一种双子表面活性剂与BSA相互作用的荧光研究

摘要

The interaction between Gemini surfactant glycol bis-N-tetradecyl nicotinate dibromide with bovine serum albumin (BSA) was studied by fluorescence spectra.The results showed that glycol bis-N-tetradecyl nicotinate dibromide quenched the intrinsic fluorescence of BSA through a combined (dynamic arid static) procedure.The binding constant (K),binding site (n) and the thermodynamic parameters were calculated,and the data revealed that the binding was a spontaneous,endothermic and entropy driving process and hydrophobic force predominated the interaction of glycol bis-N-tetradecyl nicotinate dibromide and BSA.However,the electrostatic interaction and π-π stacking should be taken into account.Hydrophobic tails of glycol bis-N-tetradecyl nicotinate dibromide embedded to the hydrophobic pocket of BSA in site Ⅰ and altered the structure of BSA.%采用荧光光谱法研究了双子表面活性剂溴化双-N-十四烷基二甘醇酯与牛血清白蛋白(BSA)的相互作用.实验结果表明该双子表面活性剂主要以静态猝灭和动态猝灭结合的方式猝灭BSA的内源荧光.计算了结合常数K和结合位点数n及热力学参数,结果表明两者的结合是一个吸热熵驱动的自发过程,疏水作用力是主要作用,但考虑到该双子表面活性剂的结构和所带的正电荷,及该条件下BSA中一些含芳香环的氨基酸残基及某些残基可能带负电荷,因此两者之间的静电相互作用和π-π堆积作用也不可忽略.竞争实验表明,表面活性剂的疏水链通过疏水作用插入到BSA的疏水微区,在位点Ⅰ结合,从而引起蛋白质的构象变化.