光谱法研究夜蓝与牛血清白蛋白的相互作用

研究了有机染料夜蓝(NB)与牛血清白蛋白(BSA)相互作用后的荧光光谱特性。结果表明:NB对BSA的荧光产生了有规律的猝灭,并且猝灭类型属于静态猝灭;得到了二者相互作用后的结合常数和结合位点数,结合位点数大约为1,说明二者为1:1结合;经计算得到了二者反应的热力学参数,通过判断得NB与BSA之间主要靠静电和疏水作用力相结合;同步荧光光谱显示了NB更接近与BSA的色氨酸残基结合;又按照Forster非辐射能量转移的理论,得到了授体(BSA)-受体(NB)的能量转移效率和结合距离,分别为0.270和2.75 nm,说明二者之间发生了非辐射能量转移。     

光谱法研究11-羟基喜树碱与牛血清白蛋白的相互作用

在生理pH条件下用荧光光谱法和紫外光谱法结合化学计量学来研究10-羟基喜树碱(10-HCPT)与牛血清白蛋白(BSA)的相互作用,结果发现,10-HCPT对BSA的内源荧光有静态猝灭作用。以华法林作为标记药物,采用三维荧光技术,分别对竞争实验过程进行扫描,进而用平行因子法(PARAFAC)处理所得三维数据,并根据蛋白质结合位上药物的置换作用确定了10-HCPT的结合位置是BSA的site I。利用同步荧光光谱,考察了10-HCPT对BSA构象的影响,10-HCPT的加入使BSA构象发生变化,BSA内部残基所处环境的疏水性下降。     

光谱法比较喜树碱与溶菌酶、过氧化氢酶的相互作用

采用紫外可见吸收、红外、荧光等多种光谱学方法研究了抗癌药物喜树碱和溶菌酶及过氧化氢酶两种蛋白之间的相互作用,结果表明,喜树碱与之均形成基态复合物并引起蛋白内源荧光猝灭。通过计算确定了喜树碱和蛋白相互作用的结合常数、结合位点数、主要作用力类型以及与蛋白中色氨酸的结合距离。喜树碱对过氧化氢酶具有较高的结合能力,这主要是由于喜树碱不仅与过氧化氢酶中的色氨酸存在相互作用,也与酶中的酪氨酸及血红素产生相互作用。喜树碱的存在可引起蛋白构象发生变化,使α-螺旋二级结构减少。     

荧光光谱法研究山姜素与牛血清白蛋白的相互作用机理

研究了模拟生理条件下,山姜素与牛血清白蛋白(BSA)的相互作用。山姜素猝灭BSA为静态猝灭过程,获得了不同温度下山姜素与BSA的结合常数和结合位点数。考察了Mg2+、Ca2+、Zn2+、Cu2+等金属离子对结合作用的影响。热力学参数研究发现静电作用力为山姜素与BSA的主要结合力。根据Frster非辐射能量转移理论,计算了山姜素与BSA之间的结合距离r0为4.07nm。同步荧光光谱法研究结果表明山姜素对酪氨酸残基的微环境产生了影响,使其疏水性增强,而对色氨酸残基的微环境没有产生影响。     

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.     

光谱法研究欧前胡素及同分异构体与牛血清白蛋白的相互作用

采用紫外光谱法、荧光光谱法和同步荧光光谱法研究了欧前胡素及其同分异构体异欧前胡素与牛血清白蛋白(BSA)的相互作用。荧光光谱表明,欧前胡素和异欧前胡素对BSA的内源荧光均有显著的猝灭作用,且猝灭机制主要为静态猝灭和非辐射能量转移。308K下欧前胡素和异欧前胡素与BSA的结合常数K分别为1.48×104、1.04×104L·mol-1,结合位点数n分别为0.915、0.742。由热力学数据确定其作用力主要为氢键和范德华力。同步荧光光谱表明,欧前胡素和异欧前胡素与BSA的结合位点更靠近BSA中的色氨酸,引起色氨酸残基附近的疏水性环境减弱,从而使得BSA的构象发生改变。研究表明,香豆素母核上3-甲基-2-丁烯氧基的位置对它们的结合有重要影响,欧前胡素与BSA的作用强于异欧前胡素。     

