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。     

大黄酸铜(Ⅱ)配合物与血清白蛋白的相互作用

采用荧光光谱法和紫外光谱法研究了大黄酸铜配合物与牛血清白蛋白之间的相互作用.大黄酸铜配合物能显著猝灭牛血清白蛋白的内源荧光并以静态猝灭为主;计算了298 K和309 K温度下结合常数、结合位点,根据热力学参数判断大黄酸铜配合物与牛血清白蛋白之间具有较强的疏水作用力;依据F?rster的偶极-偶极非辐射能量转移理论,计算出大黄酸铜在蛋白质中结合位置与色氨酸残基间的距离为3.21 nm, 表明大黄酸铜的部分片段能够插入蛋白质分子内部;用同步荧光光谱和圆二色光谱技术探讨了大黄酸铜对牛血清白蛋白构象的影响.     

Spectrometric study of the interaction between Alpinetin and bovine serum albumin using chemometrics approaches

The binding interaction of Alpinetin (APT) with bovine serum albumin (BSA) was studied by fluorescence, UV-visible and synchronous fluorescence spectroscopy (SFS) under simulated physiological conditions. The measured complex spectra were resolved by multivariate curve resolution-alternating least squares (MCR-ALS), yielding a host of data and information, which otherwise would have been impossible to obtain. The extracted profiles corresponded to the spectra of the single species in the APT/BSA mixture. In addition, the presence of the APT-BSA complex was demonstrated, and it was shown that the associated quenching of the fluorescence from the BSA protein resulted from the formation of APT-BSA complex via a static mechanism. The binding constant (K_a(ave) = 2.34 × 10⁶ L mol⁻¹) and the number of sites (n = 1) were obtained by fluorescence methods as were the thermodynamic parameters (ΔH⁰, ΔS⁰ and ΔG⁰). This work suggested that the principal binding between APT to BSA was facilitated by hydrophobic interactions. The thermodynamic parameters for APT were compared to those from the structurally similar Chrysin and Wogonin molecules. It appeared that the entropy parameters were relatively more affected by the small structural changes. SFS from the interaction of BSA and APT showed that the ligand affected the conformation of BSA. The competitive interaction of APT and site makers with BSA indicated site I as the binding area of APT in BSA.     

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.     

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.     

荧光光谱法研究一种噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物与牛血清白蛋白的相互作用

用荧光光谱法研究了在生理条件下,3-对氯苯基-2-(4-叔丁基苯氧基)-3’-氧环己烷并噻吩并[2,3-d]嘧啶-4(3H)-酮(PTP)与牛血清白蛋白(BSA)的相互作用。实验表明,PTP主要以静态猝灭方式使BSA荧光强度显著降低。计算了不同温度下二者的结合常数和结合位点数,并根据热力学参数确定了PTP与BSA之间的作用力主要为氢键或范德华力。根据Frster非辐射能量转移机理,测定了PTP与BSA相互结合时的作用距离,并用同步荧光技术讨论了其衍生物对BSA构象的影响。     

硫酸长春碱与牛血清白蛋白相互作用的研究

本文利用荧光光谱法和紫外吸收光谱法研究了硫酸长春碱（Vinblastine Sulfate,VS）与牛血清白蛋白（Bovine Serum Albumin,BSA）的相互作用,讨论了药物与蛋白相互作用时药物对蛋白微环境的影响。求得不同温度下（298K、308K和318K）药物与蛋白相互作用的结合常数及结合位点数。利用F6rster能量转移理论得药物与蛋白间的键合距离为3.34nm。热力学参数（△H=14.34kJ／mol,△S=36.92J／（mol·K））表明维持药物与蛋白质的相互作用力主要是疏水作用和静电作用。此外,基于硫酸长春碱的荧光猝灭效应,探讨了药物-蛋白质体系的几种物理化学参数包括电荷密度、离解常数及量子产率的变化效应;以及共存离子对药物-蛋白质体系结合常数的影响。     

荧光光谱法研究除草醚与牛血清白蛋白的相互作用

运用荧光光谱和紫外吸收光谱研究水溶液中除草醚(NP)与牛血清白蛋白(BSA)的相互作用.结果表明,NP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.运用位点模型计算298 K、308 K、318 K时结合常数K_A分别为6.97×10~4、5.25×10~4 、4.96×10~4 L·mol~(-1),结合位点数n分别为0.98、0.92、0.96.根据热力学参数确定其作用力以疏水作用和静电作用为主;运用F(o)rster偶极-偶极非辐射能量转移原理,测定了NP与BSA的结合距离r为2.19 nm;用同步荧光技术初步考察了NP对BSA构象的影响.     

