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.     

吡柔比星与牛血清白蛋白的相互作用研究

采用荧光光谱、紫外光谱对吡柔比星与牛血清白蛋白的相互作用进行了研究。结果表明,吡柔比星和牛血清白蛋白可形成基态配合物导致牛血清白蛋白的内源荧光猝灭,猝灭机理主要为静态猝灭和非辐射能量转移。通过计算获得了二者在不同温度下的结合常数及结合位点数。根据热力学参数判断吡柔比星与牛血清白蛋白之间的作用力主要为范德华力和氢键。根据Frster非辐射能量转移理论确定了吡柔比星和牛血清白蛋白的作用距离。研究了不同金属离子存在下对吡柔比星与牛血清白蛋白结合常数及结合位点数的影响。     

变色酸与牛血清白蛋白的相互作用

采用荧光光谱法和紫外-可见分光光度法研究了变色酸与牛血清白蛋白之间的相互作用。结果表明:变色酸对牛血清白蛋白有较强的荧光猝灭作用。根据Stern-Volmer方程得到了荧光猝灭常数,并判断由于与变色酸反应而导致牛血清白蛋白的荧光猝灭属于静态猝灭。采用Lang-muir单分子吸附模型计算了结合常数和结合位点数。从计算得到的热力学参数ΔH和ΔS推断了变色酸与血清白蛋白反应的作用力为氢键和范德华力。     

激光光散射与荧光光谱法研究大豆苷与牛血清白蛋白作用及聚集态

荧光光谱法和动态光散射法研究大豆苷与牛血清白蛋白在生理条件下的相互作用. 研究表明, 大豆苷与牛血清白蛋白能形成2∶l复合物, 荧光猝灭属于静态猝灭过程; 大豆苷与牛血清白蛋白分子间主要的结合作用力为疏水作用; 310 K下, 两者结合常数和结合位点数分别为7.4×l04 L•mol―1和1.75; 大豆苷使牛血清白蛋白的构象发生了变化; 动态光散射数据探讨了牛血清白蛋白与大豆苷分子产生聚集与之相互作用, 进一步证实了牛血清白蛋白在大豆苷水溶液中的构象变化. 实验结果为进一步研究大豆苷对心血管疾病的药理作用, 特别是对血浆蛋白构象的影响提供了重要依据.     

苏丹Ⅰ与牛血清白蛋白的相互作用特征

利用荧光技术研究了在人体生理酸度条件下,苏丹Ⅰ与牛血清白蛋白相互作用,发现苏丹Ⅰ对牛血清白蛋白有较强的荧光猝灭作用,用Stern-Volmer和Line Weaver-Burk方程处理荧光猝灭数据,得到了反应的结合常数、结合热力学性质和结合位点等参数。根据热力学常数确定了该药物与血清白蛋白之间的作用力类型,在此基础上依据F rster非辐射能量转移机理探讨了苏丹Ⅰ与BSA相互结合时其供体-受体间的距离。     

荧光光谱法研究辛硫磷与牛血清白蛋白的相互作用

用荧光光谱法研究了在生理pH条件下杀虫剂辛硫磷与牛血清白蛋白(BSA)的相互作用. 结果表明: 辛硫磷对BSA的荧光有较强的猝灭作用, 该猝灭属于静态猝灭. 根据猝灭结果求得了不同温度下辛硫磷与牛血清白蛋白结合作用的结合位点数、结合常数及反应热力学参数, 并据此确定它们之间主要的相互作用力为疏水作用力. 用同步荧光光谱法探讨了辛硫磷对BSA构象的影响.     

