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Sample records for albumin bsa conjugate

  1. Spectroscopic Study on the Interaction between Naphthalimide-Polyamine Conjugates and Bovine Serum Albumin (BSA).

    PubMed

    Tian, Zhi-Yong; Song, Li-Na; Zhao, Yuan; Zang, Feng-Lei; Zhao, Zhong-Hua; Chen, Nan-Hao; Xu, Xue-Jun; Wang, Chao-Jie

    2015-09-11

    The effect of a naphthalimide pharmacophore coupled with diverse substituents on the interaction between naphthalimide-polyamine conjugates 1-4 and bovine serum albumin (BSA) was studied by UV absorption, fluorescence and circular dichroism (CD) spectroscopy under physiological conditions (pH = 7.4). The observed spectral quenching of BSA by the compounds indicated that they could bind to BSA. Furthermore, caloric fluorescent tests revealed that the quenching mechanisms of compounds 1-3 were basically static type, but that of compound 4 was closer to a classical type. The Ksv values at room temperature for compound-BSA complexes-1-BSA, 2-BSA, 3-BSA and 4-BSA were 1.438 × 10⁴, 3.190 × 10⁴, 5.700 × 10⁴ and 4.745 × 10⁵, respectively, compared with the value of MINS, 2.863 × 10⁴ at Ex = 280 nm. The obtained quenching constant, binding constant and thermodynamic parameter suggested that the binding between compounds 1-4 with BSA protein, significantly affected by the substituted groups on the naphthalene backbone, was formed by hydrogen bonds, and other principle forces mainly consisting of charged and hydrophobic interactions. Based on results from the analysis of synchronous three-dimensional fluorescence and CD spectra, we can conclude that the interaction between compounds 1-4 and BSA protein has little impact on the BSA conformation. Calculated results obtained from in silico molecular simulation showed that compound 1 did not prefer either enzymatic drug sites I or II over the other. However, DSII in BSA was more beneficial than DSI for the binding between compounds 2-4 and BSA protein. The binding between compounds 1-3 and BSA was hydrophobic in nature, compared with the electrostatic interaction between compound 4 and BSA.

  2. Fluorescence dynamics of bovine serum albumin (BSA) conjugated CdZnS nanocrystallites

    NASA Astrophysics Data System (ADS)

    Mohanta, D.; Narayanan, S. S.; Pal, S. K.; Raychaudhuri, A. K.

    2008-08-01

    We report on the production of composite semiconductor CdZnS nanoparticles by adopting an inverse micellar route, using bis (2-ethylhexyl) sulfosuccinate (aerosol-AOT) as surfactant and with a degree of hydration w0 = [ H{2}O] : [AOT] = 8.9. Prior to bioconjugation (conjugation with bovine serum albumin (BSA)), the hydrophobic surface of the nanocrystals were made hydrophilic with thiol treatment (reacting with mercapto acetic acid). We compare photophysical nature of as prepared, thio-stabilized and bioconjugated CdZnS nanoparticles using absorption/emission spectroscopy and ultrafast photoluminescence decay measurements. The change-over from nonzero anisotropy (untreated) to zero anisotropy (bioconjugated) is assigned to the depolarized emission due to the surface reconstruction owing to BSA adsorption into the surface vacancies. Exploration of the dynamics of photophysical features would be promising for biomolecular sensing, labeling, and imaging applications.

  3. On the mechanical properties of bovine serum albumin (BSA) adhesives.

    PubMed

    Berchane, N S; Andrews, M J; Kerr, S; Slater, N K H; Jebrail, F F

    2008-04-01

    Biological adhesives, natural and synthetic, are of current active interest. These adhesives offer significant advantages over traditional sealant techniques, in particular, they are easier to use, and can play an integral part in the healing mechanism of tissue. Thus, biological adhesives can play a major role in medical applications if they possess adequate mechanical behavior and stability over time. In this work, we report on the method of preparation of bovine serum albumin (BSA) into a biological adhesive. We present quantitative measurements that show the effect of BSA concentration and cross-linker content on the bonding strength of BSA adhesive to wood. A comparison is then made with synthetic poly(glycidyl methacrylate) (PGMA) adhesive, and a commercial cyanoacrylate glue, which was used as a control adhesive. In addition, BSA samples were prepared and characterized for their water content, tensile strength, and elasticity. We show that on dry surface, BSA adhesive exhibits a high bonding strength that is comparable with non-biological commercial cyanoacrylate glues, and synthetic PGMA adhesive. Tensile testing on wet wood showed a slight increase in the bonding strength of BSA adhesive, a considerable decrease in the bonding strength of cyanoacrylate glue, and negligible adhesion of PGMA. Tests performed on BSA samples demonstrate that initial BSA concentration and final water content have a significant effect on the stress-strain behavior of the samples.

  4. Effect of bovine serum albumin (BSA) on enzymatic cellulose hydrolysis.

    PubMed

    Wang, Hui; Mochidzuki, Kazuhiro; Kobayashi, Shinichi; Hiraide, Hatsue; Wang, Xiaofen; Cui, Zongjun

    2013-06-01

    Bovine serum albumin (BSA) was added to filter paper during the hydrolysis of cellulase. Adding BSA before the addition of the cellulase enhances enzyme activity in the solution, thereby increasing the conversion rate of cellulose. After 48 h of BSA treatment, the BSA adsorption quantities are 3.3, 4.6, 7.8, 17.2, and 28.3 mg/g substrate, each with different initial BSA concentration treatments at 50 °C; in addition, more cellulase was adsorbed onto the filter paper at 50 °C compared with 35 °C. After 48 h of hydrolysis, the free-enzyme activity could not be measured without the BSA treatment, whereas the remaining activity of the filter paper activity was approximately 41 % when treated with 1.0 mg/mL BSA. Even after 96 h of hydrolysis, 25 % still remained. Meanwhile, after 48 h of incubation without substrate, the remaining enzyme activities were increased 20.7 % (from 43.7 to 52.7 %) and 94.8 % (from 23.3 to 45.5 %) at 35 and 50 °C, respectively. Moreover, the effect of the BSA was more obvious at 35 °C compared with 50 °C. When using 15 filter paper cellulase units per gram substrate cellulase loading at 50 °C, the cellulose conversion was increased from 75 % (without BSA treatment) to ≥90 % when using BSA dosages between 0.1 and 1.5 mg/mL. Overall, these results suggest that there are promising strategies for BSA treatment in the reduction of enzyme requirements during the hydrolysis of cellulose.

  5. alpha-Glucosidase-albumin conjugates: effect of chronic administration in mice

    SciTech Connect

    Allen, T.M.; Murray, L.; Bhardwaj, D.; Poznansky, M.J.

    1985-07-01

    Enzyme albumin conjugates have been proposed as a means of increasing the efficacy of enzyme use in vivo and decreasing immune response to the enzyme. Particulate drug carriers, however, have a pronounced tendency to localize in the mononuclear phagocyte (reticuloendothelial) system. The authors have examined in mice the effect on phagocytic index, tissue distribution and organ size of continued administration of conjugates of alpha-glucosidase with either homologous or heterologous albumin. Mice received 10 X 2-mg injections of bovine serum albumin (BSA) or mouse serum albumin (MSA), either free, polymerized or conjugated with alpha-glucosidase. Experiments involving BSA had to be terminated before the end of the experiment because of anaphylaxis, but these reactions were less severe to the polymerized albumin than to free albumin. Free BSA, BSA polymer and BSA-enzyme conjugates all caused a decrease in phagocytic index after six injections. Mice receiving MSA showed no evidence of anaphylaxis, but mice receiving six or more injections of free MSA, MSA polymer or MSA-enzyme conjugate had significantly decreased phagocytic indices as compared to controls. Phagocytic indices had returned to normal by 7 days after the final injection. Tissue distribution of /sup 125/I-labeled albumin preparations was determined in either naive or chronically injected mice.

  6. Peroxidase mediated conjugation of corn fibeer gum and bovine serum albumin to improve emulsifying properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emulsifying properties of corn fiber gum (CFG), a naturally-occurring polysaccharide protein complex, were improved by kinetically controlled formation of hetero-covalent linkages with bovine serum albumin (BSA), using horseradish peroxidase. The formation of hetero-crosslinked CFG-BSA conjugate...

  7. Characterization of Silver/Bovine Serum Albumin (Ag/BSA) nanoparticles structure: morphological, compositional, and interaction studies.

    PubMed

    Gebregeorgis, A; Bhan, C; Wilson, O; Raghavan, D

    2013-01-01

    The primary objective of this study was to elucidate the structure of protein conjugated silver nanoparticles prepared by chemical reduction of AgNO(3) and bovine serum albumin (BSA) mixture. The role of BSA in the formation of Ag/BSA nanoparticles was established by UV-Vis Spectroscopy. The association of silver with BSA in Ag/BSA nanoparticles was studied by the decrease in the intensity of absorbance peak at 278 nm in UV-Vis spectra and shift in cathodic peak potential in cyclic voltammogram. The molar ratio of silver to BSA in the Ag/BSA nanoparticles is 27:1, as ascertained by thermogravimetric analysis and atomic absorption spectrometry. Based on atomic force microscopy, dynamic light scattering and transmission electron microscopy (TEM) measurements, the average particle size of nanoparticles was found to be range of 11-15 nm. TEM image showed that the nanoparticle has two distinct phases and selected area electron diffraction pattern of nanoparticles indicated that the silver phase in Ag/BSA is fcc. X-ray photo electron spectroscopy measurements of freshly prepared and argon sputtered nanoparticles provided evidence that the outer and inner region of nanoparticles are mainly composed of BSA and silver respectively. The structural and compositional findings of nanoparticles could have a strong bearing on the bioavailability and antimicrobial activity of nanoparticles.

  8. Peroxidase-mediated conjugation of corn fiber gum and bovine serum albumin to improve emulsifying properties.

    PubMed

    Liu, Yan; Qiu, Shuang; Li, Jinlong; Chen, Hao; Tatsumi, Eizo; Yadav, Madhav; Yin, Lijun

    2015-03-15

    The emulsifying properties of corn fiber gum (CFG), a naturally occurring polysaccharide-protein complex, was improved by kinetically controlled formation of hetero-covalent linkages with bovine serum albumin (BSA), using horseradish peroxidase (HRP). The formation of hetero-crosslinked CFG-BSA conjugates was confirmed using ultraviolet-visible and Fourier-transform infrared analyses. The optimum CFG-BSA conjugates were prepared at a CFG:BSA weight ratio of 10:1, and peroxidase:BSA weight ratio of 1:4000. Selected CFG-BSA conjugates were used to prepare oil-in-water emulsions; the emulsifying properties were better than those of emulsions stabilized with only CFG or BSA. Measurements of mean droplet sizes and zeta potentials showed that CFG-BSA-conjugate-stabilized emulsions were less susceptible to environmental stresses, such as pH changes, high K ionic strengths, and freeze-thaw treatments than CFG- or BSA-stabilized emulsions. These conjugates have potential applications as novel emulsifiers in food industry.

  9. Synthesis and Characterization of BSA Conjugated Silver Nanoparticles (Ag/BSA Nanoparticles) and Evaluation of Biological Properties of Ag/BSA Nanoparticles and Ag/BSA Nanoparticles Loaded Poly(hydroxy butyrate valerate) PHBV Films

    NASA Astrophysics Data System (ADS)

    Ambaye, Almaz

    Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa are the etiological agents of several infectious diseases. Antibiotic resistance by these three microbes has emerged as a prevalent problem due in part to the misuse of existing antibiotics and the lack of novel antibiotics. Nanoparticles have emerged as an alternative antibacterial agents to conventional antibiotics owing to their high surface area to volume ratio and their unique chemical and physical properties. Among the nanoparticles, silver nanoparticles have gained increasing attention because silver nanoparticles exhibit antibacterial activity against a range of gram positive and gram negative bacteria. Nanoparticles of well-defined chemistry and morphology can be used in broad biomedical applications, especially in bone tissue engineering applications, where bone infection by bacteria can be acute and lethal. It is commonly noted in the literature that the activity of nanoparticles against microorganisms is dependent upon the size and concentration of the nanoparticles as well as the chemistry of stabilizing agent. To the best of our knowledge, a comprehensive study that evaluates the antibacterial activity of well characterized silver nanoparticles in particular Bovine Serum Albumin (BSA) stabilized against S. aureus and E. coli and cytotoxicity level of BSA stabilized silver nanoparticles towards osteoblast cells (MC3T3-E1) is currently lacking. Therefore, the primary objective of this study was to characterize protein conjugated silver nanoparticles prepared by chemical reduction of AgNO3 and BSA mixture. The formation of Ag/BSA nanoparticles was studied by UV-Vis spectroscopy. The molar ratio of silver to BSA in the Ag/BSA nanoparticles was established to be 27+/- 3: 1, based on Thermogravimetric Analysis and Atomic Absorption Spectroscopy. Based on atomic force microscopy, dynamic light scattering,and transmission electron microscopy(TEM) measurements, the particle size (diameter) of

  10. Terahertz spectroscopy of native-conformation and thermally denatured bovine serum albumin (BSA).

    PubMed

    Yoneyama, H; Yamashita, M; Kasai, S; Kawase, K; Ueno, R; Ito, H; Ouchi, T

    2008-07-07

    Proteins are expected to exhibit collective vibrational modes at terahertz frequencies. We have developed a promising approach to measure these motions by using a membrane device to hold samples. Samples of bovine serum albumin (BSA) in native and thermally denatured conformations were measured using terahertz time-domain spectroscopy. Clear differences were observed in transmittance and phase between native-conformation BSA samples and thermally denatured BSA samples. Time-domain data shows that samples exhibited relative time shifts when compared with a standard. Results suggest that there were differences in dielectric responses in the BSA samples, and these are probably associated with molecular conformational changes in the membrane device.

  11. Functional improvements in bovine serum albumin-fucoidan conjugate through the Maillard reaction.

    PubMed

    Kim, Do-Yeong; Shin, Weon-Sun

    2016-01-01

    The solubility, thermal stability, surface activity and emulsifying properties of native bovine serum albumin (BSA), heat-treated BSA, a BSA-fucoidan mixture, and a BSA-fucoidan conjugate were assessed. Covalent linkage of BSA with fucoidan resulted in significantly (p < 0.05) high solubility after heating at 90 °C for 15 min, particularly at pH 5. The BSA-fucoidan conjugate had a high melting temperature (97.09 ± 1.45 °C), as found by differential scanning calorimetry, indicating strong heat stability and high resistance to denaturation. Although the attachment of fucoidan, a non-surface-active hydrophilic polysaccharide, gave no change in the surface activity, the emulsifying activity and the emulsion stability of the conjugate at pH 5 were superior to those of native BSA, heat-treated BSA, and the BSA-fucoidan mixture. Conclusively, fucoidan attachment enhanced the solubility, thermal stability and emulsifying properties of the protein molecules with negative charge distribution and steric stabilization.

  12. Characterization and optimization of heroin hapten-BSA conjugates: method development for the synthesis of reproducible hapten-based vaccines.

    PubMed

    Torres, Oscar B; Jalah, Rashmi; Rice, Kenner C; Li, Fuying; Antoline, Joshua F G; Iyer, Malliga R; Jacobson, Arthur E; Boutaghou, Mohamed Nazim; Alving, Carl R; Matyas, Gary R

    2014-09-01

    A potential new treatment for drug addiction is immunization with vaccines that induce antibodies that can abrogate the addictive effects of the drug of abuse. One of the challenges in the development of a vaccine against drugs of abuse is the availability of an optimum procedure that gives reproducible and high yielding hapten-protein conjugates. In this study, a heroin/morphine surrogate hapten (MorHap) was coupled to bovine serum albumin (BSA) using maleimide-thiol chemistry. MorHap-BSA conjugates with 3, 5, 10, 15, 22, 28, and 34 haptens were obtained using different linker and hapten ratios. Using this optimized procedure, MorHap-BSA conjugates were synthesized with highly reproducible results and in high yields. The number of haptens attached to BSA was compared by 2,4,6-trinitrobenzenesulfonic acid (TNBS) assay, modified Ellman's test and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Among the three methods, MALDI-TOF MS discriminated subtle differences in hapten density. The effect of hapten density on enzyme-linked immunosorbent assay (ELISA) performance was evaluated with seven MorHap-BSA conjugates of varying hapten densities, which were used as coating antigens. The highest antibody binding was obtained with MorHap-BSA conjugates containing 3-5 haptens. This is the first report that rigorously analyzes, optimizes and characterizes the conjugation of haptens to proteins that can be used for vaccines against drugs of abuse. The effect of hapten density on the ELISA detection of antibodies against haptens demonstrates the importance of careful characterization of the hapten density by the analytical techniques described.

  13. Development of morin-conjugated Au nanoparticles: Exploring the interaction efficiency with BSA using spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Yue, Hua-Li; Hu, Yan-Jun; Huang, Hong-Gui; Jiang, Shan; Tu, Bao

    2014-09-01

    In order to enhance its interaction efficiency with biomacromolecules for the usage as a therapeutic agent, we have conjugated morin, an antioxidant activity and anti-tumor drug, with citrate-coated Au nanoparticles (M-C-AuNPs). M-C-AuNPs were prepared by reducing chloroauric acid using trisodium citrate in the boiling condition, and the resulted M-C-AuNPs were characterized by UV-vis absorption spectroscopy, Transmission Electron Microscopy (TEM), X-ray diffraction (XRD) and FTIR analysis. In this article, UV-vis absorption spectroscopy in combination with fluorescence spectroscopy, and circular dichroism (CD) spectroscopy were employed to investigate the interactions between M-C-AuNPs and bovine serum albumin (BSA), C-AuNPs and BSA in a phosphate buffer at pH 7.4. By comparing the quenching constant KSV, effective quenching constant Ka, binding constant Kb and the number of binding sites n, it is clearly suggested that M-C-AuNPs could enhance the binding force of morin with BSA, which would pave the way for the design of nanotherapeutic agents with improved functionality.

  14. Porphyrin conjugated with serum albumins and monoclonal antibodies boosts efficiency in targeted destruction of human bladder cancer cells.

    PubMed

    Pereira, Patrícia M R; Carvalho, José J; Silva, Sandrina; Cavaleiro, José A S; Schneider, Rudolf J; Fernandes, Rosa; Tomé, João P C

    2014-03-21

    The synthesis of a novel PS conjugated with bovine and human serum albumin (BSA and HSA) and a monoclonal antibody anti-CD104 is reported, as well as their biological potential against the human bladder cancer cell line UM-UC-3. No photodynamic effect was detected when the non-conjugated porphyrin was used. Yet, when it was coupled covalently with the mAb anti-CD104, BSA and HSA, the resulting photosensitizer conjugates demonstrated high efficacy in destroying the cancer cells, the mAb anti-CD104 efficacy overruling the albumins.

  15. Spectroscopic study on the interaction between mononaphthalimide spermidine (MINS) and bovine serum albumin (BSA).

    PubMed

    Tian, Zhiyong; Zang, Fenglei; Luo, Wen; Zhao, Zhonghua; Wang, Yueqiao; Xu, Xuejun; Wang, Chaojie

    2015-01-01

    The interaction mononaphthalimide spermidine (MINS, 1) and bovine serum albumin (BSA) was studied by UV/vis absorption, fluorescence and circular dichroism spectra (CD) under physiological conditions (pH=7.4). The observed spectral quenching of BSA by compound 1 indicated compound 1 could bind to BSA. Further fluorescent tests revealed that the quenching mechanism of BSA by compound 1 was overall static. Meanwhile, the obtained binding constant and thermodynamic parameters on compound-BSA interaction showed that the type of interaction force of compound 1 and BSA was mainly hydrophobic. The analysis of synchronous, three-dimensional fluorescence and CD showed that compound 1 had weak influence on the conformational changes in BSA. Molecular docking simulation was performed and docking model in silico suggested that the configuration of compound 1 was localized in enzymatic drug site II in BSA. Furthermore, naphthalimide moiety of compound 1 greatly contributed to the hydrophobic interaction between compound 1 and BSA protein, as confirmed by experimental data.

  16. Comprehensive spectroscopic probing the interaction and conformation impairment of bovine serum albumin (BSA) by herbicide butachlor.

    PubMed

    Liu, Xiaoyi; Ling, Zhaoxing; Zhou, Xing; Ahmad, Farooq; Zhou, Ying

    2016-09-01

    Butachlor is an effective herbicide to deal with undesired weeds selectively and is used at high levels in Asian countries. However, its interaction and impairment effect on BSA was still not clear. In this study, we investigated the interaction between butachlor and bovine serum albumin (BSA) by multi-spectroscopic methods including UV absorption, circular dichroism (CD) spectra, Fourier transform infrared (FTIR) spectra and fluorescence spectra under physiological conditions (pH=7.4). The results revealed that there was a static quenching of BSA induced by butachlor stemmed from the formation of complex. Based on thermodynamic data, the interaction of butachlor with BSA was due to happen, and van der Waals force as well as hydrogen bond were the major forces contributed to the interaction. The binding constant Kb and number of binding site of butachlor with BSA were 5.158×10(5) and 1.372 at 303K, respectively. The distance r between donor (BSA) and acceptor (butachlor) was 0.113nm, obtained according to the Förster theory. The results revealed that butachlor induced conformational changes in BSA but the secondary structure of BSA was still retained. In addition, the microenvironment around chromophore residues of BSA, for example, tryptophan, changed as well, resulting from the formation of more hydrogen bonds.