Binding of the bioactive component isothipendyl hydrochloride with bovine serum albumin

The binding of isothipendyl hydrochloride (IPH) to bovine serum albumin (BSA) was investigated by fluorescence spectroscopy combined with UV-visible absorption and circular dichroism (CD) techniques under simulative physiological conditions for the first time. The quenching mechanism of fluorescence BSA by IPH was discussed. The binding parameters have been evaluated by fluorescence quenching method. The thermodynamic parameters, ΔH°, ΔS° and ΔG° calculated at different temperatures indicated that the hydrophobic force played a major role in the interaction of IPH to BSA. The distance, r between donor (BSA) and acceptor (IPH) was obtained according to the Förster's theory of non-radiation energy transfer and was found to be 2.21 nm. Experimental results showed that the α-helicity of BSA decreased from 66.4% (in free BSA) to 39.1% (in bound BSA). The effect of common ions on the binding constant was also investigated.     

光谱法测定伊曲康唑与牛血清和人血清白蛋白相互作用

用荧光光谱和紫外吸收光谱法, 在pH=7.4±0.1的0.1 mol·L-1磷酸缓冲溶液中, 研究了伊曲康唑与牛血清白蛋白(BSA)和人血清白蛋白(HSA)的相互作用. 实验结果表明, 伊曲康唑与牛血清白蛋白和人血清白蛋白作用的猝灭常数均随着温度的升高而降低, 伊曲康唑可以有规律地使血清白蛋白内源荧光猝灭, 其猝灭机理可认为是伊曲康唑与白蛋白形成复合物的静态猝灭. 获得了在不同温度下, 伊曲康唑与血清白蛋白作用的结合常数以及△G、△H和△S等热力学参数. 根据所得结果可推断伊曲康唑与白蛋白的作用力主要为疏水作用力, 同时, 利用荧光共振能量转移理论(FRET)计算得出了伊曲康唑与白蛋白结合位置的距离d. 而且, 利用同步荧光光谱和紫外光谱揭示了该反应中蛋白的结构和其微环境的变化.     

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。     

Spectroscopic studies on the interaction between nicotinamide and bovine serum albumin

The interaction of nicotinamide (NA) and bovine serum albumin (BSA) was studied by fluorescence and absorption spectroscopy at different temperatures. The results revealed that NA caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants K(A), and the number of binding sites n, corresponding thermodynamic parameters DeltaG, DeltaH, DeltaS between NA and BSA at different temperatures were calculated. The primary binding pattern between NA and BSA was interpreted as hydrophobic interaction. In addition, the effect of NA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. The binding average distance, r between the donor (BSA) and acceptor (NA) was determined based on the F?rster's theory and it was found to be 3.1 nm.     

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...     

Study of the conjugation reaction between bovine serum albumin and gentamicin with Ponceau S as fluorescence probe

Abstract  

Ponceau S (PS) can quench the fluorescence of bovine serum albumin (BSA) in aqueous solution of pH 7.40. The static fluorescence-quenching process between BSA and PS was confirmed and the binding constant, the number of binding sites, and thermodynamic data for the interaction between BSA and PS were obtained. The results showed that the number of binding sites was 1 and that electrostatic attraction was important in the binding of BSA to PS. On the basis of the theory of F?rster resonance energy transfer, the binding distance (r < 7 nm) between PS and BSA was obtained. Site marker competitive experiments indicated that binding of PS to BSA primarily occurred in sub-domain IIA (site I). There was no obvious fluorescence intensity change on combining BSA and gentamicin (GM), so the conjugation reaction between BSA and GM cannot be studied by spectroscopy. It was observed that when GM was added to the BSA–PS system, the relative fluorescence intensity of the system recovered gradually with increasing concentration of GM, which showed there was a conjugation reaction between GM and BSA and that binding of GM to BSA primarily occurred in sub-domain IIA (site I).     

