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。     

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。     

荧光光谱法研究安非他酮与人血清白蛋白的相互作用

目的 研究安非他酮与人血清白蛋白(human serum albumin,HSA)的相互作用。方法 通过荧光光谱法研究安非他酮对HSA的荧光猝灭光谱和同步荧光光谱的影响。由Stern-Volmer方程确定安非他酮对HSA的荧光猝灭机制,双对数方程确定反应结合位点和结合常数。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,安非他酮对HSA有猝灭作用,在17 ℃和37 ℃时的猝灭速率常数分别为5.714 8×10³和3.126 1×10³ L·mol^-1·s^-1,反应前后的焓变和熵变均<0,结合点数为1。结论 安非他酮对HSA的猝灭过程为静态猝灭,二者间的结合力主要为氢键和范德华力。     

光谱法研究吡罗昔康与血浆蛋白质结合性质

目的研究吡罗昔康(PRCX)与人血白蛋白(HSA)的结合性质。方法采用荧光淬灭技术研究吡罗昔康对人血白蛋白内源荧光淬灭的类型,依据非辐射能量转移理论计算二者之间的结合距离,通过计算热力学参数确定二者相互作用的作用力类型,采用同步荧光和圆二色光谱研究蛋白质的构象变化。结果吡罗昔康能淬灭人血白蛋白的内源荧光,二者的结合距离小于7 nm,吡罗昔康与人血白蛋白相互作用的ΔG~0<0、ΔS~0>0、ΔH~0<0,吡罗昔康的加入导致人血白蛋白的同步荧光和圆二色光谱发生改变。结论吡罗昔康对人血白蛋白的荧光淬灭是静态淬灭,人血白蛋白与吡罗昔康之间能够发生非辐射能量转移,疏水作用力和氢键在形成人血白蛋白-吡罗昔康复合物的过程中发挥主要作用且形成复合物的过程是自发进行的,相互作用导致人血白蛋白的构象发生了变化。     

咪达唑仑与人血清白蛋白结合的荧光光谱研究

目的:研究咪达唑仑与人血清白蛋白(HSA)的结合作用。方法:分析咪达唑仑与HSA结合的荧光猝灭光谱和同步荧光光谱(激发波长和发射波长的间距(Δλ)分别为15nm和60nm);由Stern-Volmer方程确定咪达唑仑对HSA17℃和37℃时的荧光猝灭速率常数(Kq)及机制,Lineweaver-Burk双对数方程确定17℃和37℃时猝灭反应结合常数(KA)和结合位点数(n);根据反应前后的焓变ΔH和熵变ΔS的相对大小判断咪达唑仑与HSA之间的主要作用力类型。结果:荧光猝灭光谱显示咪达唑仑与HSA有荧光猝灭作用,Δλ=15nm波长的同步荧光光谱显示咪达唑仑对酪氨酸残基发生作用,未对色氨酸残基发生作用;在17℃和37℃时的Kq分别为5.0246×1011和4.757×1011L·mol-1·s-1;17℃和37℃时猝灭反应KA和n分别为2.1717×104、8.7438×103mol·L-1,1.1895、1.0769个;反应前后的ΔH和ΔS均<0。结论:咪达唑仑对人血清白蛋白的猝灭过程为静态猝灭,咪达唑仑与HSA间的作用力主要为范德华力或者氢键作用力。     

荧光光谱法研究Ca2+存在下左氧氟沙星与人血清白蛋白的结合作用

目的：研究左氧氟沙星对人血清白蛋白以及在ca^2＋存在下左氧氟沙星与人血清白蛋白的结合作用。方法：通过荧光光谱法分析了左氧氟沙星对人血清白蛋白以及ca^2＋存在条件下左氧氟沙星对人血清白蛋白荧光淬灭光谱、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,确定了左氧氟沙星对人血清白蛋白淬灭类型为静态淬灭,左氧氟沙星对人血清白蛋白的结合常数K=1．46×10^5L·mol^-1,结合位点n=1．1,根据热力学方法确定作用力类型为疏水作用力;在ca^2＋存在条件下,淬灭类型和作用力类型不变,结合常数K=2．38×10^4L·mol^-1,结合位点n：1．02。结论：在ca^2＋存在条件下,左氧氟沙星对人血清白蛋白的荧光淬灭减弱,结合常数和结合位点均变小。为研究左氧氟沙星的生物学效应,以及左氧氟沙星和Ca^2＋对蛋白质构象的影响等提供了重要信息。     