  17. Residual bovine serum albumin (BSA) quantitation in vaccines using automated Capillary Western technology.

    PubMed

    Loughney, John W; Lancaster, Catherine; Ha, Sha; Rustandi, Richard R

    2014-09-15

    Bovine serum albumin (BSA) is a major component of fetal bovine serum (FBS), which is commonly used as a culture medium during vaccine production. Because BSA can cause allergic reactions in humans the World Health Organization (WHO) has set a guidance of 50 ng or less residual BSA per vaccine dose. Vaccine manufacturers are expected to develop sensitive assays to detect residual BSA. Generally, sandwich enzyme-linked immunosorbent assays (ELISA) are used in the industry to detect these low levels of BSA. We report the development of a new improved method for residual BSA detection using the SimpleWestern technology to analyze residual BSA in an attenuated virus vaccine. The method is based on automated Capillary Western and has linearity of two logs, >80% spike recovery (accuracy), intermediate precision of CV <15%, and LOQ of 5.2 ng/ml. The final method was applied to analyze BSA in four lots of bulk vaccine products and was used to monitor BSA clearance during vaccine process purification.

  18. Preparation and in vitro photodynamic activity of novel silicon(IV) phthalocyanines conjugated to serum albumins.

    PubMed

    Huang, Jian-Dong; Lo, Pui-Chi; Chen, Yan-Mei; Lai, Janice C; Fong, Wing-Ping; Ng, Dennis K P

    2006-05-01

    The interactions of four novel silicon(IV) phthalocyanines (SiPc), namely SiPc[OC(3)H(5)(NMe(2))(2)](2) (1), SiPc[OC(3)H(5)(NMe(2))(2)](OMe) (2), {SiPc[OC(3)H(5)(NMe(3))(2)](2)}I(4) (3), and {SiPc[OC(3)H(5)(NMe(3))(2)](OMe)}I(2) (4) with human serum albumin (HSA), bovine serum albumin (BSA), and maleylated bovine serum albumin (mBSA) were studied by fluorescence spectroscopy. The fluorescence emission of the serum albumins was effectively quenched by these phthalocyanines mainly through a static quenching mechanism. The higher Stern-Volmer quenching constants for the unsymmetrically substituted phthalocyanines 2 and 4 suggested that they have a stronger interaction with these proteins than the symmetrically substituted analogues 1 and 3. A series of non-covalent BSA or mBSA conjugates of these phthalocyanines were also prepared and evaluated for their in vitro photodynamic activity against HepG2 human hepatocarcinoma cells. The bioconjugation could enhance the photocytotoxicity of 1 and 4 by up to eight folds, but the effects on 2 and 3 were negligible. The results could be partly explained by two counter-balancing effects, namely the enhanced uptake and increased aggregation tendency of phthalocyanine due to BSA conjugation. As shown by absorption spectroscopy, the tetracationic phthalocyanine 3 was significantly aggregated in the protein cavity and its photocytotoxicity remained the lowest among the four photosensitizers.

  19. Glycation does not modify bovine serum albumin (BSA)-induced reduction of rat aortic relaxation: the response to glycated and nonglycated BSA is lost in metabolic syndrome.

    PubMed

    Rubio-Ruiz, Maria Esther; Díaz-Díaz, Eulises; Cárdenas-León, Mario; Argüelles-Medina, Rabindranath; Sánchez-Canales, Patricia; Larrea-Gallo, Fernando; Soria-Castro, Elizabeth; Guarner-Lans, Verónica

    2008-07-01

    The effects of nonglycated bovine serum albumin (BSA) and advanced glycosylation end products of BSA (AGE-BSA) on vascular responses of control and metabolic syndrome (MS) rats characterized by hypertriglyceridemia, hypertension, hyperinsulinemia, and insulin resistance were studied. Albumin and in vitro prepared AGE-BSA have vascular effects; however, recent studies indicate that some effects of in vitro prepared AGEs are due to the conditions in which they were generated. We produced AGEs by incubating glucose with BSA for 60 days under sterile conditions in darkness and at 37 degrees C. To develop MS rats, male Wistar animals were given 30% sucrose in drinking water since weanling. Six month old animals were used. Blood pressure, insulin, triglycerides, and serum albumin were increased in MS rats. Contraction of aortic rings elicited with norepinephrine was stronger. There were no effects of nonglycated BSA or AGE-BSA on contractions in control or MS rats; however, both groups responded to L-NAME, an inhibitor of nitric oxide synthesis. Arterial relaxation induced using acetylcholine was smaller in MS rats. Nonglycated BSA and AGE-BSA significantly diminished relaxation in a 35% in the control group but the decrease was similar when using nonglycated BSA and AGE-BSA. This decrease was not present in the MS rats and was not due to increased RAGEs or altered biochemical characteristics of BSA. In conclusion, both BSA and AGE-BSA inhibit vascular relaxation in control artic rings. In MS rats the effect is lost possibly due to alterations in endothelial cells that are a consequence of the illness.

  20. Characterisation of bovine serum albumin-fucoidan conjugates prepared via the Maillard reaction.

    PubMed

    Kim, Do-Yeong; Shin, Weon-Sun

    2015-04-15

    Bovine serum albumin (BSA)-fucoidan conjugates were prepared by the Maillard reaction (60 °C and 79% relative humidity for 96 h), and were then identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion chromatography (SEC). Molecular characteristics of the BSA-fucoidan conjugates were investigated, using atomic force microscopy (AFM), dynamic light scattering (DLS), fluorescence spectroscopy, and circular dichroism spectroscopy. SDS-PAGE patterns provided evidence for the covalent bonding between BSA and fucoidan. SEC profiles showed that about 1.5-2.0 mol of fucoidan were covalently linked to 1 mol of BSA, resulting in high-molecular-weight compositions (conjugates). AFM images and DLS results indicated that most particles in the conjugates were nano-structured and more spherical than those of a regular BSA-fucoidan mixture. The fluorescence intensity and maximum emission wavelength of the conjugates together revealed that the BSA molecules had converted from an ordered conformation into a partially folded molten globule state.

  1. Conjugation of ampicillin and enrofloxacin residues with bovine serum albumin and raising of polyclonal antibodies against them

    PubMed Central

    Kumar, B. Sampath; Ashok, Vasili; Kalyani, P.; Nair, G. Remya

    2016-01-01

    Aim: The aim of this study is to test the potency of bovine serum albumin (BSA) conjugated ampicillin (AMP) and enrofloxacin (ENR) antigens in eliciting an immune response in rats using indirect competitive enzyme-linked immunosorbent assay (icELISA). Materials and Methods: AMP and ENR antibiotics were conjugated with BSA by carbodiimide reaction using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linker. The successful conjugation was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sprague-Dawley rats were immunized with the conjugates and blood samples were collected serially at 15 days time interval after first immunization plus first booster, second booster, third booster, and the fourth sampling was done 1½ month after the third booster. The antibody titres in the antisera of each antibiotic in all the four immunization cycles (ICs) were determined by an icELISA at various serum dilutions ranging from 1/100 to 1/6400. Results: Analysis of antibiotic-BSA conjugates by sodium dodecyl sulfate polyacrylamide gel electrophoresis and coomassie blue staining revealed high molecular weight bands of 85 kDa and 74 kDa for AMP-BSA and ENR-BSA respectively when compared to 68 kDa band of BSA. Both the antibiotic conjugates elicited a good immune response in rats but comparatively the response was more with AMP-BSA conjugate than ENR-BSA conjugate. Maximum optical density 450 value of 2.577 was recorded for AMP-BSA antisera, and 1.723 was recorded for ENR-BSA antisera at 1/100th antiserum dilution in third IC. Conclusion: AMP and ENR antibiotics proved to be good immunogens when conjugated to BSA by carbodiimide reaction with EDC as crosslinker. The polyclonal antibodies produced can be employed for detecting AMP and ENR residues in milk and urine samples. PMID:27182138

  2. Studies on interaction of colloidal Ag nanoparticles with Bovine Serum Albumin (BSA).

    PubMed

    Ravindran, Aswathy; Singh, Anupam; Raichur, Ashok M; Chandrasekaran, N; Mukherjee, Amitava

    2010-03-01

    Biofunctionalization of noble metal nanoparticles like Ag, Au is essential to obtain biocompatibility for specific biomedical applications. Silver nanoparticles are being increasingly used in bio-sensing applications owing to excellent optoelectronic properties. Among the serum albumins, the most abundant proteins in plasma, a wide range of physiological functions of Bovine Serum Albumin (BSA) has made it a model system for biofunctionalization. In absence of adequate prior reports, this study aims to investigate the interaction between silver nanoparticles and BSA. The interaction of BSA [0.05-0.85% concentrations] with Ag nanoparticles [50ppm concentration] in aqueous dispersion was studied through UV-vis spectral changes, morphological and surface structural changes. At pH 7, which is more than the isoelectric point of BSA, a decrease in absorbance at plasmon peak of uninteracted nanoparticles (425nm) was noted till 0.45% BSA, beyond that a blue shift towards 410nm was observed. The blue shift may be attributed to enhanced electron density on the particle surfaces. Increasing pH to 12 enhanced the blue shift further to 400nm. The conformational changes in BSA at alkaline pH ranges and consequent hydrophobic interactions also played an important role. The equilibrium adsorption data fitted better to Freundlich isotherm compared to Langmuir curve. The X-ray diffraction study revealed complete coverage of Ag nanoparticles by BSA. The scanning electron microscopic study of the interacted nanoparticles was also carried out to decipher morphological changes. This study established that tailoring the concentration of BSA and pH of the interaction it was possible to reduce aggregation of nanoparticles. Biofunctionalized Ag nanoparticles with reduced aggregation will be more amenable towards bio-sensing applications.

  3. Hepatoma-Targeted Radionuclide Immune Albumin Nanospheres: 131I-antiAFPMcAb-GCV-BSA-NPs

    PubMed Central

    Lin, Mei; Huang, Junxing; Zhang, Dongsheng; Jiang, Xingmao; Zhang, Jia; Yu, Hong; Xiao, Yanhong; Shi, Yujuan; Guo, Ting

    2016-01-01

    An effective strategy has been developed for synthesis of radionuclide immune albumin nanospheres (131I-antiAFPMcAb-GCV-BSA-NPs). In vitro as well as in vivo targeting of 131I-antiAFPMcAb-GCV-BSA-NPs to AFP-positive hepatoma was examined. In cultured HepG2 cells, the uptake and retention rates of 131I-antiAFPMcAb-GCV-BSA-NPs were remarkably higher than those of 131I alone. As well, the uptake rate and retention ratios of 131I-antiAFPMcAb-GCV-BSA-NPs in AFP-positive HepG2 cells were also significantly higher than those in AFP-negative HEK293 cells. Compared to 131I alone, 131I-antiAFPMcAb-GCV-BSA-NPs were much more easily taken in and retained by hepatoma tissue, with a much higher T/NT. Due to good drug-loading, high encapsulation ratio, and highly selective affinity for AFP-positive tumors, the 131I-antiAFPMcAb-GCV-BSA-NPs are promising for further effective radiation-gene therapy of hepatoma. PMID:26981334

  4. Spectrometry researches on interaction and sonodynamic damage of riboflavin (RF) to bovine serum albumin (BSA).

    PubMed

    Wang, Zhiqiu; Li, Jushi; Wang, Jun; Zou, Mingming; Wang, Siyu; Li, Ying; Kong, Yumei; Xia, Lixin

    2012-02-15

    In this paper, the riboflavin (RF) was used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to BSA in aqueous solution. Under ultrasonic irradiation, the RF could obviously damage the BSA. In addition, synchronous fluorescence spectroscopy revealed that the RF showed more accessible to tryptophan (Trp) residues than to tyrosine (Tyr) residues. Also, it damaged Trp residues more seriously than Tyr residues under ultrasonic irradiation. At last, the generation of reactive oxygen species (ROS) in sonodynamic process was estimated by the method of Oxidation-Extraction Spectrometry (OES). And then, several radical scavengers were used to determine the kind of ROS. It was found that at least the singlet oxygen ((1)O(2)) and hydroxyl radicals (*OH) were generated.

  5. Extraction and stability of bovine serum albumin (BSA) using cholinium-based Good's buffers ionic liquids.

    PubMed

    Taha, Mohamed; Quental, Maria V; Correia, Isabel; Freire, Mara G; Coutinho, João A P

    2015-07-01

    Good's buffers ionic liquids (GB-ILs), composed of cholinium-based cations and Good's buffers anions, display self-buffering characteristics in the biological pH range, and their polarity and hydrophobicity can be easily tuned by a proper manipulation of their ions chemical structures. In this work, the extraction ability for bovine serum albumin (BSA) of aqueous biphasic systems (ABS) formed by polypropylene glycol 400 (PPG 400) and several GB-ILs was evaluated. ABS formed by PPG 400 and cholinium chloride ([Ch]Cl), GBs, and sucrose were also investigated for comparison purposes. It is shown that BSA preferentially migrates for the GB-IL-rich phase, with extraction efficiencies of 100%, achieved in a single-step. Dynamic light scattering, and circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopies were employed to evaluate the effect of the investigated cholinium-based GB-ILs on the BSA stability, and compared with results obtained for the respective GBs precursors, [Ch]Cl and sucrose, a well-known protein stabilizer. Molecular docking studies were also carried out to investigate on the binding sites of GB-IL ions to BSA. The experimental results confirm that BSA has a higher stability in GB-ILs than in any of the other compounds investigated.

  6. Preparation of Bovine Serum Albumin (BSA) nanoparticles by desolvation using a membrane contactor: a new tool for large scale production.

    PubMed

    Yedomon, B; Fessi, H; Charcosset, C

    2013-11-01

    Albumin nanoparticles are attractive drug delivery systems as they can be prepared under soft conditions and incorporate several kinds of molecules. The aim of this study was to upscale the desolvation process for preparing Bovine Serum Albumin (BSA) nanoparticles using a membrane contactor. At a first step, the BSA nanoparticles were prepared at small scale using a syringe pump. BSA nanoparticles of 139 nm in size, with a polydispersity index of 0.046, were obtained at the optimal conditions: pH 8.2, 100 mg mL(-1) BSA albumin solution (2 mL), and 1 mL min(-1) flow rate of ethanol addition (8 mL). The upscaling with a membrane contactor was achieved by permeating ethanol through the pores of a Shirasu Porous Glass (SPG Technology Co., Japan) membrane and circulating the aqueous phase tangentially to the membrane surface. By increasing the pressure of the ethanol from 1 to 2.7 bars, a progressive decrease in nanoparticle size was obtained with a high nanoparticles yield (around 94-96%). In addition, the flow rate of the circulating phase did not affect the BSA nanoparticle characteristics. At the optimal conditions (pH 8.2, 100 mg mL(-1) BSA albumin solution, pressure of ethanol 2.7 bars, flow rate of the circulating phase 30.7 mL s(-1)), the BSA nanoparticles showed similar characteristics to those obtained with the syringe pump. Large batches of BSA nanoparticles were prepared up to 10 g BSA. The BSA nanoparticles were stable at least during 2 months at 4 °C, and their characteristics were reproducible. It was then concluded that the membrane contactor technique could be a suitable method for the preparation of albumin nanoparticles at large scale with properties similar to that obtained at small scale.

  7. Hyaluronic acid-serum albumin conjugate-based nanoparticles for targeted cancer therapy.

    PubMed

    Edelman, Ravit; Assaraf, Yehuda G; Levitzky, Inna; Shahar, Tal; Livney, Yoav D

    2017-02-15

    Multiple carcinomas including breast, ovarian, colon, lung and stomach cancer, overexpress the hyaluronic acid (HA) receptor, CD44. Overexpression of CD44 contributes to key cancer processes including tumor invasion, metastasis, recurrence, and chemoresistance. Herein, we devised novel targeted nanoparticles (NPs) for delivery of anticancer chemotherapeutics, comprised of self-assembling Maillard reaction-based conjugates of HA and bovine serum albumin (BSA). HA served as the hydrophilic block, and as the ligand for actively targeting cancer cells overexpressing CD44. We demonstrate that Maillard reaction-based covalent conjugates of BSA-HA self-assemble into NPs, which efficiently entrap hydrophobic cytotoxic drugs including paclitaxel and imidazoacridinones. Furthermore, BSA-HA conjugates stabilized paclitaxel and prevented its aggregation and crystallization. The diameter of the NPs was < 15 nm, thus enabling CD44 receptor-mediated endocytosis. These NPs were selectively internalized by ovarian cancer cells overexpressing CD44, but not by cognate cells lacking this HA receptor. Moreover, free HA abolished the endocytosis of drug-loaded BSA-HA conjugates. Consistently, drug-loaded NPs were markedly more cytotoxic to cancer cells overexpressing CD44 than to cells lacking CD44, due to selective internalization, which could be competitively inhibited by excess free HA. Finally, a CD44-targeted antibody which blocks receptor activity, abolished internalization of drug-loaded NPs. In conclusion, a novel cytotoxic drug-loaded nanomedicine platform has been developed, which is based on natural biocompatible biopolymers, capabale of targeting cancer cells with functional surface expression of CD44.

  8. Albumin (BSA) Adsorption over Graphene in Aqueous Environment: Influence of Orientation, Adsorption Protocol, and Solvent Treatment.

    PubMed

    Vilhena, J G; Rubio-Pereda, Pamela; Vellosillo, Perceval; Serena, P A; Pérez, Rubén

    2016-02-23

    We report 150 ns explicit solvent MD simulations of the adsorption on graphene of albumin (BSA) in two orientations and using two different adsorption protocols, i.e., free and forced adsorption. Our results show that free adsorption occurs with little structural rearrangements. Even taking adsorption to an extreme, by forcing it with a 5 nN downward force applied during the initial 20 ns, we show that along a particular orientation BSA is able to preserve the structural properties of the majority of its binding sites. Furthermore, in all the cases considered in this work, the ibuprofen binding site has shown a strong resilience to structural changes. Finally, we compare these results with implicit solvent simulations and find that the latter predicts an extreme protein unfolding upon adsorption. The origin of this discrepancy is attributed to a poor description of the water entropic forces at interfaces in the implicit solvent methods.

  9. Binding interaction of ramipril with bovine serum albumin (BSA): Insights from multi-spectroscopy and molecular docking methods.

    PubMed

    Shi, Jie-Hua; Pan, Dong-Qi; Jiang, Min; Liu, Ting-Ting; Wang, Qi

    2016-11-01

    The binding interaction between a typical angiotensin-converting enzyme inhibitor (ACEI), ramipril, and a transport protein, bovine serum albumin (BSA), was studied in vitro using UV-vis absorption spectroscopy, steady-state fluorescence spectroscopic titration, synchronous fluorescence spectroscopy, three dimensional fluorescence spectroscopy, circular dichroism and molecular docking under the imitated physiological conditions (pH=7.4). The experimental results suggested that the intrinsic fluorescence of BSA was quenched by ramipril thought a static quenching mechanism, indicating that the stable ramipril-BSA complex was formed by the intermolecular interaction. The number of binding sites (n) and binding constant of ramipril-BSA complex were about 1 and 3.50×10(4)M(-1) at 298K, respectively, suggesting that there was stronger binding interaction of ramipril with BSA. The thermodynamic parameters together with molecular docking study revealed that both van der Waal's forces and hydrogen bonding interaction dominated the formation of the ramipril-BSA complex and the binding interaction of BSA with ramipril is enthalpy-driven processes due to |ΔH°|>|TΔS°| and ΔG°<0. The spatial distance between ramipril and BSA was calculated to be 3.56nm based on Förster's non-radiative energy transfer theory. The results of the competitive displacement experiments and molecular docking confirmed that ramipril inserted into the subdomain IIA (site I) of BSA, resulting in a slight change in the conformation of BSA but BSA still retained its secondary structure α-helicity.

  10. Spectroscopic and molecular docking studies of binding interaction of gefitinib, lapatinib and sunitinib with bovine serum albumin (BSA).

    PubMed

    Shen, Guo-Feng; Liu, Ting-Ting; Wang, Qi; Jiang, Min; Shi, Jie-Hua

    2015-12-01

    The binding interactions of three kinds of tyrosine kinase inhibitors (TKIs), such as gefitinib, lapatinib and sunitinib, with bovine serum albumin (BSA) were studied using ultraviolet spectrophotometry, fluorescence spectroscopy, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR) and molecular docking methods. The experimental results showed that the intrinsic fluorescence quenching of BSA induced by the three TKIs resulted from the formation of stable TKIs-BSA complexes through the binding interaction of TKIs with BSA. The stoichiometry of three stable TKIs-BSA complexes was 1:1 and the binding constants (Kb) of the three TKIs-BSA complexes were in the order of 10(4)M(-1) at 310 K, indicating that there was a strong binding interaction of the three TKIs with BSA. Based on the analysis of the signs and magnitudes of the free energy change (ΔG(0)), enthalpic change (ΔH(0)) and entropic change (ΔS(0)) in the binding process, it can be deduced that the binding process of the three TKIs with BSA was spontaneous and enthalpy-driven process, and the main interaction forces between the three TKIs and BSA were van der Waals force and hydrogen bonding interaction. Moreover, from the results of CD, FT-IR and molecular docking, it can be concluded that there was a significant difference between the three TKIs in the binding site on BSA, lapatinib was located on site II (m) of BSA while gefitinib and sunitinib were bound on site I of BSA, and there were some changes in the BSA conformation when binding three TKIs to BSA but BSA still retains its secondary structure α-helicity.

