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1.
The interaction between promethazine hydrochloride (PMT) and bovine serum albumin (BSA) in vitro was investigated by means of fluorescence spectroscopy and absorption spectroscopy. The fluorescence of BSA was quenched remarkably by PMT and the quenching mechanism was considered as static quenching by forming a complex. The association constants Ka and the number of binding sites n were calculated at different temperatures. The BSA-PMT binding distance was determined to be less than 8 nm, suggesting that energy transfer from BSA to PMT may occur. The thermodynamic parameters of the interaction between PMT and BSA were measured according to the van’t Hoff equation. The enthalpy change (ΔH) and entropy change (ΔS) were calculated to be −23.62 kJ mol−1 and −0.10 J mol−1 K−1, respectively, which indicated that the interaction of PMT with BSA was driven mainly by van der Waals forces and hydrogen bonds. The binding process was a spontaneous process in which Gibbs free energy change (ΔG) was negative. In addition, the results of synchronous fluorescence spectra and three-dimensional fluorescence spectra showed that binding of PMT with BSA can induce conformational changes in BSA. 相似文献
2.
采用荧光光谱、紫外光谱和圆二色光谱法并结合电化学方法,研究了大黄酸与牛血清白蛋白之间的相互作用。结果表明:大黄酸对牛血清白蛋白有较强的荧光猝灭作用且为静态猝灭,并计算得出不同温度下其结合常数(KA)与结合位点数(n)分别为:3.67×105,0.95(298 K);2.60×104,0.83(309 K)。由热力学参数确定它们间的作用力主要是静电引力,并依据F rster能量转移理论求得其结合距离为3.28 nm,同步荧光光谱及圆二色谱表明大黄酸对牛血清白蛋白的构象产生影响。 相似文献
3.
Baosheng Liu Fengli Zhao Chunli Xue Jing Wang Yunkai Lu 《Journal of luminescence》2010,130(5):859-864
Chloramphenicol (CHL) and quinolone drugs like ofloxacin (OFLX), lomefloxacin (LMX) and ciprofloxacin (CPFX) can all quench the fluorescence of bovine serum albumin (BSA) in the aqueous solution of pH=7.40. This quenching effect becomes more significant when CHL and quinolone drugs coexist. Based on this, further studies on the interactions between CHL and quinolone drugs using fluorescence spectrum are established. The results showed that the interaction between the drugs would increase the binding constant and binding stability of the drug and protein, thus reducing the amount of drugs transported to their targets. Therefore, free drug concentration at targets would decrease, reducing the efficacy of the drugs. It indicated that there exists antagonistic action between drugs. The results also showed that the quenching mechanism of BSA by the drugs is a static procedure. The number of binding sites is 1 in various systems. Due to the existence of the antagonistic action between drugs, the binding distance r is reduced. Studies utilizing synchronous spectra showed that the antagonistic action between the drugs would affect the conformation of BSA, making protein molecules extend and hydrophobic decrease. The order of antagonistic action between CHL and quinolone drugs is: CPFX>OFLX>LMX with presence of BSA. 相似文献
4.
Xiaolei Shi 《Journal of luminescence》2010,130(4):637-644
The interaction between three kinds of flavonoids and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis absorption spectrometry. The results indicated that flavonoids have strong ability to quench the intrinsic fluorescence of BSA by forming complexes. The binding constants, number of binding sites, thermodynamic parameters and energy transfer mechanisms were also investigated. Conformation change of BSA was observed from synchronous, three-dimensional fluorescence and circular dichroism spectrum. 相似文献
5.
Xing-jia Guo Kui Jing Chuang Guo Yu-chun Jiang Jiang Tong Xiao-wei Han 《Journal of luminescence》2010,130(12):2281-2287
The mutual interaction of oxybutynin hydrochloride (OB) with bovine serum albumin (BSA) was investigated by fluorescence, UV–vis absorption, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopies under simulative physiological conditions. The results of fluorescence titration revealed that OB could quench the intrinsic fluorescence of BSA by static quenching and there was a single class of binding sites on BSA for this drug. The thermodynamic parameters ΔH, ΔS, and ΔG calculated at different temperatures indicated that hydrogen bonds and van der Waals interactions were the dominant intermolecular forces in stabilizing the OB–BSA complexes. According to the theory of Förster’s non-radiation energy transfer, the binding distance r between OB and BSA was evaluated to be 3.27 nm. The displacement experiments confirmed that OB could bind to site I of BSA. The FT-IR and CD spectra showed that the binding of OB to BSA induced conformational changes in BSA. 相似文献
6.
