增强型酶催化发光免疫分析法高灵敏测定血清中心肌肌钙蛋白Ⅰ

基于辣根过氧化物酶（HRP）催化 H₂O₂-Luminol系统,对一种新型酚类衍生物 4-（1,2,4-三氮唑-1-基）苯酚对化学发光的增强作用进行了研究。用HRP标记急性心肌梗死标志物心肌肌钙蛋白Ⅰ（cTnⅠ）单克隆抗体,通过cTnⅠ的双抗体夹心免疫反应,建立了简单、灵敏和快速检测人血清中的cTnⅠ含量的增强型酶发光免疫分析方法。实验结果表明,cTnⅠ在1.2 ~ 24 ng/mL浓度范围内与增强型发光强度具有良好的线性关系（R=0.99）,变异系数（n= 8）为 4.7%。最后,使用该方法对人血清样品中的cTnⅠ含量进行测定,测试结果具有较好的稳定性和精度,能够满足临床检测要求。     

Physicochemical and Antioxidant Properties of Riboflavin in Dextran70/HSA Systems

Physicochemical properties of Riboflavin (Vitamin B₂) (RF), in Dextran 70 (Dx70) (a biological relevant glucidic type macromolecule) and Human Serum Albumin (HSA) (a carrier/transport protein) based system, have been studied by absorption, fluorescence, circular dichroism and electrochemistry. No significant changes on the fluorescence of RF in Dx70/HSA systems with and without the influence of temperature (30–60 °C range) were observed. No changes on the intrinsic Tryptophan fluorescence in Dx70/RF/HSA system, have been evidenced. HSA secondary structure when RF binds in Dx70/RF/HSA systems, with a renaturation effect of Dx70, was found. In Dx70/RF/HSA system the major process which RF undergoes is the proton transfer, E_red = ?0.43 V. Using the chemiluminescence method, an improvement of the antioxidant activity of RF into the Dx70/RF/HSA system, was also found. RF concentration in Dx70/RF/HSA systems is important in RF oxidative damages when it reacts with target molecules and thus promotes their oxidation. The results have relevance in the oxidative stress process and in pharmaceutical formulations containing RF.     

Study of the Interaction of Fangchinoline with Human Serum Albumin by Fluorescence and UV Spectroscopic Method

The interaction of fangchinoline with human serum albumin (HSA) was studied by use of fluorescence quenching spectra, synchronous fluorescence spectra, and ultraviolet spectra. It was shown that fangchinoline has a strong ability to quench the fluorescence of HSA. The Stern‐Volmer curves based on the quenching of the fluorescence of HSA by fangchinoline indicated that the quenching mechanism of fangchinoline on HSA was static quenching and non‐radiation energy transfer. Based on the Förster theory of non‐radiation energy transfer, the binding distances (r) and the binding constants (K _A) between fangchinoline and HSA were found. The thermodynamic parameters obtained revealed that the interaction between fangchinoline and HSA was mainly driven by hydrophobic force. The conformational changes of HSA were investigated by use of synchronous fluorescence. The result indicates that an ionic electrostatic interaction between fangchinoline and HSA could not be excluded.     

Chemiluminescence of ozonized polyvinylchloride

Time dependences of decomposition of peroxides in samples of polyvinylchloride (PVC) ozonized under different conditions and containing different concentrations of peroxidic groups were followed by chemiluminescence method. The kinetic characteristics of the chemiluminescence reaction were determined and the mechanism accounting for the formation of hydroperoxides in PVC during ozonization was suggested.     

Multifunctional human serum albumin in the surface‐enhanced Raman spectroscopy of porphyrin: demetalation promoter,molecular spacer and stabilizer

