光谱法研究异烟肼与牛血清白蛋白的相互作用

采用荧光光谱研究了异烟肼与牛血清白蛋白（BSA）的相互作用。异烟肼对BSA的荧光有较强的猝灭作用。根据研究292K,511K温度下异烟肼对BSA的荧光猝灭光谱,发现异烟肼对BSA的荧光猝灭属于动态猝灭过程,根据Frster非辐射能量转移理论计算出异烟肼与BSA间的结合距离r=5．60nm,结合常数（Kb）分别为5．;521X10^4 L·mol～（202K）,5．189X104L·mol。（31lK）,通过计算热力学数据焓变△rHm=-20．;545kJ·mol^-1,熵变△rSm=20．8J·mol^-1表明二者主要靠静电引力结合,采用同步荧光光谱探讨了异烟肼对BSA构象的影响。     

荧光光谱法研究染料木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染料木素与牛血清白蛋白（BSA）的相互作用。不同温度（290K、300K、310K、315K）下测得的猝灭常数,证实染料木素对BSA的荧光猝灭为静态猝灭过程。根据热力学参数焓变（ΔH）小于零和熵变（ΔS）小于零（ΔH=-48.905kJ/mol,ΔS=-71.435kJ/mol）,可以判断染料木素与BSA之间主要靠氢键和范德华力相结合。生成自由能变（ΔG）为负值,表明染料木素与BSA的作用过程属自发过程。应用同步荧光光谱技术考察了染料木素对BSA构象的影响。     

用荧光光谱法研究依诺沙星与牛血清白蛋白的相互作用

应用荧光光谱法研究了生理条件下依诺沙星与牛血清白蛋白的相互作用机制。实验结果表明 ,依诺沙星和牛血清白蛋白主要凭借疏水作用力相结合 ,依诺沙星主要以静态猝灭方式使牛血清白蛋白荧光强度显著降低。探讨了铁离子、铜离子及依诺沙星与牛血清白蛋白间的竞争结合反应 ,阐明了铁离子、铜离子的浓度对依诺沙星与蛋白质结合的影响     

荧光光谱法分别测定铒和镱的多吡啶配合物与牛血清白蛋白的相互作用

目的：分别研究了稀土元素铒（Er）和镱（Yb）的多吡啶配合物与牛血清白蛋白（Bovine serum albumin,BSA）的相互作用,揭示金属药物在体内的分布、转运和代谢过程,为研究作用机制提供实验依据。方法：利用荧光光谱法探讨两种稀土多吡啶配合物与BSA的猝灭机制、结合常数、结合位点数及作用方式。结果：两种配合物能够有效的导致BSA内源荧光静态猝灭;荧光光谱结果显示两种配合物的结合常数均达到104L·mol-1数量级,且随着温度的升高逐渐降低;两种配合物与BSA的结合位点数约为1,表明形成1:1的非共健复合物;通过热力学参数推断出两种配合物与BSA之间主要靠疏水作用力（ΔH> 0,ΔS> 0）;同步荧光结果表明,两种配合物的加入使BSA的构象发生变化,影响了色氨酸残基的微环境。结论：铒和镱的多吡啶金属配合物均与BSA有很好的结合能力,且结合后改变了BSA的构象,为今后成为药物提供了可能性,也为进一步研究此类稀土配合物代谢动力学打下了基础。     

荧光法研究二氧化硫衍生物与牛血清白蛋白的相互作用

目的:研究二氧化硫衍生物与牛血清白蛋白(BSA)的相互作用.方法:用荧光猝灭光谱法和紫外可见吸收光谱法分析BSA及BSA-二氧化硫衍生物相互作用后体系的光谱特征.结果:①在不同温度下,二氧化硫衍生物能使BSA的内源荧光发生有规律的猝灭,猝灭作用可能为静态猝灭.②得出了二氧化硫衍生物和BSA相互作用的热力学常数、结合常数和结合位点数;相互作用力主要为氢键和范德华力,且作用力较弱.③三维荧光光谱表明,二氧化硫衍生物对BSA的构象影响不明显.结论:二氧化硫衍生物与BSA可能的结合方式为二氧化硫衍生物与蛋白质的氨基酸残基发生结合反应,生成不发荧光或者荧光强度较弱的基态复合物,使BSA荧光发生部分猝灭,但对BSA构象影响不明显,具体作用机制还需进一步探讨.     

