Interactive Association of Drugs Binding to Human Serum Albumin

Human serum albumin (HSA) is an abundant plasma protein, which attracts great interest in the pharmaceutical industry since it can bind a remarkable variety of drugs impacting their delivery and efficacy and ultimately altering the drug’s pharmacokinetic and pharmacodynamic properties. Additionally, HSA is widely used in clinical settings as a drug delivery system due to its potential for improving targeting while decreasing the side effects of drugs. It is thus of great importance from the viewpoint of pharmaceutical sciences to clarify the structure, function, and properties of HSA–drug complexes. This review will succinctly outline the properties of binding site of drugs in IIA subdomain within the structure of HSA. We will also give an overview on the binding characterization of interactive association of drugs to human serum albumin that may potentially lead to significant clinical applications.     

Conjugation of a Dipicolyl Chelate to Polypeptide Conjugates Increases Binding Affinities for Human Serum Albumin and Survival Times in Human Serum

The affinity for human serum albumin (HSA) of a series of 2–5 kDa peptides covalently linked to 3,5‐bis[[bis(2‐pyridylmethyl)amino]methyl]benzoic acid, a dipicolyl chelator with micromolar affinity for Zn²⁺, was found by surface plasmon resonance to increase in the presence of 1 μm ZnCl₂ at physiological pH. The dependence on polypeptide hydrophobicity was found to be minor, thus suggesting that the conjugates bound to the metal‐binding site and not to the fatty‐acid‐binding site. The affinity of the conjugates increased strongly with the positive charge of the polypeptides, thus implicating the negatively charged protein surface surrounding the metal‐binding site. The survival times of the peptides in human serum were extended as a consequence of stronger binding to HSA, thus suggesting that Zn²⁺‐chelating agents might provide a general route to increased survival time of peptides in serum in therapeutic and diagnostic applications without significantly increasing their molecular weights.     

中药活性成分山萘酚与牛血清白蛋白相互作用的研究

应用光谱法研究了中药活性成分山萘酚(Kaempferol)与牛血清白蛋白(BSA)的相互作用,探讨了山萘酚对BSA的荧光猝灭过程的机理,测定了不同温度下该结合反应的结合模式、结合常数、结合位点数、结合热力学参数等;并利用经典位点探针试剂华法林(Warfarin)和布洛芬(Ibuprofen)研究了山萘酚与BSA作用的具...     

单甲氧基聚乙二醇化学修饰人血清白蛋白及产物性能表征

用三光气活化的单甲氧基聚乙二醇5000 （mPEG）和N-羟基琥珀酰亚胺（NHS）反应制备单甲氧基聚乙二醇琥珀酸亚胺酯（SC-mPEG）,SC-mPEG修饰人血清白蛋白（HSA）制备mPEG-HSA.傅里叶变换红外光谱仪（FT-IR）、紫外分光光度计（UV）和高效液相色谱仪（HPLC）对产物结构予以分析表征.结果表明,已经成功得到目标产物,mPEG的平均活化度为75％,SC-mPEG与HSA的平均偶联度为45％.     

Enhanced Anti-Tumoral Activity of Methotrexate-Human Serum Albumin Conjugated Nanoparticles by Targeting with Luteinizing Hormone-Releasing Hormone (LHRH) Peptide

Active targeting could increase the efficacy of anticancer drugs. Methotrexate-human serum albumin (MTX-HSA) conjugates, functionalized by luteinizing hormone-releasing hormone (LHRH) as targeting moieties, with the aim of specifically targeting the cancer cells, were prepared. Owing to the high expression of LHRH receptors in many cancer cells as compared to normal cells, LHRH was used as the targeting ligand in this study. LHRH was conjugated to MTX-HSA nanoparticles via a cross-linker. Three types of LHRH targeted nanoparticles with a mean particle size between 120-138 nm were prepared. The cytotoxicity of LHRH targeted and non-targeted nanoparticles were determined on the LHRH positive and negative cell lines. The internalization of the targeted and non-targeted nanoparticles in LHRH receptor positive and negative cells was investigated using flow cytometry analysis and fluorescence microscopy. The cytotoxicity of the LHRH targeted nanoparticles on the LHRH receptor positive cells were significantly more than non-targeted nanoparticles. LHRH targeted nanoparticles were also internalized by LHRH receptor positive cells significantly more than non-targeted nanoparticles. There were no significant differences between the uptake of targeted and non-targeted nanoparticles to the LHRH receptor negative cells. The active targeting procedure using LHRH targeted MTX-HSA nanoparticles could increase the anti-tumoral activity of MTX.     