  11. Diazaoxatriangulenium: synthesis of reactive derivatives and conjugation to bovine serum albumin.

    PubMed

    Bora, Ilkay; Bogh, Sidsel A; Rosenberg, Martin; Santella, Marco; Sørensen, Thomas Just; Laursen, Bo W

    2016-01-21

    The azaoxa-triangulenium dyes are characterised by emission in the red and a long fluorescence lifetime (up to 25 ns). These properties have been widely explored for the azadioxatrianguelnium (ADOTA) dye. Here, the syntheses of reactive maleimide and NHS-ester forms of the diazaoxatriangulenium (DAOTA) system are reported. The DAOTA fluorophore was conjugated to bovine serum albumin (BSA) and investigated in comparison to the corresponding ADOTA-BSA conjugate. It was found that the fluorescence of DAOTA experienced a significantly higher degree of solvent quenching if compared to ADOTA as non-conjugated dyes in aqueous solution, while the fluorescence quenching observed upon conjugation to BSA was significantly reduced for DAOTA when compared to ADOTA. The differences in observed quenching for the conjugates can be explained by the different electronic structures of the dyes, which renders DAOTA significantly less prone to reductive photoinduced electron transfer (PET) quenching from e.g. tryptophan. We conclude that DAOTA, with emission in the red and inherent resistance to PET quenching, is an ideal platform for the development of long fluorescence lifetime probes for time-resolved imaging and fluorescence polarisation assay.

  12. Binding of chloroquine-conjugated gold nanoparticles with bovine serum albumin.

    PubMed

    Joshi, Prachi; Chakraborty, Soumyananda; Dey, Sucharita; Shanker, Virendra; Ansari, Z A; Singh, Surinder P; Chakrabarti, Pinak

    2011-03-15

    We have conjugated chloroquine, an anti-malarial, antiviral and anti-tumor drug, with thiol-functionalized gold nanoparticles and studied their binding interaction with bovine serum albumin (BSA) protein. Gold nanoparticles have been synthesized using sodium borohydride as reducing agent and 11-mercaptoundecanoic acid as thiol functionalizing ligand in aqueous medium. The formation of gold nanoparticles was confirmed from the characteristic surface plasmon absorption band at 522 nm and transmission electron microscopy revealed the average particle size to be ~7 nm. Chloroquine was conjugated to thiolated gold nanoparticles by using EDC/NHS chemistry and the binding was analyzed using optical density measurement and Fourier transform infrared spectroscopy. The chloroquine-conjugated gold nanoparticles (GNP-Chl) were found to interact efficiently with BSA. Thermodynamic parameters suggest that the binding is driven by both enthalpy and entropy, accompanied with only a minor alteration in protein's structure. Competitive drug binding assay revealed that the GNP-Chl bind at warfarin binding site I in subdomain IIA of BSA and was further supported by Trp212 fluorescence quenching measurements. Unraveling the nature of interactions of GNP-Chl with BSA would pave the way for the design of nanotherapeutic agents with improved functionality, enriching the field of nanomedicine.

  13. Probing into the binding interaction between medroxyprogesterone acetate and bovine serum albumin (BSA): spectroscopic and molecular docking methods.

    PubMed

    Fang, Fang; Pan, Dong-Qi; Qiu, Min-Jie; Liu, Ting-Ting; Jiang, Min; Wang, Qi; Shi, Jie-Hua

    2016-09-01

    To further understand the mechanism of action and pharmacokinetics of medroxyprogesterone acetate (MPA), the binding interaction of MPA with bovine serum albumin (BSA) under simulated physiological conditions (pH 7.4) was studied using fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, circular dichroism and molecular docking methods. The experimental results reveal that the fluorescence of BSA quenches due to the formation of MPA-BSA complex. The number of binding sites (n) and the binding constant for MPA-BSA complex are ~1 and 4.6 × 10(3)  M(-1) at 310 K, respectively. However, it can be concluded that the binding process of MPA with BSA is spontaneous and the main interaction forces between MPA and BSA are van der Waals force and hydrogen bonding interaction due to the negative values of ΔG(0) , ΔH(0) and ΔS(0) in the binding process of MPA with BSA. MPA prefers binding on the hydrophobic cavity in subdomain IIIA (site II'') of BSA resulting in a slight change in the conformation of BSA, but BSA retaining the α-helix structure. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Attenuation of non-enzymatic thermal glycation of bovine serum albumin (BSA) using β-carotene.

    PubMed

    Bodiga, Vijaya Lakshmi; Eda, Sasidhar Reddy; Veduruvalasa, Vijaya Durga; Mididodla, Lalitha Devi; Parise, Prabhu Kumar; Kodamanchili, Sujitha; Jallepalli, Swetha; Inapurapu, Santhi Priya; Neerukonda, Manjusha; Vemuri, Praveen Kumar; Bodiga, Sreedhar

    2013-05-01

    Although heat treatment of proteins is believed to promote and accelerate glycation, the accompanying structural changes in proteins because of heat denaturation and/or glycation are not completely understood. In addition, there is an increasing interest for inhibitors of thermal glycation in food processing. β-Carotene is a naturally occurring carotenoid found in many vegetables, fruits and herbs, with known antioxidant activity. However, it has not been identified if β-carotene possesses anti-glycation activity. We have tested the anti-glycation capacity of β-carotene in the bovine serum albumin (BSA)/glucose system that was heated to 55 and 65 °C for 3 days and studied the level of glycation, conformational alterations in BSA, and changes in hydrophobicity, due to thermal treatment and/or glycation. β-Carotene exhibited significant inhibitory effects on the formation of advanced glycation end products (AGEs) and also prevented the secondary structural changes in BSA due to thermal glycation. Our results represent the anti-glycative properties of β-carotene in food systems where such thermal conditions prevail.

  15. Characterizing the binding interaction between antimalarial artemether (AMT) and bovine serum albumin (BSA): Spectroscopic and molecular docking methods.

    PubMed

    Shi, Jie-Hua; Pan, Dong-Qi; Wang, Xiou-Xiou; Liu, Ting-Ting; Jiang, Min; Wang, Qi

    2016-09-01

    Artemether (AMT), a peroxide sesquiterpenoides, has been widely used as an antimalarial for the treatment of multiple drug-resistant strains of plasmodium falciparum malaria. In this work, the binding interaction of AMT with bovine serum albumin (BSA) under the imitated physiological conditions (pH7.4) was investigated by UV spectroscopy, fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), three-dimensional fluorescence spectroscopy and molecular docking methods. The experimental results indicated that there was a change in UV absorption of BSA along with a slight red shift of absorption wavelength, indicating that the interaction of AMT with BSA occurred. The intrinsic fluorescence of BSA was quenched by AMT due to the formation of AMT-BSA complex. The number of binding sites (n) and binding constant of AMT-BSA complex were about 1 and 2.63×10(3)M(-1) at 298K, respectively, suggesting that there was stronger binding interaction of AMT with BSA. Based on the analysis of the signs and magnitudes of the free energy change (ΔG(0)), enthalpic change (ΔH(0)) and entropic change (ΔS(0)) in the binding process, it can be concluded that the binding of AMT with BSA was enthalpy-driven process due to |ΔH°|>|TΔS°|. The results of experiment and molecular docking confirmed the main interaction forces between AMT and BSA were van der Waals force. And, there was a slight change in the BSA conformation after binding AMT but BSA still retains its secondary structure α-helicity. However, it had been confirmed that AMT binds on the interface between sub-domain IIA and IIB of BSA.

  16. Trimellitic anhydride-conjugated serum albumin activates rat alveolar macrophages in vitro

    PubMed Central

    Valstar, Dingena L; Schijf, Marcel A; Stelekati, Erietta; Nijkamp, Frans P; Bloksma, Nanne; Henricks, Paul AJ

    2006-01-01

    Background Occupational exposure to airborne low molecular weight chemicals, like trimellitic anhydride (TMA), can result in occupational asthma. Alveolar macrophages (AMs) are among the first cells to encounter these inhaled compounds and were previously shown to influence TMA-induced asthma-like symptoms in the Brown Norway rat. TMA is a hapten that will bind to endogenous proteins upon entrance of the body. Therefore, in the present study we determined if TMA and TMA conjugated to serum albumin induced the production of the macrophage mediators nitric oxide (NO), tumour necrosis factor (TNF), and interleukin 6 (IL-6) in vitro using the rat AM cell line NR8383 and primary AMs derived from TMA-sensitized and naïve Brown Norway rats. Methods Cells were incubated with different concentrations of TMA, TMA conjugated to bovine serum albumin (BSA), and BSA as a control for 24 h and the culture supernatant was analyzed for mediator content. Results TMA alone was not able to induce the production of mediators by NR8383 cells and primary AMs from sensitized and sham-treated rats. TMA-BSA, on the contrary, dose-dependently stimulated the production of NO, TNF, and IL-6 by NR8383 cells and of NO and TNF, but not IL-6, by primary AMs independent of sensitization. Conclusion Results suggest that although TMA is a highly reactive compound, conjugation to a suitable protein is necessary to induce mediator production by AMs. Furthermore, the observation that effects of TMA-BSA were independent of sensitization suggests involvement of an immunologically non-specific receptor. In the discussion it is argued that a macrophage scavenger receptor is a likely candidate. PMID:16796737

  17. Adsorption of Bovine Serum Albumin (BSA) at the Oil/Water Interface: A Neutron Reflection Study.

    PubMed

    Campana, M; Hosking, S L; Petkov, J T; Tucker, I M; Webster, J R P; Zarbakhsh, A; Lu, J R

    2015-05-26

    The structure of the adsorbed protein layer at the oil/water interface is essential to the understanding of the role of proteins in emulsion stabilization, and it is important to glean the mechanistic events of protein adsorption at such buried interfaces. This article reports on a novel experimental methodology for probing protein adsorption at the buried oil/water interface. Neutron reflectivity was used with a carefully selected set of isotopic contrasts to study the adsorption of bovine serum albumin (BSA) at the hexadecane/water interface, and the results were compared to those for the air/water interface. The adsorption isotherm was determined at the isoelectric point, and the results showed that a higher degree of adsorption could be achieved at the more hydrophobic interface. The adsorbed BSA molecules formed a monolayer on the aqueous side of the interface. The molecules in this layer were partially denatured by the presence of oil, and once released from the spatial constraint by the globular framework they were free to establish more favorable interactions with the hydrophobic medium. Thus, a loose layer extending toward the oil phase was clearly observed, resulting in an overall broader interface. By analogy to the air/water interface, as the concentration of BSA increased to 1.0 mg mL(-1) a secondary layer extending toward the aqueous phase was observed, possibly resulting from the steric repulsion upon the saturation of the primary monolayer. Results clearly indicate a more compact arrangement of molecules at the oil/water interface: this must be caused by the loss of the globular structure as a consequence of the denaturing action of the hexadecane.

  18. Enzyme-linked immunosorbent assay (ELISA) and blocking with bovine serum albumin (BSA)--not all BSAs are alike.

    PubMed

    Xiao, Yuhong; Isaacs, Stuart N

    2012-10-31

    The enzyme-linked immunosorbent assay (ELISA) is an extremely common and powerful laboratory technique for detecting proteins by antibodies. Researchers frequently use bovine serum albumin (BSA) as a blocking agent to prevent non-specific binding of antigens and antibodies to the microtiter well. While studying the interactions of the vaccinia virus complement control protein (VCP) with complement, we found non-specific binding of VCP to BSA and identify a BSA preparation that did not result in non-specific binding. This work draws attention to the fact that not all BSA preparations are alike. It also highlights the need to perform critical controls to ensure that ELISA reactants do not inappropriately bind to the blocking agent.

  19. Spectroscopic, structural and thermodynamic properties of chlorpyrifos bound to serum albumin: A comparative study between BSA and HSA.

    PubMed

    Han, Xiao-Le; Tian, Fang-Fang; Ge, Yu-Shu; Jiang, Feng-Lei; Lai, Lu; Li, Dong-Wei; Yu, Qiu-Liyang; Wang, Jia; Lin, Chen; Liu, Yi

    2012-04-02

    Chlorpyrifos (CPF) is a widely used organophosphate insecticide which could bind with human serum albumin (HSA) and bovine serum albumin (BSA). The binding behavior was studied employing fluorescence, three-dimensional fluorescence, Circular dichroism (CD) spectroscopy, UV-vis absorption spectroscopy, electrochemistry and molecular modeling methods. The fluorescence spectra revealed that CPF causes the quenching of the fluorescence emission of serum albumin. Stern-Volmer plots were made and quenching constants were thus obtained. The results suggested the formation of the complexes of CPF with serum albumins, which were in good agreement with the results from electrochemical experiments. Association constants at 25°C were 3.039 × 10(5) mol L(-1) for HSA, and 0.3307 × 10(5) mol L(-1) for BSA, which could affect the distribution, metabolism, and excretion of pesticide. The alterations of protein secondary structure in the presence of CPF were confirmed by the evidences from UV and CD spectra. Site competitive experiments also suggested that the primary binding site for CPF on serum albumin is close to tryptophan residues 214 of HSA and 212 of BSA, which was further confirmed by molecular modeling.

  20. Preparation and sonodynamic activities of water-soluble tetra-α-(3-carboxyphenoxyl) zinc(II) phthalocyanine and its bovine serum albumin conjugate.

    PubMed

    Xu, He-Nan; Chen, Hai-Jun; Zheng, Bi-Yuan; Zheng, Yun-Quan; Ke, Mei-Rong; Huang, Jian-Dong

    2015-01-01

    Sonodynamic therapy (SDT) is a new approach for cancer treatment, involving the synergistic effect of ultrasound and certain chemical compounds termed as sonosensitizers. A water-soluble phthalocyanine, namely tetra-α-(3-carboxyphenoxyl) zinc(II) phthalocyanine (ZnPcC4), has been prepared and characterized. The interactions between ZnPcC4 and bovine serum albumin (BSA) were also investigated by absorption and fluorescence spectroscopy. It was found that there were strong interactions between ZnPcC4 and BSA with a binding constant of 6.83×10(7)M(-1). A non-covalent BSA conjugate of ZnPcC4 (ZnPcC4-BSA) was prepared. Both ZnPcC4 and ZnPcC4-BSA exhibited efficient sonodynamic activities against HepG2 human hepatocarcinoma cells. Compared with ZnPcC4, conjugate ZnPcC4-BSA showed a higher sonodynamic activity with an IC50 value of 7.5μM. Upon illumination with ultrasound, ZnPcC4-BSA can induce an increase of intracellular reactive oxygen species (ROS) level, resulting in cellular apoptosis. The results suggest that the albumin conjugates of zinc(II) phthalocyanines functionalized with carboxyls can serve as promising sonosensitizers for sonodynamic therapy.

  1. Binding studies of lophirone B with bovine serum albumin (BSA): Combination of spectroscopic and molecular docking techniques

    NASA Astrophysics Data System (ADS)

    Chaves, Otávio Augusto; da Silva, Veridiana A.; Sant'Anna, Carlos Maurício R.; Ferreira, Aurélio B. B.; Ribeiro, Tereza Auxiliadora N.; de Carvalho, Mário G.; Cesarin-Sobrinho, Dari; Netto-Ferreira, José Carlos

    2017-01-01

    The interaction between the transport protein bovine serum albumin (BSA) and the natural product lophirone B, was investigated by spectroscopic techniques combined with a computational method (molecular docking). From the KSV and kq values it was concluded that lophirone B quenches the fluorescence of BSA by dynamic and static mechanisms. The Ka values, of the order of 104 M-1, and the number of binding sites (n ≈ 1), indicate that the binding is moderate and there is just one main binding site in BSA for lophirone B. The negative ΔG° values are in accordance with the spontaneity of the process and the positive ΔH° and ΔS° values indicate that the binding is entropically driven; the main binding forces for the association BSA:lophirone B are probably lipophilic interactions. Circular dichroism (CD) studies show there is not a significant perturbation on the secondary structure of the albumin upon the binding process. In order to better understand the spectroscopic results, a computational method was applied: molecular docking suggests Trp-213 site, as the main binding site for the ligand. Lophirone B seems to be exposed to the aqueous media as well as accommodated inside the protein cavity, resulting in a moderate affinity for the albumin. The Arg-198, His-287, Lys-294 and Lys-439 residues are interacting via hydrogen bonding with lophirone B, whereas the interaction with Trp-213 residue occurs through a lipophilic interaction.

  2. Synthesis and characterization of folate decorated albumin bio-conjugate nanoparticles loaded with a synthetic curcumin difluorinated analogue.

    PubMed

    Gawde, Kaustubh A; Kesharwani, Prashant; Sau, Samaresh; Sarkar, Fazlul H; Padhye, Subhash; Kashaw, Sushil K; Iyer, Arun K

    2017-02-14

    Albumin-bound paclitaxel colloidal nanoparticle (Abraxane®) is an FDA approved anticancer formulation available in the market. It is a suspension which is currently used therapeutically for treating cancers of the breast, lung, and pancreas among others. CDF is a novel new and potent synthetic curcumin analogue that is widely used for breast and ovarian cancer. The aim of this study was to use biocompatible albumin as well as folate decorated albumin to formulate colloidal nanoparticles encapsulating curcumin difluorinated (CDF). CDF has demonstrated a 16-fold improvement in stability and remarkable anticancer potency compared to its natural derivative, curcumin. CDF showed marked inhibition of cancer cell growth through down-regulation of multiple miRNAs, up-regulation of phosphatase and tensin homolog (PTEN), and attenuation of histone methyl transferase EZH2. However, CDF is highly hydrophobic and photodegradable with sparing aqueous solubility. In this study, we have formulated albumin nanoparticle using a modified desolvation method, which yielded high CDF loading in a nanoformulation. The physicochemical properties of CDF loaded albumin and folate-decorated albumin nanosuspensions were assessed for particle size, morphology, zeta potential, drug encapsulation efficiency/loading, solubility and drug release. Importantly, the folate ligand decorated albumin nanoparticles were formulated in principle to passively and actively target folate-overexpressing-cancers. In this study, the synthesis and optimization of BSA and folate decorated BSA conjugated CDF nanoparticles are assessed in detail that will be useful for its future clinical translation.

  3. Exploration of zwitterionic cellulose acetate antifouling ultrafiltration membrane for bovine serum albumin (BSA) separation.

    PubMed

    Liu, Yang; Huang, Haitao; Huo, Pengfei; Gu, Jiyou

    2017-06-01

    This study focused on the preparation of a new kind of membrane material, zwitterionic cellulose acetate (ZCA), via a three-step procedure consist of oxidization, Schiff base and quaternary amination reaction, and the fabrication of antifouling ZCA ultrafiltration membrane by the non-solvent-induced phase separation method (NIPS). The morphologies, surface chemical structures and compositions of the obtained CA and ZCA membranes were thoroughly characterized by field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. Meanwhile, the thermal stability, porosity and average pore size of two investigated membranes were also studied. As a result, the ZCA membrane displayed significantly improved hydrophilicity and water permeability compared with those of the reference CA membrane, despite a slight decrease in the protein rejection ratio. According to the cycle ultrafiltration performance of bovine serum albumin (BSA) solution and protein adsorption experiment, ZCA membrane exhibited better flux recovery property and fouling resistant ability, especially irreversible fouling resistant ability, suggesting superior antifouling performance. This new approach gives polymer-based membrane a long time life and excellent ultrafiltration performance, and seems promising for potential applications in the protein separation.

  4. Adsorption of bovine serum albumin (BSA) onto lecithin studied by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy.

    PubMed

    Tantipolphan, R; Rades, T; McQuillan, A J; Medlicott, N J

    2007-06-07

    The adsorption of bovine serum albumin (BSA) to lecithin was investigated by ATR-FTIR spectroscopy. Lecithin films were prepared by casting aliquots of 3.2 microg lecithin in methanol onto ZnSe ATR prisms. Surface morphology and the thickness of the films were investigated by laser scanning confocal electron microscopy and scanning electron microscopy and the thickness of the films used for adsorption studies was estimated to be 40 A. The dependency of the CO peak area on the lecithin mass in the calibration curve confirms that the thickness of the film is below the penetration depth of the infrared evanescent wave. Size exclusion HPLC and fluorescence spectroscopy show that BSA conformation in up to 1M NaCl and CaCl(2) solutions is similar to that in water with no aggregation or changes in protein conformation seen over 4h. The kinetics of BSA adsorption on the lecithin film from water, NaCl and CaCl(2) solutions demonstrates that ions promote the protein adsorption. BSA bound more in the presence of NaCl compared to CaCl(2) at equivalent concentrations. The adsorption appeared greatest at a 0.1M concentration for both NaCl and CaCl(2). The results are explained in terms of absorptive reactivity of BSA and lecithin surfaces upon salt addition.

  5. Extraction and stability of bovine serum albumin (BSA) using cholinium-based Good’s buffers ionic liquids

    PubMed Central

    Taha, Mohamed; Quental, Maria V.; Correia, Isabel; Freire, Mara G.; Coutinho, João A. P.

