左氧氟沙星和氧氟沙星与清蛋白的结合位点及荧光淬灭分析

摘要目的研究左氧氟沙星和氧氟沙星与人血清清蛋白的结合作用。方法通过荧光光谱法分析左氧氟沙星和氧氟沙星对人血清清蛋白荧光淬灭光谱,同步荧光光谱,根据热力学方程讨论两者间主要的作用力类型。结果在生理条件（pH＝7.4,37 ℃）下,根据Stem Volmer方程和荧光淬灭双倒数图,左氧氟沙星和氧氟沙星对人血清清蛋白淬灭类型为静态淬灭,左氧氟沙星对人血清清蛋白的结合常数K＝1.46×105 L•mol－1,结合位点n＝1.11,氧氟沙星对人血清清蛋白的结合常数K＝4.31×104 L•mol－1,结合位点n＝1.04,根据热力学方法确定作用力类型均为疏水作用力。结论与左氧氟沙星比较,氧氟沙星对人血清清蛋白的荧光淬灭减弱,结合常数和结合位点均变小,结合位置也有明显区别;这些数据给研究左氧氟沙星和氧氟沙星的药理作用和生物学效应,以及左氧氟沙星和氧氟沙星对蛋白质构象的影响等提供了重要信息。     

西尼地平与人血清白蛋白相互作用的荧光光谱法研究

本文采用荧光分光光度法研究了西尼地平与人血清白蛋白(HSA)间的相互作用。根据Stern-Volmer方程确定了西尼地平对人血清白蛋白的猝灭类型为静态猝灭。通过计算求得生理条件下(pH=7.4)西尼地平与HSA的结合常数为3.3×105,结合位点数为1.24。实验考察了pH及微量金属离子对药物与HSA相互作用的影响。最后根据热力学方法确定了该药物与人血清白蛋白之间的作用力类型为静电作用力。     

阿司匹林与人血清白蛋白的相互作用研究

目的以光谱技术研究阿司匹林分子与人血清白蛋白(HSA)间结合作用机制。方法通过荧光光谱法确定阿司匹林对HSA的荧光猝灭机制。由Lineweaver-Burk双倒数作图法确定反应的解离常数。根据热力学方程讨论两者间主要的作用力类型。结合同步荧光技术考察阿司匹林对人血清白蛋白构象的影响。结果阿司匹林对HSA的荧光猝灭机制为静态猝灭。在37℃和25℃时阿司匹林与HSA的解离常数分别为KD37=1.44×10-3mol.L-1,KD25=1.96×10-3mol.L-1。结合反应热力学参数为ΔH=-19.73kJ.mol-1,△G=-16.21kJ.mol-1,ΔS=-11.77kJ.mol-1。结论两者结合的主要作用力类型是范德华力。阿司匹林与白蛋白结合后使蛋白质构象发生变化。     

金合欢素-7-O-葡萄糖苷与BSA相互作用的荧光光谱法研究

应用荧光光谱法研究了生理条件下金合欢素-7-O-葡萄糖苷与牛血清白蛋白（BSA）的相互作用。结果表明,其对BSA荧光的猝灭机制属于形成复合物的静态猝灭过程,并求得结合常数Ka为8.57×104L.mol-1,结合位点数n为1。根据热力学参数确定了其与BSA之间的主要作用力类型为静电作用力。采用同步荧光考察了药物对BSA构象的影响。此外,讨论了共存离子Cu2＋,Al3＋,Zn2＋,Mg2＋对药物与BSA结合作用的影响。     

吖啶药物与血清蛋白的相互作用研究

应用荧光谱法,研究（N-（N-（2-（4-吗啉）乙胺）-4-酰胺吖啶）-α-丙氨酸（MACA）与血清白蛋白（HSA）的相互作用,确定MACA-HSA的静态荧光猝灭机制和疏水力相互作用,系统考察MACA与HSA的结合常数、结合位点数、热力学函数,两者在不同温度下的结合常数分别为2.51×10^5（298K）、1.78×10^5（308K）、1.32×10^5（318K）;结合位点数分别为1.05、1.08、1.10,MACA和HSA结合作用的ΔH和ΔS分别为-25.39kJ·mol^-1和18.20kJ·mol^-1。     

灯盏乙素与牛血清白蛋白相互作用的研究

目的采用荧光、紫外光谱法研究在模拟人体生理条件下灯盏乙素与牛血清白蛋白(BSA)之间的相互作用。方法将灯盏乙素对牛血清白蛋白进行荧光淬灭滴定,利用Scatchard模型和F"rster非辐射能量转移理论得出灯盏乙素和牛血清白蛋白的结合参数。结果灯盏乙素与BSA的结合常数K=1.240×106,结合距离r=2.94nm,相互作用力主要为疏水作用力。结论阐明了灯盏乙素和牛血清白蛋白相互作用的机制,建立了灯盏乙素和牛血清白蛋白的结合模型。     