荧光光谱法研究顺铂与牛血清白蛋白的键合

摘 要 目的：探讨在人体生理条件下顺铂与牛血清白蛋白(BSA)的结合作用。 方法: 采用荧光光谱法研究顺铂与BSA的作用机制;考察其结合常数、结合位点数和作用力类型;考察顺铂对BSA构象的影响。结果: 顺铂对BSA的猝灭过程是形成基态复合物的静态猝灭,顺铂与BSA结合位点数和结合常数分别为1.36×10⁴ L·moL^-1和0.991,两者以氢键和范德华力为主。同步荧光表明两者结合作用影响色氨酸残基所处的微环境。结论:顺铂能与BSA结合并改变BSA的构象。     

荧光光谱法研究忍冬苷与牛血清白蛋白的相互作用

本文首次采用荧光光谱法研究了忍冬瞢与牛血清白费白（BSA）在模拟人体生理条件下的相互作用。结果表明忍冬苷对BSA的荧光猝灭作用属于静态猝灭．且296K下结合常数Ka为3．82×10^-5L·mol^-1,结合位点数n为1．16;热力学分析表明二者主要靠氢键和范德华力结合;位点竞争实验则显示忍冬苷主要通过Site I与BSA相结合;最后还考察了几种常见的共存离子对相互作用的影响。     

异硫氰酸荧光素标记人血清白蛋白

目的：用异硫氰酸荧光素（FTTC）对人血清白（HSA）进行荧光标记。方法：采用直接标记法,并考查不同料比时的荧光素分子与蛋白分子的结合情况,荧光标记物（FTTC－HSA）的荧光光谱及荧光寿命情况,结果：FTTC－HSA的激发波长为500nm,荧光波长为530nm;其固态和液态低温保存时荧光寿命分别为一年和37天。     

荧光光谱法研究灯盏花素与牛血清白蛋白相互作用

目的 采用荧光光谱法研究灯盏花素与牛血清白蛋白(BSA)在生理条件下(pH 7.4)的相互作用机制。 方法 固定BSA浓度,依次加入不同浓度的灯盏花素溶液,在激发波长为280 nm下,290~500 nm的波长范围内进行荧光猝灭光谱、同步荧光光谱扫描。 结果 灯盏花素对BSA的荧光猝灭类型是静态猝灭;在温度288 K和310 K时,二者的结合常数KA分别为8.295×10⁵和3.302×10⁵ L·mol^-1;二者的结合位点数n分别为1.239 3和1.177 0。由热力学参数焓变(ΔH=-31.080 kJ·mol^-1)小于零和熵变(ΔS=5.392 J·mol^-1·K^-1)大于零,确定灯盏花素与BSA之间的作用力类型为静电作用力;生成自由能变(ΔG)为负值,表明灯盏花素与BSA的作用过程是一个自发过程。此外,应用同步荧光光谱考察了灯盏花素对BSA构象的影响。 结论 经过荧光光谱分析,可以确定灯盏花素与白蛋白的作用机制,为其开发成治疗心血管疾病新药提供理论依据。     

Molecular simulation study of the specific combination between four kinds of phthalic acid esters and human serum albumin

The interaction between endocrine disruptor phthalic acid esters (PAEs) and human serum albumin (HSA) was studied by fluorescence spectroscopy and molecular modeling methods. The efficiency of energy transfer and the distance between HSA and PAEs were calculated. The results showed that all of the four kinds of PAEs could quench the intrinsic fluorescence of the HSA, with the mechanisms of static quenching and non-radiative energy transfer. Molecular docking study and thermodynamic analysis revealed that the binding behavior was mainly governed by hydrophobic force. And the results of site marker competitive experiments and modeling method suggested that the four PAEs would mainly bind to the HSA in sub-domain IIIA, which demonstrated that the experimental results could coordinate with the theoretical results. Molecular dynamic simulation (MD) revealed that HSA did have a slight conformational change when it bound with PAEs. It also verified the greater stability of HSA–PAEs complex compared to free protein.     