荧光光谱法研究间硝基苯胺与牛血清白蛋白的相互作用

应用荧光光谱法研究间硝基苯胺与牛血清白蛋白的相互作用。激发波长为280nm,发射波长为342nm,在pH 7.50的Tris-盐酸缓冲溶液中反应150min后,间硝基苯胺对牛血清白蛋白的猝灭效果最为明显。289K,304K和318K下的结合常数分别为1.667×104,1.428×104,1.250×104L·mol-1。根据分子间的相互作用力与相关热力学参数间的相互关系,结合间硝基苯胺与牛血清白蛋白相互作用的焓变(ΔH)0和熵变(ΔS)0,可推断两者的相互作用力主要为静电作用力。结果表明:间硝基苯胺对牛血清白蛋白的荧光猝灭方式为静态猝灭,最后用紫外吸收光谱法对其作用机理进行了确认。     

光谱法研究染料木素与牛血清白蛋白的相互作用

采用荧光和紫外-可见吸收光谱,研究了染料木素与牛血清白蛋白(BSA)的相互作用.结果表明染料木素对BSA有较强的荧光猝灭作用;根据Stern-Volmer方程得到染料木素与BSA之间的结合常数KA为4.37×106(27 ℃)、6.45×10b(37℃)和6.76×106(47℃).根据Forster非辐射能量转移理论,求出了染料木素与BSA之间的结合距离为2.64 nm(27℃)、2.68mm(37℃)和2.71 nm(47℃).热力学数据表明该药物与牛血清白蛋白的相互作用是一个吉布斯自由能降低的自发过程,且二者之间的主要作用力类型为静电引力,同时用同步荧光光谱探讨了染料木素对BSA构象的影响.     

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     

荧光光谱法研究拉贝洛尔与牛血清白蛋白相互作用特征

应用荧光光谱和紫外-可见吸收光谱研究了拉贝洛尔与牛血清白蛋白(Bovine Serum Albumin,BSA)结合反应的光谱学特征.实验结果表明,在弱酸性条件下拉贝洛尔对BSA的猝灭机理为静态猝灭,而在中性和弱碱性时则为动态猝灭;根据 F(o)rster非辐射能量转移理论计算出310K和pH7.41时拉贝洛尔与BSA...     

Spectroscopic investigation of interaction between mangiferin and bovine serum albumin

The mechanism of interaction between mangiferin (MA) and bovine serum albumin (BSA) in aqueous solution was investigated by fluorescence spectra, synchronous fluorescence spectra, absorbance spectra and Fourier transform infrared (FT-IR) spectroscopy. The binding constants and binding sites of MA to BSA at different reaction times were calculated. And the distance between MA and BSA was estimated to be 5.20 nm based on Föster's theory. In addition, synchronous fluorescence and FT-IR measurements revealed that the secondary structures of the protein changed after the interaction of MA with BSA. As a conclusion, the interaction between the anti-diabetes Chinese medicine MA and BSA may provide some significant information for the mechanism of the traditional chinese medicine MA on the protein level to cure diabetes or other diseases.     

Study on the interaction between methyl violet and bovine serum albumin by spectral analyses

In this article the interaction between methyl violet (MV) and bovine serum albumin (BSA) was studied with spectroscopy. The results indicated that the fluorescence intensity of BSA was quenched strongly by MV through a static quenching procedure. The association constants, the number of binding sites and basic thermodynamic parameters were obtained based on fluorescence quenching data. The effect of MV on the conformation of BSA had been investigated with synchronous fluorescence spectroscopy and circular dichroism (CD) spectrum.     

布南色林与人血清白蛋白相互作用的光谱学研究

采用荧光光谱研究了模拟生理务件下抗精神病药布南色林与人血清白蛋白的相互作用,结果表明,布南色林对人血清白蛋白的内源性荧光具有猝灭作用且猝灭方式为静态猝灭.布南色林与人血清白蛋白形成了1∶1的复合物,结合常数K=1.80×104L/mol,且金属离子对结合反应具有较显著的影响.根据不同温度下的热力学函数确定了布南色林与人...     