    2017-01-01

    Good’s buffers ionic liquids (GB-ILs), composed of cholinium-based cations and Good’s buffers anions, display self-buffering characteristics in the biological pH range, and their polarity and hydrophobicity can be easily tuned by a proper manipulation of their ions chemical structures. In this work, the extraction ability for bovine serum albumin (BSA) of aqueous biphasic systems (ABS) formed by polypropylene glycol 400 (PPG 400) and several GB-ILs was evaluated. ABS formed by PPG 400 and cholinium chloride ([Ch]Cl), GBs, and sucrose were also investigated for comparison purposes. It is shown that BSA preferentially migrates for the GB-IL-rich phase, with extraction efficiencies of 100%, achieved in a single-step. Dynamic light scattering, and circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopies were employed to evaluate the effect of the investigated cholinium-based GB-ILs on the BSA stability, and compared with results obtained for the respective GBs precursors, [Ch]Cl and sucrose, a well-known protein stabilizer. Molecular docking studies were also carried out to investigate on the binding sites of GB-IL ions to BSA. The experimental results confirm that BSA has a higher stability in GB-ILs than in any of the other compounds investigated.

  6. Binding of an Oligomeric Ellagitannin Series to Bovine Serum Albumin (BSA): Analysis by Isothermal Titration Calorimetry (ITC).

    PubMed

    Karonen, Maarit; Oraviita, Marianne; Mueller-Harvey, Irene; Salminen, Juha-Pekka; Green, Rebecca J

    2015-12-16

    A unique series of oligomeric ellagitannins was used to study their interactions with bovine serum albumin (BSA) by isothermal titration calorimetry. Oligomeric ellagitannins, ranging from monomer to heptamer and a mixture of octamer-undecamers, were isolated as individual pure compounds. This series allowed studying the effects of oligomer size and other structural features. The monomeric to trimeric ellagitannins deviated most from the overall trends. The interactions of ellagitannin oligomers from tetramers to octa-undecamers with BSA revealed strong similarities. In contrast to the equilibrium binding constant, enthalpy showed an increasing trend from the dimer to larger oligomers. It is likely that first the macrocyclic part of the ellagitannin binds to the defined binding sites on the protein surface and then the "flexible tail" of the ellagitannin coats the protein surface. The results highlight the importance of molecular flexibility to maximize binding between the ellagitannin and protein surfaces.

  7. In vitro study on binding interaction of quinapril with bovine serum albumin (BSA) using multi-spectroscopic and molecular docking methods.

    PubMed

    Shi, Jie-Hua; Pan, Dong-Qi; Jiang, Min; Liu, Ting-Ting; Wang, Qi

    2016-08-07

    The binding interaction between quinapril (QNPL) and bovine serum albumin (BSA) in vitro has been investigated using UV absorption spectroscopy, steady-state fluorescence spectroscopic, synchronous fluorescence spectroscopy, 3D fluorescence spectroscopy, Fourier transform infrared spectroscopy, circular dichroism, and molecular docking methods for obtaining the binding information of QNPL with BSA. The experimental results confirm that the quenching mechanism of the intrinsic fluorescence of BSA induced by QNPL is static quenching based on the decrease in the quenching constants of BSA in the presence of QNPL with the increase in temperature and the quenching rates of BSA larger than 10(10) L mol(-1) s(-1), indicating forming QNPL-BSA complex through the intermolecular binding interaction. The binding constant for the QNPL-BSA complex is in the order of 10(5) M(-1), indicating there is stronger binding interaction of QNPL with BSA. The analysis of thermodynamic parameters together with molecular docking study reveal that the main binding forces in the binding process of QNPL with BSA are van der Waal's forces and hydrogen bonding interaction. And, the binding interaction of BSA with QNPL is an enthalpy-driven process. Based on Förster resonance energy transfer, the binding distance between QNPL and BSA is calculated to be 2.76 nm. The results of the competitive binding experiments and molecular docking confirm that QNPL binds to sub-domain IIA (site I) of BSA. It is confirmed there is a slight change in the conformation of BSA after binding QNPL, but BSA still retains its secondary structure α-helicity.

  8. Coaxial electrospinning of (fluorescein isothiocyanate-conjugated bovine serum albumin)-encapsulated poly(epsilon-caprolactone) nanofibers for sustained release.

    PubMed

    Zhang, Y Z; Wang, X; Feng, Y; Li, J; Lim, C T; Ramakrishna, S

    2006-04-01

    As an aim toward developing biologically mimetic and functional nanofiber-based tissue engineering scaffolds, we demonstrated the encapsulation of a model protein, fluorescein isothiocyanate-conjugated bovine serum albumin (fitcBSA), along with a water-soluble polymer, poly(ethylene glycol) (PEG), within the biodegradable poly(epsilon-caprolactone) (PCL) nanofibers using a coaxial electrospinning technique. By variation of the inner flow rates from 0.2 to 0.6 mL/h with a constant outer flow rate of 1.8 mL/h, fitcBSA loadings of 0.85-2.17 mg/g of nanofibrous membranes were prepared. Variation of flow rates also resulted in increases of fiber sizes from ca. 270 nm to 380 nm. The encapsulation of fitcBSA/PEG within PCL was subsequently characterized by laser confocal scanning microscopy, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analysis. In vitro release studies were conducted to evaluate sustained release potential of the core-sheath-structured composite nanofiber PCL-r-fitcBSA/PEG. As a negative control, composite nanofiber PCL/fitcBSA/PEG blend was prepared from a normal electrospinning method. It was found that core-sheath nanofibers PCL-r-fitcBSA/PEG pronouncedly alleviated the initial burst release for higher protein loading and gave better sustainability compared to that of PCL/fitcBSA/PEG nanofibers. The present study would provide a basis for further design and optimization of processing conditions to control the nanostructure of core-sheath composite nanofibers and ultimately achieve desired release kinetics of bioactive proteins (e.g., growth factors) for practical tissue engineering applications.

  9. Folate/NIR 797-conjugated albumin magnetic nanospheres: synthesis, characterisation, and in vitro and in vivo targeting evaluation.

    PubMed

    Tang, Qiusha; An, Yanli; Liu, Dongfang; Liu, Peidang; Zhang, Dongsheng

    2014-01-01

    A practical and effective strategy for synthesis of Folate-NIR 797-conjugated Magnetic Albumin Nanospheres (FA-NIR 797-MAN) was developed. For this strategy, Magnetic Albumin Nanospheres (MAN), composed of superparamagnetic iron oxide nanoparticles (SPIONs) and bovine serum albumin (BSA), were covalently conjugated with folic acid (FA) ligands to enhance the targeting capability of the particles to folate receptor (FR) over-expressing tumours. Subsequently, a near-infrared (NIR) fluorescent dye NIR 797 was conjugated with FA-conjugated MAN for in vivo fluorescence imaging. The FA-NIR 797-MAN exhibited low toxicity to a human nasopharyngeal epidermal carcinoma cell line (KB cells). Additionally, in vitro and in vivo evaluation of the dynamic behaviour and targeting ability of FA-NIR 797-MAN to KB tumours validated the highly selective affinity of FA-NIR 797-MAN for FR-positive tumours. In summary, the FA-NIR 797-MAN prepared here exhibited great potential for tumour imaging, since the near-infrared fluorescence contrast agents target cells via FR-mediated endocytosis. The high fluorescence intensity together with the targeting effect makes FA-NIR 797-MAN a promising candidate for imaging, monitoring, and early diagnosis of cancer at the molecular and cellular levels.

  10. Albumin-conjugated C34 Peptide HIV-1 Fusion Inhibitor

    PubMed Central

    Stoddart, Cheryl A.; Nault, Geneviève; Galkina, Sofiya A.; Thibaudeau, Karen; Bakis, Peter; Bousquet-Gagnon, Nathalie; Robitaille, Martin; Bellomo, Maryanne; Paradis, Véronique; Liscourt, Patricia; Lobach, Alexandra; Rivard, Marie-Ève; Ptak, Roger G.; Mankowski, Marie K.; Bridon, Dominique; Quraishi, Omar

    2008-01-01

    Entry inhibitors of human immunodeficiency virus, type 1 (HIV-1) have been the focus of much recent research. C34, a potent fusion inhibitor derived from the HR2 region of gp41, was engineered into a 1:1 human serum albumin conjugate through stable covalent attachment of a maleimido-C34 analog onto cysteine 34 of albumin. This bioconjugate, PC-1505, was designed to require less frequent dosing and less peptide than T-20 and was assessed for its antifusogenic activity both in vitro and in vivo in the SCID-hu Thy/Liv mouse model. PC-1505 was essentially equipotent to the original C34 peptide and to T-20 in vitro. In HIV-1-infected SCID-hu Thy/Liv mice, T-20 lost activity with infrequent dosing, whereas the antiviral potency of PC-1505 was sustained, and PC-1505 was active against T-20-resistant (“DIV”) virus with a G36D substitution in gp41. The in vivo results are the direct result of a significantly improved pharmacokinetic profile for the C34 peptide following albumin conjugation. Contrary to previous reports that the gp41 NHR trimer is poorly accessible to C34 fused to protein cargoes of increasing size (Hamburger, A. E., Kim, S., Welch, B. D., and Kay, M. S. (2005) J. Biol. Chem. 280, 12567–12572), these results are the first demonstration of the capacity for a large, endogenous serum protein to gain unobstructed access to the transient gp41 intermediates that exist during the HIV fusion process, and it supports further development of albumin conjugation as a promising approach to inhibit HIV-1 entry. PMID:18809675

  11. Investigation on interaction and sonodynamic damage of fluorescein derivants to bovine serum albumin (BSA) under ultrasonic irradiation.

    PubMed

    Zou, Mingming; Zhang, Lei; Wang, Jun; Wang, Qi; Gao, Jingqun; Fan, Ping

    2013-06-01

    The fluorescein derivants (Fluorescein: (2-(6-Hydroxy-3-oxo-(3H)-xanthen-9-yl) benzoic acid), Fluorescein-DA: (Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein) and Fluorescein-DA-Fe(III): (Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein-Ferrous(III)) with a tricyclic plane structure were used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) under ultrasonic irradiation through fluorospectrometry and UV-vis spectrophotometry. Besides, because of the existence of Fe(III) ion in Fluorescein-DA-Fe(III), under ultrasonic irradiation the sonocatalytic activity in the damage of BSA molecules was also found. Three-dimensional fluorescence spectra and three-dimensional fluorescence contour profile spectra were mentioned to determine the fluorescence quenching and the conformation change of BSA in the absence and presence of these fluorescein derivants. As judged from the experimental results, the fluorescence quenching of BSA in aqueous solution caused by these fluorescein derivants were all attributed to static quenching process. The damage degree and mode were related to some factors such as ultrasonic irradiation time, fluorescein derivant concentration and ionic strength. Finally, several quenchers were used to determine the amount and kind of generated reactive oxygen species (ROS) during sonodynamic and sonocatalytic reaction processes. It suggests that these fluorescein derivants induce protein damage via various ROS, at least, including singlet oxygen ((1)O2) and hydroxyl radicals (OH). Perhaps, this paper may offer some important subjects for broadening the application of these fluorescein derivants in sonodynamic therapy (SDT) and sonocatalytic therapy (SCT) technologies for tumor treatment.

  12. Investigation on interaction and sonodynamic damage of fluorescein derivants to bovine serum albumin (BSA) under ultrasonic irradiation

    NASA Astrophysics Data System (ADS)

    Zou, Mingming; Zhang, Lei; Wang, Jun; Wang, Qi; Gao, Jingqun; Fan, Ping

    2013-06-01

    The fluorescein derivants (Fluorescein: (2-(6-Hydroxy-3-oxo-(3H)-xanthen-9-yl) benzoic acid), Fluorescein-DA: (Bis [N,N-bis (carboxymethyl) aminomethyl] fluorescein) and Fluorescein-DAsbnd Fe(III): (Bis [N,N-bis (carboxymethyl) aminomethyl] fluoresceinsbnd Ferrous(III)) with a tricyclic plane structure were used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) under ultrasonic irradiation through fluorospectrometry and UV-vis spectrophotometry. Besides, because of the existence of Fe(III) ion in Fluorescein-DAsbnd Fe(III), under ultrasonic irradiation the sonocatalytic activity in the damage of BSA molecules was also found. Three-dimensional fluorescence spectra and three-dimensional fluorescence contour profile spectra were mentioned to determine the fluorescence quenching and the conformation change of BSA in the absence and presence of these fluorescein derivants. As judged from the experimental results, the fluorescence quenching of BSA in aqueous solution caused by these fluorescein derivants were all attributed to static quenching process. The damage degree and mode were related to some factors such as ultrasonic irradiation time, fluorescein derivant concentration and ionic strength. Finally, several quenchers were used to determine the amount and kind of generated reactive oxygen species (ROS) during sonodynamic and sonocatalytic reaction processes. It suggests that these fluorescein derivants induce protein damage via various ROS, at least, including singlet oxygen (1O2) and hydroxyl radicals (rad OH). Perhaps, this paper may offer some important subjects for broadening the application of these fluorescein derivants in sonodynamic therapy (SDT) and sonocatalytic therapy (SCT) technologies for tumor treatment.

  13. Probing Conformational Change of Bovine Serum Albumin-Dextran Conjugates under Controlled Dry Heating.

    PubMed

    Xia, Shuqin; Li, Yunqi; Zhao, Qin; Li, Ji; Xia, Qiuyang; Zhang, Xiaoming; Huang, Qingrong

    2015-04-29

    The time-dependent conformational change of bovine serum album (BSA) during Maillard reaction with dextran under controlled dry heating has been studied by small-angle X-ray scattering, fluorescence spectroscopy, dynamic light scattering, and circular dichroism analysis. Through the research on the radii of gyration (Rg), intrinsic fluorescence, and secondary structure, conjugates with dextran coating were found to inhibit BSA aggregation and preserve the secondary structure of native BSA against long-time heat treatment during Maillard reaction. The results suggested that the hydrophilic dextran was conjugated to the compact protein surface and enclosed it and more dextran chains were attached to BSA with the increase of the heating time. The study presented here will be beneficial to the understanding of the conformational evolution of BSA molecules during the dry-heating Maillard reaction and to the control of the protein-polysaccharide conjugate structure.

  14. Spectroscopic investigation on assisted sonocatalytic damage of bovine serum albumin (BSA) by metronidazole (MTZ) under ultrasonic irradiation combined with nano-sized ZnO.

    PubMed

    Gao, Jingqun; Liu, Bin; Wang, Jun; Jin, Xudong; Jiang, Renzheng; Liu, Lijun; Wang, Baoxin; Xu, Yongnan

    2010-11-01

    The previous work proved that the bovine serum albumin (BSA) could be damaged under the combined action of ultrasonic irradiation and ZnO. In this work, the assisted sonocatalytic damage of BSA using metronidazole (MTZ) as a sensitizer was further investigated by means of UV-vis and fluorescence spectra. The results indicated that the adding of MTZ could obviously promote the sonocatalytic damage of BSA under ultrasonic irradiation in the presence of nano-sized ZnO powder. Furthermore, it was found that the damage degree of BSA was aggravated by some influencing factors except ionic kind and strength. In addition, the damage site of BSA was also studied with synchronous fluorescence technology. It was found that the damage site was mainly at tryptophan (Trp) residue.

  15. Spectroscopic investigation on assisted sonocatalytic damage of bovine serum albumin (BSA) by metronidazole (MTZ) under ultrasonic irradiation combined with nano-sized ZnO

    NASA Astrophysics Data System (ADS)

    Gao, Jingqun; Liu, Bin; Wang, Jun; Jin, Xudong; Jiang, Renzheng; Liu, Lijun; Wang, Baoxin; Xu, Yongnan

    2010-11-01

    The previous work proved that the bovine serum albumin (BSA) could be damaged under the combined action of ultrasonic irradiation and ZnO. In this work, the assisted sonocatalytic damage of BSA using metronidazole (MTZ) as a sensitizer was further investigated by means of UV-vis and fluorescence spectra. The results indicated that the adding of MTZ could obviously promote the sonocatalytic damage of BSA under ultrasonic irradiation in the presence of nano-sized ZnO powder. Furthermore, it was found that the damage degree of BSA was aggravated by some influencing factors except ionic kind and strength. In addition, the damage site of BSA was also studied with synchronous fluorescence technology. It was found that the damage site was mainly at tryptophan (Trp) residue.

  16. Interaction of bovine serum albumin (BSA) with novel gemini surfactants studied by synchrotron radiation scattering (SR-SAXS), circular dichroism (CD), and nuclear magnetic resonance (NMR).

    PubMed

    Gospodarczyk, W; Szutkowski, K; Kozak, M

    2014-07-24

    The interaction of three dicationic (gemini) surfactants-3,3'-[1,6-(2,5-dioxahexane)]bis(1-dodecylimidazolium) chloride (oxyC2), 3,3'-[1,16-(2,15-dioxahexadecane)]bis(1-dodecylimidazolium) chloride (oxyC12), and 1,4-bis(butane)imidazole-1-yl-3-dodecylimidazolium chloride (C4)--with bovine serum albumin (BSA) has been studied by the use of small-angle X-ray scattering (SAXS), circular dichroism (CD), and (1)H nuclear magnetic resonance diffusometry. The results of CD studies show that the conformation of BSA was changed dramatically in the presence of all studied surfactants. The greater decrease (from 56 to 24%) in the α-helical structure of BSA was observed for oxyC2 surfactant. The radii of gyration estimated from SAXS data varied between 3 and 26 nm for the BSA/oxyC2 and BSA/oxyC12 systems. The hydrodynamic radius of the BSA/surfactant system estimated from NMR diffusometry varies between 5 and 11 nm for BSA/oxyC2 and 5 and 8 nm for BSA/oxyC12.

  17. Effect of apatite formation of biphasic calcium phosphate ceramic (BCP) on osteoblastogenesis using simulated body fluid (SBF) with or without bovine serum albumin (BSA).

    PubMed

    Huang, Li; Zhou, Bo; Wu, Huayu; Zheng, Li; Zhao, Jinmin

    2017-01-01

    Although biphasic calcium phosphate ceramic (BCP) holds promise in therapy of bone defect, surface mineralization prior to implantation may improve the bioactivity to better integrate with the host. Immersion in simulated body fluid (SBF) and bovine serum albumin-simulated body fluid (BSA-SBF) are common methods to form apatite interface layer. This study was intended to investigate the effect of SBF and BSA-SBF treatment on the bioactivity of BCP in vitro. In this study, osteoblasts were grown on BCP with or without treatment of SBF or BSA-SBF, and detected with general observation, scanning electron microscope (SEM), cell proliferation assay, morphology observation, viability assay, alkaline phosphatase (ALP) activity assay, and osteogenic specific gene expression of alkaline phosphatase (ALPL), bone gamma-carboxyglutamate (gla) protein (BGLAP), bone morphogenetic protein 2 (BMP2), bone sialoprotein (BSP), type I collagen (COLI) and runt-related transcription factor 2 (RUNX2) after culture of 2, 5 and 8days. As the results shown, BCP pre-incubated in SBF and BSA-SBF up-regulated ALP activity and osteogenic related genes and proteins, which testified the positive effect of SBF and BSA-SBF. Especially, BSA-SBF enhanced the cell growth significantly. This study indicated that treatment by BSA-SBF is of importance for BCP before clinical application.

  18. Hydrophobic conjugated microporous polymers for sorption of human serum albumin

    NASA Astrophysics Data System (ADS)

    Zheng, Chunli; Du, Miaomiao; Feng, Shanshan; Sun, Hanxue; Li, An; He, Chi; Zhang, TianCheng; Wang, Qiaorui; Wei, Wei

    2016-02-01

    This paper investigated the sorption of human serum albumin (HSA) from water by three kinds of conjugated microporous polymers (CMPs) with surface hydrophobicity and intrinsic porosity. It was found that the three CMPs captured HSA with fast sorption kinetics and good working capacity. Equilibrium was obtained at 80 min for all the tests, and the maximum sorption quantity (qm) ranged from 0.07 to 0.14 mg/mg. With the increase in the particle external surface area of the CMPs, a greater extent of HSA sorption was achieved. Moreover, promoting the dispersion of CMPs in HSA aqueous solution was also beneficial to the extraction. Attenuated Total Reflection Fourier Transform Infrared spectroscopy verified the interactions between the CMPs and the Nsbnd H, Cdbnd O, and Csbnd N groups of HSA. This paper might provide fundamental guidance for the practical application of CMPs to proteins separation and recovery.

  19. Controllable synthesis and adjustable antineoplastic activity of bovine serum albumin-conjugated PbS/Ag2S core/shell nano-composites.

    PubMed

    Wang, Hua-Jie; Yu, Xue-Hong; Cao, Ying; Zhou, Bei; Wang, Cai-Feng

    2012-08-01

    Series of mono-dispersed bovine serum albumin (BSA)-conjugated PbS/Ag(2)S core/shell nano-composites with different Pb/Ag ratios had been successfully synthesized by an ion-exchange method under the gentle conditions using BSA-conjugated PbS nano-crystals as precursors, which were prepared by a biomimetic method. Fourier transform infrared spectra analysis and transmission electron microscopy (TEM) observation demonstrated that BSA was a key factor to control the morphology and size of final products. Additionally, the real-time TEM observation, X-ray powder diffraction and atomic absorption spectroscopy analysis were applied to monitor the synthesis process. The results indicated that the shell thickness and ratio of Pb to Ag could be controlled by adjusting the ion-exchange time. Both metabolic and morphological methods revealed that the proliferation of rat pheochromocytoma (PC 12) cells could be inhibited by BSA-conjugated PbS/Ag(2)S core/shell nano-composites, and the antineoplastic activity was Pb/Ag ratio-dependent. It might be explained by a Trojan horse-type mechanism. Summarily, the present study would be helpful to find a new core/shell nano-composite with higher and controllable antineoplastic activity due to the synergistic reaction of different metal ions.

