亲和毛细管电泳法和荧光法研究氟喹诺酮类药物与牛血清白蛋白的相互作用

分别采用亲和毛细管电泳法和荧光法对6种氟喹诺酮类药物(司帕沙星、洛美沙星、左氧氟沙星、诺氟沙星、培氟沙星和氟罗沙星)与牛血清白蛋白的相互作用进行考察. 结合比均为1∶1, 结合常数在104 L/mol量级, 热力学参数表明体系间的相互作用力以范德华作用力和氢键力为主. 另外, 亲和毛细管电泳实验结果表明, 缓冲溶液pH值和离子强度增大会造成结合常数在一定程度上的减小, 使相互作用减弱. 同时, 荧光猝灭实验结合紫外光谱扫描说明体系间为静态猝灭. 所得到的数据对进一步研究氟喹诺酮类药物的作用机理、提高药效和开发新一代氟喹诺酮类药物具有一定的参考意义.     

核黄素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、同步荧光光谱研究了核黄素与牛血清白蛋白(BSA)相互作用的光谱行为。结果发现,在温度为293 K和310 K时核黄素与BSA的结合常数(Kb)分别为4.879×105L.mol-1和1.880×105L.mol-1,结合热力学方程计算得到了对应温度下的热力学参数。结果表明核黄素对BSA有较强的荧光猝灭作用,其荧光猝灭过程属于动态猝灭机制,二者主要靠疏水作用力结合。采用同步荧光光谱探讨了核黄素对BSA构象的影响。     

荧光光谱法研究染料木苷与牛血清白蛋白的相互作用

采用荧光光谱法,在pH=7.4的磷酸盐缓冲溶液(PBS)中研究了染料木苷(Genistin,Ge)与牛血清白蛋白(BSA)的作用方式及作用机理.结果表明,Ge可静态猝灭BSA的内源荧光,二者之间的结合位点数为1.4,温度对结合常数影响不大,300K、306 K、310 K和313 K的结合常数平均为4.31×104 L...     

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     

荧光光谱法研究木犀草素与牛血清白蛋白的相互作用

在pH为7.40的Tris-HCl缓冲体系中,采用荧光光谱技术研究了木犀草素与牛血清白蛋白(BSA)的相互作用。根据测定292K、299K、311K温度下的猝灭常数,证实了木犀草素对BSA的荧光猝灭为静态猝灭过程,根据Frster非辐射能量转移理论计算出木犀草素与BSA间的结合距离r=2.75nm,由热力学参数焓变(△H)小于零和熵变(△S)大于零,推断出木犀草素与BSA之间主要靠静电引力相结合,生成自由能变(△G)为负值,表明木犀草素与BSA的作用过程是一个自发过程;同时,应用同步荧光光谱考察了木犀草素对BSA构象的影响。     

荧光光谱法研究牛血清蛋白在盐酸胍体系中的变性

应用荧光光谱技术,对盐酸胍与牛血清蛋白在30℃水溶液中的结合作用及造成牛血清蛋白变性的过程进行了研究,考察了盐酸胍诱导牛血清蛋白变性时荧光强度和峰位的变化规律,并计算出伸展分数fu,变性平衡常数Ku,伸展吉布斯自由能△Gu,衡量蛋白质对变性剂稳定性的参量△GH2o,衡量蛋白质变性协同性的参量m和变性中点C1/2.研究结...     

十溴联苯醚与牛血清白蛋白相互作用的荧光光谱研究

在模拟生理条件下,采用荧光光谱法研究十溴联苯醚(Deca-BDE)与牛血清白蛋白(BSA)的相互作用.结果表明: Deca-BDE对BSA的内源荧光有静态猝灭作用.Deca-BDE与BSA在277, 298和310 K的结合常数分别为1.92×105, 1.97×105和2.16×105 L/mol.Deca-BDE在BSA接近于色氨酸残基附近有2个结合位点.热力学参数表明, Deca-BDE与BSA相结合的主要驱动力是疏水作用力. 与Deca-BDE结合后,BSA色氨酸残基附近肽键伸展程度增加,蛋白分子结构疏松.     