阿魏酸哌嗪与牛血清白蛋白相互作用的研究

在模拟人体生理条件下,用常规荧光光谱法和紫外-可见吸收光谱法研究阿魏酸哌嗪和牛血清白蛋白结合反应的特征,并利用同步荧光法和三维荧光法研究了阿魏酸哌嗪与牛血清白蛋白作用前后白蛋白的构象变化.研究表明:阿魏酸哌嗪与牛血清白蛋白形成复合物,从而猝灭牛血清白蛋白的内源性荧光.该过程为静态猝灭过程.根据Stem-Volmer方程求出不同温度下的结合位点数和结合常数;根据Fsmter非辐射能量转移理论可求出其作用距离r=2.33nm:根据基本热力学参数△H、△S和△G判断阿魏酸哌嗪和牛血清白蛋白主要通过氢键和范德华力发生相互作用.     

绞股蓝皂苷与牛血清白蛋白相互作用的荧光光谱研究

用荧光光谱技术研究了绞股蓝皂苷与牛血清白蛋白(BSA)在pH=7.40的Tris-HCl缓冲溶液中的相互作用;通过计算确定了绞股蓝皂苷与BSA的结合位点数和结合常数,利用热力学分析探讨了绞股蓝皂苷与BSA之间的结合方式;同时采用同步荧光技术考察了绞股蓝皂苷对BSA构象的影响.结果表明,绞股蓝皂苷对牛血清白蛋白的荧光猝灭过程为静态猝灭;二者主要靠疏水作用和静电引力结合.     

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.     

Fluorometric investigation on the interaction of oleanolic acid with bovine serum albumin

The interactions between oleanolic acid and bovine serum albumin (BSA) have been studied by fluorescence, circular dichroism (CD), UV–vis absorption and Fourier transform infrared spectroscopy (FTIR) under physiological conditions. Spectroscopic analysis of the emission quenching at different temperatures has revealed that the quenching mechanism of bovine serum albumin by oleanolic acid is static quenching mechanism. The binding sites number n and binding constants K are obtained at various temperatures. The distance r between oleanolic acid and the protein is evaluated according to the theory of Forster energy transfer. The results by FTIR, CD and UV–vis absorption spectra experiment indicate that the secondary structures of protein have been perturbed in the presence of oleanolic acid. The thermodynamic parameters ΔH⁰, ΔG⁰, and ΔS⁰ are calculated according to van’t Hoff equation, which indicates that the hydrogen bonds and van der-waals are the intermolecular forces stabilizing the complex. Molecular modeling studies the interaction BSA with oleanolic acid.     

Fluorometric investigation of the interaction of bovine serum albumin with surfactants and 6-mercaptopurine

Fluorescence quenching in solutions of bovine serum albumin has been investigated in the presence of 6-mercaptopurine and ionic surfactants. Spectroscopic analysis of the emission quenching at different temperatures revealed that the quenching mechanism of bovine serum albumin by 6-mercaptopurine was dynamic quenching mechanism. The Stern–Volmer quenching model has been successfully applied, and the activation energy of the interaction between 6-mercaptopurine and bovine serum albumin as much as 4.26 kJ mol⁻¹ was calculated. The distance r between donor (bovine serum albumin) and acceptor (6-mercaptopurine) was obtained according to fluorescence resonance energy transfer (FRET). The result of synchronous fluorescence spectra shows that the conformation of bovine serum albumin has been changed at the present of 6-mercaptopurine.     

速灭威与牛血清白蛋白作用的研究

在pH=7.4的生理条件下,应用荧光光谱法研究了速灭威与牛血清白蛋白间相互作用。结果表明:速灭威对牛血清白蛋白的荧光有较强的猝灭作用,测定不同温度下的猝灭常数,证实了速灭威对牛血清白蛋白的荧光猝灭过程机理为静态猝灭。根据猝灭结果计算了不同温度下的结合位点数、结合常数。应用同步荧光光谱法探讨了速灭威对牛血清白蛋白构象的影响。依据f ster非辐射能量转移理论确定受体间的结合距离和能量转移效率。     

肌醇与牛血清白蛋白相互作用的荧光光谱研究

应用荧光光谱研究了肌醇与牛血清白蛋白(BSA)分子间的相互作用;求出了猝灭常数,讨论了肌醇对BSA构象的影响,并依据能量转移理论确定了肌醇与蛋白的最近距离.结果表明,肌醇与BSA两者间的相互作用为单一的动态猝灭过程.