenching by forming the The probable quenching mechanism of fluorescence sophordine - LYS complex. The binding constants Ka and number of binding sites n of sophordine with lysozyme were obtained by fluorescence quenching method. The thermodynamic parameters of the interaction of sophordine with lysozyme were measured according to the van＇s Hoff equation. The enthalpy change （ΔH） and the entropy change （ΔS） were calculated to be - 73.19 kJ ·mol^-1, - 130.86 J·mol^-1·K^-1 respectively,which indicated that the interaction between sophordine and lysozyme was driven mainly by hydrogen bond and van der Waals forces. The result of synchronous fluorescence spectra demonstrated that sophordine did not change the microenvironment around the tryptophan residues. In addition, the metal ions can effect on the binding constants of sophordine with lysozyme .

关 键 词：槐定碱 溶菌酶 荧光光谱法 热力学参数 

分 类 号：O657.3[理学—分析化学]