新型糖基阳离子表面活性剂与牛血清白蛋白的相互作用研究

采用荧光光谱法和三维荧光光谱法研究了糖基阳离子表面活性剂N,N-二甲基-N[3-(糖酰胺基)]丙基-N-十四烷基溴化铵(C_(14)DGPB)与牛血清白蛋白(BSA)的相互作用。考察了各因素对C_(14)DGPB与BSA相互作用的影响。结果表明,当作用时间为30 min,NaCl的浓度为0.03 mol/L,pH=6.6时,为C_(14)DGPB与BSA相互作用的较佳条件;通过计算可以得到不同温度下C_(14)DGPB对BSA的动态猝灭常数、结合参数和热力学参数;由热力学参数确定它们之间的作用力主要是疏水作用力,对酪氨酸和色氨酸的疏水微环境影响较大。     

牛血清白蛋白的荧光稳定性研究

研究了牛血清白蛋白(BSA)在不同条件下荧光发射光谱的稳定性。结果表明,Tris-HCl、PBS和PB等缓冲液种类,常量和微量等石英比色皿类型,对于BSA的荧光稳定性没有明显影响。激发波长260 nm与280 nm对于BSA的荧光稳定性有显著性差异。超声和金属离子的干扰,都会导致BSA荧光强度的降低,在5%的误差范围内,各金属离子允许存在的倍数分别为:Cu2+(8),Zn2+(40),Mg2+(96),Ca2+(120)。本研究对于蛋白质溶液的制备和前处理具有一定的理论和实际意义。     

药根碱与牛血清白蛋白相互作用的光谱研究

采用荧光和UV光谱法研究了盐酸药根碱(Jat)与牛血清白蛋白(BSA)相互作用的光谱特性.结果表明:Jat对于BSA荧光猝灭主要是静态猝灭和非辐射能量转移;Jat浓度增大,BSA荧光峰被猝灭的同时出现峰裂分现象,原来345 nm处的单峰逐渐裂分为二重峰,其中一峰峰值蓝移,另一峰峰值红移至λcm=362～365 nm;测...     

Fluorescent amino-substituted squaraine probes for bovine serum albumin

The synthesis and spectroscopic properties of fluorescent amino-substituted squaraine dyes have been presented. The interaction between bovine serum albumin (BSA) and fluorescence probes derived from squaric acid was studied by UV-vis and fluorescence spectroscopies. The Benesi–Hildebrand, Lehrer, and Stern–Volmer equations were used to present the influence of BSA concentration on the binding constant for the process of association with squaraine dyes, as well as the effect of the concentration of fluorescence probes on the quenching process. It was also shown that the interaction between BSA and squaraine dyes is spontaneous. The number of binding sites to bovine serum albumin for a series of squaraine dyes has also been calculated.     

维生素C与牛血清白蛋白相互作用的研究

用荧光光谱法、紫外光谱法研究了生理条件下维生素C(Vc)与牛血清白蛋白(BSA)相互作用的光谱特性.测定了Vc与BSA在21、34℃两个温度下的结合常数KA(21℃:4.381×105 L/mol,34℃:4.061×105 L/mol)和结合位点数n(21℃:1.08,34℃:1.10).结果表明:Vc对BSA有明显...     

荜茇宁与牛血清白蛋白相互作用的研究

用荧光光谱及紫外光谱法研究生理条件下荜茇宁与生物大分子牛血清白蛋白(BSA)的相互作用.实验结果表明,荜茇宁与BSA形成基念复合物从而猝火BSA的内源性荧光,猝灭原因主要为静态猝灭和非辐射能量转移.根据Forster 偶极-偶极非辐射能量转移理论,确定荜茇宁与BSA有较强的相互作用,可以被蛋白质所储存和运输.荜茇宁与B...     