Electrochemical Studies of Camptothecin and Its Interaction with Human Serum Albumin

Camptothecin, an anticancer component from Camptotheca acuminate, may interact with human serum albumin (HSA) at the subdomain IIA (site I), and then convert to its inactive form(carboxylate form). In this paper, the detailed electrochemical behaviors of camptothecin at a pyrolytic graphite electrode is presented. The interaction between camptothecin and HSA is also studied by electrochemical technique. By comparing with bovine serum albumin (BSA), which is highly homologous to HSA, we prove that camptothecin can specifically bind to HSA. Meanwhile, the inhibitory influence of sodium salicylate to this binding is also discussed.     

重组人血白蛋白与小分子药物结合功能研究

目的研究重组人血白蛋白与小分子药物的结合功能。方法在366nm下检测地西泮与人血白蛋白结合前后吸收值的变化,计算二者的结合常数;华法令与人血白蛋白结合后,用SephadexG-25HPLC柱进行分离,对游离华法令和二者结合产物分别积分,得到华法令与人血白蛋白的结合率。结果重组人血白蛋白与地西泮的结合常数为14·68mol Diaze-pam/mol rHSA,天然人血白蛋白与地西泮结合常数为12·82mol Diazepam/mol HSA。重组人血白蛋白中华法令的结合率为8·69%,而天然人血白蛋白中华法令的结合率为6·73%。结论重组人血白蛋白与天然人血白蛋白小分子药物结合功能基本一致。     

Electrochemical site marker competitive method for probing the binding site and binding mode between bovine serum albumin and alizarin red S

A novel electrochemical site marker competitive method is proposed for the study of the binding site and the binding mode between bovine serum albumin (BSA) and alizarin red S (ARS). Two known site-selective markers for BSA, bilirubin (BR, for site I) and diazepam (DIA, for site II), were selected to bind to the two potential binding sites of BSA (site I and site II). The resulting BR–BSA or DIA–BSA complex was added into an ARS solution for binding site competition studies. From the current response of ARS after site competition, binding site I of BSA was identified as the binding site of BSA to ARS. Further investigation of the binding events by electrochemistry, fluorescence, and molecular docking techniques revealed that ARS was buried in the hydrophobic cavity of subdomain IIA, mainly through five hydrogen bonds between ARS and residues ARG(193), ARG(255), LYS(220), ARG(197), and ALA(289) of BSA. These efforts will aid in a better understanding of the toxicological action of active components in anthraquinone dyes.     

人血清白蛋白对变色酸2R的退色光谱性质及其分析应用

在pH为2.60的B-R缓冲介质中,变色酸2R与人血清白蛋白形成复合物,导致变色酸2R退色,吸光度的降低与人血清白蛋白的浓度成正比.线性范围为0～60 μg/mL,灵敏度ε=5.53×105 L·mol-1·cm-1.用于人血清白蛋白的测定,方法稳定,手续简便,结果满意.     

Characterization of the Interaction between Eupatorin and Bovine Serum Albumin by Spectroscopic and Molecular Modeling Methods

This study investigated the interaction between eupatorin and bovine serum albumin (BSA) using ultraviolet-visible (UV-vis) absorption, fluorescence, synchronous fluorescence, circular dichroism (CD) spectroscopies, and molecular modeling at pH 7.4. Results of UV-vis and fluorescence spectroscopies illustrated that BSA fluorescence was quenched by eupatorin via a static quenching mechanism. Thermodynamic parameters revealed that hydrophobic and electrostatic interactions played major roles in the interaction. Moreover, the efficiency of energy transfer, and the distance between BSA and acceptor eupatorin, were calculated. The effects of eupatorin on the BSA conformation were analyzed using UV-vis, CD, and synchronous fluorescence. Finally, the binding of eupatorin to BSA was modeled using the molecular docking method.     

