Mechanistic investigation on binding interaction of bioactive imidazole with protein bovine serum albumin--a biophysical study

The interaction between bioactive imidazole derivative (PPP) and bovine serum albumin (BSA) was investigated using fluorescence and UV-vis spectral studies. The experimental results showed that the fluorescence quenching of BSA by imidazole derivative was the result of the formation of BSA-PPP complex and the effective quenching constants (K(SV)) were 2.66×10(4), 2.56×10(4), and 2.10×10(4) at 301, 310 and 318 K, respectively. Static quenching and non-radiative energy transfer were confirmed to the result in the fluorescence quenching. The binding site number n, apparent binding constant K(A) and corresponding thermodynamic parameters (ΔG, ΔH and ΔS) were measured at different temperatures. The process of binding of PPP molecule on BSA was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased.     

Binding interaction of bioactive imidazole with bovine serum albumin--a mechanistic investigation

A novel Y-shaped imidazole derivative 4-((E)-2-(4,5-diphenyl-1-p-tolyl-1H-imidazol-2-yl)vinyl)phenol has been synthesized and characterised by IR, UV-vis, mass and NMR spectral techniques. The mutual interaction of this imidazole derivative (DPTIV) with bovine serum albumin (BSA) was investigated using photoluminescent studies. The fluorescence quenching mechanism of BSA by DPTIV was analyzed and the binding constant has been calculated. The binding distance between DPTIV and BSA was obtained based on the theory of Forester's non-radiation energy transfer. The effect of some common ions on the binding constant between DPTIV and BSA was also examined.     

Study on the Interaction Between Bovine Serum Albumin and Potassium Perfluoro Octane Sulfonate

The interactions between potassium perfluorooctanesulfonate (PFOS) and bovine serum albumin (BSA) were studied by fluorescence spectroscopy. The association constants between PFOS and BSA were obtained by fluorescence enhancing and fluorescence quenching respectively. Furthermore, fluorescence quenching was studied at different temperatures, and the binding constant was also determined by the method of fluorescence quenching. According to the thermodynamic parameters, the main binding force could be judged. The experimental results revealed that BSA and PFOS had strong interactions. The mechanism of quenching belonged to dynamic quenching and the main sort of binding force was hydrophobic force. IR-spectra proved the interaction changed the conformation of BSA.     

Spectroscopic analysis of the interaction between bilirubin and bovine serum albumin

The interactions between bilirubin (BR) and bovine serum albumin (BSA) have been studied by fluorescence spectroscopy. The association constant between BR and BSA was obtained by fluorescence enhancement titration. Furthermore, fluorescence quenching was studied at different temperatures, and the binding constant was also determined by the method of fluorescence quenching. The two methods yielded similar results. It indicated that the former method could be successfully applied to the determination of BR. The results showed that the binding of BR to BSA induced conformational changes in BSA. Based on the theory of F?rster energy transfer, the distance between BR and protein were calculated. According to the thermodynamic parameters, the main binding force could be judged. The experimental results revealed that BSA and BR had strong interactions. The mechanism of quenching belonged to static quenching and the main sort of binding force was van der Waals interactions and hydrogen bonds.     

荧光光谱法研究注射用头孢美唑钠与牛血清白蛋白的相互作用

运用荧光光谱法研究了注射用头孢美唑钠(Cefmetazole Sodium,CS)与牛血清白蛋白(BSA)的相互作用.CS对BSA具有荧光猝灭作用,其猝灭方式为静态猝灭,求出了猝灭常数,结合常数及结合位点数.在297 K和311 K时用Stern-Volmer方程和热力学方程处理实验数据,得到了结合常数KA、热力学参数...     

Characterization of the interaction between farrerol and bovine serum albumin by fluorescence and circular dichroism

The binding of farrerol to bovine serum albumin (BSA) in aqueous solution was investigated by fluorescence quenching spectra, synchronous fluorescence spectra, circular dichroism (CD) and the three-dimensional (3D) fluorescence spectra at pH 7.40. The results of fluorescence titration indicated that farrerol could quench the intrinsic fluorescence of BSA in a static quenching way. The cause of showing upward curvy patterns in Stern-Volmer plots was analyzed. The binding sites number n and binding constant K using fluorescence quenching equation at 310 K were calculated. The binding distance and the energy transfer efficiency between farrerol and BSA were also obtained according to the theory of F?rster's non-radiation energy transfer. The effect of some metal ions on the binding constant of farrerol with BSA was also studied. The effect of farrerol on the conformation of BSA was analyzed using CD, synchronous fluorescence spectra and three-dimensional (3D) fluorescence spectra under experimental conditions. Furthermore, the fluorescence displacement experiments indicated that farrerol could bind to the site I of BSA.     