甘氨酸镧（Ⅲ）配合物与牛血清白蛋白的相互作用研究

红外光谱和X射线衍射分析表明甘氨酸与镧(Ⅲ)作用形成配合物。利用同步荧光光谱和荧光光谱探究了牛血清白蛋白(BSA)和甘氨酸镧(Ⅲ)配合物之间的相互作用。结果可知甘氨酸镧(Ⅲ)配合物与牛血清白蛋白的荧光猝灭为静态猝灭,根据双对数方程处理荧光猝灭数据得到了甘氨酸镧(Ⅲ)配合物与牛血清白蛋白在不同温度下的结合常数Kb和结合位点数n。热力学数据表明配合物与BSA作用主要是疏水作用力。利用同步荧光光谱法研究了甘氨酸镧(Ⅲ)配合物对于牛血清白蛋白的构象影响。     

荧光光度法研究甲氨蝶呤和蛋白质的相互作用

应用荧光光度法研究了水溶液中甲氨蝶呤与牛血清白蛋白以及人血清白蛋白分子间的结合反应,讨论了甲氨堞呤对蛋白质内源荧光的猝灭机理,测定出甲氨蝶呤与牛血清白蛋白以及人血清白蛋白的结合常数分别为6.76×105L·mol-1,2.69×105L·mol-1,相应的结合位点数分别为1.09,1.02.依据F(o)rster非辐射能量转移理论确定了供体-受体间的结合距离和能量转移效率,并用同步荧光技术考察了甲氨蝶呤对蛋白质构象的影响.     

吡罗昔康与蛋白质作用特征的热力学研究

用荧光光谱法和吸收光谱法研究了吡罗昔康与牛血清白蛋白结合反应,显示吡罗昔康能强烈猝灭对牛血清白蛋白的荧光强度,根据荧光猝灭数据,并由Stern-Volmer和Lineweaver-Burk方程分析并处理实验数据,得到反应的结合常数、热力学参数等。     

头孢噻肟-Cu(Ⅱ)-牛血清白蛋白相互作用的荧光光谱法研究

用荧光光谱法研究了生理酸度条件下,头孢噻肟对牛血清白蛋白,Cu(Ⅱ)对牛血清白蛋白以及Cu(Ⅱ)对头孢噻肟和牛血清白蛋白荧光光谱特性的影响。结果表明:Cu(Ⅱ)和头孢噻肟均可使牛血清白蛋白的荧光强度发生静态猝灭,并且在Cu(Ⅱ)存在下,头孢噻肟对牛血清白蛋白的荧光猝灭作用显著增强。根据荧光猝灭双倒数图计算头孢噻肟和牛血清白蛋白的结合常数为3.11×104L/mol,结合位点数为1.03;二元配合物Cu(Ⅱ)与牛血清白蛋白之间的结合常数为1.13×103L/mol,结合位点数为0.74。     

Investigation of the Interaction between N,N′‐Di(4‐Chlorophenyl)Thiourea and Human Serum Albumin by Fluorescence Spectroscopy: Synchronous Fluorescence Determination of Human Serum Albumin

Under physiological conditions, interaction between N,N′‐di(4‐chlorophenyl)thiourea synthesized and human serum albumin was investigated by using fluorescence spectroscopy and UV absorption spectrum. The intrinsic fluorescence of human serum albumin was quenched by N,N′‐di(4‐chlorophenyl)‐thiourea through a static quenching procedure. The binding constants (K) at 14 °C and 24 °C were obtained, and the values were 2.541 × 10⁵ M^?1 and 2.021 × 10⁵ M^?1, respectively. Thermodynamic parameter enthalpy change (ΔH) and entropy change (ΔS) were calculated to be ‐16.19 KJ/mol and 47.05 J·mol¹·K^?1, respectively, which indicated that hydrophobic force played a major role in interaction. The binding distance was evaluated on the basis of the theory of Föster energy transfer. The effects of various metal ions on the binding constants of N,N′‐di(4‐chlorophenyl)thiourea with human serum albumin were studied. A synchronous fluorescence technique for determination of human serum albumin was developed, and the method was successfully applied to the detection of HSA in human serum samples.     

