大黄酸及大黄素和牛血清白蛋白的相互作用

采用荧光猝灭和红外光谱方法考察了两种大黄蒽醌类化合物(大黄酸和大黄素)与模型蛋白牛血清白蛋白之间的相互作用.结果表明,大黄酸和大黄素主要通过静电作用与牛血清白蛋白形成基态化合物,从而使其内部荧光猝灭,并获得了二者相互作用的结合常数、结合位点数及大黄酸和大黄素与色氨酸结合的空间距离.金属离子对这两种大黄蒽醌类化合物与牛血...     

Influences of urea on the interaction of 32π-Norcorrole with bovine serum albumin

The aim of the present study is to investigate the urea-induced denaturation of bovine serum albumin. The native and denatured bovine serum albumin interactions with 32π-Norcorrole were investigated, respectively. The circular dichroism spectra indicated that the α-helix content of bovine serum albumin reduces in the presence of urea and 32π-Norcorrole. The Stern–Volmer quenching constant indicated that both dynamic and static quenching exist in the interaction; moreover, the denaturation of bovine serum albumin leads to the decrease of Stern–Volmer quenching constant. Binding constant illustrated that the native bovine serum albumin has stronger combination capacity than the denatured bovine serum albumin. The fluorescence lifetime studies demonstrated that denaturation lead to the fluorescence decay of bovine serum albumin. The binding sites experiment and molecular docking studies demonstrated that the binding site of 32π-Norcorrole on bovine serum albumin is mainly located in site I.     

光谱法研究盐酸非那吡啶与牛血清白蛋白的结合作用

运用光谱学方法研究了在生理pH值条件下盐酸非那吡啶(PHE)与牛血清白蛋白之间的结合作用。通过荧光光谱和紫外吸收光谱确定了盐酸非那吡啶对牛血清白蛋白的荧光猝灭机理。依据Scatchard方程测定了不同温度下该结合反应的结合常数和结合位点数。根据热力学方程讨论了两者间的主要作用力类型。结合同步荧光光谱分析了盐酸非那吡啶对牛血清白蛋白构象的影响。盐酸非那吡啶对牛血清白蛋白的荧光猝灭机制主要为静态猝灭和非辐射能量转移。在15, 25, 37℃时盐酸非那吡啶与牛血清白蛋白的结合常数K_b分别为2.47×107, 9.15×106, 4.36×106 L·mol-1,它们之间平均结合位点数n为1。结合反应的热力学参数为ΔH=-71.2 kJ·mol-1,ΔS=124.8 J·mol-1·K-1。热力学函数计算结果表明,该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。依据Frster能量转移理论确定PHE与BSA间的结合距离为1.61 nm。两者结合的主要作用力类型是静电作用力。盐酸非那吡啶在体内能够被血清蛋白存储和转运,但结合时对蛋白构象有一定影响。     

几种光谱法研究牛血清白蛋白与胭脂红作用

采用荧光发射光谱研究了牛血清白蛋白与胭脂红相互作用的发射光谱特征,计算了不同温度下二者结合常数KA、结合位点数n、热力学参数ΔGΘ、ΔSΘ、ΔHΘ及室温下牛血清白蛋白与胭脂红的能量转移距离。结果显示,胭脂红有效猝灭牛血清白蛋白内源荧光是通过范德华力和氢键作用使牛血清白蛋白分子与胭脂红分子结合为配合物造成的;4种氨基酸（脯氨酸、精氨酸、赖氨酸和甘氨酸）的存在均能使二者结合常数下降。应用同步荧光、瑞利共振散射光谱技术表征,发现牛血清白蛋白与胭脂红相互作用后牛血清白蛋白的色氨酸和酪氨酸残基位于疏水性比较弱的区域。     

Studies on the interaction of gliclazide with bovine serum albumin by fluorescence and synchronous fluorescence spectroscopy

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 (K_a), 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.     

水杨酸与牛血清蛋白相互作用的荧光光谱研究

应用荧光光谱研究了水杨酸与牛血清蛋白 (BSA)分子间的相互作用。研究表明 :水杨酸对BSA内源荧光的猝灭机制属于形成化合物所引起的静态猝灭 ,猝灭常数Ksv 为 1 0 97× 10 4 (mol·L- 1 ) - 1 ;水杨酸与BSA反应的结合常数为 7 377× 10 4 ,结合位点数为 1,当水杨酸浓度较低 (摩尔比小于 1∶1)时 ,它与Trp残基或其附近基团结合但并不引起Trp残基微环境的改变 ;根据F rster非辐射能量转移理论 ,计算了授体 受体间的结合距离和能量转移效率     

Study on the competitive reaction between bovine serum albumin and neomycin with ponceau S as fluorescence probe

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.     