光谱法研究牡荆素与蛋白质相互作用及共存金属离子的影响

利用荧光光谱法和紫外-可见光谱法研究了牡荆素(VT)与牛血清白蛋白(BSA)之间的相互作用.VT对BSA的荧光猝灭为动态猝灭过程,测定了不同温度下的猝灭常数;根据F(o)rster非辐射能量转移理论,计算出VT在BSA中的结合位置与色氨酸残基间的距离为2.675.nm;通过热力学参数推断出VT与BSA之间主要靠疏水作用...     

阿霉素与牛血清白蛋白结合作用的研究

结合荧光光谱和吸收光谱研究了阿霉素与牛血清白蛋白间的结合作用，确定了 阿霉素对牛血清白蛋白的荧光猝灭过程的猝灭机理，测定了不同酸度条件下该结合 反应的结合常数、结合位点数，依据能量转移理认确定了药物和蛋白间的结合距离 。通过比较阿霉素和去糖基阿霉素与牛血清白蛋白的相互作用，结合阿霉素对蛋白 构象的影响，讨论了药物与蛋白的结合模式。     

荧光光谱法研究茶碱与牛血清白蛋白的相互作用

荧光光谱法研究茶碱与牛血清白蛋白的相互作用;茶碱;牛血清白蛋白;荧光猝灭;能量转移     

桔皮苷与牛血清白蛋白相互作用的研究

运用荧光光谱、紫外光谱法研究了桔皮苷与牛血清白蛋白(BSA)的相互作用。桔皮苷分子与BSA作用导致BSA内源荧光猝灭,猝灭机理主要为静态猝灭,并存在非辐射能量转移。测定了不同温度下该反应的结合常数、结合位点数及结合热力学参数。结果表明:桔皮苷与BSA之间主要为氢键或范德华作用力,作用过程是一个熵增加、自由能降低的自发分子间作用过程;测得了供体与受体间结合距离r和能量转移效率E;并用同步荧光技术考察了桔皮苷对BSA构象的影响。     

金属离子对次野鸢尾黄素与牛血清白蛋白相互作用的影响

应用荧光光度法研究了金属离子Fe3 、Ca2 、Cu2 或Mn2 对次野鸢尾黄素(IFR)与牛血清白蛋白(BSA)相互作用的影响.实验结果表明,不存在金属离子时,IFR对BSA的荧光猝灭过程为动态猝灭,其结合过程的表观结合常数KA值为104～105数量级,结合位点数n约等于1.由热力学参数得出IFR与BSA结合过程是一个熵增加、Gibbs自由能降低的自发过程,分子间相互作用力以疏水作用力为主.在Fe3 或Ca2 抖的存在下,IFR对BSA的荧光猝灭类型由动态猝灭转变为静态猝灭,作用力类型也由以疏水作用力为主转变为以氢键与范德华力为主或以静电引力为主.Cu2 或Mn3 存在下,IFR对BSA的荧光猝灭类型及分子间作用力类型均没有发生改变.四种金属离子的参与都使得IFR与BSA结合作用的袁观结合常数发生了明显的变化,但结合位点数仍维持在1左右.     

二价铅离子与牛血清白蛋白相互作用的荧光光谱研究

用荧光法研究了二价铅离子与牛血清白蛋白的相互作用,测定了不同条件下pb2+与BSA作用的荧光光谱,并通过热力学计算探讨了二者的作用方式、BSA荧光的猝灭机理、Pb2+与BSA之间的结合常数及结合位点.结果表明,Pb2+对BSA的荧光猝灭属于静态猝灭,pb2+通过疏水作用力进入BSA的疏水腔与之发生相互作用,反应的△G=...     

几种金属离子对胭脂红与牛血清白蛋白相互作用的影响——荧光光谱研究

利用荧光光谱法研究了不同温度(15、27、39℃)下食用合成色素胭脂红对牛血清白蛋白(BSA)的内源荧光猝灭特性,考察了Cu2+、Ni 2+、Pb2+等金属离子对二者相互作用的影响,并测定了不同温度下的猝灭常数KSV、结合常数KA和结合位点数n.结果表明,3种金属离子基本不影响胭脂红对BSA荧光猝灭机理,但Cu2+、Ni 2+、Pb2+离子都与BSA有一定的结合能力,可在不同程度上增强胭脂红与BSA的结合作用及其对BSA内源荧光的猝灭.     

伊文思蓝作荧光探针研究牛血清白蛋白与氨苄青霉素之间的竞争反应

用伊文思蓝(Evans blue, EB)作荧光探针研究了氨苄青霉素(Ampicillin, A)对牛血清白蛋白(Bovine serum albumin, BSA)的竞争反应. 伊文思蓝与牛血清白蛋白作用, 使牛血清白蛋白荧光发生猝灭, 根据Stern-Volmer方程及荧光寿命研究了荧光猝灭的类型及机理. 结果表明, 猝灭类型为静态猝灭, 即伊文思蓝和牛血清白蛋白形成了一种稳定的复合物. 伊文思蓝与牛血清白蛋白的结合常数KBSA-EB=1.122×106 L/mol, 结合点数n=0.9935, 并确定了EB和BSA之间的热力学常数及作用力类型. 当加入氨苄青霉素后, 牛血清白蛋白的相对荧光强度恢复. 这表明氨苄青霉素与伊文思蓝对牛血清白蛋白发生了竞争反应. 探讨了该竞争反应的相关机理, 求出了伊文思蓝与氨苄青霉素的结合常数为KEB-A=7.131×105 L/mol.     