Fei Ding 《Journal of luminescence》2009,129(6):650-655
In this paper, the interaction between barbital and bovine serum albumin (BSA) was investigated by the method of fluorescence spectroscopy under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by barbital was the result of the formation of BSA-barbital complex, and the effective quenching constants (Ka) were 1.468×104, 1.445×104 and 1.403×104 M−1 at 297, 303 and 310 K, respectively. The thermodynamic parameters enthalpy change (ΔH) and entropy change (ΔS) for the reaction were calculated to be −2.679 kJ mol−1 and 70.76 J mol−1 K−1, respectively, according to the van’t Hoff equation. The results indicated that hydrophobic and electrostatic interactions were the dominant intermolecular force in stabilizing the complex. The results of synchronous fluorescence spectra showed that binding of barbital with BSA can induce conformational changes in BSA. In addition, the effects of Cu2+ and Zn2+ on the constants of BSA-barbital complex were also discussed. 相似文献
7.
The fluorescence and ultraviolet spectroscopies were explored to study the interaction between edaravone (EDA) and bovine serum albumin (BSA) under imitated physiological condition. The experimental results show that the fluorescence quenching mechanism between EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites, and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between EDA and BSA was calculated to be 3.10 nm. The effect of EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. In addition, the effects of some common metal ions Mg2+, Ca2+, Cu2+, and Ni2+ on the binding constant between EDA and BSA were examined. 相似文献
8.
The interactions of bovine serum albumin (BSA) with two local anesthetics, procaine hydrochloride (PCH) and tetracaine hydrochloride (TCH) were studied using spectroscopic methods such as fluorescence and ultraviolet visible (UV-vis), and electrochemical techniques including cyclic voltammetry (CV) and differential pulsed stripping voltammetry (DPSV). The results obtained from these techniques turned out that both PCH and TCH could bind to BSA. The binding constants (KA) and the number of binding sites (n) of the two drugs with BSA at different temperatures were determined, respectively. At 291 K, KA was found as 2.40×104 and 1.42×104 L mol−1 and n was 1.03 and 0.99 for PCH-BSA and TCH-BSA, respectively. According to van’t Hoff equation, the thermodynamic parameters, ΔG, ΔH and ΔS, were obtained, showing the involvement of hydrophobic and electrostatic force in these interactions. Based on the theory of the Förster energy transference, the distance between the acceptor (PCH or TCH) and the donor (BSA) were determined as 2.32 and 3.62 nm for PCH and TCH, respectively. The effects of Fe3+, Cu2+, Mg2+, Mn2+, Zn2+ and Ca2+ on the binding of PCH or TCH to BSA were also evaluated. 相似文献
9.
In this paper, the binding of trazodone hydrochloride (TZH) to bovine serum albumin (BSA) was investigated by spectroscopic (fluorescence, spectrophotometry and circular dichroism) techniques under simulative physiological conditions. A strong fluorescence quenching reaction of TZH to BSA was observed and the quenching mechanism was suggested as dynamic quenching according to the Stern-Volmer equation. The binding constants of TZH with BSA at 288, 302 and 309 K were calculated as (1.56±0.003)×104, (2.31±0.002)×104 and (5.44±0.004)×104 M−1, respectively. The thermodynamic parameters, ΔH0 and ΔS0 were obtained to be 39.86±0.008 kJ mol−1 and 217.89±0.011 J mol−1 K−1, respectively, which indicated the presence of hydrophobic forces between TZH and BSA. The spectral results observed showed that the binding of TZH to BSA induced conformational changes in BSA. Based on the Förster's theory of non-radiation energy transfer, the binding average distance, r between donor (BSA) and acceptor (TZH) was found to be 2.4 nm. The effect of common ions on binding of TZH to BSA was also examined. 相似文献
10.