参类中药材的荧光光谱法研究

建立了应用导数荧光光谱法、同步荧光光谱法、三维荧光光谱法分析鉴定参类中药材的的新方法。该方法能显现光谱之间的差异,提高光谱识别能力,使谱图指纹特征明显,为快速、简便鉴定参类提供了可供参考的科学依据。     

应用荧光光谱法研究污泥活性变化

本研究以LIVE/DEAD Baclight染色法测定活性污泥中的活菌水平以表征其活性,采用荧光染色剂SYTO!9和碘化丙啶（PI）对活性污泥进行染色,并利用日立F-7000荧光分光光度计测量其绿色荧光（Fg,波长500—510 nm）强度来表征活性污泥中活菌水平。该法直接对稀释后的污泥悬浊液进行测量,简化了测量步骤。通过纯菌E.coli的LIVE/DEAD染色试验,发现活菌比例与绿色/红色荧光的比值存在较高的相关性,相关系数R2=0.982。通过污泥衰减试验发现,污泥衰减7天后,激发波长485nm处绿光/红光的比值分别由3.69降为了1.74,活菌所占比例下降了52.85%,同时用软件灰度分析法计算污泥衰减后活菌比例下降了55.14%,两种方法所得结果较为接近。     

核酸与血清白蛋白荧光分析的进展

总结了近年来荧光分析法在核酸和血清白蛋白中应用的进展,并对其面临的挑战作了探讨和展望.     

应用荧光光谱法研究丁香酸与鱼精DNA相互作用

应用荧光光谱方法对丁香酸与鱼精DNA的相互作用机理进行研究,当加入鱼精DNA后丁香酸的内源性荧光发生明显猝灭,结果表明在DNA与丁香酸浓度比在4≤CfsDNA/C SY≤32范围内,计算其stern-volmer猝灭速率常数为1.52×1012L·mol-1·s-1,属静态猝灭机理,说明二者之间形成复合物。根据静态猝灭理论研究发现结合丁香酸与DNA之间的结合比为1:1,常数为KfsDNA/SY=1.85×104L·mol-1,二者结合使得丁香酸分子结构发生一定程度改变。     

Characterization of the interaction between bovine serum albumin and doxycycline by chemiluminescence and molecular docking

The interaction of bovine serum albumin with doxycycline was investigated using chemiluminescence and molecular docking. Doxycycline at concentrations from 1.0 to 2.5 × 10³ pmol · L^?1 quenched the chemiluminescence from the luminol–bovine serum albumin system. The data were analyzed using a chemiluminescence mathematic model for protein–ligand interaction, log[(I₀ – I)/I] = logK + nlog[D]. The binding constant of bovine serum albumin with doxycycline was 3.36 × 10⁵ L · mol^?1 at 298 K with one binding site. The binding constant, enthalpy change, entropy change, and binding free energy change showed that the bonding of doxycycline to bovine serum albumin was spontaneous and enthalpy driven via hydrogen bonding and van der Waals forces. Further molecular docking analysis substantiated that doxycycline was well positioned in the pocket at the subdomain IIA (site I) of bovine serum albumin with a binding constant of 3.31 × 10⁵ L · mol^?1. Doxycycline served as both a hydrogen acceptor and donor and mainly interacted with the Arg217 residue through four hydrogen bonds with an average length of 2.55 Å. The chemiluminescence mechanism of doxycycline on luminol–bovine serum albumin system was evaluated, showing that a ternary complex of luminol–bovine serum albumin–doxycycline was formed with luminol and doxycycline at sites III and I of bovine serum albumin.     