Wettability and surface free energy of bovine serum albumin films

Measurements of the contact angle for water, glycerol, formamide, ethylene glycol, and diiodomethane on polymethyl methacrylate covered by adsorptive bovine serum albumin (BSA) films were made. Adsorption was performed from solutions in the concentration range 0–100 g/L. From the obtained contact angles the Lifshitz-van der Waals components and the values of the electron-acceptor and electrondonor parameters of the acid-based components of the films were calculated for six triplets of liquids. The biggest changes in the BSA film structure occurred under a monolayer coverage (i.e., at BSA concentrations of <2.5 g/L). On the basis of the contact angles of glycerol, ethylene glycol, and formamide it was concluded that the density of BSA polar groups was almost constant. The surface density of the hydrophobic part of the BSA film also seemed constant regardless of the concentration of the solution from which the BSA adsorptive film was created. This conclusion could be drawn from the almost constant contact angle of diiodomethane.     

壳聚糖修饰磁性纳米粒子对BSA的吸附性能

采用化学共沉淀法制备磁性Fe3O4纳米粒子,以（3-氯丙基）三甲氧基硅烷为偶联剂将壳聚糖共价键合到磁性Fe3O4纳米粒子的表面,通过红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）及热重分析（TGA）对其进行了表征。主要研究了不同影响因素（吸附时间、pH值、牛血清白蛋白浓度）下壳聚糖修饰的磁性纳米粒子对牛血清白蛋白（BSA）的吸附性能。结果得到壳聚糖修饰的磁性Fe3O4纳米粒子粒径为20 nm左右,壳聚糖在磁性Fe3O4纳米粒子表面的接枝率为15.40%。研究表明：在不同条件下,与未修饰的磁性Fe3O4纳米粒子相比,经壳聚糖修饰的Fe3O4纳米粒子对BSA均表现出较强的吸附能力。     

对硝基氯苯与牛血清白蛋白的相互作用研究

在模拟动物体生理条件下,用荧光光谱、三维荧光光谱、同步荧光光谱、紫外-可见吸收光谱等方法研究了在不同温度下,对硝基氯苯(PCNB)与牛血清白蛋白(BSA)结合反应的光谱行为。试验发现,PCNB对BSA有较强的荧光猝灭作用。用Stern-Volmer和Lineweaver-Burk方程及热力学方程分别处理试验数据,发现BSA与PCNB发生反应生成了新的复合物,属于静态荧光猝灭,得到了它们相互作用的生成常数KLB(1.557×104L/mol)、热力学参数(ΔHθ=-89.962kJ/mol,ΔSθ=-217.98J/K,ΔGθ=-23.93kJ/mol)和结合位点数(1.080)等。位点竞争实验结果显示PCNB与BSA的作用位置主要在BSA的SiteⅠ(Sub-domainⅡA)位。证明二者主要靠氢键和范德华力结合,同时用三维荧光光谱及同步荧光光谱法探讨了PCNB对BSA构象的影响,为研究PCNB的毒性和生物学效应提供了重要信息。     

混合模式吸附中辛酸钠和牛血清白蛋白间相互作用

混合模式吸附是一种抗体分离新方法,适量添加辛酸钠,可以减弱血清白蛋白等杂质吸附,提高抗体结合的选择性。本文以MEP HyperCel介质和牛血清白蛋白（BSA）为模型,结合静态吸附平衡和等温滴定量热（ITC）法,考察了辛酸钠浓度、pH、盐和温度等影响,探讨了辛酸钠的作用机制。随辛酸钠浓度增大,BSA和牛血免疫球蛋白的饱和吸附量均呈现先降低后升高的趋势,不过辛酸钠对BSA影响更显著,ITC分析表明辛酸钠与BSA之间存在较强的相互作用,且以疏水作用为主导。添加辛酸钠后,BSA吸附量随pH或温度升高而降低,不同盐具有不同效果,ITC分析表明pH、盐和温度均不同程度影响辛酸钠-BSA相互作用,从而影响MEP HyperCel吸附BSA。结果表明,等温滴定量热分析与宏观吸附现象相一致,可量化分析小分子-蛋白间相互作用,为研究蛋白吸附过程中小分子添加物的作用机制提供了新思路。     