荧光光谱法研究昂丹司琼与人血清白蛋白的相互作用

目的利用荧光光谱法研究昂丹司琼(OND)与人血清白蛋白(HSA)的相互作用。方法采用荧光光谱法。结果在296K和310K时OND与HSA的结合常数分别为3.24×104L/mol,4.68×104L/mol,热力学参数ΔH为20.08kJ/mol。结论 OND对HSA的荧光猝灭机制主要为静态猝灭,二者有一个结合位点,其作用力类型以疏水作用力为主。     

白皮杉醇与牛血清白蛋白相互作用的研究

目的应用荧光光谱法和紫外光谱技术对白皮杉醇（piceatann01）与牛血清白蛋白（BSA）之间的相互作用进行研究。方法计算白皮杉醇与BSA的结合常数K、结合位点数及热力学函数△G、△S、△H,分析白皮杉醇对BSA的荧光淬灭过程及其与BSA的相互作用类型;运用Foerster’S偶极．偶极非辐射能量转移原理测定了白皮杉醇与BSA的结合距离。结果随着白皮杉醇浓度升高,BSA内源荧光强度有规律的下降;随温度的升高,静态淬灭常数和结合常数均下降;热力学函数△G〈0、△S〉0、△H〈0。结论白皮杉醇对BSA的荧光淬灭属于自发的以疏水作用力为主导的非辐射能量转移的静态淬灭过程。     

加替沙星与牛血清白蛋白相互作用的研究

目的研究不同酸度条件下, 加替沙星与牛血清白蛋白之间的相互作用.方法采用荧光光谱和紫外光谱法进行研究.结果运用荧光猝灭双倒数图计算了在不同条件下二者的结合常数K, 根据Foster非辐射理论计算在正常生理条件下二者的结合距离r, 并通过热力学参数确定了二者的作用力类型.结论加替沙星与牛血清白蛋白之间有较强的相互作用, 以电荷作用力为主.     

吲哚菁类探针与血清蛋白的相互作用研究

目的应用荧光光谱法,研究了新型水溶性吲哚基同型聚合体菁类探针I与牛血清蛋白（BSA）的相互作用。方法探索吲哚探针I-BSA的静态荧光猝灭机制和静电相互作用,系统考察了吲哚探针I与BSA的结合常数、结合位点数、热力学函数。结果确定了两者在不同温度下的结合常数分别为3.72×10^5（293K）、3.59×10^5（298K）、3.40×10^5（303K）;结合位点数分别为1.02、0.99、0.98,吲哚探针I和BSA结合作用的ΔH,ΔS和ΔG分别为-2.242kJ.mol^-1,98.80kJ.mol^-1和-31.69kJ.mol^-1（298K）。结论吲哚探针I与牛血清蛋白之间的结合作用力主要为静电作用。     

荧光光谱法研究顺铂对表柔比星与人血白蛋白结合作用的影响

目的研究顺铂对表柔比星与人血清白蛋白(HSA)结合作用的影响。方法通过荧光光谱法研究顺铂和表柔比星对HSA的荧光猝灭光谱,同步荧光光谱。由Lineweaver-Burk双倒数作图法确定反应的解离常数,根据热力学方程讨论两者间主要的作用力类型。结果荧光猝灭光谱显示,顺铂和表柔比星与HSA都有荧光猝灭作用。顺铂、表柔比星对HSA的猝灭过程为静态猝灭。表柔比星与HSA的结合点数为1,主要作用力为疏水作用力。顺铂不影响表柔比星对HSA的内源荧光猝灭作用,但能增加表柔比星与HSA的结合常数(KA)。结论顺铂不影响表柔比星的血药浓度,但能增加表柔比星与HSA的结合力。     

Study of the interaction between fluoroquinolones and bovine serum albumin

The mechanism of interaction between norfloxacin (NRF) and ciprofloxacin (CPF) with bovine serum albumin has been investigated using circular dichroism, fluorescence and absorption spectroscopy. The quenching mechanism of fluorescence of bovine serum albumin by fluoroquinolones was discussed. The binding sites number n and apparent binding constant K were measured by fluorescence quenching method. The thermodynamic parameters obtained from data at different temperatures were calculated. The distance r between donor (bovine serum albumin) and acceptor (fluoroquinolones) was obtained according to Forster theory of non-radiation energy transfer. The effect of common ions on binding constant was also investigated. The results of synchronous fluorescence spectra, UV–vis absorption spectra and circular dichroism of BSA in presence of fluoroquinolones show that the conformation of bovine serum albumin changed.     

Interaction of triprolidine hydrochloride with serum albumins: thermodynamic and binding characteristics, and influence of site probes

The interaction between triprolidine hydrochloride (TRP) to serum albumins viz. bovine serum albumin (BSA) and human serum albumin (HSA) has been studied by spectroscopic methods. The experimental results revealed the static quenching mechanism in the interaction of TRP with protein. The number of binding sites close to unity for both TRP-BSA and TRP-HSA indicated the presence of single class of binding site for the drug in protein. The binding constant values of TRP-BSA and TRP-HSA were observed to be 4.75 ± 0.018 × 10(3) and 2.42 ± 0.024 × 10(4)M(-1) at 294 K, respectively. Thermodynamic parameters indicated that the hydrogen bond and van der Waals forces played the major role in the binding of TRP to proteins. The distance of separation between the serum albumin and TRP was obtained from the F?rster's theory of non-radioactive energy transfer. The metal ions viz., K(+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Mn(2+) and Zn(2+) were found to influence the binding of the drug to protein. Displacement experiments indicated the binding of TRP to Sudlow's site I on both BSA and HSA. The CD, 3D fluorescence spectra and FT-IR spectral results revealed the changes in the secondary structure of protein upon interaction with TRP.     