柠檬酸钠与牛血清白蛋白的相互作用

用荧光光谱法研究了柠檬酸钠与牛血清白蛋白( BSA)的作用机制.实验表明,柠檬酸钠对BSA具有荧光猝灭作用,其猝灭方式为静态猝灭,并求出了猝灭常数、结合常数及结合位点数.     

The investigation of the interaction between edaravone and bovine serum albumin by spectroscopic approaches

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.     

锌离子与牛血清白蛋白相互作用的研究

用荧光光谱法研究了锌离子(Zn2+)与牛血清白蛋白(BSA)的作用机制.实验表明,Zn2+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.利用同步荧光光谱研究了Zn2+对BSA分子荧光光谱的影响.     

富勒醇与血清白蛋白相互作用的光谱学研究

采用荧光光谱法和紫外-可见吸收光谱法研究了不同温度下富勒醇与血清白蛋白的相互作用机理,研究结果表明,富勒醇对人和牛血清白蛋白的内源荧光有明显的猝灭作用, 猝灭过程均为静态猝灭,并测定和计算得到不同温度下富勒醇与血清白蛋白反应的结合常数(K_HSA273 K1.546×104,K_HSA293 K1.513×104;K_BSA273 K13.920×104,K_BSA293 K939.500×104)、结合位点数(n_HSA293 K0.952 2;n_BSA293 K1.376 2)。通过结合反应的热力学数据分析,推测出富勒醇与血清白蛋白之间主要靠疏水作用结合;富勒醇与BSA结合强度明显大于富勒醇与HSA的结合强度,BSA的结合常数受温度影响更大;人和牛血清白蛋白在273和293 K的结合位点数在0.901→1.376之间,BSA与富勒醇结合位点数略大于HAS。同时采用分子模拟对接方法,预测富勒醇对牛血清白蛋白的结合部位和作用方式;通过AlignX序列分析法得到BSA与HSA的氨基酸序列相似度较高,在序列160和185附近氨基酸序列差异性较大,推测这是影响两种蛋白质之间与富勒醇作用方式的关键位点。     

荧光光度法研究金莲橙G与牛血清白蛋白的作用

利用荧光光度法研究了金莲橙G与牛血清白蛋白(BSA)的相互作用。金莲橙G对牛血清白蛋白的内源荧光有显著的猝灭作用,是形成超分子复合物的静态猝灭过程。测定了金莲橙G与BSA结合常数以及其相互作用的热力学参数,并根据Ross理论,和作用过程的热力学参数确定了金莲橙G与牛血清白蛋白之间主要结合力是静电引力。由Foerster非辐射能量转移理论,推导出能量供体金莲橙G与受体BSA间的结合距离。     

Synthesis of Amide Compounds of Ferulic Acid and Their Association with Bovine Serum Albumin

ABSTRACT

In this work, three new amide compounds of ferulic acid (FA) were synthesized. The fluorescence and ultraviolet spectroscopy were explored to study the interactions between three amide compounds of FA and bovine serum albumin (BSA) under imitated physiological conditions. The experimental results showed that the fluorescence quenching mechanism between BSA and three amide compounds of FA were mainly static quenching and nonradiation energy transfer at 25°C, 30°C, and 37°C. The Stern–Volmer quenching constants, the binding constants, and the number of binding sites and corresponding thermodynamic parameters ΔH, ΔG, and ΔS were calculated at different temperatures. From the thermodynamic parameters, we concluded that the action force was mainly a hydrophobic interaction. According to the F?rster theory of nonradiation energy transfer, the binding distances (r) between BSA and amide compounds are less than 7 nm. Furthermore, the effects of amide compounds on the conformation of BSA were analyzed using synchronous fluorescence spectroscopy.     

注射用头孢美唑钠与牛血清白蛋白相互作用的研究

荧光光谱法研究了注射用头孢美唑钠（Cefmetazole Sodium for Injection,CS）与牛血清白蛋白（BSA）的作用机制。结果表明,头孢美唑钠对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。研究了Zn2＋对头孢美唑钠与BSA作用的影响,Zn2＋的加入使得头孢美唑钠与BSA的结合常数与结合位点数减小。     

L-半胱氨酸修饰的金纳米粒子与牛血清白蛋白相互作用的荧光光谱研究

采用荧光猝灭光谱和同步荧光光谱研究了L-半胱氨酸修饰的金纳米粒子(Cys-GNPs)与牛血清白蛋白(BSA)间的相互作用。根据荧光猝灭相关方程计算了Cys-GNPs与BSA相互作用的结合常数和结合位点数,探讨了其荧光猝灭机制为静态猝灭,并且根据热力学参数确定了二者间的作用力类型,推断出Cys-GNPs和BSA间主要靠疏水作用力结合。同步荧光光谱表明,二者的相互作用没有导致牛血清白蛋白的构象及色氨酸残基的微环境发生明显变化。     

Interactions between imazethapyr and bovine serum albumin: Spectrofluorimetric study