含缩醛正离子类脂分子与蛋白质的相互作用

Interactions of a series of dialkyl cationic lipids linking with bovine serum albumin (BSA) through acetal (linker) have been studied by the fluorescence spectroscopy. At low concentrations of cationic lipids, the fluorescence intensity of BSA decreased with binding of cationic lipid, and the maximum of emission wavelength shifted from (344±1)nm to (331±1)nm. It indicates that the BSA goes to uncoiled flexible conformation from its native structure. When the concentrations of lipids increased, the fluorescence intensity increased rapidly and then maintained unchanged. It reveals that two tryptophan residues of BSA are all enwrapped in the bilayer membrane, owing to the hydrophobic interactions between lipids and BSA.     

荧光光谱法研究纳米硫化锌与牛血清白蛋白的相互作用

采用水相法合成了ZnS纳米颗粒,通过XRD及TEM技术对纳米ZnS进行了表征,结果表明纳米ZnS的粒径约为7～8 nm.利用荧光光谱考察了纳米ZnS与牛血清白蛋白(BSA)的相互作用,结果显示,两者的相互作用可导致BSA内源荧光猝灭,推测其猝灭机理为静态猝灭,结合常数Ka=1.73×105 L·mol-1,结合位点数n...     

Study of the Binding of Herbacetin to Bovine Serum Albumin by Fluorescence Spectroscopy

In this paper, the interaction between herbacetin and BSA was investigated by fluorescence and three-dimensional fluorescence spectroscopy under simulated physiological conditions. It was proved that the fluorescence quenching of BSA by herbacetin was mainly the result of the formation of a herbacetin–BSA complex. The modified Stern–Volmer quenching constant and the corresponding thermodynamic parameters ΔH ⁰, ΔG ⁰ and ΔS ⁰ were calculated at different temperatures. The results indicated that electrostatic interactions were the predominant intermolecular forces in stabilizing the complex. The distance r=3.23 nm between the donor (BSA) and acceptor (herbacetin) was obtained according to Förster’s nonradioactive energy transfer theory. The synchronous fluorescence and three-dimensional fluorescence spectra results showed that the hydrophobity of amino acid residues increased in the presence of herbacetin. These results revealed that the microenvironment and conformation of BSA changed during the binding reaction.     

纳米金与牛血清白蛋白作用的毛细管电泳研究

开展了针对微量纳米金与牛血清白蛋白相互作用的毛细管电泳研究, 测得二者的结合常数为28.6 L/μmol, 每个纳米金颗粒吸附约24个牛血清白蛋白分子. 结果表明, 牛血清白蛋白可改善并稳定纳米金的峰形, 二者作用时温育介质的pH以及电泳所用的缓冲溶液浓度对毛细管电泳(CE)效率有重要影响. 此法可推广到其它纳米颗粒的吸附研究中.     

硫唑嘌呤和巯嘌呤与牛血清白蛋白作用的荧光光谱研究

采用荧光光谱法和紫外可见光谱法研究了硫唑嘌呤(AZP)和巯嘌呤(6-MP)与牛血清白蛋白(BSA)的结合反应特性.测定了不同温度下的结合常数KA及结合位点数n,研究证明AZP和6-MP对BSA内源荧光的猝灭机理均为静态猝灭,且主要以疏水作用力与BSA作用;利用同步荧光技术发现AZP和6-MP对BSA的构象均有影响;AZP和6-MP与BSA摩尔比为1:l时,根据Forster偶极-偶极非辐射能量转移理论,计算出作用距离rAZP-2.94,r6-MP-4.10,说明AZP和6-MP与BSA的猝灭过程中都存在能量转移效应.     

荧光光谱法研究大豆甙元与牛血清白蛋白的相互作用

采用荧光光谱技术研究了大豆甙元与牛血清白蛋白(BSA)的相互作用.研究结果表明:290 K、303 K、310K、315 K温度下大豆甙元对BSA的猝灭速率常数Ksv随着温度升高逐渐降低,且均大于最大动态猝灭速率常数2×1010 L·mol -1·s-1,表明大豆甙元对BSA的荧光猝灭属静态猝灭过程.根据F(o)rst...     