Human serum albumin (HSA), a model protein, was introduced to the surface‐enhanced Raman spectroscopy (SERS) of cationic porphyrin 5,10,15,20‐tetrakis(1‐methyl‐4‐pyridyl)‐21H,23H‐porphine (H₂TMPyP4). HSA was found to have a great influence not only on Ag nanoparticle aggregation state but also on the interaction between Ag nanoparticle and H₂TMPyP4 molecules. In the (H₂TMPyP4‐Ag colloid)/HSA system, addition of H₂TMPyP4 to Ag colloid led to a quick Ag colloid aggregation, and subsequent HSA addition could stabilize this system. The SERS spectrum was dominated by a combination of Ag(II)TMPyP4 and free base H₂TMPyP4. More interestingly, a photoinduced demetalation of Ag(II)TMPyP4 to free base H₂TMPyP4 was observed in the (H₂TMPyP4‐Ag colloid)/HSA system. This demetalation process was partially reversible when the laser was turned off or the laser power was reduced. In this case, HSA acts as both a stabilizer and a demetalation promoter. In the (HSA‐H₂TMPyP4)/Ag colloid system, when H₂TMPyP4 was premixed with HSA prior to the Ag colloid addition, no obvious Ag colloid aggregation appeared, and the SERS spectrum was just characteristic of free base H₂TMPyP4. In this case, HSA is proposed to function as both a stabilizer and a molecular spacer. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis and evaluation of the potential deleterious effects of ZnO nanomaterials (nanoneedles and nanoflowers) on blood components,including albumin,erythrocytes and human isolated primary neutrophils

The application of zinc oxide (ZnO) nanoparticles in biomaterials has increased significantly in the recent years. Here, we aimed to study the potential deleterious effects of ZnO on blood components, including human serum albumin (HSA), erythrocytes and human isolated primary neutrophils. To test the influence of the morphology of the nanomaterials, ZnO nanoneedles (ZnO-nn) and nanoflowers (ZnO-nf) were synthesized. The zeta potential and mean size of ZnO-nf and ZnO-nn suspensions in phosphate-buffered saline were ?10.73 mV and 3.81 nm and ?5.27 mV and 18.26 nm, respectively. The incubation of ZnO with HSA did not cause its denaturation as verified by the absence of significant alterations in the intrinsic and extrinsic fluorescence and in the circular dichroism spectrum of the protein. The capacity of HSA as a drug carrier was not affected as verified by employing site I and II fluorescent markers. Neither type of ZnO was able to provoke the activation of neutrophils, as verified by lucigenin- and luminol-dependent chemiluminescence and by the extracellular release of hydrogen peroxide. ZnO-nf, but not ZnO-nn, induced the haemolysis of erythrocytes. In conclusion, our results reinforce the concept that ZnO nanomaterials are relatively safe for usage in biomaterials. A potential exception is the capacity of ZnO-nf to promote the lysis of erythrocytes, a discovery that shows the importance of the morphology in the toxicity of nanoparticles.     

Studies on the Interaction of Tricyclazole with β-cyclodextrin and human Serum Albumin by Spectroscopy

The interaction of tricyclazole (TCZ) with β-cyclodextrin (β-CD) and human serum albumin (HSA) were studied by fluorescence spectrum, UV-visible spectrum and second-order scattering technology. It was shown that TCZ has quite a strong ability to quench the fluorescence launching from HSA by reacting with it and forming a certain kind of new compound. The quenching and the energy transfer mechanisms were discussed, respectively. The binding constants and thermodynamic parameters at four different temperatures, the binding locality, and the binding power were obtained. The conformation of HSA was discussed by synchronous and three-dimensional fluorescence techniques. The inclusion reaction between β-CD and TCZ was explored by scattering method, the inclusion constants and the thermodynamic parameters at 297 K and 311 K were figured out, respectively. The mechanism of inclusion reaction was speculated and linkage among the toxicity of TCZ, the exterior environment and its concentration was attempted to explain on molecule level.     

Embedding Uq(sl(2)) and Sine Algebras in Generalized Clifford Algebras

We establish the connection between certain quantum algebras and generalizedClifford algebras (GCA). To be precise, we embed the quantum tori Lie algebraand U _q (sl(2)) in GCA.     