The interaction between imazethapyr (IMA) and bovine serum albumin (BSA) was investigated by fluorescence spectroscopy. The Stern–Volmer quenching constant (K_SV) at three temperatures was evaluated in order to determine the quenching mechanism. The dependence of fluorescence quenching on viscosity was also evaluated for this purpose. The results showed that IMA quenches the fluorescence intensity of BSA through a static quenching process. The values of the binding constant for the formed BSA–IMA complex and the number of binding sites were found to be 1.51×10⁵ M^?1 and 0.77, respectively, at room temperature. Based on the calculated thermodynamic parameters, the forces that dominate the binding process are hydrogen bonds and van der Waals forces, and the binding process is spontaneous and exothermic. The quenching of protein fluorescence by iodide ion was used to probe the accessibility of tryptophan residues in BSA and the change in accessibility induced by the presence of IMA. According to the obtained results, the BSA–IMA complex is formed in the site where the Trp-134 is located, causing it to become less exposed to the solvent.     

光谱法研究酸度对一种白杨素衍生物与牛血清白蛋白相互作用的影响

在3种酸度条件下,采用多种光谱技术对一种白杨素衍生物和牛血清白蛋白的相互作用进行了研究.结果表明该衍生物和牛血清白蛋白可形成基态复合物,静态、动态猝灭方式同时存在,以静态猝灭为主.通过计算获得了在不同温度及酸度条件下的结合常数及结合位点数.该衍生物在碱性条件下和牛血清白蛋白的结合能力较强.在pH 7.40的生理条件下,...     

甲钴胺与牛血清白蛋白相互作用的光谱特性

应用荧光光谱法、紫外吸收光谱法及共振光散射法,研究了甲钴胺 (Mecobalamin) 与牛血清白蛋白 (BSA) 之间的相互作用。在pH=7.40的三羟甲基胺基甲烷-盐酸 (Tris-HCl) 缓冲溶液中,随着甲钴胺浓度的增加,BSA的荧光强度、共振散射光强度逐渐减弱。通过计算不同温度(293,303,310 K)下的猝灭常数 (K_sv=5.40×10⁴,6.90×10⁴,8.00×10⁴ L/mol) 及扫描紫外吸收光谱,确定了甲钴胺对牛血清白蛋白的猝灭机理为动态猝灭。测定了该反应的表观结合常数 (K_A=1.68×10⁴,4.34×10⁴,7.90×10⁴ L/mol)和结合位点数 (n≈1)。利用热力学参数 (ΔH>0、ΔG<0和ΔS>0) 确定了分子间的作用力性质,作用力主要是疏水作用力,作用过程是自发的。同时应用同步荧光技术研究了甲钴胺对BSA构象的影响。结果表明,甲钴胺没有引起BSA构象的变化。     

同步荧光光谱法结合分子对接研究金雀花碱与牛血清白蛋白间相互作用

金雀花碱(Cy)是一种生物碱,主要存在于豆科毒豆属植物种子中。Cy具有较强的生物活性,特别是作为戒烟药物已得到广泛应用。在模拟生理条件下,应用荧光光谱法研究了Cy同牛血清白蛋白(BSA)之间的相互作用以及Cy猝灭BSA荧光发射的机理。详细考查了水浴温度、水浴时间以及溶液pH等因素对荧光猝灭的影响,并且通过Stem-Volmer方程计算了Cy与BSA间的结合类型、结合位点数目以及结合常数。结果表明,Cy与BSA可形成摩尔比为1∶1的非共价复合物,其结合常数为5.6×103,其猝灭类型为静态猝灭。同步荧光光谱研究结果表明,Cy的结合主要影响BSA 的Trp残基的荧光发射。进一步应用分子对接研究表明,氢键与疏水作用是Cy与BSA形成复合物的主要推动力。Cy与BSA中Trp213及其周围的氨基酸残基间存在氢键与疏水作用,这种作用将改变Trp213所处微环境的疏水情况,从而导致BSA的荧光发生猝灭。     

The Application of Two-dimensional Fluorescence Correlation Spectroscopy on the Interaction Between Bovine Serum Albumin and Paeonolum in the Presence of Fe(III)

The effect of Fe³⁺ on the interaction between bovine serum albumin (BSA) and paeonolum (PAL), which was extracted from the traditional Chinese herb, Paeonia suffruticosa Andr, was investigated by UV and fluorescence spectroscopy. Two-dimensional correlation spectroscopy was applied to the analysis of fluorescence spectra. The results of spectroscopic measurements suggested that PAL had a strong ability to quench the intrinsic fluorescence of BSA through static quenching procedure in the presence of Fe(III). Thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) were calculated. The binding parameters including binding constant (K), and the distance (r) between PAL and BSA were evaluated on the basis of the theory of Föster energy transfer. Owing to the spectral resolution enhancement in 2D correlation spectroscopy, the structure change of PAL–Fe³⁺ can be observed.