Interaction of anthracycline disaccharide with human serum albumin: investigation by fluorescence spectroscopic technique and modeling studies

Anthracyclines are considered to be some of the most effective anticancer drugs for cancer therapy. However, drug resistance and cardiotoxicity of anthracyclines limit their clinical application. An 3′-azido disaccharide analogue of daunorubicin, 7-[4-O-(2,6-dideoxy-3-O-methyl-α-l-arabino-hexopyranosyl)-3-azido-2,3,6-trideoxy-α-l-lyxo-hexopyranosyl]daunorubicinone (ADNR-3), was shown to exhibit 10-fold better activity than parent compound daunorubicin against the drug-resistant cells and completely overcomes the drug resistance with same IC₅₀ in both drug-resistant and drug-sensitive cells. In this paper, the interactions between ADNR-3 and human serum albumin (HSA) have been studied by spectroscopic techniques. By the analysis of fluorescence spectrum and fluorescence intensity, it was observed that the ADNR-3 has a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The association constants of ADNR-3 with HSA were determined at different temperatures based on fluorescence quenching results. The negative ΔH and positive ΔS values in case of ADNR-3–HSA complexes showed that both hydrogen bonds and hydrophobic interactions play a role in the binding of ADNR-3 to HSA. Furthermore, synchronous fluorescence spectroscopy data and UV–vis absorbance spectra have suggested that the association between ADNR-3 and HSA changed the molecular conformation of HSA and the hydrophobic interactions play a major role in ADNR-3–HSA association. Moreover, the study of computational modeling indicated that ADNR-3 could bind to the site I of HSA and hydrophobic interaction was the major acting force for the second type of binding site, which was in agreement with the thermodynamic analysis. The distance, r, between donor (HSA) and acceptor (ADNR-3) was obtained according to the Förster's theory of non-radiation energy transfer. In addition, the effects of common ions on the binding constants of ADNR-3–HSA complexes were also investigated.     

Fluorescence study on site-specific binding of perfluoroalkyl acids to human serum albumin

Binding of five perfluoroalkyl acids with human serum albumin (HSA) was investigated by site-specific fluorescence. Intrinsic fluorescence of tryptophan-214 in HSA was monitored upon addition of the chemicals. Although perfluorobutyl acid (PFBA) and perfluorobutane sulfonate (PFBS) did not cause fluorescence change, perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorododecanoic acid (PFDoA) induced fluorescence quenching, from which binding constant of 2.7 × 10⁵ M⁻¹ for PFOA and 2.2 × 10⁴ M⁻¹ for PFOS was calculated. Two fluorescent probes, dansylamide (DA) and dansyl-l-proline (DP), were employed in fluorescence displacement measurements to study the interaction at two Sudlow’s binding sites. At Site I, both PFBA and PFBS displaced DA with binding constants of 1.0 × 10⁶ M⁻¹ and 2.2 × 10⁶ M⁻¹. At Site II, PFBS and PFDoA displaced DP with binding constants of 6.5 × 10⁶ M⁻¹ and 1.2 × 10⁶ M⁻¹, whereas PFBA did not bind. The data were compared with fatty acids to evaluate the potential toxicological effect of these environmental chemicals. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Characterization of the binding of benzodiazepines to human serum albumin

Summary The binding of eleven benzodiazepine derivatives to human serum albumin (HSA) was determined by means of sephadex gel filtration.The albumin binding of the substances was characterized by the percentage of bound drug, the binding constants k ⁺, K ₁ and m, the number of binding sites per albumin molecule, and the free binding energy. Under the conditions chosen in these experiments there seems to exist only one binding site of the same type for all investigated benzodiazepines at the HSA molecule. The affinities of the benzodiazepines to this binding site are very different. It is discussed which part of the benzodiazepine molecule represents the main binding group.     