The interaction of disperse blue SBL (DBSBL) with bovine serum albumin (BSA) was investigated using fluorescence, UV-visible and far-UV circular dichroism (CD) spectroscopy. The results showed that the fluorescence of BSA was quenched by DBSBL through static quenching after correcting for the inner filter effects (IFE). The binding constant Kb of DBSBL with BSA at 288, 298 and 303 K were 0.116×106, 3.18×106 and 12.3×106 L mol−1, respectively. The thermodynamic parameters, standard enthalpy change (ΔH0) and standard entropy change (ΔS0), for the reaction were evaluated to be 227.2 kJ mol−1 and 886 J mol−1 K−1 according to the van’t Hoff equation. The above data suggested that the forces acting between DBSBL and BSA were predominantly hydrophobic interactions. The results of UV-visible absorption and far-UV CD spectroscopy also revealed that the conformation and microenvironment of BSA molecule were changed after DBSBL binding to BSA. At 288 K one binding site was present but at higher temperatures a second binding site was detected between DBSBL and the BSA molecule. The lower bound for the distance between the bound dye and the Trp residue is 2.35 nm as calculated from Forster energy transfer. 相似文献
11.
荧光光谱法研究共存碳纳米管对牛血清白蛋白与加替沙星相互作用的影响 总被引:2,自引:0,他引:2
在模拟生理条件下,用荧光光谱法研究了碳纳米管对牛血清白蛋白和加替沙星荧光光谱特性的影响以及有无碳纳米管共存时加替沙星对牛血清白蛋白荧光光谱特性的影响.实验结果表明,加替沙星和碳纳米管都可以使牛血清白蛋白的荧光强度发生静态猝灭.在碳纳米管的存在下,加替沙星与牛血清白蛋白的结合作用有所减弱.Stern-Volmer荧光猝灭... 相似文献
12.
Spectrofluorimetric study on the interaction between antimicrobial drug sulfamethazine and bovine serum albumin 总被引:1,自引:0,他引:1
Abdulilah Dawoud Bani-Yaseen 《Journal of luminescence》2011,131(5):1042-1047
The interaction between the antimicrobial drug sulfamethazine (STM) and bovine serum albumin (BSA) has been studied using steady state and synchronous fluorescence spectroscopy. Fluorescence emission data revealed that BSA (2×10−6 M) fluorescence was statically quenched by STM at various concentrations, which implies that STM-BSA complex has been formed. The fluorescence emission data was analyzed via applying the Stern-Volmer analysis in combination with thermodynamic investigation, where obtained results revealed that quenching is static with quenching constants of 2.371, 1.658, and 0.916×105 M−1 at 298, 304, and 310 K, respectively. Binding constants and number of binding sites at different temperatures were also determined by applying the Scatchard method, which in turn were used to construct the van't Hoff plot in order to estimate the enthalpy (ΔH) and entropy changes (ΔS) for the complexation process. An average of 1.00±0.17 was estimated for the number of sites of BSA, which indicated that STM binds to BSA with stoichiometric ratio of 1:1. The values that were estimated from the van't Hoff plot for ΔH and (ΔS) were −36.8 kJ mol−1 and −14.9 J mol−1 K−1, respectively, which indicate that the STM-BSA complex is stabilized with hydrogen bonds and van der Waals interactions. Synchronous fluorescence data was obtained at Δλ of 15 and 60 nm, where obtained results confirmed that STM binds to BSA at the tryptophan residue (Trp. 213). In addition, the distance between STM and the Trp. 213 was estimated via employing the Förster's non-radiative energy-transfer theory, and was found to be 2.73 nm, which in turn indicated that STM can bind to BSA with high probability. 相似文献
13.