The Influence of Human Serum Albumin on The Photogeneration of Singlet Oxygen by meso-Tetra(4-Sulfonatophenyl)Porphyrin. An Infrared Phosphorescence Study

meso-Tetra(4-sulfonatophenyl)porphyrin (TPPS₄) is a water soluble photosensitizer, which is currently clinically tested as a PDT drug. In our contribution, we present IR spectral- and time-resolved phosphorescence data reflecting the influence of human serum albumin (HSA) on singlet oxygen photogeneration by TPPS₄. IR emission of TPPS₄ was studied in samples containing various concentrations of HSA in phosphate buffer. The observed changes in spectral and temporal behaviour of TPPS₄ and singlet oxygen phosphorescence caused by the addition of HSA are equivalent to the effect of nitrogen purging of HSA-free solutions of TPPS₄. The main feature induced by addition of HSA appears to be the occurrence of a long-lived (tens of microseconds) photosensitizer phosphorescence at 900 nm besides ordinary short-lived (≈2 μs) one at 820 nm. It is accompanied by presence of a long-lived component of singlet oxygen emission with lifetime roughly corresponding to that of the long photosensitizer phosphorescence component. Moreover, the quantum yield of singlet oxygen phosphorescence decreases with increasing HSA concentration, while total quantum yield of TPPS₄ phosphorescence rises. These facts are explained by a shielding effect of HSA on bound molecules of TPPS₄ against quenching by oxygen which is analogous to oxygen removal by nitrogen purging.     

Effect of the luminol signal enhancer on the chemiluminescence intensity and kinetics

The novel p-phenol derivatives, 4-(1-imidazolyl)-phenol, 4-hydroxybiphenyl, 4-hydroxy-4′-iodobiphenyl were employed as highly potent signal enhancers of luminol-hydrogen peroxide (H₂O₂)-horseradish peroxidase (HRP) chemiluminescence (CL) system. The CL reaction conditions were optimized, and the enhancement characteristics of these enhancers were compared with each other. The employment of these molecules greatly affected important assay parameters. Practically, the use of a novel enhancer, even a slightly change of the structure (or concentration) of 4-substituted phenol derivative, could affect assay properties quite dramatically. Furthermore, the use of different enhancers in the luminol–H₂O₂–HRP system can affect not only the intensity of the CL signal, which is well known, but also its kinetics. The experiment data indicated that the stronger intensity was combined with a more rapid decrease of the CL signal.     

Joaquin Sorolla's pigment characterisation of the paintings ‘Vision of Spain’ by means of EDXRF portable system

In this work, portable energy dispersive X‐ray fluorescence (EDXRF) spectrometry was employed to the characterisation of the palette used by the Spanish artist Joaquín Sorolla (1863–1923) in the paintings ‘Vision of Spain’, a set of 14 oils on canvas painted by Sorolla between 1911 and 1919 by order of Mr Archer Huntington to decorate the library of the Hispanic Society of America (HSA) in New York. The analyses, sponsored by BANCAJA and provided by the HSA, were carried out in situ, prior to the cleaning and restoration process, while the paintings hanging on the walls of the library of the HSA. The results revealed that the paintings were made over different priming layers containing, respectively, lead white, zinc and barium compounds, lead white mixed with zinc white or lead white mixed with zinc and barium compounds. The EDXRF analyses of coloured zones identified up to 29 inorganic pigments and, in some cases, the probable use of organic pigments. Sorolla used traditional pigments as earth pigments, lead white, vermillion, etc., and modern pigments as cadmium yellow, zinc white, cobalt‐based blue, chromium‐based green, manganese‐based violet, etc. These results provide valuable information about the Sorolla's palette during the last stage of his life. Copyright © 2011 John Wiley & Sons, Ltd.     

In Vitro Study of Ketoprofen and Indapamide Used in Multidrug Therapy: 1H-NMR Analysis

ABSTRACT

Interaction of ketoprofen (KP, a nonsteroidal anti-inflammatory drug) and indapamide (IDP, a thiazide-related diuretic) with human serum albumin (HSA) in low-affinity binding sites (LAS) and competition between these medicines used in multidrug therapy have been studied by proton nuclear magnetic resonance (¹H-NMR) spectroscopy.

The analysis of chemical shifts, Δσ (ppm), of drug proton resonances and the values of the association constant, K_a [M^?1], were used to estimate the effect of IDP and KP on the KP–HSA and IDP–HSA complexes, respectively. The results showed the changes in the affinity of human serum albumin toward the drug with different mechanisms of action (KP and IDP) and the competition in the binding to HSA.     

