17α-乙炔基雌二醇与人血清白蛋白的作用机制研究EI北大核心CSCD

运用多种光谱方法结合分子模拟技术研究了17α-乙炔基雌二醇(EE2)与人血清白蛋白(HSA)的结合机制。结果表明,EE2通过静态猝灭机制与HSA形成基态复合物,EE2主要结合在HSA亚域IIA的Site I位点,并与氨基酸残基Lys195,Lys199,His288和His242发生作用。25℃下EE2与HSA的结合常数为6.85×10^(4)L/mol,氢键和疏水相互作用为该结合的主要驱动力。巯基含量的增加和α-螺旋含量的减少表明EE2的结合使HSA的二级结构变得伸展。分子动力学模拟进一步阐明了EE2的结合对HSA结构稳定性的影响。     

流动注射化学发光法灵敏检测人血清白蛋白

基于人血清白蛋白(HSA)在碱性介质中对luminol-H2O2化学发光体系有很强的增敏作用,提出了一种流动注射化学发光测定HSA的新方法。在优化条件下,HSA的线性范围为7.5×10-10～2.8×10-7mol/L,检出限为9.1×10-11mol/L,样品检测频率达102个/h。对2.0×10-8mol/L HSA平行测定11次,RSD为0.9%。方法可应用于实际样品人血清中HSA含量的测定。结合化学发光光谱和紫外可见吸收光谱,对该反应机理进行了探讨。     

杜鹃素新结构衍生物与人血清白蛋白相互作用的光谱及分子对接

采用光谱法及分子对接法考察了该化合物与人血清白蛋白(HSA)的相互作用。荧光光谱分析表明,DJS-NO_2对HSA的荧光有明显的猝灭作用,其机制属于静态荧光猝灭;温度为25℃和37℃时,猝灭常数分别为6.691×10~(13)mol/(L·s)和3.433×10~(13)mol/(L·s);结合常数分别为4.914×10~5mol/L和4.610×10~5mol/L,具有一个结合位点。热力学分析表明,该化合物与HSA之间的结合以疏水作用力为主;三维荧光光谱分析表明DJS-NO_2导致HSA氨基酸残基微环境和二级构象发生变化。圆二色谱分析显示二者的结合使得HSA的α-螺旋含量减少,提示HSA构象发生变化。分子模拟结果显示DJS-NO_2主要与HSA的位点I结合,且该化合物通过氢键与ALA118结合最紧密。     

光催化活性二氧化钛溶胶的低温制备与表征

以钛酸丁酯为原料,在70 ℃制备了具有光催化活性的TiO2溶胶.用X射线衍射仪(XRD)和透射电子显微镜(TEM)表征了溶胶结构;用紫外-可见分光光度计研究了TiO2溶胶对甲基橙的吸附和光催化降解性能.XRD图谱表明TiO2溶胶粒子的一次粒径约4 nm,晶型主要为锐钛矿型,并含有少量结晶不完善的板钛矿型;TEM图像表明溶胶中TiO2粒子分散良好,二次粒径约10 nm.吸附实验表明TiO2溶胶使甲基橙溶液褪色约17%;光催化实验表明TiO2溶胶光催化性能优异,自然光催化降解甲基橙溶液(10 mg/L),16min后甲基橙浓度几乎降为0.     

人血清中总蛋白的四羧基铁酞菁二级散射法测定

在pH3.8的Britton-Robinson (B-R)缓冲溶液中,蛋白质与四羧基铁(Ⅲ)酞菁(Fe(Ⅲ)Pc (COOH)4)结合,使二级散射信号ISOS增强,且增强的二级散射信号与蛋白质浓度呈良好的线性关系.在最大的二级散射波长(λSOSmax)处分别对牛血清白蛋白(BSA)、人血清白蛋白(HSA)、人免疫球蛋白(IgG)、α-糜蛋白酶(α-Chy)进行测定,线性范围分别为0.0～1.80mg/L、0.0～1.60 mg/L、0.03～1.20mg/L、0.0～1.20mg/L;相应检出限分别为0.501、0.354、3.63、1.18μg/L.将该方法应用于实际人血清样品中总蛋白的测定,结果与考马斯亮蓝法基本一致.     