  20. Cooperative cytotoxic activity of Zn and Cu in bovine serum albumin-conjugated ZnS/CuS nano-composites in PC12 cancer cells

    NASA Astrophysics Data System (ADS)

    Wang, Hua-Jie; Yu, Xue-Hong; Wang, Cai-Feng; Cao, Ying

    2013-11-01

    Series of self-assembled and mono-dispersed bovine serum albumin (BSA)-conjugated ZnS/CuS nano-composites with different Zn/Cu ratios had been successfully synthesized by a combination method of the biomimetic synthesis and ion-exchange strategy under the gentle conditions. High-resolution transmission electron microscopy observation, Fourier transform infrared spectra and zeta potential analysis demonstrated that BSA-conjugated ZnS/CuS nano-composites with well dispersity had the hierarchical structure and BSA was a key factor to control the morphology and surface electro-negativity of final products. The real-time monitoring by atomic absorption spectroscopy and powder X-ray diffraction revealed that the Zn/Cu ratio of nano-composites could be controlled by adjusting the ion-exchange time. In addition, the metabolic and morphological assays indicated that the metabolic proliferation and spread of rat pheochromocytoma (PC12) cells could be inhibited by nano-composites, with the high anti-cancer activity at a low concentration (4 ppm). What were more important, Zn and Cu in nano-composites exhibited a positive cooperativity at inhibiting cancer cell functions. The microscope observation and biochemical marker analysis clearly revealed that the nano-composites-included lipid peroxidation and disintegration of membrane led to the death of PC12 cells. Summarily, the present study substantiated the potential of BSA-conjugated ZnS/CuS nano-composites as anti-cancer drug.

  1. Synthesis of a dibenz[b,e]oxepin-bovine serum albumin conjugate for radioimmunoassay of KW-4679 ((Z)-11-[3-(dimethylamino)propylidene]-6,11- dihydrodibenz[b,e]oxepin-2-acetic acid hydrochloride).

    PubMed

    Ohshima, E; Sato, H; Obase, H; Uchimura, T; Kuwabara, T; Kobayashi, S

    1992-09-01

    (Z)-11-[3-(Dimethylamino)propylidene]-2-(methoxycarbonyl)methyl-6, 11- dihydrodibenz[b,e]oxepin-9-acrylic acid (5) was prepared for application to the radioimmunoassay of KW-4679 (1, (Z)-11-[3-(dimethylamino)propylidene]-6,11-dihydrodibenz[b,e ] oxepin-2-acetic acid hydrochloride). The acrylic acid moiety in the 9-position of 5 was employed for coupling with an amino group of bovine serum albumin (BSA) to provide 17. Subsequently, the conjugate 17 was treated with aqueous NaOH to hydrolyze the terminal methoxycarbonyl group in the 2-position of the BSA conjugated 5. Antiserum raised against the antigenic BSA-conjugate 4 finally obtained was specific for 1.

  2. SPR studies of the adsorption of silver/bovine serum albumin nanoparticles (Ag/BSA NPs) onto the model biological substrates.

    PubMed

    Bhan, Chandra; Brower, Tina Louise; Raghavan, Dharmaraj

    2013-07-15

    The primary objective of this study is to investigate the interactive forces that promote the adsorption of bio-conjugated nanoparticles onto proteins. To elucidate the interactive forces, we demonstrate an approach using synthetic and model biological surfaces to study adsorption of bio-conjugated nanoparticles. Real-time adsorption of BSA conjugated silver nanoparticles (Ag/BSA NPs) on the immobilized substrates was followed by surface plasmon resonance (SPR). The extent of adsorption of the nanoparticles on the synthetic surface was found to be larger for self-assembled monolayers (SAMs) with ionizable terminal groups and lower for SAMs with unionizable terminal groups. For model biological substrate, the extent of nanoparticles adsorption was found to relate to the pKa of immobilized proteins. For collagen immobilized substrate, the adsorption of Ag/BSA nanoparticles showed a significantly higher SPR response than that of free BSA. The extent of nanoparticles adsorption on the collagen immobilized substrate was also influenced by the type and concentration of electrolyte used in dispersing nanoparticles. Our findings indicate that the adsorption of nanoparticles to immobilized surface has contributions from electrostatic interactions, hydrophobic, and/or hydrogen bonding. This work provides the framework to study interactions that may arise when bio-conjugated nanoparticles are transported in biological systems.

  3. Spectroscopic analyses on interaction of o-Vanillin-D-Phenylalanine, o-Vanillin-L-Tyrosine and o-Vanillin-L-Levodopa Schiff Bases with bovine serum albumin (BSA).

    PubMed

    Gao, Jingqun; Guo, Yuwei; Wang, Jun; Wang, Zhiqiu; Jin, Xudong; Cheng, Chunping; Li, Ying; Li, Kai

    2011-04-01

    In this work, three o-Vanillin Schiff Bases (o-VSB: o-Vanillin-D-Phenylalanine (o-VDP), o-Vanillin-L-Tyrosine (o-VLT) and o-Vanillin-L-Levodopa (o-VLL)) with alanine constituent were synthesized by direct reflux method in ethanol solution, and then were used to study the interaction to bovine serum albumin (BSA) molecules by fluorescence spectroscopy. Based on the fluorescence quenching calculation, the bimolecular quenching constant (K(q)), apparent quenching constant (K(sv)), effective binding constant (K(A)) and corresponding dissociation constant (K(D)) as well as binding site number (n) were obtained. In addition, the binding distance (r) was also calculated according to Foster's non-radioactive energy transfer theory. The results show that these three o-VSB can efficiently bind to BSA molecules, but the binding array order is o-VDP-BSA>o-VLT-BSA>o-VLL-BSA. Synchronous fluorescence spectroscopy indicates that the o-VDP is more accessibility to tryptophan (Trp) residues of BSA molecules than to tyrosine (Tyr) residues. Nevertheless, the o-VLT and o-VLL are more accessibility to Tyr residues than to Trp residues.

  4. Antimicrobial and cell viability measurement of bovine serum albumin capped silver nanoparticles (Ag/BSA) loaded collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film.

    PubMed

    Bakare, Rotimi; Hawthrone, Samantha; Vails, Carmen; Gugssa, Ayele; Karim, Alamgir; Stubbs, John; Raghavan, Dharmaraj

    2016-03-01

    Bacterial infection of orthopedic devices has been a major concern in joint replacement procedures. Therefore, this study is aimed at formulating collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film loaded with bovine serum albumin capped silver nanoparticles (Ag/BSA NPs) to inhibit bacterial growth while retaining/promoting osteoblast cells viability. The nanoparticles loaded collagen immobilized PHBV film was characterized for its composition by X-ray Photoelectron Spectroscopy and Anodic Stripping Voltammetry. The extent of loading of Ag/BSA NPs on collagen immobilized PHBV film was found to depend on the chemistry of the functionalized PHBV film and the concentration of Ag/BSA NPs solution used for loading nanoparticles. Our results showed that more Ag/BSA NPs were loaded on higher molecular weight collagen immobilized PHEMA-g-PHBV film. Maximum loading of Ag/BSA NPs on collagen immobilized PHBV film was observed when 16ppm solution was used for adsorption studies. Colony forming unit and optical density measurements showed broad antimicrobial activity towards Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa at significantly lower concentration i.e., 0.19 and 0.31μg/disc, compared to gentamicin and sulfamethoxazole trimethoprim while MTT assay showed that released nanoparticles from Ag/BSA NPs loaded collagen immobilized PHBV film has no impact on MCTC3-E1 cells viability.

  5. Study of photoinduced energy and electron transfer in alpha-terthienyl-bovine serum albumin conjugates: a laser flash photolysis study.

    PubMed

    Boch, R; Mohtat, N; Lear, Y; Arnason, J T; Durst, T; Scaiano, J C

    1996-07-01

    The photochemistry of alpha-terthienyl (alpha-T) has been examined in bovine serum albumin (BSA). Freely associated and covalently conjugated alpha-T chromophores show similar behavior toward nonpolar quenchers such as oxygen and benzoquinone but show significant differences in the case of quenching by methyl viologen, a watersoluble cationic electron acceptor; in this case, triplet quenching reveals two distinct alpha-T populations, attributed to chromophores in sites showing very different accessibility from the aqueous phase. Rate constants for triplet quenching in BSA are generally slower than those observed in homogeneous solution for free alpha-T. For example, in the case of oxygen, the rate constant is about one order of magnitude smaller when alpha-T is associated or conjugated with the protein compared with alpha-T in solution. While triplet yields for alpha-T are essentially the same in solution and in the protein environment, the yield of detectable singlet oxygen is substantially reduced in the protein. This is attributed to a geminate reaction within the protein involving singlet oxygen trapping in the vicinity of the generation site.

  6. CdSe-ZnS quantum dots as temperature sensors during thermal coagulation of bovine serum albumin (BSA) solder

    NASA Astrophysics Data System (ADS)

    Jaschinski, Evelin; Wehner, Martin

    2012-06-01

    Laser tissue soldering (LTS) has variously interesting applications such as wound closure, anastomosis of blood vessels, and sealing corneal wounds. Since tissue properties such as optical absorption or thermal conductivity may differ, temperature control is essential to obtain full coagulation and to minimize thermal side effects. In this article, a non-invasive technique is proposed for temperature sensing by using CdSe-ZnS quantum dots (QDs) dissolved in protein solder, namely bovine serum albumin (BSA). The temperature measurement is conducted by monitoring the change in the photoluminescence spectra of the QDs. It is shown that the peak emission wavelength of about 653 nm of CdSe-ZnS QDs shifts linearly in a temperature range from 30 °C to 70 °C, with a coefficient of 0.153 nm °C-1 with increasing temperature. The wavelength shift can be determined by applying a small spectrometer with a CCD-array detector. The uncertainty associated with this method is estimated to be less than 6 °C in temperature. As the temperature increases, the measured signal strength initially remains constant and then falls off abruptly when exceeding 55 °C. The signal drop correlates with a phase change from a clear, low-scattering protein solution to strong-scattering solid material.

  7. Interaction of phenolic compounds with bovine serum albumin (BSA) and α-amylase and their relationship to astringency perception.

    PubMed

    Ferrer-Gallego, Raúl; Gonçalves, Rui; Rivas-Gonzalo, Julián Carlos; Escribano-Bailón, María Teresa; de Freitas, Victor

    2012-11-15

    The ability of grape seed extracts to bind to bovine serum albumin (BSA) and α-amylase was studied by fluorescence quenching of protein intrinsic fluorescence and nephelometry. The influence of grape seed ripeness on astringency was also evaluated. From the spectra obtained, the modified Sterm-Volmer (K(app)) and the bimolecular quenching constants were calculated. Results showed that grape seed extracts had good affinity for proteins. The association strength of tannin-protein interactions varied with changes in tannin structure associated with the degree of ripeness affecting the binding/quenching process. In all cases studied, higher values of K(app) were obtained in samples at harvest which have greater ability to bind to proteins than have samples at post-veraison time. Nephelometric assays show the same trend as do fluorescence quenching studies. A possible explanation for this is that, as seeds ripen, their tannins increase in molecular mass, which relates to an increase in hydrophobicity of the molecules, and this increases protein affinity. However, that is contrary to the reported decrease in astringency of grape seeds during maturity. This indicates that tannin-protein interactions are not the only explanation for the complex sensations of astringency of grape seeds.

  8. [Investigation on damage of bovine serum albumin (BSA) catalyzed by nano-sized silicon dioxide (SiO2) under ultrasonic irradiation using spectral methods].

    PubMed

    Wang, Jun; Ding, Na; Zhang, Zhao-hong; Guo, Ying; Wang, Shi-xian; Xu, Rui; Zhang, Xiang-dong

    2009-04-01

    The damage of bovine serum albumin (BSA) molecules under ultrasonic irradiation in the presence of nano-sized silicon dioxide (SiO2) particles was studied by UV-Vis and fluorescence spectra. In addition, the influences of ultrasonic irradiation time, nano-sized SiO2 addition amount, solution acidity (pH) and ultrasonic irradiation power on the damage of BSA molecules in aqueous solution were also detected. For BSA solution of 1.0 x 10(-5) mol x L(-1) at (37.0+/-0.2) degrees C, the UV-Vis spectra of BSA solutions showed that the absorption peaks of BSA displayed obvious hyperchromic effect with the increase in some influence factors such as ultrasonic irradiation time, nano-sized SiO2 addition amount, pH value and ultrasonic irradiation power. However, the fluorescence spectra of BSA solutions showed the phenomenon of fluorescence quenching with the increase in ultrasonic irradiation time, nano-sized SiO2 addition amount, pH value and ultrasonic irradiation power. Moreover, the possible mechanism behind the damage of BSA molecule in the presence of nano-sized SiO2 powders under ultrasonic irradiation was discussed. It was considered that the damage of BSA molecules was attributed to the formation of *OH radicals resulting from the sonoluminescence and high-heat excitation of ultrasonic cavitation. The research results could be of great significance to using sonocatalytic method to treat tumour in clinic application and for developing nano-sized drug in the future.

  9. Intercalation of bovine serum albumin coated gold clusters between phospholipid bilayers: temperature-dependent behavior of lipid-AuQC@BSA assemblies with red emission and superlattice structure.

    PubMed

    Söptei, Balázs; Mihály, Judith; Visy, Júlia; Wacha, András; Bóta, Attila

    2014-04-10

    A method has been developed to encapsulate bovine serum albumin (BSA)-coated gold quantum clusters (AuQC@BSA) in a multilamellar system of dipalmitoylphosphatidylcholine (DPPC). Results have shown that intercalation of AuQC@BSA particles into lipid bilayers occurs in the presence of CaCl2. Intense red photoluminescence emission was observed after encapsulation of the clusters. A well-defined structure was found with periodic distances drastically larger than that in the pure DPPC/water system. Although Ca(2+) ions can change the dipole characteristics of the lipid bilayer surface, leading to unbinding between the bilayers of multilamellar DPPC/water system, the repulsion is shielded in the presence of AuQC@BSA particles. A coherent superlattice structure evolves due to mixed Ca(2+)-DPPC and Ca(2+)-AuQC@BSA interactions. Studies at different temperatures have suggested a correlation between the luminescence properties of the clusters and phase transition of the lipid layers. The temperature-dependent behavior assumes the connection between the coating and the lipid bilayer surface. Temperature-dependent features of lipid intercalated Au clusters provide new opportunities in their application.

  10. Robust size control of bovine serum albumin (BSA) nanoparticles by intermittent addition of a desolvating agent and the particle formation mechanism.

    PubMed

    Paik, Sae-Yeol-Rim; Nguyen, Hoang Hai; Ryu, Jina; Che, Jeong-Hwan; Kang, Tae Seok; Lee, Jong Kwon; Song, Chi Won; Ko, Sanghoon

    2013-11-15

    In polymeric nanoparticle preparation, despite similar conditions, large fluctuations in particle size distributions are usually observed. Herein, we demonstrate that the intermittent addition of a desolvating agent can improve reproducibility in the preparation of polymeric bovine serum albumin (BSA) nanoparticles. Using this modification, BSA nanoparticles of controlled size can be manufactured with narrow particle size distributions. In our study, ethanol as a desolvating agent was added intermittently to 1% BSA solutions at different pHs with stirring at 700rpm. The effect of the preparation parameters on size and optical density of the fabricated nanoparticles were studied. The average particles sizes of BSA nanoparticles prepared at pH values of 6, 7 and 9 were approximately 100, 200 and 300nm, respectively. As ethanol addition increased, desolvation of BSA molecules resulted in formation of loose-structured particles with pH-dependent size. Beyond that, only particle density increased, but size remained unchanged with further addition of ethanol. Consistently uniform particle size distribution was achieved by adding ethanol intermittently.

  11. Albumin-Folate Conjugates for Drug-targeting in Photodynamic Therapy.

    PubMed

    Butzbach, Kathrin; Rasse-Suriani, Federico A O; Gonzalez, M Micaela; Cabrerizo, Franco M; Epe, Bernd

    2016-07-01

    Photodynamic therapy (PDT) is based on the cytotoxicity of photosensitizers in the presence of light. Increased selectivity and effectivity of the treatment is expected if a specific uptake of the photosensitizers into the target cells, often tumor cells, can be achieved. An attractive transporter for that purpose is the folic acid receptor α (FRα), which is overexpressed on the surface of many tumor cells and mediates an endocytotic uptake. Here, we describe the synthesis and photobiological characterization of polar β-carboline derivatives as photosensitizers covalently linked to folate-tagged albumin as the carrier system. The particles were taken up by KB (human carcinoma) cells within <90 min and then co-localized with a lysosomal marker. FRα antibodies prevented the uptake and also the corresponding conjugate without folate was not taken up. Accordingly, a folate-albumin-β-carbolinium conjugate proved to be phototoxic, while the corresponding albumin-β-carbolinium conjugates without FA were nontoxic, both with and without irradiation. An excess of free folate as competitor for the FRα-mediated uptake completely inhibited the photocytotoxicity. Interestingly, the albumin conjugates are devoid of photodynamic activity under cell-free conditions, as shown for DNA as a target. Thus, phototoxicity requires cellular uptake and lysosomal degradation of the conjugates. In conclusion, albumin-folate conjugates appear to be promising vehicles for a tumor cell targeted PDT.

  12. Highly sensitive chemiluminescent analysis of residual bovine serum albumin (BSA) based on a pair of specific monoclonal antibodies and peroxyoxalate-glyoxaline-PHPPA dimer chemiluminescent system in vaccines.

    PubMed

    Xue, Pan; Zhang, Kui; Zhang, Zhujun; Li, Yun; Liu, Feng; Sun, Yuanjie; Zhang, Xiaoming; Song, Chaojun; Fu, Aihua; Jin, Boquan; Yang, Kun

    2012-03-01

    Enzyme-linked immunosorbent assay (ELISA), horseradish peroxidase (HRP)-catalyzed fluorescent reaction, and oxalate chemiluminescence analysis have been combined to develop a highly sensitive, simple, and rapid method for analysis of bovine serum albumin (BSA) based on a pair of specific monoclonal antibodies in vaccines. A typical "sandwich type" immunoassay was used. Reaction of 3-(4-hydroxyphenyl propionate) (PHPPA) with hydrogen peroxide-urea, catalyzed by HRP, produced fluorescence of 3-(4-hydroxyphenyl propionate) dimer, which was detected by chemiluminescence analysis with the bis(2,4,6-trichlorophenyl)oxalate (TCPO)-H(2)O(2)-glyoxaline-PHPPA dimer chemiluminescent system. This method exhibited high performance with a linear correlation between response and amount of bovine serum albumin (BSA) in the range 0.1 to 100.0 ng mL(-1) (r = 0.9988), and the detection limit was 0.03 ng mL(-1) (S/N = 3). Intra- and interassay coefficient variations were all lower than 9.0% at three concentrations (1.0, 20.0, and 80.0 ng mL(-1)). The proposed method has been used for successful analysis of the amount of residual BSA in vaccines. The results obtained compared well with those obtained by conventional colorimetric ELISA and luminol chemiluminescent ELISA.

  13. Spectroscopic analyses on sonocatalytic damage to bovine serum albumin (BSA) induced by ZnO/hydroxylapatite (ZnO/HA) composite under ultrasonic irradiation.

    PubMed

    Wang, Zhiqiu; Li, Ying; Wang, Jun; Zou, Mingming; Gao, Jingqun; Kong, Yumei; Li, Kai; Han, Guangxi

    2012-08-01

    ZnO/hydroxylapatite (ZnO/HA) composite with HA molar content of 6.0% was prepared by the method of precipitation and heat-treated at 500°C for 40min and was characterized by powder X-ray diffraction (XRD). The sonocatalytic activities of ZnO/HA composite was carried out through the damage of bovine serum albumin (BSA) in aqueous solution. Furthermore, the effects of several factors on the damage of BSA molecules were evaluated by means of UV-vis and fluorescence spectra. Experimental results indicated that the damage degree of BSA aggravated with the increase of ultrasonic irradiation time, irradiation power and ZnO/HA addition amount, but weakened with the increase of solution acidity and ionic strength. In addition, the damage site to BSA was also studied by synchronous fluorescence technology and the damage site was mainly at tryptophan (Trp) residue. This paper provides a valuable reference for driving sonocatalytic method to treat tumor in clinic application.

  14. Savinase action on bovine serum albumin (BSA) monolayers demonstrated with measurements at the air-water interface and liquid Atomic Force Microscopy (AFM) imaging.

    PubMed

    Balashev, Konstantin; Callisen, Thomas H; Svendsen, Allan; Bjørnholm, Thomas

    2011-12-01

    We studied the enzymatic action of Savinase on bovine serum albumin (BSA) organized in a monolayer spread at the air/water interface or adsorbed at the mica surface. We carried out two types of experiments. In the first one we followed the degradation of the protein monolayer by measuring the surface pressure and surface area decrease versus time. In the second approach we applied AFM imaging of the supported BSA monolayers adsorbed on mica solid supports and extracted information for the enzyme action by analyzing the obtained images of the surface topography in the course of enzyme action. In both cases we obtained an estimate for the turnover number (TON) of the enzyme reaction.

  15. Rapid detection of Cu(2+) by a paper-based microfluidic device coated with bovine serum albumin (BSA)-Au nanoclusters.