Study of the interaction between 2,5-di-[2-(4-hydroxy-phenyl)ethylene]-terephthalonitril and bovine serum albumin by fluorescence spectroscopy

A new compound, 2,5-di-[2-(4-hydroxy-phenyl)ethylene]-terephthalonitrile (DHPEPN), was synthesized. The interaction between bovine serum albumin (BSA) and DHPEPN in Tris-HCl buffer solution (pH 7.4) was investigated using fluorescence and UV-vis absorption spectroscopy. The mechanism of BSA fluorescence quenched by DHPEPN is discussed according to the Stern-Volmer equation. The binding constant and the thermodynamic parameters ΔH, ΔS, ΔG at different temperatures were calculated. The results indicate that the van der Waals interaction and hydrogen bonding play major roles in the binding process. The distance between BSA and DHPEPN is estimated to be 3.59 nm based on the F?rster resonance energy transfer theory. The spectral changes of synchronous fluorescence and three-dimensional fluorescence suggest that both of the microenvironment of DHPEPN and the conformation of BSA are changed during binding between DHPEPN and BSA.     

N,N'-双(4-氯苄基)-1,2-丙二胺合铜(Ⅱ)配合物的合成、晶体结构、抑菌活性及与BSA的相互作用

合成了N,N'-双(4-氯苄基)-1,2-丙二胺铜(Ⅱ)配合物·(NH₄)·Cl₂, 通过元素分析和IR光谱对其进行了表征, 并通过X射线单晶衍射确定了其晶体结构. 晶体结构分析表明, 该晶体属于三斜晶系, P1空间群, 晶胞参数a=1.35222(16) nm, b=1.37899(17) nm, c=1.39806(19) nm; α=60.954(1)°, β=87.502(2)°, γ=65.970(1)°, V=2.0424(4) nm³, D_c=1.357 g/cm³, Z=2, F(000)=862, R₁=0.0925, wR₂=0.2668, S=1.001. 配合物的金属中心与来自2个配体的4个氮原子和1个末端氯原子配位, 形成了轻微扭曲的四方锥几何构型, 扭曲指数τ=0.04(1). 抗菌实验结果显示, 配合物对大肠杆菌、 枯草杆菌和金色葡萄球菌均表现出良好的抑菌作用. 采用荧光光谱研究了不同温度下配合物与牛血清白蛋白(BSA)的相互作用, 结果表明, 配合物对BSA 的荧光猝灭属于静态猝灭. 计算了不同温度下配合物与BSA间的结合常数(K_a), 结合位点(n≈1)及相关热力学参数(ΔH＞0, ΔS＞0, ΔG＜0), 结果表明, 二者主要靠疏水作用力结合. 依据Föster的非辐射能量转移理论, 求得给体(BSA)与受体(配合物)间的距离r=2.56 nm, 说明配合物与BSA 之间可能发生了非辐射能量转移.     

Study on the Synergism Effect of Lomefloxacin and Ofloxacin for Bovine Serum Albumin in Solution by Spectroscopic Techniques

Both lomefloxacin (LOM) and ofloxacin (OFL) have a powerful ability to quench the fluorescence of bovine serum albumin (BSA). The fluorescence quenching action is much stronger when the two drugs coexist. The synergism between LOM and OFL was studied using fluorescence and ultraviolet spectroscopy under imitated physiological conditions. The results show that static quenching and non-radiation energy transfer are the main reasons for the fluorescence quenching. The synergism results in both the reduction of the binding stability between drugs and BSA and an increase of the free drug concentration, which will increase the efficacy of drugs. The thermodynamic parameters at different temperatures were calculated and the binding distances r between the drugs and BSA were obtained based on Försters theory of non-radiation energy transfer. The synchronous fluorescence spectra indicated that the effect of synergism affected the conformation of BSA.     

Interaction Between Ranitidine Hydrochloride and Bovine Serum Albumin in Aqueous Solution

The interaction between ranitidine hydrochloride (RAN) and bovine serum albumin (BSA) in aqueous solution was investigated by means of fluorescence, synchronous fluorescence, and UV-Vis spectroscopy. The fluorescence of BSA was quenched remarkably by RAN and the quenching mechanism was concluded to be static quenching. The binding constants K and the number of binding sites n were calculated at three different temperatures. The RAN–BSA binding distance was determined to be less than 8 nm, suggesting that energy transfer may occur from BSA to RAN. The interaction process is spontaneous. Based on the obtained thermodynamic parameters, electrostatic forces may play a major role in this process. In addition, the effect of RAN on the conformation of BSA was analyzed using synchronous fluorescence spectra.     

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     

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.