文多灵碱键合人血清白蛋白位点的表征

本文利用荧光增敏光谱法及紫外吸收光谱法结合计算机模拟技术研究了模拟生理条件下文多灵碱的光谱特征及它与人血清白蛋白(human serum albumin,HSA)的键合作用。同步荧光及紫外光谱图的信息表明文多灵碱对蛋白微环境有影响。荧光光谱表明文多灵碱对HSA有较强的荧光增敏作用,根据荧光滴定的数据求得不同温度下(303、310和317K)药物与蛋白相互作用的结合常数及结合位点数。分子模拟的结果显示了文多灵碱与HSA的键合模式和键合机制,表明药物与蛋白有较强的键合作用,维持药物与蛋白的相互作用力主要是疏水作用,兼有4个氢键(位于氨基酸残基Arg218、Lys195、Arg222和Ala291位)。位点竞争实验显示文多灵碱键合在HSA的siteII区。通过计算得到的热力学参数(依据范德霍夫公式计算得ΔH0与ΔS0的值分别为-10.30kJ·mol-1和79.98J·mol-1·K-1)确定了药物与蛋白的相互作用力类型主要为疏水兼静电作用。     

光谱法与分子模拟表征2种呫吨酮类化合物键合人血清白蛋白

目的:表征2种呫吨酮类化合物(1-hydroxy-7-methoxyxanthone,HM;dehydrocycloguanandin,DC)与人血清白蛋白(human serum albumin,HSA)的键合作用。方法:在模拟生理条件下,应用计算机模拟技术,并结合荧光光谱法和紫外吸收光谱法研究药物与蛋白的相互作用。结果:分子模拟显示了DC及HM与HSA的键合区域和键合模式,表明维持药物与蛋白质的相互作用力主要是疏水作用,兼有位于不同氨基酸残基的氢键。荧光光谱实验结果表明:这2种呫吨酮类化合物对HSA的荧光在一定的浓度范围内都有猝灭作用,猝灭方式均为静态猝灭。紫外光谱图表明它们对蛋白微环境有影响。根据荧光滴定数据,求出了不同温度下(296,303,310 K)反应的结合常数及反应热力学参数。通过竞争实验确定了这2种药物在蛋白上的不同结合位点。结论:在分子水平上揭示了这2种呫吨酮类化合物与HSA有不同的、较强的键合作用。     

荧光光谱法研究塞曲司特与牛血清白蛋白的相互作用

目的:研究不同pH条件下塞曲司特与牛血清白蛋白的相互作用机制.方法:利用荧光光谱法,并以Stern-Volmer方程确定药物与蛋白的作用类型.结果:根据Stern-Volmer方程求出了不同二者pH条件下塞曲司特与牛血清白蛋白之间的猝灭常数,并依据 Foster能量转移理论确定了生理条件下药物与蛋白的结合距离为 2.53 nm.结论:在pH 5.0和人体生理pH条件下塞曲司特对牛血清白蛋白具有荧光猝灭作用且为动态猝灭过程,在pH 8.4时塞曲司特与牛血清白蛋白之间的猝灭为静态猝灭;人体生理pH条件下塞曲司特与牛血清白蛋白之间相互作用力主要为范德华力.     

In silico prediction of human serum albumin binding for drug leads

Introduction: Binding of drugs to human serum albumin (HSA) strongly influences their pharmacokinetic behavior and is associated with drug safety issues, low clearance, low brain penetration, as well as drug-drug interactions. Thus, in silico prediction of HSA binding contributes significantly to the discovery of new drug candidates.

Areas covered: The authors provide a short overview on the principles of HSA binding and the crystal structure of HSA, as well as discussing and analyzing the recent structure- and ligand-based HSA binding models. The authors also present the advantages and limitations of each methodology to construct efficient local or global models and outline the critical structural features contributing to HSA.

Expert opinion: The in silico estimation of drug binding to HSA in early drug discovery contributes to the lead optimization process. Local models are useful for the design of new compounds with reduced HSA binding for a particular target receptor, while real-time quantitative structure-activity relationships or global models combining structure- and ligand-based approaches serve for compound libraries screening. However, research efforts on other important plasma proteins should be strengthened in the perspective to enable predictions of total plasma protein binding for clinical candidates.     

阿柔比星与人血白蛋白相互作用的特点

目的研究阿柔比星与人血清白蛋白的相互作用特点。方法用荧光猝灭光谱及同步荧光光谱技术测定在不同温度下阿柔比星对人血清白蛋白荧光的猝灭规律。结果阿柔比星对人血清白蛋白荧光呈规律性猝灭,17℃时的n为1.11,K为6.21×104,37℃时的n为1.12,K为6.41×104。阿柔比星使白蛋白的同步光谱中最大发射峰红移。结论阿柔比星与人血清白蛋白只有一个结合位点,表现为疏水作用,两者结合使白蛋白的极性略有增加。