氨苄青霉素与牛血清蛋白结合作用的研究

模拟人体pH的条件,在不同温度下,采用荧光光谱和同步荧光光谱,研究了氨苄青霉素与牛血清蛋白(BSA)的相互作用。研究表明,在pH7.38的Tris-HCl缓冲体系中,氨苄青霉素和牛血清蛋白发生内源荧光猝灭,属于静态猝灭机制。计算得到牛血清蛋白与氨苄青霉素在17和37℃下静态猝灭的猝灭常数分别为5.40078×1011和5.92449×1011L.mol-1.s-1,结合常数分别为1.26×104和2.76×104L/mol,结合点位数均为1。根据热力学方程得出氨苄青霉素与牛血清蛋白相互作用的参数,ΔH0,ΔS0说明了氨苄青霉素与牛血清蛋白相互作用以疏水作用为主,同时也存在静电引力。用同步荧光研究了氨苄青霉素对BSA构象的影响。     

Preparation and characterization of molecularly imprinted polymer of bovine serum albumin

Molecularly imprinted polymer beads of bovine serum albumin (BSA) were prepared via inverse phase suspension polymerization, using BSA as the template molecule, a combination of acrylamide and methacrylic acid (MAA) as double functional monomers, and N, N′‐methylene bisacrylamide as the crosslinker. The effect of different monomer ratios and degrees of crosslinking were investigated. When both selectivity and physical properties of the resultant polymer beads were taken into account, the ratio of MAA in the total monomers was chosen at 40% (m/m) and the degree of crosslinking at 30% (n/n), the resultant polymer beads had good selectivity (α = 2.77) and good physical properties. The effects of pH and temperature were studied. It turned out that the functionalization of polymers of BSA prepared via inverse‐phase suspension polymerization exhibited specific recognition for BSA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Studies on the interaction of CdTe QDs with bovine serum albumin

BACKGROUND: Quantum dots (QDs) have attracted much attention in biological and medical applications. In particular, the interaction of QDs with bovine serum albumin (BSA) is crucial, and has been systematically investigated by various spectroscopic techniques under the physiological conditions. RESULTS: The effects of ionic strength and pH on the interaction of CdTe QDs with BSA were studied by changing NaCl concentration and pH in mixed solution and making fluorescence spectroscopic measurements. The Stern‐Volmer quenching constant (K_a) of different ionic strength and pH were calculated, and information on the structural features of BSA were discussed by means of circular dichroism (CD) spectrum. CONCLUSION: Both fluorescence (FL) and circular dichroism (CD) results indicated that hydrophobic and electrostatic interactions play a major role in the binding reaction, and the nature of quenching is static, resulting in forming QDs‐BSA complexes. Copyright © 2012 Society of Chemical Industry     

Competitive interaction of polyanions and anionic dye with bovine serum albumin

The binding of anionic dye, p-(2-amino-6-sulfonyl-8-naphthylazo)benzene sulfonic acid disodium salt (ASANA) to bovine serum albumin (BSA) at pH 7.5 has been studied by spectrophotometric techniques. The values of the dissociation constants were obtained with the use of the Benesi-Hildebrand equation for ASANA. Competitive binding of polyanions, sodium poly(styrene sulfonate) (PSSNa), potassium poly(vinyl sulfonate) (PVSK), poly(acrylic acid) (PAA), and poly(methacrylic acid) (PMAA) and anionic dye to BSA was evaluated through the variations in the different spectra of BSA-dye-polymer systems.     

有机氯农药与牛血清白蛋白作用机理研究

利用荧光光谱法研究了5种有机氯农药（OCPs） δ-BHC、α-氯丹、艾氏剂、o,p＇-DDT、HCB和牛血清白蛋白（BSA）的相互作用机理.280 nm波长下,OCPs可使BSA色氨酸残基发生荧光猝灭现象.通过光谱数据,绘制了Stern-Volmer曲线,测定了平衡常数和25,37℃下OCPs-BSA的结合常数.结果显示,5种OCPs猝灭蛋白质的过程均为熵驱动的静态猝灭过程,通过较弱的疏水作用力与蛋白质相互结合,结合点位数近似为1,这种结合作用会随着温度的升高而增强.     