荧光光谱法研究原花青素与牛血清白蛋白的相互作用

在pH=7.40的Tris-HCl缓冲体系中,采用荧光光谱技术研究了原花青素与牛血清白蛋白(BSA)的相互作用.根据295 K、303 K、310 K、315 K温度下的猝灭常数,表明原花青素对BSA的荧光猝灭为静态猝灭过程,由热力学参数焓变(△rHm)和熵变(△rSm)均大于零,推断出原花青素与BSA之间主要靠疏水作...     

Characterization of the Interaction between Bovine Serum Albumin and Lomefloxacin by Capillary Zone Electrophoresis

Three capillary zone electrophoresis (CZE) methods of the frontal analysis (FA), vacancypeak (VP) and simplified Hummel-Dreyer (SHD) were applied to investigate interaction betweenbovine serum albumin (BSA) and lomefloxacin, the experimental condition was established after alarge number of tests. Based on the site-binding model, the binding parameters were measuredaccording to the site model by Scatchard.     

荧光光谱法研究注射用头孢美唑钠与牛血清白蛋白的相互作用

运用荧光光谱法研究了注射用头孢美唑钠(Cefmetazole Sodium,CS)与牛血清白蛋白(BSA)的相互作用.CS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.在297 K和311 K时用Stern-Volmer方程和热力学方程处理实验数据,得到了结合常数KA、热力学参数...     

毛细管电泳法研究牛血清白蛋白与盐酸异丙肾上腺素的相互作用

本研究分别采用区段-区段动力学毛细管电泳法(Plug-Plug Kinetic Capillary Electrophoresis,ppKCE),及以药物为添加剂的亲和毛细管电泳法(Affinity Capillary Electrophoresis,ACE)对盐酸异丙肾上腺素(Hydrochloric Acid Isoproterenol,HAI)与牛血清白蛋白(Bovine Serum Albumin,BSA)的结合作用进行研究。实验结果显示,ppKCE法可同时测得HAI与BSA相互作用体系的结合速率常数kon和离解速率常数koff分别为163.60L·mol-1·s-1、3.50×10-2±0.95×10-2s-1(n=3)。ppKCE法和ACE法测得HAI与BSA的结合常数Kb分别为4.67×103 L·mol-1、6.02×103 L·mol-1,两种方法所得结果能够较好吻合。证明毛细管电泳法在药物-蛋白相互作用研究领域的可靠性,可用于测定药物与蛋白的相互作用,从而用于新药筛选研究。     

Investigation of the Interaction between Isoflavonoids and Bovine Serum Albumin by Fluorescence Spectroscopy

The interactions of bovine serum albumin （BSA） with three structurally related isoflavonoids, genistein, puerarin and daidzein, were studied under physiological conditions by fluorescence spectroscopic technique. The quenching mechanism of these compounds with BSA was suggested as static quenching and the binding constants were determined at different temperatures based on the fluorescence quenching results. The transfer efficiency of energy and distance between the acceptor and BSA were investigated on the basis of the mechanism of the Forster energy transference. According to the thermodynamic parameters it has been suggested that the acting force be mainly hydrophobic force. The comparison of binding potency of the three isoflavonoids to BSA showed that the substitution by 5-OH and 8-Glc could enhance the binding affinity. All these obtained in the work can make us better understand the mode of the action and pharmacological activities of the isoflavonoids.     

荧光光谱法研究氰戊菊酯与牛血清白蛋白的结合反应

在生理酸度条件下,应用荧光光谱法和紫外一可见光谱法,研究了在不同温度下氰戊菊酯与牛血清白蛋白（BSA）的结合反应。实验发现,氰戊菊酯对BSA的内源荧光有较强的猝灭作用,且此荧光猝灭机理为动态猝灭。由热力学参数焓变△H=17.78kJ·mol^-1,熵变△S=143.65J·mol^-1·K^-1,推断出氰戊菊酯与BSA结合反应主要由疏水作用力驱动。根据Fǒrster非辐射能量转移理论,计算出供体（BSA）-受体（氰戊菊酯）间的结合距离为4.28nm,能量转移效率为0.0699。三维荧光光谱表明氰戊菊酯的存在使BSA的构象发生了变化。此外,还考察了某些金属离子对氰戊菊酯与BSA结合反应的影响。