光谱法研究噻菁染料与血清蛋白的相互作用

本文通过吸收和荧光光谱法研究了一种噻菁染料与人血清蛋白及牛血清蛋白的相互作用。吸收光谱数据表明,与血清蛋白结合后,噻菁染料单体的吸收峰发生红移,同时强度也有很大变化;还通过吸收光谱计算确定了噻菁染料与血清蛋白的结合位点数（ n ）。与人血清蛋白或牛血清蛋白结合后,噻菁染料的荧光量子产率增加。分析噻菁染料的荧光强度随溶液中血清蛋白浓度的变化得到了二者反应的表观结合常数（ K _a）和自由能变化（ ΔG ）。根据表观结合常数（ K _a）可以判断,人血清蛋白比牛血清蛋白与噻菁染料的结合更强。     

Interaction of Bovine Serum Albumin with N‐(4‐Ethoxyphenyl)‐N′‐(4‐Antipyrinyl)Thiourea (EPAT) Using Spectroscopies

The interaction between N‐(4‐ethoxyphenyl)‐N′‐(4‐antipyrinyl)thiourea (EPAT) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy in combination with UV absorption spectroscopy. The intrinsic fluorescence of bovine serum albumin was quenched by EPAT through a static quenching procedure. The binding constants of EPAT with BSA were estimated according to the fluorescence quenching results at different temperatures. The thermodynamic parameters: enthalpy change (ΔH) and entropy change (ΔS) were calculated to be ?10.69 kJ/mol and 42.64 J·mol^?1·K^?1 according to thermodynamic equations, respectively, and indicating that the binding force was suggested to be mainly a hydrophobic force. The effect of common ions on the binding constant was also investigated. A new fluorescence spectroscopy assay of the proteins was presented in this paper. The determination results of the proteins in bovine serum by means of this method were very close to those obtained using Coomassie Brilliant Blue G‐250 colorimetry.     

Fluorescent investigation of the interactions between N-(p-chlorophenyl)-N'-(1-naphthyl) thiourea and serum albumin: synchronous fluorescence determination of serum albumin

The interactions between N-(p-chlorophenyl)-N′-(1-naphthyl) thiourea and serum albumin were investigated by fluorescence spectroscopy and UV absorption spectrum under physiological conditions. The results of spectroscopic measurements suggested that N-(p-chlorophenyl)-N′-(1-naphthyl) thiourea should have a strong ability to quench the intrinsic fluorescence of both bovine serum albumin and human serum albumin through static quenching procedure, and the hydrophobic interaction was the predominant intermolecular force stabilizing the complex. Thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) were calculated according to the Vant’Hoff equation. The binding distances between N-(p-chlorophenyl)-N′-(1-naphthyl) thiourea and the proteins were evaluated on the basis of the theory of Föster energy transfer. In addition, the effects of other ions on the binding constants of complexes were also discussed. Synchronous fluorescence technology was successfully applied to the determination of serum albumins added to the CPNT solution.     

芦丁金属配合物的合成、表征及与血清白蛋白的相互作用

本文合成了芦丁的过渡金属配合物，通过红外及元素分析等方法对其进行了表征。采用荧光光谱和紫外光谱法研究了芦丁的过渡金属配合物与牛血清白蛋白(BSA)和人血清白蛋白(HSA)的相互作用。通过二者的荧光光谱的变化，求得芦丁过渡金属配合物与血清白蛋白的结合常数。探讨了它们之间作用力的类型。     

长春新碱与人血清白蛋白的相互作用研究

利用荧光和圆二色光谱研究了长春新碱(VCR)与人血清白蛋白(HSA)之间的相互作用. 通过荧光猝灭测得在288, 298和308 K时, VCR与HSA的结合常数K分别为2.14×10⁴, 1.73×10⁴ 和1.35×10⁴ L•mol^－1, 表明VCR与HSA间具有较强的结合作用, 属于静态猝灭. 计算出焓变(ΔH)为 －17.38 kJ•mol^－1, 熵变(ΔS)为22.62 J•mol^－1•K^－1, 结合分子模型理论计算的结果, 表明VCR与HSA相互作用时在色氨酸(Trp) 214残基和VCR分子中吲哚基间作用力以疏水作用力为主, 但在 VCR和HSA 分子间以静电引力为主. 圆二色光谱(CD)的数据表明相互作用后HSA的二级结构发生了改变：HSA的α-螺旋的含量从51.7%下降到32.9%, β-折叠的含量增加了9.2%.     

