6-乙基-4-乙氧羰基-2-(4-氰基苯基)喹啉与BSA相互作用研究  

Interaction of 6-ethyl-4-ethoxycarbonyl-2-( 4-cyanophenyl) quinoline with bovine serum albumin

作　　者：程姣燕 邓志红[1] 黄小艳[1] 余茜[1] 黄振钟[1] 

机构地区：[1]江西师范大学化学化工学院,南昌330022

出　　处：《分析试验室》2016年第5期515-520,共6页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金项目(21564005)资助

摘　　要：合成了一种新型喹啉类化合物6-乙基-4-乙氧羰基-2-(4-氰基苯基)喹啉(EECCPQ),用核磁氢谱(~1H NM R)、碳谱(^(13)C NM R)以及傅里叶红外光谱(FTIR)对其进行了表征。采用荧光光谱(FL)、紫外可见光谱(UV)、时间分辨光谱(TRF)、圆二色光谱(CD)和分子模拟法研究了EECCPQ与牛血清白蛋白(BSA)的相互作用。由紫外吸收光谱和Stern-Volmer方程推断EECCPQ与BSA形成复合物,导致BSA内源荧光降低;依所测荧光寿命数据得出荧光猝灭机理主要为静态猝灭;根据双对数方程计算出不同温度下EECCPQ与BSA的结合常数和结合位点。热力学分析得出ΔH<0,△S<0和△G<0,表明体系是熵增加、Gibbs自由能降低的自发分子间作用过程,氢键和范德华力起着重要的内驱力作用;据Frster非辐射能量转移理论得EECCPQ与BSA的结合距离r=3.19 nm(299 K);同步荧光光谱显示EECCPQ的加入影响了BSA所处的微环境;CD光谱揭示BSA二级结构从α-螺旋向无规则卷曲转变;分子对接表明EECCPQ作用于BSA中亚域ⅡA的疏水腔区域(位点Ⅰ)。A novel quinoline compound,6-ethyl-4-ethoxycarbonyl-2-（ 4-cyanophenyl） quinoline（ EECCPQ）,was synthesized and characterized by1 H NMR,13 C NMR and FTIR. The interaction between EECCPQ and bovine serum albumin（ BSA） was researched by fluorescence spectroscopy（ FL）, ultraviolet absorption spectroscopy（ UV）,time resolved fluorescence spectroscopy（ TRF）,circular dichroism spectrum（ CD） and molecular docking. UV and Stern-Volmer equation showed that EECCPQ might bind to BSA via the formation of the EECCPQ-BSA. Fluorescence quenching of BSA by EECCPQ was found to be mainly a static process base on abtained fluorescence lifetime. The binding constants and binding sites at three different temperatures were calculated according to the double logarithmic equation. The thermodynamic parameters ΔH,ΔG and ΔS were obtained by the thermodynamic equations,which indicated that the action force was mainly hydrogen bonds and van der Waals forces. The binding distance between BSA and the tryptophan residue of EECCPQ was estimated to be 3. 19 nm（ 299 K） by Frest non-radiative energy transfer theory. The spectral changes of synchronous fluorescence indicated that the addition of EECCPQ caused the change of microenviroment for BSA. CD spectra suggested that the secondary structure of BSA changed from α-helix to random coil. Molecular docking investigation further identified that EECCPQ bound to BSA on site I in subdomain IIA

关 键 词：6-乙基-4-乙氧羰基-2-(4-氰基苯基)喹啉 牛血清蛋白 荧光寿命 分子模拟 

分 类 号：R917[医药卫生—药物分析学]