The effects of various drugs on the binding site of bilirubin in serum albumin

In the presence of various drugs, the concentration of free bilirubin which was released from the first binding site of bilirubin in serum albumin was evaluated, using a sensitive method based on static fluorescence quenching of dansyl serum albumin. Bilirubin bound to human serum albumin more strongly than to bovine serum albumin. Non-steroidal anti-inflammatory drugs, fenamates and allylphenyl propionic acids, affected the bilirubin-serum albumin interaction. Flufenamic acid and ketoprofen released bilirubin from human serum albumin. The bilirubin bound to the serum albumin was not influenced by the presence of indomethacin, but clidanac strongly dissociated bilirubin from the bilirubin-serum albumin complex. Sulfa-drugs, antibiotics, steroidal agents, warfarine, tolubutamide and phenytoin showed no significant effects on the bilirubin-serum albumin interaction. The fluorescence quenching method may be useful to evaluate the interaction of drug-bilirubin-serum albumin.     

Study of the interaction between monoammonium glycyrrhizinate and bovine serum albumin

The interaction between monoammonium glycyrrhizinate (MAG) and bovine serum albumin (BSA) were studied by fluorescence and absorption spectroscopy. The quenching mechanism of fluorescence of bovine serum albumin by monoammonium glycyrrhizinate was discussed. The binding sites number n and apparent binding constant K were measured by fluorescence quenching method. The thermodynamic parameters DeltaH degrees , DeltaG degrees , DeltaS degrees at different temperatures were calculated. The distance r between donor (bovine serum albumin) and acceptor (monoammonium glycyrrhizinate) was obtained according to Forster theory of non-radiation energy transfer. The results of synchronous fluorescence spectra and UV-vis absorption spectra show that the conformation of bovine serum albumin has been changed.     

Fluorometric investigation of the interaction between methylene blue and human serum albumin

The interaction between methylene blue (MB) and human serum albumin (HSA) was investigated by fluorescence spectroscopy and UV-vis absorbance spectroscopy. In the mechanism discussion, it was proved that the fluorescence quenching of HSA by MB is a result of the formation of MB-HSA complex and electrostatic interactions play a major role in stabilizing the complex. The Stern-Volmer quenching constant K(SV) and corresponding thermodynamic parameters DeltaH, DeltaG and DeltaS were calculated. Binding studies concerning the number of binding sites n and apparent binding constant Kb were performed by fluorescence quenching method. The distance r between the donor (HSA) and the acceptor (MB) was obtained according to fluorescence resonance energy transfer (FRET). Wavelength shifts in synchronous fluorescence spectra showed the conformation of HSA molecules is changed in the presence of MB.     

Analysis of binding interaction between puerarin and bovine serum albumin by multi-spectroscopic method

The interaction of puerarin and bovine serum albumin (BSA) was investigated by means of fluorescence spectroscopy, resonance light-scattering spectroscopy, infrared spectroscopy, and synchronous fluorescence spectra. The apparent binding constants (K(a)) between puerarin and BSA were 1.13 x 10(4) (20 degrees C), and 1.54 x 10(4) lmol(-1) (30 degrees C), and the binding sites values (n) were 0.95+/-0.02. The experimental results showed that the puerarin could be inserted into the BSA, quenching the inner fluorescence by forming the puerarin-BSA complex. The addition of increasing puerarin to BSA solution leads to the gradual decrease in RLS intensity, exhibiting the formation of the aggregate in solution. It was found that both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The positive entropy change and enthalpy change indicated that the interaction of puerarin and BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative. The competing binding reaction with BSA between Fe(3+), Cu(2+) and puerarin was investigated. The effect of Fe(3+) and Cu(2+) on the binding of puerarin with BSA is discussed.     

顺铂对阿霉素与人血清白蛋白结合的相互作用光谱研究

目的 研究顺铂对阿霉素与人血清白蛋白结合的相互作用。方法 采用荧光光谱法研究不同浓度顺铂对阿霉素与人血清白蛋白结合的相互作用。结果 顺铂与阿霉素对人血清白蛋白都有猝灭作用。顺铂对白蛋白的猝灭方式为动态猝灭,而阿霉素对白蛋白的猝灭方式为静态猝灭。结论 温度为17℃和37℃时,阿霉素与白蛋白的结合常数分别为2.13×104,2.76×10^4 L.mol l,2者的结合位点数为1。当加入不同浓度的顺铂后,阿霉素与白蛋白的结合常数有所变化,而结合位点数仍然为1。