基于无金属可见光诱导原子转移自由基聚合方法制备人血清白蛋白超微印迹传感器及其性能

将荧光标记的人血清白蛋白(HSA)既作模板分子又作催化剂,利用无金属可见光诱导的原子转移自由基聚合方法,在纳米金(nAu)修饰的铂超微电极(Pt UME)表面制备分子印迹聚合物(MIPs),构建超微印迹传感器(MIPs/nAu/Pt UME),利用电化学循环伏安法、交流阻抗法、扫描电子显微镜和X射线光电子能谱等方法对所得传感器进行表征。进一步,以MIPs/nAu/Pt UME为工作电极,自制铂微电极为参比电极,铂丝为对电极,构建只需5μL待测液的微体积检测体系,通过差分脉冲伏安法方法对HSA进行检测。在最优条件下,超微印迹传感器检测HSA的线性范围为1.0×10^-9～1.0×10^-2 mg/L,检出限为3.4×10^-10 mg/L,相关系数为R²=0.9980。考察了血红蛋白、肌红蛋白、小鼠IgG和牛血清白蛋白对检测HSA的干扰,并探究了传感器的一致性和重现性。最后,利用MIPs/nAu/Pt UME对实际样品进行检测,得到加标回收率为96.0%～104.5%,表明制备的传感器具有一定的实际应用性。     

基于高灵敏探针海萤荧光素类似物的化学发光法检测尿微量白蛋白

海萤荧光素类似物FCLA能检测1O2并产生532nm的化学发光,白蛋白(HSA)能强烈增强FCLA-1O2化学发光。基于此,建立了一种有效、高灵敏的检测HSA的化学发光(CL)检测技术。在选定的最佳实验条件下,HSA浓度与增强化学发光信号在0.34～5.5mg/L之间呈良好的线性关系;检出限为0.017mg/L(3σ)。对比荧光光谱分析法、同步荧光扫描法及瑞利光散射法等传统方法,本方法成本低廉、灵敏度高。实际尿样检测与临床检测结果一致,同时还初步探讨了HSA增敏CL的机制。     

基于铽-沙拉沙星配合物的荧光增强测定人血清白蛋白

Tb3+和沙拉沙星(SRFX)反应生成二元配合物,发射Tb3+的特征荧光。人血清白蛋白(HSA)能够增强Tb3+-SRFX配合物的荧光强度,据此,建立了荧光法测定HSA的新方法。在最佳测定条件下,当HSA的浓度在0.50～90.0 mg/L时,Tb3+-SRFX-HSA体系荧光强度的增强和HSA的浓度有良好的线性关系,方法的检出限为0.13 mg/L。用该方法测定了人血清中HSA的含量,回收率在99.2%～99.6%之间。同时对荧光强度增强的机理进行了探讨。     

β-1,2,3,4,6-五-O-倍酰-D-葡萄糖与人血清白蛋白的相互作用研究

应用红外光谱和荧光光谱方法研究了人血清白蛋白 (HSA)与 β 1,2 ,3 ,4,6 五 O 倍酰 D 葡萄糖 (PGG)的相互作用 .荧光光谱结果显示 ,PGG在CPGG/CHSA<0 5和 0 5 相似文献   

人血清白蛋白亲和毛细管电泳法分离马来酸曲美布汀对映体

以人血清白蛋白（HSA）为手性选择剂,采用亲和毛细管电泳法分离马来酸曲美布汀对映体。以50mmol/L NaH2PO4(pH5.55)为运行缓冲液,以含500μmol/L HSA的运行缓冲液为分离缓冲液,利用部分灌注技术消除高浓度人血清白蛋白对被分析物检测的干扰,灌注分离缓冲液时间1为160s。在此条件下,以来酸曲美布汀两对映体的分离度为1.2。     

Electrospray ionization mass spectrometry for the quantitation of albumin in human serum

Capillary reversed-phase liquid chromatography was coupled to electrospray ionization mass spectrometry for determining the concentration of human serum albumin (HSA) in a fresh frozen serum reference material. A biotinylated HSA (bHSA) was prepared and used as an internal standard for the serum albumin determination. The average HSA concentration of the serum sample was determined by mass spectrometry to be 41.5 ± 2.8 g/L at the 95% confidence limit for the measured value. The HSA concentration of the fresh frozen serum was also assayed using the bromocresol green dye-binding method, producing a value of 42.3 ± 1.5 g/L. Calibration curves generated from HSA standards spiked with bHSA showed excellent linearity and the relative standard deviation for replicate analysis of a bHSA spiked serum sample was less than 3%.     