    PubMed

    Fang, Xueen; Zhao, Qianqian; Cao, Hongmei; Liu, Juan; Guan, Ming; Kong, Jilie

    2015-11-21

    In this work, bovine serum albumin (BSA)-Au nanoclusters were used to coat a paper-based microfluidic device. This device acted as a Cu(2+) biosensor that showed fluorescence quenching on detection of copper ions. The detection limit of this sensor could be adjusted by altering the water absorbing capacity of the device. Qualitative and semi-quantitative results could be obtained visually without the aid of any advanced instruments. This sensor could test Cu(2+) rapidly with high specificity and sensitivity, which would be useful for point-of-care testing (POCT).

  16. Fabrication of coated bovine serum albumin (BSA)-epigallocatechin gallate (EGCG) nanoparticles and their transport across monolayers of human intestinal epithelial Caco-2 cells.

    PubMed

    Li, Zheng; Ha, Jungheun; Zou, Tao; Gu, Liwei

    2014-06-01

    The bovine serum albumin (BSA)-epigallocatechin gallate (EGCG) nanoparticles were fabricated using a desolvation method, and coated with poly-ε-lysine or chitosan. BSA-EGCG nanoparticles (BEN), poly-ε-lysine coated BSA-EGCG nanoparticles (PBEN), and chitosan coated BSA-EGCG nanoparticles (CBEN) had a spherical morphology and a size of 186, 259, and 300 nm, respectively. The loading efficiency of EGCG in these nanoparticles was 32.3%, 35.4%, and 32.7%, whereas the loading capacity was 18.9%, 17.0%, and 16.0% (w/w), respectively. Poly-ε-lysine or chitosan coating prevented the aggregation of nanoparticles at pH 4.5-5.0. However, they caused particle aggregation at pH 6.5-7.0. BEN had negative zeta-potentials between pH 4.5 and 6.0. Poly-ε-lysine or chitosan coating changed the zeta-potentials to positive. The release study of EGCG from the nanoparticles in the simulated gastric or intestinal fluid with or without digestive enzymes showed that poly-ε-lysine and chitosan coatings delayed EGCG release from the nanoparticles. Poly-ε-lysine or chitosan coating improved the stability of EGCG during storage at 60 °C compared with EGCG in the uncoated particles. EGCG in BEN, PBEN, and CBEN had a decreasing apparent permeability coefficient (Papp) on Caco-2 monolayers, whereas pure EGCG showed relatively stable Papp during the incubation over time. EGCG in CBEN showed significantly higher Papp, suggesting that chitosan coated BSA-EGCG nanoparticles may improve the absorption of EGCG.

  17. Spectroscopic analyses on interaction of Amantadine-Salicylaldehyde, Amantadine-5-Chloro-Salicylaldehyde and Amantadine-o-Vanillin Schiff-Bases with bovine serum albumin (BSA)

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqiu; Gao, Jingqun; Wang, Jun; Jin, Xudong; Zou, Mingming; Li, Kai; Kang, Pingli

    2011-12-01

    In this work, three Tricyclo [3.3.1.1(3,7)] decane-1-amine (Amantadine) Schiff-Bases, Amantadine-Salicylaldehyde (AS), Amantadine-5-Chloro-Salicylaldehyde (AS-5-C) and Amantadine-o-Vanillin (AS-o-V), were synthesized by direct heating reflux method in ethanol solution and characterized by infrared spectrum and elementary analysis. Fluorescence quenching was used to study the interaction of these Amantadine Schiff-Bases (AS, AS-5-C and AS-o-V) with bovine serum albumin (BSA). According to fluorescence quenching calculations the bimolecular quenching constant ( Kq), apparent quenching constant ( KSV), effective binding constant ( KA) and corresponding dissociation constant ( KD), binding site number ( n) and binding distance ( r) were obtained. The results show that these Amantadine Schiff-Bases can obviously bind to BSA molecules and the binding strength order is AS < AS-5-C = AS-o-V. Synchronous fluorescence spectroscopy reveals that these Amantadine Schiff-Bases adopt different way to bind with BSA molecules. That is, the AS and AS-5-C are accessibility to tryptophan (Trp) residues more than the tyrosine (Tyr) residues, while the AS-o-V is equally close to the Tyr and Trp residues.

  18. Spectroscopic analyses on interaction of Amantadine-Salicylaldehyde, Amantadine-5-Chloro-Salicylaldehyde and Amantadine-o-Vanillin Schiff-Bases with bovine serum albumin (BSA).

    PubMed

    Wang, Zhiqiu; Gao, Jingqun; Wang, Jun; Jin, Xudong; Zou, Mingming; Li, Kai; Kang, Pingli

    2011-12-01

    In this work, three Tricyclo [3.3.1.1(3,7)] decane-1-amine (Amantadine) Schiff-Bases, Amantadine-Salicylaldehyde (AS), Amantadine-5-Chloro-Salicylaldehyde (AS-5-C) and Amantadine-o-Vanillin (AS-o-V), were synthesized by direct heating reflux method in ethanol solution and characterized by infrared spectrum and elementary analysis. Fluorescence quenching was used to study the interaction of these Amantadine Schiff-Bases (AS, AS-5-C and AS-o-V) with bovine serum albumin (BSA). According to fluorescence quenching calculations the bimolecular quenching constant (K(q)), apparent quenching constant (K(SV)), effective binding constant (K(A)) and corresponding dissociation constant (K(D)), binding site number (n) and binding distance (r) were obtained. The results show that these Amantadine Schiff-Bases can obviously bind to BSA molecules and the binding strength order is ASBSA molecules. That is, the AS and AS-5-C are accessibility to tryptophan (Trp) residues more than the tyrosine (Tyr) residues, while the AS-o-V is equally close to the Tyr and Trp residues.

  19. Surface modification of PLGA nanoparticles via human serum albumin conjugation for controlled delivery of docetaxel

    PubMed Central

    2013-01-01

    Background Poly lactic-co-glycolic acid (PLGA) based nanoparticles are considered to be a promising drug carrier in tumor targeting but suffer from the high level of opsonization by reticuloendothelial system due to their hydrophobic structure. As a result surface modification of these nanoparticles has been widely studied as an essential step in their development. Among various surface modifications, human serum albumin (HSA) possesses advantages including small size, hydrophilic surface and accumulation in leaky vasculature of tumors through passive targeting and a probable active transport into tumor tissues. Methods PLGA nanoparticles of docetaxel were prepared by emulsification evaporation method and were surface conjugated with human serum albumin. Fourier transform infrared spectrum was used to confirm the conjugation reaction where nuclear magnetic resonance was utilized for conjugation ratio determination. In addition, transmission electron microscopy showed two different contrast media in conjugated nanoparticles. Furthermore, cytotoxicity of free docetaxel, unconjugated and conjugated PLGA nanoparticles was studied in HepG2 cells. Results Size, zeta potential and drug loading of PLGA nanoparticles were about 199 nm, −11.07 mV, and 4%, respectively where size, zeta potential and drug loading of conjugated nanoparticles were found to be 204 nm, −5.6 mV and 3.6% respectively. Conjugated nanoparticles represented a three-phasic release pattern with a 20% burst effect for docetaxel on the first day. Cytotoxicity experiment showed that the IC50 of HSA conjugated PLGA nanoparticles (5.4 μg) was significantly lower than both free docetaxel (20.2 μg) and unconjugated PLGA nanoparticles (6.2 μg). Conclusion In conclusion surface modification of PLGA nanoparticles through HSA conjugation results in more cytotoxicity against tumor cell lines compared with free docetaxel and unconjugated PLGA nanoparticles. Albumin conjugated PLGA nanoparticles may

  20. Galectin Binding to Neo-Glycoproteins: LacDiNAc Conjugated BSA as Ligand for Human Galectin-3.

    PubMed

    Böcker, Sophia; Laaf, Dominic; Elling, Lothar

    2015-07-24

    Carbohydrate-lectin interactions are relatively weak. As they play an important role in biological recognition processes, multivalent glycan ligands are designed to enhance binding affinity and inhibitory potency. We here report on novel neo-glycoproteins based on bovine serum albumin as scaffold for multivalent presentation of ligands for galectins. We prepared two kinds of tetrasaccharides (N-acetyllactosamine and N,N-diacetyllactosamine terminated) by multi-step chemo-enzymatic synthesis utilizing recombinant glycosyltransferases. Subsequent conjugation of these glycans to lysine groups of bovine serum albumin via squaric acid diethyl ester yielded a set of 22 different neo-glycoproteins with tuned ligand density. The neo-glycoproteins were analyzed by biochemical and chromatographic methods proving various modification degrees. The neo-glycoproteins were used for binding and inhibition studies with human galectin-3 showing high affinity. Binding strength and inhibition potency are closely related to modification density and show binding enhancement by multivalent ligand presentation. At galectin-3 concentrations comparable to serum levels of cancer patients, we detect the highest avidities. Selectivity of N,N-diacetyllactosamine terminated structures towards galectin-3 in comparison to galectin-1 is demonstrated. Moreover, we also see strong inhibitory potency of our scaffolds towards galectin-3 binding. These novel neo-glycoproteins may therefore serve as selective and strong galectin-3 ligands in cancer related biomedical research.

  1. Photosensitizer-Conjugated Human Serum Albumin Nanoparticles for Effective Photodynamic Therapy

    PubMed Central

    Jeong, Hayoung; Huh, MyungSook; Lee, So Jin; Koo, Heebeom; Kwon, Ick Chan; Jeong, Seo Young; Kim, Kwangmeyung

    2011-01-01

    Photodynamic therapy (PDT) is an emerging theranostic modality for various cancers and diseases. The focus of this study was the development of tumor-targeting albumin nanoparticles containing photosensitizers for efficient PDT. To produce tumor-targeting albumin nanoparticles, the hydrophobic photosensitizer, chlorin e6 (Ce6), was chemically conjugated to human serum albumin (HSA). The conjugates formed self-assembled nanoparticle structures with an average diameter of 88 nm under aqueous conditions. As expected, the Ce6-conjugated HSA nanoparticles (Ce6-HSA-NPs) were nontoxic in their native state, but upon illumination with the appropriate wavelength of light, they produced singlet oxygen and damaged target tumor cells in a cell culture system. Importantly, when the nanoparticles were injected through the tail vein into tumor-bearing HT-29 mice, Ce6-HSA-NPs compared with free Ce6 revealed enhanced tumor-specific biodistribution and successful therapeutic results following laser irradiation. These results suggest that highly tumor-specific albumin nanoparticles have the potential to serve not only as efficient therapeutic agents, but also as photodynamic imaging (PDI) reagents in cancer treatment. PMID:21562630

  2. Synthesis of F16 conjugated with 5-fluorouracil and biophysical investigation of its interaction with bovine serum albumin by a spectroscopic and molecular modeling approach.

    PubMed

    Xiang, Chen; Li, Dong-Wei; Qi, Zu-De; Jiang, Feng-Lei; Ge, Yu-Shu; Liu, Yi

    2013-01-01

    5-Fluorouracil (5-FU) has been widely used as a chemotherapy agent in the treatment of many types of solid tumors. Investigation of its antimetabolites led to the development of an entire class of fluorinated pyrimidines. However, the toxicity profile associated with 5-FU is significant and includes diarrhea, mucositis, hand-foot syndrome and myelosuppression. In aiming at reducing of the side effects of 5-FU, we have designed and synthesized delocalized lipophilic cations (DLCs) as a vehicle for the delivery of 5-FU. DLCs accumulate selectively in the mitochondria of cancer cells because of the high mitochondrial transmembrane potential (ΔΨm). Many DLCs exhibited anti-cancer efficacy and were explored as potential anti-cancer drugs based on their selective accumulation in the mitochondria of cancer cells. F16, the DLC we used as a vehicle, is a small molecule that selectively inhibits tumor cell growth and dissipates mitochondrial membrane potential. The binding of the conjugate F16-5-FU to bovine serum albumin (BSA) was investigated using spectroscopic and molecular modeling approaches. Fluorescence quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between F16-5-FU and BSA. The activation energy of the interaction between F16-5-FU and BSA was calculated and the unusually high value was discussed in terms of the special structural block indicated by the molecular modeling approach. Molecular modeling showed that F16-5-FU binds to human serum albumin in site II, which is consistent with the results of site-competitive replacement experiments. It is suggested that hydrophobic and polar forces played important roles in the binding reaction, in accordance with the results of thermodynamic experiments.

  3. Interaction of bovine (BSA), rabbit (RSA), and porcine (PSA) serum albumins with cationic single-chain/gemini surfactants: a comparative study.

    PubMed

    Gull, Nuzhat; Sen, Priyankar; Khan, Rizwan Hasan; Kabir-ud-Din

    2009-10-06

    The interactions among bovine, rabbit, and porcine serum albumins and single-chain cationic surfactant cetyltrimethylammonium bromide (CTAB) versus its gemini counterpart (designated as G4) have been studied. The studies were carried out in an aqueous medium at pH 7.0 using UV, intrinsic and extrinsic fluorescence spectroscopy, and far-UV circular dichroism techniques. The results indicate that compared to CTAB, G4 interacts strongly with the serum albumins, resulting in a significantly larger unfolding or decrease in alpha-helical content as reflected by the significantly larger decrease in ellipticity in the far-UV range. Unlike CTAB, a remarkable increase in the alpha-helical content of BSA at 625 microM G4 and at 250 microM G4 for RSA and PSA is observed. The appearance of conformational changes and saturation points in the proteins occurs at considerably lower [G4] compared to [CTAB]. The results obtained from the multi-technique approach are ascribed to the stronger forces in G4 owing to the presence of two charged headgroups and two hydrocarbon tails. Keeping the results in view, it is suggested that the gemini surfactants may be effectively used in the renaturation of proteins produced in genetically engineered cells via the artificial chaperone protocol and may also prove useful in drug delivery as solubilizing agents to recover proteins from insoluble inclusion bodies.

  4. Bovine serum albumin with glycated carboxyl groups shows membrane-perturbing activities.

    PubMed

    Yang, Shin-Yi; Chen, Ying-Jung; Kao, Pei-Hsiu; Chang, Long-Sen

    2014-12-15

    The aim of the present study aimed to investigate whether glycated bovine serum albumin (BSA) showed novel activities on the lipid-water interface. Mannosylated BSA (Man-BSA) was prepared by modification of the carboxyl groups with p-aminophenyl α-d-mannopyranoside. In contrast to BSA, Man-BSA notably induced membrane permeability of egg yolk phosphatidylcholine (EYPC)/egg yolk sphingomyelin (EYSM)/cholesterol (Chol) and EYPC/EYSM vesicles. Noticeably, Man-BSA induced the fusion of EYPC/EYSM/Chol vesicles, but not of EYPC/EYSM vesicles. Although BSA and Man-BSA showed similar binding affinity for lipid vesicles, the lipid-bound conformation of Man-BSA was distinct from that of BSA. Moreover, Man-BSA adopted distinct structure upon binding with the EYPC/EYSM/Chol and EYPC/EYSM vesicles. Man-BSA could induce the fusion of EYPC/EYSM/Chol vesicles with K562 and MCF-7 cells, while Man-BSA greatly induced the leakage of Chol-depleted K562 and MCF-7 cells. The modified BSA prepared by conjugating carboxyl groups with p-aminophenyl α-d-glucopyranoside also showed membrane-perturbing activities. Collectively, our data indicate that conjugation of carboxyl groups with monosaccharide generates functional BSA with membrane-perturbing activities on the lipid-water interface.

  5. Zinc phthalocyanine-conjugated with bovine serum albumin mediated photodynamic therapy of human larynx carcinoma

    NASA Astrophysics Data System (ADS)

    Silva, E. P. O.; Santos, E. D.; Gonçalves, C. S.; Cardoso, M. A. G.; Soares, C. P.; Beltrame, M., Jr.

    2016-10-01

    Phthalocyanines, which are classified as second-generation photosensitizers, have advantageous photophysical properties, and extensive studies have demonstrated their potential applications in photodynamic therapy. The present work describes the preparation of a new zinc phthalocyanine conjugated to bovine serum albumin (compound 4a) and its photodynamic efficiency in human larynx-carcinoma cells (HEp-2 cells). The unconjugated precursor (compound 4) was also studied. Compounds 4 and 4a penetrated efficiently into the cell, exhibiting cytoplasmic localization, and showed no cytotoxicity in the dark. However, high photodynamic activities were observed in HEp-2 cells after treatments with 5 µM photosensitizers and 4.5 J cm-2 light. These conditions were sufficient to decrease the cell viability to 57.93% and 32.75% for compounds 4 and 4a, respectively. The present results demonstrated high photodynamic efficiency of zinc phthalocyanine conjugated with bovine serum albumin in destroying the larynx-carcinoma cells.

  6. Sugar-dependent photodynamic effect of glycoconjugated porphyrins: a study on photocytotoxicity, photophysical properties and binding behavior to bovine serum albumin (BSA).

    PubMed

    Obata, Makoto; Hirohara, Shiho; Sharyo, Kohei; Alitomo, Hiroki; Kajiwara, Kazumi; Ogata, Shin-ichi; Tanihara, Masao; Ohtsuki, Chikara; Yano, Shigenobu

    2007-08-01

    The photocytotoxicity of four glycoconjugated porphyrins, namely 5,10,15,20-tetrakis[4-(beta-D-glucopyranosyloxy)phenyl]porphyrin (p-1a), 5,10,15,20-tetrakis[4-(beta-D-galactopyranosyloxy)phenyl]porphyrin (p-1b), 5,10,15,20-tetrakis[4-(beta-D-xylopyranosyloxy)phenyl]porphyrin (p-1c) and 5,10,15,20-tetrakis[4-(beta-D-arabinopyranosyloxy)phenyl]porphyrin (p-1d), was evaluated in HeLa cells in the concentration range from 1 to 7 microM using a light dose of 16 J x cm(-2) with a wavelength greater than 500 nm. The photocytotoxicity depends on the sugar moieties, and increases in the order of p-1dalbumin (BSA). In particular, the oscillator strength in the range above 500 nm increases in the order of p-1d=p-1aBSA was evaluated by means of electronic absorption, fluorometric and circular dichroic (CD) titrations. Fluorometric titration showed no differences in the apparent binding constants, K, between the glycoconjugated porphyrins p-1a, p-1b, p-1c and p-1d. On the other hand, the number of binding sites, n, depends on the sugar moieties of the glycoconjugated porphyrin, and increases in the order of p-1bBSA. However, it was found that the n value was poorly related to the photophysical properties in physiological media and the photocytotoxicity. Even though the role of the sugar moieties on

  7. Curcumin-albumin conjugates as an effective anti-cancer agent with immunomodulatory properties.

    PubMed

    Aravind, S R; Krishnan, Lissy K

    2016-05-01

    Curcumin (diferuloylmethane) is an active ingredient in turmeric (Curcuma longa) with anti-inflammatory, antioxidant, chemopreventive, chemosensitization, and radiosensitization properties. Conjugation of curcumin (Curc) to albumin (Alb) has been found to increase the aqueous solubility of the drug. The current study aimed to prove the safe use of the Curc-Alb conjugate in animals and to demonstrate that it retains drug action both in vitro and in vivo. Dalton's lymphoma ascites (DLA) cell viability was inhibited by the Curc-Alb conjugate in a dose dependent manner in vitro, as evidenced by the MTT assay. Administration of up to 11.4 mg of conjugated curcumin per kg body weight to healthy animals was non-toxic both in terms of lethality and weight loss. Histological analysis of vital organs (kidney, liver and spleen) also did not show toxic effects. Favorable immuno-modulatory activity was observed after continuous administration of sub-acute doses of the conjugate which caused increase in total leukocyte count, platelet count, and viable cell count in bone marrow, and enhanced proliferation of lymphocyte in vitro upon culture. In vivo studies in the DLA tumor model in mice demonstrated that conjugated drug induces tumor reduction and prevention. Significant tumor reduction was observed when the Curc-Alb conjugate was administered intraperitoneally in DLA-induced mice after 1 day (prevention therapy) and 7 days (reduction therapy) of tumor induction. There was significant reduction in both tumor volume and tumor cell numbers in the treated animals as well as a marked increase in their mean survival time and percent increase in life span. The effect was greater when the conjugate was administered soon after inducing the tumor as compared to when treatment was started after allowing tumor to grow for 7 days. Thus, the results of the present study suggest that curcumin albumin conjugate has immunomodulatory and tumor growth inhibition properties. The study postulates

  8. Spectroscopic analyses on interaction of o-Vanillin- D-Phenylalanine, o-Vanillin- L-Tyrosine and o-Vanillin- L-Levodopa Schiff Bases with bovine serum albumin (BSA)

    NASA Astrophysics Data System (ADS)

    Gao, Jingqun; Guo, Yuwei; Wang, Jun; Wang, Zhiqiu; Jin, Xudong; Cheng, Chunping; Li, Ying; Li, Kai

    2011-04-01

    In this work, three o-Vanillin Schiff Bases (o-VSB: o-Vanillin- D-Phenylalanine (o-VDP), o-Vanillin- L-Tyrosine (o-VLT) and o-Vanillin- L-Levodopa (o-VLL)) with alanine constituent were synthesized by direct reflux method in ethanol solution, and then were used to study the interaction to bovine serum albumin (BSA) molecules by fluorescence spectroscopy. Based on the fluorescence quenching calculation, the bimolecular quenching constant ( Kq), apparent quenching constant ( Ksv), effective binding constant ( KA) and corresponding dissociation constant ( KD) as well as binding site number ( n) were obtained. In addition, the binding distance ( r) was also calculated according to Foster's non-radioactive energy transfer theory. The results show that these three o-VSB can efficiently bind to BSA molecules, but the binding array order is o-VDP-BSA > o-VLT-BSA > o-VLL-BSA. Synchronous fluorescence spectroscopy indicates that the o-VDP is more accessibility to tryptophan (Trp) residues of BSA molecules than to tyrosine (Tyr) residues. Nevertheless, the o-VLT and o-VLL are more accessibility to Tyr residues than to Trp residues.