腺苷与人血清白蛋白间相互作用的荧光光谱及分子模型法研究

在模拟人体生理条件下,结合紫外光谱和分子对接模型运用荧光光谱研究了腺苷与人血清白蛋白(HSA)间的键合作用。腺苷有较强的能力猝灭人血清白蛋白的内源荧光,且根据Stern-Volmer方程判断出猝灭机制为静态猝灭。本文运用相应的荧光值和Vant’Hoff热力学方程求得了不同温度下的结合常数(K)以及一些热力学参数,如焓变(ΔH)和熵变(ΔS)。结果表明：键合过程中疏水作用力对新化合物的稳定性起主要作用,这与分子对接模型方法研究的结果基本一致。另外还研究了常见离子对结合常数的影响。     

Interaction between Xanthoxylin and Bovine Serum Albumin

在模拟生理条件下,采用荧光光谱法、圆二色光谱法和红外光谱法研究了花椒油素(XT)与牛血清白蛋白（BSA）的相互作用。结果表明花椒油素与牛血清白蛋白之间发生动态和静态联合猝灭,二者间的的猝灭常数(K)在286, 298和310 K分别为3.31 × 105, 到2.03 × 105 和 0.94 × 105 L∙mol-1. 热力学参数表明, 花椒油素与牛血清白蛋白间以疏水作用力为主。圆二色光谱和红外光谱法表明加入花椒油素后,牛血清白蛋白的二级结构发生了变化,其中α-螺旋减少了3.9%。另外,我们还研究了共存离子对两者结合的影响。     

Spectroscopic Studies on the Interaction of Asiatic Acid with Bovine Serum Albumin

Fluorescence spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy, circular dichroism (CD) and FT‐Raman spectroscopy were employed to analyze the binding of the asiatic acid (AA) to bovine serum albumin (BSA) under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by AA was the result of the formation of BSA‐AA complex. The fluorescence quenching mechanism of BSA by AA was a static quenching procedure. According to the Van′t Hoff equation, the thermodynamic parameters enthalpy change (ΔH⁰) and entropy change (ΔS⁰) for the reaction were evaluated to be ?12.55 kJ·mol^?1 and 67.08 kJ·mol^?1, respectively, indicating that hydrophobic and electrostatic interactions played a major role in stabilizing the complex. The influence of AA on the conformation of BSA has also been analyzed on the basis of FT‐IR, CD and FT‐Raman spectra.     

Study of interaction of Potassium Dodecatangestato Cobaltate(III) with Bovine Serum Albumin using Fluorescence Spectroscopy

The binding of potassium dodecatangestato cobaltate(III) (PDC) as a water-soluble polyoxometal with bovine serum albumin (BSA) as a major transporting protein of plasma, has been investigated at pH 7.2, 5?mM phosphate buffer, 27°C and various ionic strength by fluorescence spectroscopy.

The results show that the binding of PDC to BSA quenches BSA emission and the Stern–Volmer linear relationship can be applied for the quenching process.

The values of Stern–Volmer constant, K _sv, which can be considered as a binding constant for formation of 1:1 complex at 0.01, 0.1 and 0.2?M NaCl are 8.56 × 10⁵, 5.72 × l0⁵ and 9.60 × 10⁵, respectively. The interpretation of the results represents that binding affinity depends on both electrostatic forces and conformational stability of BSA. A step-by-step aggregation model, which has been developed by Borissevich et al., was used to determine the average aggregation number of BSA, ?J?, from the fluorescence quenching. The results show that the binding of PDC to BSA does not induce any considerable aggregation in BSA molecules. Therefore, it can be concluded that there are no considerable conformational changes in BSA molecules during its interaction with PDC.