The interactions of mitomycin C (MMC), fluorouracil (FU), mercaptopurine (MP) and doxorubicin hydrochloride (DXR) with bovine serum albumin (BSA) were studied by spectroscopic method. Quenching of fluorescence of serum albumin by these drugs was found to be a static quenching process. The binding constants (KA) were 9.66×103, 2.08×103, 8.20×102 and 7.50×103 L mol−1 for MMC-, FU-, MP- and DXR-BSA, respectively, at pH 7.4 Britton-Robinson buffer at 28 °C. The thermodynamic functions such as enthalpy change (ΔH), entropy change (ΔS) and Gibbs free-energy change (ΔG) for the reactions were also calculated according to the thermodynamic equations. The main forces in the interactions of these drugs with BSA were evaluated. It was found that the interactions of MMC and FU with BSA were exothermic processes and those of MP and DXR with BSA were endothermic. In addition, the binding sites on BSA for the four drugs were probed by the changes of binding properties of these drugs with BSA in the presence of two important site markers such as ibuprofen and indomethacin. Based on the Föster theory of non-radiation energy transfer, the binding distances between the drugs and tryptophane were calculated and they were 3.00, 1.14, 2.85, and 2.79 nm for MMC, FU, MP and DXR, respectively. 相似文献
14.
Min Xu Feng-Juan Chen Liang Huang Pin-xian Xi Zheng-zhi Zeng 《Journal of luminescence》2011,131(8):1557-1565
The water-soluble Pr (Ⅲ) and Nd (Ⅲ) complexes with an ofloxacin derivative have been prepared and characterized. The single-crystal X-ray diffraction showed that the Pr (III) and Nd (III) complexes have the similar molecular structure. Under physiological pH condition, the effects of [PrL(NO3)2(CH3OH)](NO3) and [NdL(NO3)2(CH3OH)](NO3) on bovine serum albumin (BSA) were examined using fluorescence spectroscopy in combination with UV-vis absorbance and circular dichroism (CD) spectra. The result reveals that the quenching mechanism of fluorescence of BSA by two complexes is a static quenching process and the number of binding sites is about 1 for both. The thermodynamic parameters (ΔH=−14.52 kJ mol−1, ΔS=56.54 J mol−1 K−1 for [PrL(NO3)2(CH3OH)](NO3) and ΔH=−24.63 kJ mol−1, ΔS=22.07 J mol−1 K−1 for [NdL(NO3)2(CH3OH)](NO3)) indicate that hydrophobic and electrostatic interactions are the main binding force in the complexes-BSA system. The binding average distance between complexes and BSA was obtained on the basis of Förster's theory. In addition, it was proved by the CD spectra that the BSA secondary structure was changed in the presence of complexes in an aqueous solution. 相似文献
15.
Belal H.M. Hussein 《Journal of luminescence》2011,131(5):900-908
The absorption and fluorescence spectra of 7, 8-dihydroxy-4-methylcoumarin (DHMC) in ethanol-water (1:9 v/v) solution at varying pH values were investigated . The interaction between DHMC and bovine serum albumin (BSA) was investigated by fluorescence, FT-IR, and circular dichroism (CD) spectroscopy. The Stern-Volmer quenching constant (KSV), the quenching rate constant of the bimolecular reaction (Kq), the binding constant, and number of binding sites (n) of DHMC with BSA were evaluated. The results showed that DHMC quenches the fluorescence intensity of BSA through a static quenching process. Positive value of entropy change (ΔS) and negative value of enthalpy change (ΔH) of the BSA-DHMC interaction were obtained according to the van't Hoff equation. The interaction between DHMC and BSA was driven mainly by hydrophobic forces. The binding process was spontaneous and exothermic. The binding distance between the tryptophan residue in BSA and the DHMC was found to be about 2.6 nm based on the Förster theory of non-radiation energy transfer. 相似文献
16.
Baosheng Liu Chunli Xue Jing Wang Chao Yang Fengli Zhao Yunkai Lv 《Journal of luminescence》2010,130(11):1999-1938
A competitive reaction exists between bovine serum albumin (BSA) and neomycin (NM) when ponceau S (PS) is chosen as fluorescent probe. This reaction was studied by fluorescence spectroscopy and UV-vis absorption spectroscopy. The static fluorescence quenching process between BSA and PS was confirmed and the binding constant, the number of binding sites and type of interaction forces between BSA and PS were obtained. It was observed that when NM was added into BSA-PS system, the relative fluorescence intensity of BSA was recovered gradually with increase in concentration of NM, which shows that there existed competitive reaction between BSA and NM. According to competitive reaction mechanism, the equilibrium concentration of PS, the binding constant and the type of interaction forces between PS and NM were obtained. 相似文献
17.