  9. Conjugation and fluorescence quenching between bovine serum albumin and L-cysteine capped CdSe/CdS quantum dots.

    PubMed

    Wang, Qisui; Ye, Fangyun; Liu, Peng; Min, Xinmin; Li, Xi

    2011-04-01

    Water-soluble, biological-compatible, and excellent fluorescent CdSe/CdS quantum dots (QDs) with L-cysteine as capping agent were synthesized in aqueous medium. Fluorescence (FL) spectra, absorption spectra, and transmission electron microscopy (TEM) were employed to investigate the quality of the products. The interactions between QDs and bovine serum albumin (BSA) were studied by absorption and FL titration experiments. With addition of QDs, the FL intensity of BSA was significantly quenched which can be explained by static mechanism in nature. When BSA was added to the solution of QDs, FL intensity of QDs was faintly quenched. Fluorescent imaging suggests that QDs can be designed as a probe to label the Escherchia coli (E. coli) cells. These results indicate CdSe/CdS/L-cysteine QDs can be used as a probe for labeling biological molecule and bacteria cells.

  10. Resonance energy transfer between fluorescent BSA protected Au nanoclusters and organic fluorophores

    NASA Astrophysics Data System (ADS)

    Raut, Sangram; Rich, Ryan; Fudala, Rafal; Butler, Susan; Kokate, Rutika; Gryczynski, Zygmunt; Luchowski, Rafal; Gryczynski, Ignacy

    2013-12-01

    Bovine serum albumin (BSA) protected nanoclusters (Au and Ag) represent a group of nanomaterials that holds great promise in biophysical applications due to their unique fluorescence properties and lack of toxicity. These metal nanoclusters have utility in a variety of disciplines including catalysis, biosensing, photonics, imaging and molecular electronics. However, they suffer from several disadvantages such as low fluorescence quantum efficiency (typically near 6%) and broad emission spectrum (540 nm to 800 nm). We describe an approach to enhance the apparent brightness of BSA Au clusters by linking them with a high extinction donor organic dye pacific blue (PB). In this conjugate PB acts as a donor to BSA Au clusters and enhances its brightness by resonance energy transfer (RET). We found that the emission of BSA Au clusters can be enhanced by a magnitude of two-fold by resonance energy transfer (RET) from the high extinction donor PB, and BSA Au clusters can act as an acceptor to nanosecond lifetime organic dyes. By pumping the BSA Au clusters using a high extinction donor, one can increase the effective brightness of less bright fluorophores like BSA Au clusters. Moreover, we prepared another conjugate of BSA Au clusters with the near infrared (NIR) dye Dylight 750 (Dy750), where BSA Au clusters act as a donor to Dy750. We observed that BSA Au clusters can function as a donor, showing 46% transfer efficiency to the NIR dye Dy750 with a long lifetime component in the acceptor decay through RET. Such RET-based probes can be used to prevent the problems of a broad emission spectrum associated with the BSA Au clusters. Moreover, transferring energy from BSA Au clusters to Dy750 will result in a RET probe with a narrow emission spectrum and long lifetime component which can be utilized in imaging applications.Bovine serum albumin (BSA) protected nanoclusters (Au and Ag) represent a group of nanomaterials that holds great promise in biophysical applications due to

  11. Interaction between the Natural Components in Danhong Injection (DHI) with Serum Albumin (SA) and the Influence of the Coexisting Multi-Components on the SaB-BSA Binding System: Fluorescence and Molecular Docking Studies

    PubMed Central

    Hao, Jia; Zhang, Yingyue; Wang, Xingrui; Yan, Huo; Liu, Erwei; Gao, Xiumei

    2015-01-01

    Danhong injection (DHI) is a widely used Chinese Materia Medica standardized product for the clinical treatment of ischemic encephalopathy and coronary heart disease. The bindings of eight natural components in DHI between bovine serum albumin (BSA) were studied by fluorescence spectroscopy technology and molecular docking. According to the results, the quenching process of salvianolic acid B and hydroxysafflor yellow A was a static quenching procedure through the analysis of quenching data by the Stern-Volmer equation, the modified Stern-Volmer equation, and the modified Scatchard equation. Meanwhile, syringin (Syr) enhanced the fluorescence of BSA, and the data were analyzed using the Lineweaver-Burk equation. Molecular docking suggested that all of these natural components bind to serum albumin at the site I location. Further competitive experiments of SaB confirmed the result of molecular docking studies duo to the displacement of warfarin by SaB. Base on these studies, we selected SaB as a research target because it presented the strongest binding ability to BSA and investigated the influence of the multi-components coexisting in DHI on the interaction between the components of the SaB-BSA binding system. The participation of these natural components in DHI affected the interaction between the components of the SaB-BSA system. Therefore, when DHI is used in mammals, SaB is released from serum albumin more quickly than it is used alone. This work would provide a new experiment basis for revealing the scientific principle of compatibility for Traditional Chinese Medicine. PMID:26035712

  12. Interaction between the Natural Components in Danhong Injection (DHI) with Serum Albumin (SA) and the Influence of the Coexisting Multi-Components on the SaB-BSA Binding System: Fluorescence and Molecular Docking Studies.

    PubMed

    Hao, Jia; Zhang, Yingyue; Wang, Xingrui; Yan, Huo; Liu, Erwei; Gao, Xiumei

    2015-01-01

    Danhong injection (DHI) is a widely used Chinese Materia Medica standardized product for the clinical treatment of ischemic encephalopathy and coronary heart disease. The bindings of eight natural components in DHI between bovine serum albumin (BSA) were studied by fluorescence spectroscopy technology and molecular docking. According to the results, the quenching process of salvianolic acid B and hydroxysafflor yellow A was a static quenching procedure through the analysis of quenching data by the Stern-Volmer equation, the modified Stern-Volmer equation, and the modified Scatchard equation. Meanwhile, syringin (Syr) enhanced the fluorescence of BSA, and the data were analyzed using the Lineweaver-Burk equation. Molecular docking suggested that all of these natural components bind to serum albumin at the site I location. Further competitive experiments of SaB confirmed the result of molecular docking studies duo to the displacement of warfarin by SaB. Base on these studies, we selected SaB as a research target because it presented the strongest binding ability to BSA and investigated the influence of the multi-components coexisting in DHI on the interaction between the components of the SaB-BSA binding system. The participation of these natural components in DHI affected the interaction between the components of the SaB-BSA system. Therefore, when DHI is used in mammals, SaB is released from serum albumin more quickly than it is used alone. This work would provide a new experiment basis for revealing the scientific principle of compatibility for Traditional Chinese Medicine.

  13. Fluorescence enhancement of europium(III) perchlorate by benzoic acid on bis(benzylsulfinyl)methane complex and its binding characteristics with the bovine serum albumin (BSA).

    PubMed

    Zhang, Jing; Li, Wen-Xian; Ao, Bo-Yang; Feng, Shu-Yan; Xin, Xiao-Dong

    2014-01-24

    A novel ligand with double sulfinyl groups, bis(benzylsulfinyl)methane L, was synthesized by a new method. Its novel ternary complex, EuL2.5⋅L'·(ClO4)2⋅5H2O, has been synthesized [using L as the first ligand, and benzoic acid L' as the second ligand], and characterized by elemental analysis, molar conductivity, coordination titration analysis, FTIR, TG-DSC, (1)H NMR and UV-vis. In order to study the effect of the second ligand on the fluorescence properties of rare-earth sulfoxide complex, a novel binary complex EuL2.5·(ClO4)3·3H2O has been synthesized. Photoluminescent measurement showed that the first ligand L could efficiently transfer the energy to Eu(3+) ions in the complex. Furthermore, the detailed luminescence analyses on the rare earth complexes indicated that the ternary Eu (III) complex manifested stronger fluorescence intensities, longer lifetimes, and higher fluorescence quantum efficiencies than the binary Eu (III) materials. After introducing the second ligand L', the fluorescence emission intensities and fluorescence lifetimes of the ternary complex enhanced more obviously than the binary complex. This illustrated that the presence of both the first ligand L and the second ligand L' could sensitize fluorescence intensities of Eu (III) ions. The fluorescence spectra, fluorescence lifetime and phosphorescence spectra were also discussed. To explore the potential biological value of Eu (III) complexes, the binding interaction among Eu (III) complexes and bovine serum albumin (BSA) was studied by fluorescence spectrum. The result indicated that the reaction between Eu (III) complexes and BSA was a static quenching procedure. The binding site number, n, of 0.60 and 0.78, and binding constant, Ka, of 0.499 and 4.46 were calculated according to the double logarithm regression equation, respectively for EuL2.5⋅L'⋅(ClO4)2⋅5H2O and EuL2.5⋅(ClO4)3⋅3H2O systems.

  14. Fluorescence enhancement of europium(III) perchlorate by benzoic acid on bis(benzylsulfinyl)methane complex and its binding characteristics with the bovine serum albumin (BSA)

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Li, Wen-Xian; Ao, Bo-Yang; Feng, Shu-Yan; Xin, Xiao-Dong

    2014-01-01

    A novel ligand with double sulfinyl groups, bis(benzylsulfinyl)methane L, was synthesized by a new method. Its novel ternary complex, EuL2.5ṡL‧·(ClO4)2ṡ5H2O, has been synthesized [using L as the first ligand, and benzoic acid L‧ as the second ligand], and characterized by elemental analysis, molar conductivity, coordination titration analysis, FTIR, TG-DSC, 1H NMR and UV-vis. In order to study the effect of the second ligand on the fluorescence properties of rare-earth sulfoxide complex, a novel binary complex EuL2.5·(ClO4)3·3H2O has been synthesized. Photoluminescent measurement showed that the first ligand L could efficiently transfer the energy to Eu3+ ions in the complex. Furthermore, the detailed luminescence analyses on the rare earth complexes indicated that the ternary Eu (III) complex manifested stronger fluorescence intensities, longer lifetimes, and higher fluorescence quantum efficiencies than the binary Eu (III) materials. After introducing the second ligand L‧, the fluorescence emission intensities and fluorescence lifetimes of the ternary complex enhanced more obviously than the binary complex. This illustrated that the presence of both the first ligand L and the second ligand L‧ could sensitize fluorescence intensities of Eu (III) ions. The fluorescence spectra, fluorescence lifetime and phosphorescence spectra were also discussed. To explore the potential biological value of Eu (III) complexes, the binding interaction among Eu (III) complexes and bovine serum albumin (BSA) was studied by fluorescence spectrum. The result indicated that the reaction between Eu (III) complexes and BSA was a static quenching procedure. The binding site number, n, of 0.60 and 0.78, and binding constant, Ka, of 0.499 and 4.46 were calculated according to the double logarithm regression equation, respectively for EuL2.5ṡL‧ṡ(ClO4)2ṡ5H2O and EuL2.5ṡ(ClO4)3ṡ3H2O systems.

  15. Reversible binding of tolmetin, zomepirac, and their glucuronide conjugates to human serum albumin and plasma.

    PubMed

    Ojingwa, J C; Spahn-Langguth, H; Benet, L Z

    1994-02-01

    Acyl glucuronides of drugs and bilirubin have been shown in the past decade to be reactive metabolites undergoing acyl migration and irreversible binding. The latter reaction has been hypothesized to be facilitated by or to proceed through the formation of a reversible complex. Furthermore, it has been suggested that the decreased binding seen in patients with compromised excretory function may be due to competition by elevated plasma concentrations of the glucuronides. In these reversible binding studies, we characterized the extent and the "site" of binding of tolmetin, zomepirac, their glucuronides and isomeric conjugates. We also examined the displacement between the parent drugs and their glucuronide conjugates using a rapid ultrafiltration method. Tolmetin exhibited three classes of binding sites with a primary association constant of 1.7 x 10(6) M-1 (Kd1 = 0.60 microM). The primary association constant of zomepirac (1.16 x 10(6) M-1, Kd1 = 0.86 microM) is similar to that of tolmetin. The beta 1 and alpha/beta 3 glucuronides of both compounds bind to a lesser extent than their parent aglycones. The isomeric glucuronide conjugates of both compounds showed much stronger binding than the beta/1 conjugates. Of the four glucuronides investigated, tolmetin glucuronide-alpha/beta 3 isomer was bound by fatty acid free human serum albumin with the highest affinity (4.6 x 10(5) M-1, Kd = 2.22 microM). Protein binding of the parent drugs and conjugates were decreased significantly at pH 5.0. In displacement studies, except for salicylate and acetylsalicylate, drugs known to bind to Sites I and II as well as the digitoxin and tamoxifen binding sites had little inhibitory effect on the binding of tolmetin, zomepirac, and their glucuronide conjugates.

  16. Improved drug targeting of cancer cells by utilizing actively targetable folic acid-conjugated albumin nanospheres.

    PubMed

    Shen, Zheyu; Li, Yan; Kohama, Kazuhiro; Oneill, Brian; Bi, Jingxiu

    2011-01-01

    Folic acid-conjugated albumin nanospheres (FA-AN) have been developed to provide an actively targetable drug delivery system for improved drug targeting of cancer cells with reduced side effects. The nanospheres were prepared by conjugating folic acid onto the surface of albumin nanospheres using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as a catalyst. To test the efficacy of these nanospheres as a potential delivery platform, doxorubicin-loaded albumin nanospheres (DOX-AN) and doxorubicin-loaded FA-AN (FA-DOX-AN) were prepared by entrapping DOX (an anthracycline, antibiotic drug widely used in cancer chemotherapy that works by intercalating DNA) into AN and FA-AN nanoparticles. Cell uptake of the DOX was then measured. The results show that FA-AN was incorporated into HeLa cells (tumor cells) only after 2.0h incubation, whereas HeLa cells failed to incorporate albumin nanospheres without conjugated folic acid after 4.0h incubation. When HeLa cells were treated with the DOX-AN, FA-DOX-AN nanoparticles or free DOX, cell viability decreased with increasing culture time (i.e. cell death increases with time) over a 70h period. Cell viability was always the lowest for free DOX followed by FA-DOX-AN4 and then DOX-AN. In a second set of experiments, HeLa cells washed to remove excess DOX after an initial incubation for 2h were incubated for 70h. The corresponding cell viability was slightly higher when the cells were treated with FA-DOX-AN or free DOX whilst cells treated with DOX-AN nanoparticles remained viable. The above experiments were repeated for non-cancerous, aortic smooth muscle cells (AoSMC). As expected, cell viability of the HeLa cells (with FA receptor alpha, FRα) and AoSMC cells (without FRα) decreased rapidly with time in the presence of free DOX, but treatment with FA-DOX-AN resulted in selective killing of the tumor cells. These results indicated that FA-AN may be used as a promising actively targetable drug delivery system to improve drug

  17. RGD-conjugated albumin nanoparticles as a novel delivery vehicle in pancreatic cancer therapy.

    PubMed

    Ji, Shunrong; Xu, Jin; Zhang, Bo; Yao, Wantong; Xu, Wenyan; Wu, Wenzhe; Xu, Yongfeng; Wang, Hao; Ni, Quanxing; Hou, Huimin; Yu, Xianjun

    2012-02-15

    Integrin αvβ3 receptor is expressed on several types of cancer cells, including pancreatic cancer cells, and plays an important role in tumor growth and metastasis. The ability to target the integrin αvβ3 receptor on cancer cells increases the efficacy of targeted therapy and reduces the side effects. The aim of this study is to develop a novel arginine-glycine-aspartic acid (RGD) peptide -conjugated albumin nanoparticle to enhance the intracellular uptake of anticancer drug into the pancreatic cancer cells through receptor-mediated endocytosis. In the cellular uptake studies, the fluorescent signal of RGD-conjugated BSANPs in BxPC3 cells was higher than that of BSANPs without RGD conjugation as determined by fluorescence spectrophotometer. We also found that BSANPs bound to BxPC3 cells in a time- and concentration-dependent manner. The uptake of RGD-conjugated BSANPs by pancreatic cancer cells was inhibited by an excess amount of free RGD peptide, indicating that the binding and/or uptake were mediated by the αvβ3 receptor. Furthermore, the nanoparticles were found to be located close to the nuclei by using laser scanning confocal microscopy. Besides, no significant in vitro cytotoxicity was observed as measured with MTT assay. Both in vitro and in vivo antitumor efficacy was improved by targeting gemcitabine-loaded nanoparticles to BxPC-3 cells using RGD peptides. Therefore, the RGD-conjugated BSANPs hold great potential as an effective drug delivery system to deliver therapeutic agents to pancreatic cancer.

  18. Effects of Kamdhenu Ark and Active Immunization by Gonadotropin Releasing Hormone Conjugate (GnRH-BSA) on Gonadosomatic Indices (GSI) and Sperm Parameters in Male Mus musculus

    PubMed Central

    Ganaie, Javid Ahmad; Gautam, Varsha; Shrivastava, Vinoy Kumar

    2011-01-01

    Background Active immunization against GnRH decreases the secretion of gonadotropins and causes cessation of gonadal function, thereby, inducing infertility. Based on the immunoenhancing activity of Kamdhenu ark (distilled cow urine), this study was performed to evaluate its effects on the gonadosomatic indices (GSI) and sperm parameters in male mice receiving a GnRH contraceptive vaccine. Methods Sixty adult male mice of Parke's strain were divided into three groups of twenty. Group I served as the controls, while group II was immunized by GnRH-BSA conjugate (50/0.2/35 µg/ml/g BW) by four intraperitoneal injections at different intervals on days 1, 30, 60 and 90. However, group III was supplemented daily by oral Kamdhenu ark (100 ppm) along with GnRH-BSA immunizations. The animals were sacrificed after 30, 60, 90 and 120 days and their testis and epididymis were dissected out weighed and semen analysis was performed. Results GSI values, sperm motility, sperm count and sperm morphology in male Mus musculus were decreased significantly in all the experimental groups as compared to the control group (p<0.01). Kamdhenu ark significantly enhanced the effect of GnRH vaccine on the aforesaid parameters especially in 90 and 120 days treated groups (p<0.05). Conclusion The changes witnessed in sperm parameters suggested that the GnRH-BSA immunization suppressed the activities of gonadotropins and testosterone directly through hypothalamo-hypophysial-gonadal axis and indirectly by acting on the testes which may modulate the sperm morphology, sperm count and motility. However, Kamdhenu ark seems to have enhanced these effects because of its immune-modulatory properties too. PMID:23926493

  19. Site-selective conjugation of an anticoagulant aptamer to recombinant albumins and maintenance of neonatal Fc receptor binding.

    PubMed

    Schmøkel, Julie; Voldum, Anders; Tsakiridou, Georgia; Kuhlmann, Matthias; Cameron, Jason; Sørensen, Esben; Wengel, Jesper; Howard, Kenneth A

    2017-03-31

    Aptamers are an attractive molecular medicine that offers high target specificity. Nucleic acid-based aptamers however, are prone to nuclease degradation and rapid renal excretion that require blood circulatory half-life extension enabling technologies. The long circulatory half-life, predominately facilitated by engagement with the cellular recycling neonatal Fc receptor (FcRn), and ligand transport properties of albumin promote it as an attractive candidate to improve the pharmacokinetic profile of aptamers. This study investigates the effect of Cys34 site-selective covalent attachment of a factor IXa anticoagulant aptamer on aptamer functionality and FcRn engagement using recombinant human albumin (rHA) of either a wild type (WT) or an engineered human FcRn high binding variant (HB). Aptamer-albumin conjugates, connected covalently through a heterobifunctional succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate linker, were successfully prepared and purified by high performance liquid chromatography as confirmed by gel electrophoresis band-shift analysis and matrix-assisted laser desorption/ionization time of flight. Minimal reduction (~ 25%) in activity of WT-linked aptamer to that of aptamer alone was found using an anticoagulant activity assay measuring temporal levels of activated partial thrombin. Covalent aptamer-albumin conjugation, however, substantially compromised binding to FcRn, to 10% affinity of that of non-conjugated WT, determined by biolayer interferometry. Binding could be rescued by aptamer conjugation to recombinant albumin engineered for higher FcRn affinity (HB) that exhibited an 8-fold affinity compared to WT alone. This work describes a novel albumin-based aptamer delivery system whose FcRn binding can be increased using a high binding engineered albumin.

  20. A novel immunoassay for residual bovine serum albumin (BSA) in vaccines using laser-induced fluorescence millimeter sensor array detection platform.

    PubMed

    Zhang, Xiaoming; Song, Chaojun; Chen, Lili; Zhang, Kui; Fu, Aihua; Jin, Boquan; Zhang, Zhujun; Yang, Kun

    2011-05-15

    A highly sensitive and stable sandwich fluorescence immunoassay for the quantitative detection of residual BSA in vaccines based on the labels of the functionalized fluorescent core-shell silica nanoparticles and laser-induced fluorescence millimeter sensor array detection platform has been developed. On a glass slide with low fluorescence background, capture antibody against BSA was immobilized, after BSA was captured, another identify antibody against BSA which was labeled with the new fluorescent silica nanoparticles was used to recognize the BSA. The fluorescence issued from the fluorescent silica nanoparticles was successfully detected by the laser induced fluorescence millimeter sensor assay detection platform which was made by us. This method exhibited high performance with a linear correlation between response and amount of BSA in the range 1.0-100 ng/mL and the detection limit was 0.3 ng/mL (3σ). The relative standard deviation (R.S.D.) was 6.7% at the concentration of 20 ng/mL for 5 parallel measurements of BSA.