单扫描极谱法快速测定蛋白质的研究

在pH 4.7的HAc-NaAc缓冲溶液中,邻二氮菲与蛋白质相互作用,使邻二氮菲在-0.99 V(vs.SCE)处的还原峰电流下降,电流降低值与所加的蛋白质(人血清白蛋白、牛血清白蛋白、溶菌酶)的量在一定范围内呈线性关系,线性范围分别为2.0~22 mg/L,2.0~20 mg/L和4.0~26 mg/L;检测限分别为1.0 mg/L,1.0 mg/L,2.0mg/L。运用该方法测定了人血清中白蛋白的含量,结果满意。     

基于牛血清白蛋白偶联微球的蛋白-药物结合常数快速测定方法研究

以氨基化多孔微粒为固相介质,牛血清白蛋白(BSA)为模型蛋白,通过戊二醛交联反应,制备牛血清白蛋白偶联微球,与药物结合,通过离心沉降微球,高效液相色谱法测定上清液中药物浓度的变化,并代入Rosenthal模型,研发出一种新型方法用于药物蛋白结合常数(Ka)的快速测定。利用该方法测定了瑞替加滨与BSA的结合常数,并与传统荧光光谱法对比,两种方法结果一致。键合蛋白微球经PBS缓冲液充分洗脱后,可重复利用。     

平衡透析法研究小檗碱与人血清白蛋白的相互作用

蛋白质和小分子相互作用的研究,对促进生命科学的发展有着重要意义。在本实验中,平衡透析法结合紫外可见吸收光谱研究了中药有效成分小檗碱跟人血清白蛋自的相互作用。实验表明,在37℃的水浴恒温培养4h后,两物质发生相互作用,紫外光谱有所改变,同时,通过方程拟合,测得其结合常数为1．32×10^3（mol·L^-1）^-1,最大结合量为406umol·L^-1。     

光谱法研究迷迭香酸和牛血清白蛋白的相互作用

利用荧光和圆二色光谱研究了迷迭香酸(RA)与牛血清白蛋白(BSA)之间的相互作用.通过荧光猝灭测得在301、308和315 K时,RA与BSA的结合常数K分别为4.18×10~4、3.62×10~4和2.52×10~4 L/mol,表明RA与BSA间具有较强的结合作用,属于静态猝灭.热力学参数计算结果表明RA与BSA相互作用力以范德华力及氢键作用力为主.圆二色光谱、红外及拉曼光谱、荧光同步光谱研究表明相互作用后BSA的二级结构发生微小变化.此外,常见金属离子对结合有较为显著的影响.     

高磁场响应性蛋白偶联磁性微球的制备及其在药物-蛋白结合常数测定中的应用

以蛋白偶联磁性微球(MB)为固相基质,通过磁场下快速分离蛋白和上清,高效液相色谱法测定上清中的药物浓度,建立了测定药物与蛋白结合常数(Ka)的新方法。选择对药物非特异性吸附较少和磁响应性较高的四氧化三铁磁性微球为载体,分别以1-(3-二甲氨基丙基)-3-乙基碳二亚胺盐酸盐/N-羟基琥珀酰亚胺(EDC/NHS)及戊二醛作为偶联剂,制备牛血清白蛋白(BSA)包覆的磁性微球(MB-BSA),两种偶联方法所得磁性微球的蛋白最大键合量均为50μg/mg。以布洛芬为模型药物,研究药物在蛋白偶联磁性微球上的吸附行为及药物-蛋白的相互作用模式,优化药物吸附和解吸过程。利用高效液相色谱法测定经磁性分离的上清液中的游离药物浓度,通过罗森塔尔方程计算药物与BSA结合常数。最后将所建立的方法应用到色氨酸、安立生坦、瑞替加滨、罗氟司特等4种不同药物与蛋白的结合常数的测定,获得满意结果。