Determination of serum albumin in the presence of poly(diallyldimethylammonium chloride) by resonance light scattering technique

By means of the resonance light scattering (RLS) technique, a new method was developed to determine the bovine serum albumin (BSA) and human serum albumin (HSA) by the interaction of serum albumin with poly(diallyldimethylammonium chloride) (PDDA). At Tris-NaOH buffer solution, the RLS intensity of serum albumin at the wavelength 320, 550 and 590 nm was obviously enhanced in the presence of PDDA. The influences of some experimental factors, including incubation time, addition sequence of reagents, pH value, concentration of PDDA and foreign substances, on the enhancement of the RLS intensity were examined. The optimum conditions of the experiment were selected. Under the selected experimental condition, the enhanced RLS intensities were directly proportional to the concentrations in the range of (0.0250-2.75)x10(-6) mol/L for BSA and (0.0235-1.17)x10(-6) mol/L for HSA. The detection limits (S/N=3) were 8.40x10(-9) mol/L for BSA and 7.39x10(-9) mol/L for HSA. The synthetic samples were analysed and the results obtained were satisfactory.     

波长检测型表面等离子体子共振生物传感器测定β-环糊精与血清白蛋白的相互作用

采用自行组装的表面等离子体子共振(SPR)传感装置, 固定入射角, 以波长为变量, 以电荷耦合器件(CCD)为检测系统, 用对金和蛋白质均有较强作用的巯基丙酸作为基底膜, 分别监测了β-环糊精(CD)与人血清白蛋白(HSA)、牛血清白蛋白(BSA)反应的动力学过程, 并分别计算了它们的动力学常数、热力学常数及键合百分率. 此外, 对传感器的再生性也进行了研究. 结果表明, β-CD与HSA, BSA相互作用的平衡常数分别是7.79和51.00 μmol/L, 且键合百分率都很高, 分别是98.77%和94.25%. 这些结果有力地说明了β-CD作为药物载体, 可以提高生物利用度, 延长药物半衰期.     

Microdetermination of Proteins by Enhanced Rayleigh Light Scattering Spectroscopy with Thorin

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Binding of glycyrrhizin to human serum and human serum albumin

The binding of glycyrrhizin (GLZ) to human serum and human serum albumin (HSA) was examined by an ultrafiltration technique. Specific and nonspecific bindings were observed in both human serum and HSA. The association constants (K) for the specific bindings were very similar: 1.31 x 10(5) M-1 in human serum and 3.87 x 10(5) M-1 in HSA. The number of binding sites (n) and the linear binding coefficient (phi) in HSA were 1.95 and 3.09 x 10(3) M-1, respectively. When the human serum protein concentration was assumed to be 4.2% (equal to the measured serum albumin concentration), n in human serum was 3.09, which is similar to the n value in HSA, and phi in human serum was 0.71 x 10(3) M-1, which is reasonably close to that for HSA. The binding pattern of GLZ with human serum protein on Sephadex G-200 column chromatography showed that GLZ binds to only the albumin fraction. It was concluded that the GLZ-binding sites in human serum exist mainly on albumin and GLZ binds to specific and nonspecific binding sites at lower and higher concentrations than approximately 2 mM, respectively.     

以溴甲酚紫为电化学探针测定血清白蛋白

常见的蛋白质定量分析方法、电化学行为及其分析应用已有报道．本文基于酸性条件下蛋白质可与溴甲酚紫(BP)结合生成一种超分子复合物,使溴甲酚紫还原峰电流降低,建立了一种测定蛋白质的新方法,并用于测定人血清样品中的白蛋白含量．     

芘与人血清白蛋白和牛血清白蛋白结合位点微环境极性的差异

利用芘(Pyr)的微环境极性探针性质, 采用稳态荧光光谱、 荧光共振能量转移技术结合分子对接法, 对比分析了Pyr分别与人血清白蛋白(HSA)和牛血清白蛋白(BSA)作用机制的差异. 结果表明, HSA和BSA中Pyr的I₁/I₃平均值分别为1.36和0.92; Pyr与HSA和BSA的结合常数分别为1.86×10⁷和1.71×10⁵ L/mol; Pyr与HSA和BSA中色氨酸残基表观距离分别为2.37和2.34 nm. Pyr在HSA和BSA中不同的结合位点位于ⅠB子域和ⅠA子域, 其结合位点周围氨基酸残基的极性是影响Pyr I₁/I₃值的主要原因之一. 实验证实Pyr与HSA和BSA结合作用位点处的微环境极性存在差异.     