灯盏花素与牛血清白蛋白相互作用的荧光光谱研究

采用荧光光谱法和紫外吸收光谱法研究了灯盏花素(BR)与牛血清白蛋白(BSA)的相互作用;利用热力学方程计算了295K和308K下的热力学参数ΔH、ΔG和ΔS,根据Stern-Volmer方程求出了猝灭常数和结合常数.结果表明,BR对BSA的荧光具有猝灭作用,其猝灭机制为动态-静态联合猝灭,BSA发射峰略有蓝移.BR与BSA之间的作用力主要为疏水作用.     

光谱法研究核壳量子点CdTe/CdS与牛血清白蛋白的相互作用

应用荧光光谱、圆二色光谱和紫外吸收光谱等技术研究核壳量子点CdTe/CdS与牛血清白蛋白(BSA)相互作用的结果表明,CdTe/CdS对BSA的荧光猝灭机理为静态猝灭。根据不同温度下量子点对BSA的荧光猝灭作用计算了结合常数、热力学参数,证明了量子点与BSA相互作用力主要是范德华力或氢键作用力。探讨了量子点对BSA构象的影响。     

三种香豆素类中药小分子与牛血清白蛋白的相互作用

运用荧光光谱(FS)、紫外光谱(UV)法研究了三种香豆素中药小分子与牛血清白蛋白(BSA)的相互作用.实验结果表明,香豆素类小分子能够插入BSA分子内部与BSA形成基态复合物导致BSA内源荧光猝灭,猝灭机理主要为静态猝灭和非辐射能量转移.药物分子极性及体积增大对BSA内源性荧光猝灭效应增强,与BSA中荧光性氨基酸残基之间的空间距离r增大,表观结合常数K_A增大且结合位点数n减少.结合过程的热力学参数变化表明上述相互作用过程是一个熵增加、Gibbs自由能降低的自发分子间作用过程,其中香豆素与BSA之间以疏水作用为主,而伞形花内酯、七叶内酯与BSA之间则还存在偶极-偶极作用,表明药物分子极性同样影响其与BSA间相互作用力的类型.     

用荧光法研究对-二甲氨甲基-杯[8]芳烃与牛血清白蛋白的相互作用

本文研究了对-二甲氨甲基-杯[8]芳烃(CX8)与牛血清白蛋白(BSA)结合反应的荧光光谱和紫外-可见吸收光谱。实验发现CX8对BSA有较强的荧光猝灭作用,且CX8的紫外吸收光谱和BSA的荧光发射光谱有一定程度的重叠;CX8对BSA的猝灭属静态猝灭,疏水作用是两者之间的主要作用。确定了供体-受体间的结合距离r=1.76 nm,能量转移效率E=0.58;得出了结合反应的结合常数、结合位置和结合过程基本热力学性质的变化等。此外,还考察了酸度对BSA和CX8结合反应的影响。     

Eu3+存在下盐酸头孢替安与牛血清白蛋白相互作用的研究

运用荧光光谱、紫外吸收光谱研究了Eu3+存在下盐酸头孢替安(Cefotiam Hydro-chloride,CH)与牛血清白蛋白(BSA)的相互作用.CH对BSA具有荧光猝灭作用,其猝灭机制为静态猝灭,BSA发射峰蓝移,二者之间的作用力主要为疏水作用和弱的静电作用.Eu3+的存在使得BSA发射峰蓝移程度降低,猝灭常数、结合常数、结合位点数减小,但没有改变CH对BSA的猝灭机制,热力学参数ΔH和ΔS都增大.从热力学参数的变化及Eu3+的竞争作用分析了Eu3+对CH与BSA作用影响的原因.     

锌(Ⅱ)存在下灯盏花素与BSA相互作用的光谱分析

运用荧光光谱、吸收光谱研究了灯盏花素(Breviscapinun,BR)与牛血清白蛋白(Bovine Serum Albumin,BSA)的相互作用.BR对BSA的荧光光谱具有猝灭作用,其猝灭机制为静态-动态联合猝灭,BSA发射峰蓝移.Zn2+的存在使得BSA发射峰蓝移程度降低,猝灭常数、结合常数、结合位点数减小.在较大浓度Zn2+存在下,BR与BSA作用的相关系数增大,猝灭机制变为静态猝灭.从Zn2+与BR的竞争作用,热力学参数的变化、配位化合物的形成3个方面分析了影响BR与BSA作用的因素.