Feng Ge Chaoyin Chen Diqiu Liu Benyong Han Xiangfeng Xiong Shenglan Zhao 《Journal of luminescence》2010,130(1):168-173
The binding properties on theasinesin to human serum albumin (HSA) have been studied for the first time using fluorescence spectroscopy in combination with UV–vis absorbance spectroscopy. The results showed that theasinesin strongly quenched the intrinsic fluorescence of HSA through a static quenching procedure, and non-radiation energy transfer happened within molecules. The number of binding site was 1, and the efficiency of Förster energy transfer provided a distance of 4.64 nm between tryptophan and theasinesin binding site. At 298, 310 and 323 K, the quenching constants of HSA–theasinesin system were 2.55×103, 2.16×103 and 1.75×103 mol L−1. ΔHθ, ΔSθ and ΔGθ were obtained based on the quenching constants and thermodynamic theory (ΔHθ<0, ΔSθ>0 and ΔGθ<0). These results indicated that hydrophobic and electrostatic interactions are the mainly binding forces in the theasinesin–HSA system. In addition, the results obtained from synchronous fluorescence spectra showed that the binding of theasinesin with HSA could induce conformational changes in HSA. 相似文献
18.
Interaction of the flavonoid hesperidin with bovine serum albumin: A fluorescence quenching study 总被引:1,自引:0,他引:1
The interaction between the flavonoid hesperidin and bovine serum albumin (BSA) was investigated by fluorescence and UV/Vis absorption spectroscopy. The results revealed that hesperidin caused the fluorescence quenching of BSA through a static quenching procedure. The hydrophobic and electrostatic interactions play a major role in stabilizing the complex. The binding site number n, and apparent binding constant KA, corresponding thermodynamic parameters ΔGo, ΔHo, ΔSo at different temperatures were calculated. The distance r between donor (BSA) and acceptor (hesperidin) was obtained according to fluorescence resonance energy transfer. The effect of Cu2+, Zn2+, Ni2+, Co2+, and Mn2+ on the binding constants between hesperidin and BSA were studied. The effect of hesperidin on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy and UV/Vis absorption spectroscopy. 相似文献
19.
The interaction between gliclazide and bovine serum albumin was investigated by fluorescence and synchronous fluorescence spectroscopy. From the experimental results, it was found that the quenching mechanism was static. The results of the synchronous fluorescence obtained indicated that the binding of gliclazide with bovine serum albumin could affect conformation in bovine serum albumin. In addition, the binding constants (Ka), binding sites (n), thermodynamic parameters, binding forces, Hill’s coefficient, and binding rate of gliclazide to protein calculated from two methods using the same equation were consistent at three different temperatures (298, 310, 318 K). This indicated that as a useful supplement to the conventional method, synchronous fluorescence spectroscopy could be used to study the mechanism of drugs and proteins. The conclusion was verified by UV/vis method. 相似文献
20.
Reeta Punith 《Journal of luminescence》2010,130(11):2052-2058
The mechanism of interaction of the non-steroidal anti-inflammatory drugs, isoxicam (IXM) and tenoxicam (TXM) with bovine serum albumin (BSA) has been studied using spectroscopic techniques, viz., spectrofluorescence, circular dichroism (CD), UV-visible absorption and FT-IR under simulative physiological conditions. Stern-Volmer analysis of fluorescence quenching data shows the presence of the static quenching mechanism. Thermodynamic parameters (negative ΔH0 and positive ΔS0 values obtained in the present study) revealed that the hydrophobic interactions played a major role in the interaction of these drugs with BSA. The distance, r between the donor (BSA) and acceptor (IXM/TXM) was calculated based on the Forster’s theory of non-radiation energy transfer and the values were observed to be 3.85 nm and 2.60 nm in IXM-BSA and TXM-BSA system, respectively. CD and FT-IR studies indicated that the binding of IXM/TXM to BSA induced conformational changes in BSA. The effect of common ions on the binding of IXM/TXM to BSA has been investigated. 相似文献