The Interaction of a New Schiff Base Ligand with Human Serum Albumin: Molecular Docking and Molecular Dynamics Simulation Studies

The interaction of a new heterocyclic Schiff base bearing pyridine and pyrimidine cycles, with human serum albumin (HSA) using molecular docking and molecular dynamics simulation methods was examined. Molecular docking studies showed that the ligand was bonded to the IB domain of the protein. It was found that there was one hydrogen bond interaction between HSA and the ligand. The standard Gibbs free energy for binding of the ligand to HSA was calculated as ?9.63 kcal.mol^?1. The results of the molecular dynamics simulation showed that the root mean square deviation (RMSD) of the non-liganded HSA and the HSA–ligand complex reached equilibration after 1000 ps. The study of the radius of gyration revealed that there was a conformational change when the HSA–ligand complex was formed. Finally, analyzing the RMS fluctuations (RMSF) suggested that the structure of the ligand binding site remained approximately rigid during the simulation.     

有机化合物的化学发光

在过去十多年里,有关有机化合物化学发光的研究增长很快,在三个方面取得了新进展:(1)1,2-二氧杂丁烷体系化学发光的发现和研究,有助于人们了解单分子化学激发作用;(2)开展了电子转移化学发光的研究,用电生化学发光技术,研究电子转移的化学激发过程;(3)确认了化学引发电子变换发光(CIEEL)为一般化学发光机理。 本文将介绍化学发光有机反应的分类,说明化学发光的一般要求,叙述三个化学发光机理以及列出一些重要的化学发光体系。 在过氧化草酸芳酯体系中,我们提出了一种合成草酸芳酯的新方法,其反应如下: 2ArOH+(COOH)2+POCl3→(COOAr)2+HPO3+3HCl     

Study of Protein–Probe Interaction and Protective Action of Surfactant Sodium Dodecyl Sulphate in Urea-Denatured HSA using Charge Transfer Fluorescence Probe Methyl Ester of N,N-Dimethylamino Naphthyl Acrylic Acid

We have demonstrated that the intramolecular charge transfer (ICT) probe Methyl ester of N,N-dimethylamino naphthyl acrylic acid (MDMANA) serves as an efficient reporter of the proteinous microenvironment of Human Serum Albumin (HSA). This work reports the binding phenomenon of MDMANA with HSA and spectral modulation thereupon. The extent of binding and free energy change for complexation reaction along with efficient fluorescence resonance energy transfer from Trp-214 of HSA to MDMANA indicates strong binding between probe and protein. Fluorescence anisotropy, red edge excitation shift, acrylamide quenching and time resolved measurements corroborate the binding nature of the probe with protein and predicts that the probe molecule is located at the hydrophobic site of the protein HSA. Due to the strong binding ability of MDMANA with HSA, it is successfully utilized for the study of stabilizing action of anionic surfactant Sodium Dodecyl Sulphate to the unfolding and folding of protein with denaturant urea in concentration range 1M to 9M.     

多光谱法和分子对接研究α-熊果苷与人血清白蛋白的相互作用

α-熊果苷是一种能够止咳平喘的植物提取物,有关它与蛋白质的相互作用及作用机理报道较少。应用光谱学与分子对接技术研究了在不同条件下α-熊果苷与人血清白蛋白（HSA）的相互作用。研究结果显示：随着α-熊果苷浓度的增大,HSA荧光强度得到了显著增强并且荧光光谱发生了蓝移。利用荧光增敏的各种有关方程求得了α-熊果苷在不同温度下与HSA作用的结合常数, 通过范特霍夫方程计算HSA与α-熊果苷相互作用过程中的ΔH=-23.29 kJ·mol-1和ΔS=40.96 J·mol-1·K-1,说明α-熊果苷与HSA之间的主要作用力是氢键和疏水作用力。通过紫外吸收光谱、同步荧光光谱、三维荧光光谱等光谱学方法研究发现α-熊果苷使HSA的构象发生改变。通过HSA与α-熊果苷作用前后圆二色二级结构的定量分析可得知,HSA与α-熊果苷复合物的形成使蛋白质螺旋稳定性降低。最后应用分子对接实验,验证了α-熊果苷与HSA间的相互作用位点在HSA的siteⅡ（亚域ⅢA）,α-熊果苷能通过氢键和疏水作用力等多种作用力很好的结合在亚域ⅢA的疏水腔中。从实验中获得的数据能够阐明α-熊果苷对HSA的作用机制,同时能够有助于理解α-熊果苷在人体的储藏运输过程中对蛋白质功能的影响。     