一种缩氨基硫脲类衍生物探针测定生物样品中的蛋白质含量

在Tris-HCl缓冲溶液体系中(pH=7.4),研究了1,4-二羟基-2-甲酰基-9,10-蒽醌缩对甲氧基苯基氨基硫脲(EN)与人血清白蛋白(HSA)体系的荧光猝灭光谱和三维荧光光谱,证明EN与HSA可以发生相互作用,使人血清白蛋白的疏水微环境的极性以及构象发生变化。 考察了Δλ值、反应介质和离子强度等因素对体系同步荧光光谱特征及强度的影响。 在此基础上,建立了以EN为分子探针,运用固定波长同步荧光光谱法测定生物样品中的蛋白质含量的方法。 在最佳实验条件下,体系同步荧光强度与HSA在1.380~165.6 mg/L范围内呈良好的线性关系。 对11份空白溶液进行平行测定,检出限达到0.414 mg/L,相对标准偏差为1.52%。 运用此方法对血清、唾液、尿液进行了加标回收实验,回收率在98.4%～105%。 且同步荧光光谱法测定结果与考马斯亮蓝法基本一致。     

Voltammetric Studies on Chromotrope 2B‐Protein Interaction and Its Analytical Application

In this paper the interaction of chromotrope 2B (Ch2B) with proteins was studied by the electrochemical method. Ch2B is an azo dye and shows irreversible electrochemical responses on the mercury electrode in a pH 3.0 Britton‐Robinson (B‐R) buffer solution. After the addition of human serum albumin (HSA) into the Ch2B solution, an interaction took place, and a supramolecular complex was formed in the mixed solution. The electrochemical parameters of the Ch2B‐HSA interaction system were calculated and compared. The results showed that in the absence and presence of HSA in Ch2B solution, the electrochemical parameters such as the formal potential E⁰, the electrode reaction standard rate constant k_s, etc. showed no significant changes, which indicated that an electro‐inactive supramolecular biocomplex was formed. The free concentration of Ch2B in reaction solution was decreased, and this resulted in the decrease of the peak current. The binding constant and the binding ratio were calculated as 7.85 × 10⁹ and 1:2, respectively, and the interaction mechanism was discussed. Based on the decrease of the peak current, this new electrochemical method was proposed for the determination of HSA in the concentration range of 2.0?25.0 mg/L with the linear regression equation as ΔIp′ (nA) = 50.56C (mg/L) — 6.72 (γ = 0.995). This method was further used to determine other different kinds of proteins, such as bovine serum albumin (BSA), oval albumin, etc‥ The new method was successfully applied to detect the content of albumin in healthy human serum samples with the results in good agreement with the traditional Coomassie Brilliant Blue G‐250 spectrophotometric method.     

Resonance light scattering technique for the determination of proteins with polymethacrylic acid (PMAA)

As a resonance light scattering (RLS) probe, the polyelectrolyte polymethacrylic acid (PMAA) was applied in this assay. The bovine serum albumin (BSA) and human serum albumin (HSA) were determined by the electrostatic interaction of PMAA and proteins. At pH 3.8 Na(2)HPO(4)-citric acid buffer solution, the RLS intensities of PMAA-BSA (HSA) system were greatly enhanced. The characteristic peaks were appeared at the wavelength 320, 546 and 594 nm. The optimization conditions of the reaction were also examined and selected. Under the selected conditions, the RLS intensities were proportional to the protein concentrations in the range of (0.0200-2.00) x 10(-6) mol/L for BSA and (0.0200-2.40) x 10(-6) mol/L for HSA. The influences of some foreign substances were also examined. The synthetic samples containing proteins and some real samples were analyzed and the results obtained were satisfactory.