阳极氧化铝膜过滤BSA溶液过程中的污染分析

采用阳极氧化铝膜过滤牛血清蛋白溶液,考察了孔径20、100、200 nm 3种膜的过滤通量随时间的变化关系,在相同的操作条件下孔径20 nm的膜具有较高的渗透通量(400 L/(m2.h))和较小的过滤阻力(8.3×1011/m)。还考察了蛋白质浓度、泵送时间及清洗对膜污染情况的影响。结果表明,在实验的范围和条件下,随蛋白质浓度的增大,膜污染加重,稳定通量增大;泵送时间增长,膜污染速度加快,通量增大;通过纯水清洗加超声清洗的方法去除可逆污染,清洗后膜与新膜过滤通量相当。     

表面等离子共振技术快速测定牛血清白蛋白含量

目的采用表面等离子共振(surface plasmon resonance,SPR)技术快速检测痕量牛血清白蛋白(bovine serum albumin,BSA)含量。方法将兔抗BSA抗体标记到表面等离子共振芯片表面,监测BSA与抗体结合后SPR芯片表面的变化,利用SPR技术建立快速检测痕量BSA的新方法,对建立的方法进行检出限、定量限和最佳线性范围的确定,并进行重复性验证及初步应用。结果抗体的标记水平为10 000 RU,对BSA具有良好的亲和能力;基于信噪比为3时,BSA的检出限为0.003 ng/ml,基于信噪比为10时,BSA的定量限为0.01 ng/ml,BSA浓度在0.01~100 ng/ml范围内,与SPR仪响应值的变化量呈良好的线性关系,R2=0.997 9;用建立的SPR方法检测不同浓度BSA的日内RSD为3.3%~4.6%,日间RSD为3.4%~4.8%,均小于5%;SPR方法和间接竞争酶联免疫测定法(indirect competitive ELISA,icELISA)检测不同浓度BSA含量的结果比较,差异无统计学意义(P0.05)。结论已建立了采用SPR技术检测BSA的新方法,可用于痕量BSA的快速检测。     

苯甲酸与牛血清白蛋白相互作用的荧光光谱研究

采用荧光光谱、三维荧光光谱、同步荧光光谱研究了苯甲酸与牛血清白蛋白(BSA)分子之间的相互作用机制、特征及苯甲酸对牛血清白蛋白构象的影响。根据不同温度下苯甲酸对牛血清白蛋白的荧光猝灭作用,利用Stem-Volmer和Lineweaver-Burk方程和热力学方程分别处理实验数据,求得它们之间的结合常数K为1.096×103L/mol、结合位点数n为1.12(20℃),ΔH=-31.8 kJ/mol,ΔG=-17.1 kJ/mol,ΔS=-50.2 J.mol-1.K-1。研究发现苯甲酸对BSA内源性荧光的猝灭作用属于静态猝灭,苯甲酸与BSA分子之间的相互作用是一个吉布斯自由能降低的自发过程,两者之间的主要作用力类型为氢键力或范德华力。     

离子型表面活性剂与牛血清白蛋白作用的比较研究

采用荧光光谱、紫外吸收光谱、动态光散射和Zeta电位法对比研究了十二烷基硫酸钠(SDS)和十二烷基三甲基溴化铵(DTAB)与牛血清白蛋白(BSA)的相互作用机理。结果表明：SDS和DTAB均能猝灭BSA内源荧光,298 K时的猝灭常数Ksv分别为2.64×104和304.21 L/mol。同步荧光光谱和三维荧光光谱显示SDS和DTAB对BSA的构象产生了影响。SDS对BSA荧光猝灭机理为动静联合猝灭机制;热力学计算表明,SDS与BSA的结合过程中,静电力起主导作用,并且能与BSA形成SDS/BSA超分子复合物;DTAB对BSA荧光猝灭机理为动态猝灭,作用力主要是疏水作用。SDS和DTAB与BSA的平均结合距离分别为2.77和4.73 nm。综合结合常数、粒径和Zeta电位等变化,在相同条件下具有较大电荷密度和较小体积极性头基的SDS与BSA具有更强的结合作用。