Studies of Benzothiazole and Benzoselenazole Squaraines as Fluorescent Probes for Albumins Detection

Series of squaraine benzothiazole and benzoselenazole dyes were studied as possible fluorescent probes for the detection of proteins, particularly albumins. It was shown that majority of the studied squaraines give significant fluorescent response on the human serum albumin (HSA) and bovine serum albumin presence. For squaraine dyes with N-hexyl pendent groups (P-1, P-2, P-3, P-5) about 100−540-fold fluorescence intensity increase upon albumins addition was observed. At the same time in presence of other proteins, namely insulin, avidin from hen egg white, immunoglobulin G (IgG), carbonic anhydrase fluorescence enhancement values were considerably lower —up to 43 times in IgG presence. It was noted that generally, squaraines with long N-hexyl pendent groups demonstrate higher emission increase values upon proteins addition comparing with their analogues with short N-ethyl tails. It was shown that fluorescence intensity enhancement for benzothiazole squaraine dye P-3, relates linearly to the HSA concentration over the wide range—from 0.2 to 500 μg/ml. Together with noticeable selectivity of this dye to albumins, existence of wide dynamic range gives possibility to propose P-3 dye as probe for HSA quantification.     

Microwave-Triggered Metal-Enhanced Chemiluminescence (MT-MEC): Application to Ultra-fast and Ultra-sensitive Clinical Assays

In this rapid communication we describe a new approach to protein detection with chemiluminescence. By combining common practices in protein detection with chemiluminescence, microwave technology, and metal-enhanced chemiluminescence, we show that we can use low power microwaves to substantially increase enzymatic chemiluminescent reaction rates on metal substrates. As a result, we have found that we can in essence trigger chemiluminescence with low power microwave (Mw) pulses and ultimately, perform on-demand protein detection assays. Using microwave triggered metal-enhanced chemiluminescence (MT-MEC), we not only improve the sensitivity of immunoassays with enhanced signal-to-noise ratios, but we also show that we can accurately quantify protein concentrations by integrating the photon flux for discrete time intervals.     

Fluorescence spectrometric studies on the binding of puerarin to human serum albumin using warfarin, ibuprofen and digitoxin as site markers with the aid of chemometrics

The interaction of puerarin with human serum albumin (HSA) in pH 7.4 Tris-HCl buffer has been investigated by fluorescence, Fourier transform infrared (FT-IR) and circular dichroism (CD) spectroscopy. The results revealed the presence of static type of quenching mechanism in the binding of puerarin to HSA. The association constants (K_a) between puerarin and HSA were obtained according to Modified Stern-Volmer equation. The calculated thermodynamic parameters indicated that the binding of puerarin to HSA was driven mainly by hydrophobic interaction. The competitive experiments of site markers suggested that the binding site of puerarin to HSA was located in the region of subdomain IIA (sudlow site I). Further, a chemometrics approach, parallel factor analysis (PARAFAC), was applied to resolve the measured three-way synchronous fluorescence spectra data of the competitive interaction between puerarin and warfarin with HSA. The concentration information for the three reaction components, warfarin, puerarin and puerarin−HSA, in the system at equilibrium was obtained simultaneously. The PARAFAC analysis indicated that puerarin in the puerarin-HSA complex was displaced by warfarin, which confirmed the binding site of puerarin to HSA was located in site I. Moreover, the results of CD and FT-IR spectra demonstrated that the secondary structure of HSA was changed in the presence of puerarin.     

Fluorescence of an eosine probe in solutions of human serum albumin with organic and inorganic ligands

The fluorescence of an eosine molecular probe in solutions of human serum albumin (HSA) in the presence of an inorganic (CsCl) and organic (sodium dodecyl sulfate, SDS) ligand was studied. The interaction of HSA molecules with these ligands was analyzed. It was demonstrated that the presence of CsCl, a low-molecular-weight salt, in the solutions influences the efficiency of the complexation of eosine with HSA. Data on the dynamics of the conformation rearrangement of HSA during denaturation under the action of SDS were obtained.