Fixation for biological ultrastructure. I. A viscometric analysis of the interaction between glutaraldehyde and bovine serum albumin

The increase in viscosity resulting from mixing concentrated solutions of albumin with dilute glutaraldehyde has been investigated. The viscosity changes are slow at first, very sensitive to small changes in glutaraldehyde concentration, and non-linear with time. The cross-linking of the albumin by glutaraldehyde seems to be retarded by the weak mechanical shear forces produced by the viscometer. The significance of these findings to the events in tissue fixation is discussed.     

Combined molecular docking,homology modeling and DFT method for the modification of bovine serum albumin (BSA) to improve fluorescence spectroscopy for phthalate acid esters chelated with BSA

While phthalate acid esters (PAEs) cannot fluoresce alone, they can be detected by fluorescence spectroscopyafter chelation with bovine serum albumin (BSA). In this study, the types of amino acid residues at the active site of PAEschelated with BSA were determined using molecular docking technology. A modification scheme of BSA with higherdetection sensitivity fluorescence spectroscopy for PAEs was proposed based on the docking results and constructedfor a novel BSA structure with a higher detection sensitivity of fluorescence spectroscopy using a homologousmodeling method. Density functional theory (DFT) was employed to explore the influence before and after BSAmodification on PAEs’ detection through fluorescence spectroscopy. The results showed that the docking scoresbetween BSAs and dimethyl phthalate (DMP), dibutyl phthalate (DBP) and di-n-octyl phthalate (DNOP) wereincreased up to 26.45%, 16.82% and 16.30%, respectively, indicating that the active site modification of BSA couldenhance the binding affinity between BSA and PAEs. The fluorescence intensity of PAEs chelated with modified BSAswere calculated. The fluorescence intensity of fluorescence spectroscopy for DMP, DBP and DNOP chelated withBSAs after modification was increased up to 2.8-, 104.51- and 62.43-fold, respectively, which achieved the purpose oftheoretically modifying BSA to improve the detection sensitivity of fluorescence spectroscopy for PAEs.     

三维荧光光谱检测地沟油

利用三维荧光光谱检测灵敏度高、选择性强和快速无污染的优点,对掺入了不同比例地沟油的植物油进行了检测。实验结果表明,当掺入的地沟油的含量超过10%时,根据三维荧光光谱的荧光图案特征和特定荧光激发波长的荧光强度下降程度,可以作为判断该植物油是否掺入了地沟油的依据。使用三维荧光光谱检测地沟油优于其他检测方法,其灵敏度和快速、实时的特点适合用于地沟油的测定。     

不连续缓冲体系毛细管电泳技术用于BSA分析的研究

本工作开发了一种在平衡过程和电泳过程采用不连续缓冲体系进行样品毛细管电泳分析的技术.当采用低浓度的磷酸盐缓冲液平衡毛细管,高浓度的磷酸盐缓冲液电泳分离牛血清白蛋白(BSA)时,在电泳过程中可以浓缩进样样品.相反当高浓度缓冲液平衡、低浓度缓冲液电泳时,样品的分离度提高.单独在电泳缓冲液中添加甲醇可提高牛血清白蛋白的分离效果.     

Fixation for biological ultrastructure. II. Cross-linking of bovine serum albumin by nanosecond pulses of ionizing radiation

Very large doses of ionizing radiation were delivered quickly to concentrated albumin solutions by pulses of 500 keV in air. The electrons penetrated the aluminium foil bottom of the test cell and into the solution. A dose of 4.6 Mrad (4.6 × 10⁴ Gy) produced a gel in the albumin solution comparable to the long-term effect of 0.36% glutaraldehyde in the same albumin solution. The cross-links created by the radiation leading to gel formation are probably irreversible and quite different from those leading to gelation in the glutaraldehyde-albumin reaction. Single large pulses of ionizing radiation may be useful for fast fixation of cells and tissues for microscopy.