  1. Chemical Conjugation of Evans Blue Derivative: A Strategy to Develop Long-Acting Therapeutics through Albumin Binding

    PubMed Central

    Chen, Haojun; Wang, Guohao; Lang, Lixin; Jacobson, Orit; Kiesewetter, Dale O.; Liu, Yi; Ma, Ying; Zhang, Xianzhong; Wu, Hua; Zhu, Lei; Niu, Gang; Chen, Xiaoyuan

    2016-01-01

    The efficacy of therapeutic drugs is highly dependent on their optimal in vivo pharmacokinetics. Albumin conjugation is considered to be one of the most effective means of protracting the short lifespan of peptides and proteins. In this study, we proposed a novel platform for developing long lasting therapeutics by conjugating a small molecular albumin binding moiety, truncated Evans blue, to either peptides or proteins. Using the anti-diabetic peptide drug Exendin-4 as a model peptide, we synthesized a new long-acting Exendin-4 derivative (denoted as Abextide). Through complexation with albumin in situ, the biological half-life of Abextide was significantly extended. The hypoglycemic effect of Abextide was also improved remarkably over Exendin-4. Thus, Abextide has considerable potential to treat type 2 diabetes. This strategy as a general technology platform can be applied to other small molecules and biologics for the development of long-acting therapeutic drugs. PMID:26877782

  2. Investigation of Bovine Serum Albumin (BSA) Attachment onto Self-Assembled Monolayers (SAMs) Using Combinatorial Quartz Crystal Microbalance with Dissipation (QCM-D) and Spectroscopic Ellipsometry (SE).

    PubMed

    Phan, Hanh T M; Bartelt-Hunt, Shannon; Rodenhausen, Keith B; Schubert, Mathias; Bartz, Jason C

    2015-01-01

    Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various self-assembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The quantity of adsorbed bovine serum albumin protein increased with increasing bovine serum albumin concentration. After equilibrium sorption was reached at pH 7.0, desorption of bovine serum albumin occurred when pH was lowered to 2.0, which is below the isoelectric point of bovine serum albumin. Our data provide further evidence that combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry is a sensitive analytical tool to evaluate attachment and detachment of adsorbed proteins in systems with environmental implications.

  3. Investigation of Bovine Serum Albumin (BSA) Attachment onto Self-Assembled Monolayers (SAMs) Using Combinatorial Quartz Crystal Microbalance with Dissipation (QCM-D) and Spectroscopic Ellipsometry (SE)

    PubMed Central

    Phan, Hanh T. M.; Bartelt-Hunt, Shannon; Rodenhausen, Keith B.; Schubert, Mathias; Bartz, Jason C.

    2015-01-01

    Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various self-assembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The quantity of adsorbed bovine serum albumin protein increased with increasing bovine serum albumin concentration. After equilibrium sorption was reached at pH 7.0, desorption of bovine serum albumin occurred when pH was lowered to 2.0, which is below the isoelectric point of bovine serum albumin. Our data provide further evidence that combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry is a sensitive analytical tool to evaluate attachment and detachment of adsorbed proteins in systems with environmental implications. PMID:26505481

  4. Molecular interactions between some non-steroidal anti-inflammatory drugs (NSAID's) and bovine (BSA) or human (HSA) serum albumin estimated by means of isothermal titration calorimetry (ITC) and frontal analysis capillary electrophoresis (FA/CE).

    PubMed

    Ràfols, Clara; Zarza, Sílvia; Bosch, Elisabeth

    2014-12-01

    The interactions between some non-steroidal anti-inflammatory drugs, NSAIDs, (naproxen, ibuprofen and flurbiprofen) and bovine (BSA) or human (HSA) serum albumin have been examined by means of two complementary techniques, isothermal titration calorimetry (ITC) and frontal analysis/capillary electrophoresis (FA/CE). It can be concluded that ITC is able to measure with high precision the strongest drug-albumin interactions but the higher order interactions can be better determined by means of FA/CE. Then, the combination of both techniques leads to a complete evaluation of the binding profiles between the selected NSAIDs and both kind of albumin proteins. When BSA is the binding protein, the NSAIDs show a strong primary interaction (binding constants: 1.5 × 10(7), 8 × 10(5) and 2 × 10(6) M(-1) for naproxen, ibuprofen and flurbiprofen, respectively), and also lower affinity interactions of the same order for the three anti-inflammatories (about 1.7 × 10(4) M(-1)). By contrast, when HSA is the binding protein two consecutive interactions can be observed by ITC for naproxen (9 × 10(5) and 7 × 10(4) M(-1)) and flurbiprofen (5 × 10(6) and 6 × 10(4) M(-1)) whereas only one is shown for ibuprofen (9 × 10(5) M(-1)). Measurements by FA/CE show a single interaction for each drug being the ones of naproxen and flurbiprofen the same that those evaluated by ITC as the second interaction events. Then, the ability of both techniques as suitable complementary tools to establish the whole interaction NSAIDs-albumin profile is experimentally demonstrated and allows foreseeing suitable strategies to establish the complete drug-protein binding profile. In addition, for the interactions analyzed by means of ITC, the thermodynamic signature is established and the relative contributions of the enthalpic and entropic terms discussed.

  5. Long-circulating self-assembled cholesteryl albumin nanoparticles enhance tumor accumulation of hydrophobic anticancer drug.

    PubMed

    Battogtokh, Gantumur; Kang, Ji Hee; Ko, Young Tag

    2015-10-01

    The objective of this study was to develop an albumin nanoparticle with improved stability and drug loading capacity. Generation of nanomaterials having physiologically stable and high potential for drug delivery is still challenging. Herein we synthesized cholesteryl albumin conjugate using N,N-disuccinimidyl carbonate coupling reagent and prepared paclitaxel-loaded cholesteryl albumin nanoparticle (PTX-Chol-BSA) by self-assembly with the mean hydrodynamic diameter of 147.6±1.6nm and with high loading capacity. PTX-Chol-BSA nanoparticle showed much higher colloidal stability than a simple complex of PTX and BSA (PTX-BSA) and sustained release profile. PTX-Chol-BSA nanoparticles exhibited greater cellular uptake and cytotoxicity in B16F10 and MCF-7 cancer cell lines, as compared with PTX in Cremophor EL/ethanol (PTX-Cre/EtOH) and PTX-BSA formulations. A pharmacokinetic study in tumor-bearing mice showed that the area under the concentration-time curve (AUC0-8 h) following the administration of PTX-Chol-BSA was 1.6-2-fold higher than those following the administration of PTX-Cre/EtOH and PTX-BSA. In addition, the tumor AUC0-8 h of PTX-Chol-BSA was around 2-fold higher than that of PTX-BSA. Furthermore, in vivo antitumor efficacy results revealed that PTX-Chol-BSA nanoparticles have greater antitumor efficacy. In conclusion, we demonstrated the potential of PTX-Chol-BSA nanoparticles for anti-tumor chemotherapy, with enhanced in vitro and in vivo behaviors, as compared to PTX-BSA and PTX-Cre/EtOH.

  6. Protein conjugation with PAMAM nanoparticles: Microscopic and thermodynamic analysis.

    PubMed

    Chanphai, P; Froehlich, E; Mandeville, J S; Tajmir-Riahi, H A

    2017-02-01

    PAMAM dendrimers form strong protein conjugates that are used in drug delivery systems. We report the thermodynamic and binding analysis of polyamidoamine (PAMAM-G4) conjugation with human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (b-LG) in aqueous solution at physiological pH. Hydrophobicity played a major role in PAMAM-protein interactions with more hydrophobic b-LG forming stronger polymer-protein conjugates. Thermodynamic parameters showed PAMAM-protein bindings occur via hydrophobic and H-bonding contacts for b-LG, while van der waals and H-bonding interactions prevail in HSA and BSA-polymer conjugates. The protein loading efficacy was 45-55%. PAMAM complexation induced major alterations of protein conformation. TEM images show major polymer morphological changes upon protein conjugation.

  7. The Effect of a BSA Conjugate of a Synthetic Hexasaccharide Related to the Fragment of Capsular Polysaccharide of Streptococcus pneumoniae Type 14 on the Activation of Innate and Adaptive Immune Responses

    PubMed Central

    Akhmatova, Nelli K.; Kurbatova, Ekaterina A.; Akhmatov, Elvin A.; Egorova, Nadezhda B.; Logunov, Denis Yu.; Gening, Marina L.; Sukhova, Elena V.; Yashunsky, Dmitry V.; Tsvetkov, Yury E.; Nifantiev, Nikolay E.

    2016-01-01

    We report the effect of a bovine serum albumin (BSA) conjugate of a synthetic hexasaccharide (HS) related to the fragment of the capsular polysaccharide (PS) of Streptococcus pneumoniae type 14 on the stimulation of innate immune system and the subsequent development of a PS-specific antibody response. Glycoconjugate (GC) in the presence (GC + AL) or absence of aluminum hydroxide was administered to mice twice. GC increased the number of TLR2-expressing cells and induced the maturation of dendritic cells (CD11c+, CD80+ and, MHCII+), which secreted IL-1β, IL-6, and TNFα into the culture medium. The level of IL-1β, IL-10, IFNγ, and TNFα in the blood increased within 24 h after the single GC administration to mice. On day 7, the numbers of splenic CD4+ and CD8+ T lymphocytes and B lymphocytes increased. After the second immunization, the levels of CD4+ and CD8+ T lymphocytes were lower than in the control, whereas the B cell, NK cell, and MHC class II-expressing cell numbers remained enhanced. However, of the presence of anti-PS, IgG antibodies were not detected. The addition of aluminum hydroxide to GC stimulated the production of GM-CSF, IL-1β, IL-5, IL-6, IL-10, IL-17, IFNγ, and TNFα. Anti-PS IgG1 antibody titers 7 days after the second immunization were high. During that period, normal levels of splenic CD4+ T lymphocytes were maintained, whereas reduced CD8+ T lymphocyte numbers and increased levels of B lymphocytes, NK cells, and MHC class II-expressing cell numbers were observed. Anti-PS IgG levels diminished until day 92. A booster immunization with GC + AL stimulated the production of anti-PS IgG memory antibodies, which were determined within 97 days. The elucidation of specific features of the effect of the synthetic HS conjugate on the stimulation of innate, cell-mediated immunity, and antibody response can favor the optimization of GC vaccine design. PMID:27446078

  8. Stress-sensitive organs and blood corticosterone after immobilization of active and passive rats immunized with glutamate-bovine serum albumin conjugate.

    PubMed

    Umryukhin, A E; Sotnikov, S V; Chekmareva, N Yu; Vetrile, L A; Zakharova, I A

    2014-12-01

    We studied stress-induced organ and hormonal responses in behaviorally active and passive rats against the background of immunization with glutamate-BSA conjugate. The relative weight of the adrenal glands after immobilization was lower in rats immunized with the conjugate in comparison with non-immunized animals. The weight of the adrenal glands in behaviorally active rats decreased in parallel with the decrease in blood corticosterone. In behaviorally active and passive rats immunized with the conjugate, ulcer formation in the stomach was slightly intensified after immobilization. It was hypothesized that immunization with glutamate-BSA conjugate suppresses activity of the hypothalamic-pituitary-adrenal feedback mechanism underlying the production of glucocorticoid hormones, which is manifested in slightly increased ulceration due to attenuation of the gastroprotective action of corticosterone under stress.

  9. Gold nanoparticles surface modification using BSA and cysteine

    NASA Astrophysics Data System (ADS)

    Cardoso-Avila, P. E.; Pichardo-Molina, J. L.; Upendra Kumar, K.; Barbosa-Sabanero, G.; Barbosa-Garcia, O.

    2011-08-01

    Metal nanometer-size particles show intriguing optical properties which depend on their shape, size and local environment. For these reasons, these materials have received a lot of attention in different scientific areas, and several applications can be found, for example: fabrication of bio-sensor, electronic devices, catalysis and new drugs. However, in the case of biomedical applications, metallic nanoparticles need to satisfy several requirements: bio-compatibility, stability and functionality. To satisfy these requirements, metallic nanoparticles need to be modified in their surfaces. In this work we report the synthesis and the modification of gold nanoparticles (GNPs) surface. GNPs were fabricated following the Turkevich's method, and the bio-conjugation (surface modification) was done using cysteine and bovine serum albumin (BSA). Our results of Uv-vis spectroscopy show that BSA and cysteine permit to increase the stability of GNPs in presence of NaCl, the stability is function of BSA concentration. Also to verify the bio-conjugation we used Raman spectroscopy and gel electrophoresis.

  10. Specific targeting delivery to MUC1 overexpressing tumors by albumin-chitosan nanoparticles conjugated to DNA aptamer.

    PubMed

    Esfandyari-Manesh, Mehdi; Mohammadi, Ali; Atyabi, Fatemeh; Nabavi, Seyedeh Maryam; Ebrahimi, Seyedeh Masoumeh; Shahmoradi, Elnaz; Varnamkhasti, Behrang Shiri; Ghahremani, Mohammad Hossein; Dinarvand, Rassoul

    2016-12-30

    Chitosan-coated human serum albumin nanoparticles were functionalized by MUC1 aptamer to obtain a selective drug carrier toward cancers overexpressing MUC1. The negative charges of albumin nanoparticles were shifted to positive charges by surface modification with chitosan, and MUC1 was conjugated through an acrylate spacer. The cytotoxicity of targeted nanoparticles was significantly more than non-aptamer nanoparticles, and also the chitosan-coated nanoparticles had more cytotoxic effects than the negatively charged albumin nanoparticles. The IC50 of targeted nanoparticles was 28 and 26% of free paclitaxel in MCF7 and T47D cells at 48h, respectively. Confocal laser scanning electron microscopy showed that aptamer conjugation and positive charge increase the cellular uptake. 66% of paclitaxel was released within 32h, but 100% of drug was released at pH=5.5 (similar cancer cells). The paclitaxel plasma amount was at a good level of 17.6% at 2h for increasing the chance of cellular uptake.

  11. Photophysical behavior and photodynamic therapy activity of conjugates of zinc monocarboxyphenoxy phthalocyanine with human serum albumin and chitosan

    NASA Astrophysics Data System (ADS)

    Oluwole, David O.; Prinsloo, Earl; Nyokong, Tebello

    2017-02-01

    Zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc) was linked to human serum albumin (HSA) and chitosan via amide bond formation. The photophysical behavior and photodynamic therapy (PDT) activity (against human breast adenocarcinoma cell line (MCF-7 cells) of ZnMCPPc alone and its conjugates were investigated. The conjugates showed improved fluorescence, triplet and singlet oxygen quantum yields when compared to ZnMCPPc alone. The in vitro dark cytotoxicity and PDT studies were carried out at a dose of 3.6 μg/mL to 57.1 μg/mL. The in vitro dark cytotoxicity studies of ZnMCPPc showed cell viability < 50% at 28.6 μg/mL and 57.1 μg/mL, while the conjugates showed > 50% in all their tested concentrations (3.6 to 57.1) μg/mL. Thus, conjugation of ZnMCPPc to HSA and chitosan improves its dark cytotoxicity, an important criteria for molecules meant for photodynamic therapy. Complex 1 showed the most efficacious PDT activity with cell viability < 50% at concentration range of (14.3 to 57.1) μg/mL in comparison to the conjugates which only showed < 50% cell viability at 28.6 μg/mL and 57.1 μg/mL for 1-HSA and 57.1 μg/mL for 1-Chitosan.

  12. Liposomal Conjugates for Drug Delivery to the Central Nervous System

    PubMed Central

    Helm, Frieder; Fricker, Gert

    2015-01-01

    Treatments of central nervous system (CNS) diseases often fail due to the blood–brain barrier. Circumvention of this obstacle is crucial for any systemic treatment of such diseases to be effective. One approach to transfer drugs into the brain is the use of colloidal carrier systems—amongst others, liposomes. A prerequisite for successful drug delivery by colloidal carriers to the brain is the modification of their surface, making them invisible to the reticuloendothelial system (RES) and to target them to specific surface epitopes at the blood–brain barrier. This study characterizes liposomes conjugated with cationized bovine serum albumin (cBSA) as transport vectors in vitro in porcine brain capillary endothelial cells (PBCEC) and in vivo in rats using fluorescently labelled liposomes. Experiments with PBCEC showed that sterically stabilized (PEGylated) liposomes without protein as well as liposomes conjugated to native bovine serum albumin (BSA) were not taken up. In contrast, cBSA-liposomes were taken up and appeared to be concentrated in intracellular vesicles. Uptake occurred in a concentration and time dependent manner. Free BSA and free cBSA inhibited uptake. After intravenous application of cBSA-liposomes, confocal fluorescence microscopy of brain cryosections from male Wistar rats showed fluorescence associated with liposomes in brain capillary surrounding tissue after 3, 6 and 24 h, for liposomes with a diameter between 120 and 150 nm, suggesting successful brain delivery of cationized-albumin coupled liposomes. PMID:25835091

  13. Covalent complexes of albumin with serotonin, ketanserin and lysergic acid antagonize the activity of serotonin in human platelets

    SciTech Connect

    VanderBerg, S.R.; Gonias, S.L.

    1989-01-01

    Covalent conjugates of bovine serum albumin (BSA) and 5-HT, ketanserin or d-lysergic acid were synthesized and characterized by polyacrylamide gel electrophoresis, whole blood clearance experiments in mice and aggregation studies with human platelets. Using the standard synthesis procedure, each mol of BSA bound 13.4 mol of (/sup 3/H)5-HT. Derivatization did not cause significant protein aggregation as determined by electrophoresis. All three conjugates antagonized the ability of 5-HT to amplify aggregation caused by low concentrations of ADP. The antagonist activity of each conjugate was concentration dependent; 2.6 ..mu..M 5-HT-BSA completely inhibited the aggregation caused by 13 ..mu..M 5-HT. None of the BSA drug conjugates, including 5-HT-BSA, amplified platelet aggregation caused by ADP in the absence of 5-HT. Aggregation by ristocetin, collagen, epinephrine or ADP alone was not significantly affected by the conjugates. Whole blood elimination experiments in mice demonstrated that the three conjugates and underivatized BSA are equally stable in the circulation. These prototypic 5-HT drug-protein conjugates may be useful for probing 5-HT/sub 2/ receptor-ligand interactions in human platelets.

  14. Glycolaldehyde and maleyl conjugated human serum albumin as potential macrophage-targeting carriers for molecular imaging purposes.

    PubMed

    Gustafsson, Björn; Hedin, Ulf; Caidahl, Kenneth

    2015-01-01

    Maleylated bovine serum albumin is a known ligand for targeting macrophages and has potential as a carrier for molecular imaging purposes. We present a novel synthesis of glycolaldehyde-conjugated human serum albumin (GA-HSA) and maleylated human serum albumin (Mal-HSA). Seventeen modifications of fluorescently tagged GA-HSA and Mal-HSA molecules with different degrees of conjugation were prepared. The comparative uptake studies, using 12 of these modifications, were done in vitro on mouse monocytes/macrophages (RAW264.7), and evaluated qualitatively by confocal microscopy and quantitatively by flow cytometry. The GA modifications are taken up by the macrophages approximately 40% better than the maleyl modifications at low concentrations (≤ 3 μM), while at higher concentrations it appears that the maleyl modifications are taken up around 25-44% better than the GA-modified HSA. However, high uptake at low concentrations will be beneficial for in vivo localizing inflammation in areas with low penetration of the probe as in an atherosclerotic plaque. Further, another advantage of GA-HSA is that GA competes less than the maleyl group for the free reactive amine sites that are to be used for conjugation of metal chelating ligands (e.g. tetraazacyclododecanetetraacetic acid and triazacyclononanetriacetic acid). Metal ions such as Gd(3+) and Mn(2+) can be chelated for positive Magnetic Resonance (MR) contrast and positron emitting ions such as (64) Cu(2+) and (68) Ga(3+) for Positron Emission Tomography (PET) imaging. These are important properties, especially, when considering the MR contrast possibilities owing to the low sensitivity of the technique, and would motivate the use of GA-HSA before Mal-HSA.

  15. Nonspecific Interaction of Streptavidin with Urease-Conjugated Antibodies

    DTIC Science & Technology

    1991-11-01

    Mouse immunoglobulin G, biotinylated anti-mlgG ( goat ), urease-conjugated anti-mlgG ( goat ), bovine serum albumin (BSA), sodium chloride, sodium...are not limited to the polyclonal ( goat ) anti-mIgG system. In Figure 6 the concentration of SA which correspoa’ded to maximum signal was...similarity of the titrations of urease-conjugated polyclonal ( goat ) anti-mlgG and monoclonal anti-NDV suggests that these results with SA were not due to

  16. An efficient and low toxic human serum albumin conjugated polyethylenimine nano-sized complex for gene delivery

    NASA Astrophysics Data System (ADS)

    Chen, Jiin-Long; Peng, Ssu-Wei; Ko, Wei-Hsu; Wu, Ching-Jan; Li, Teung-Wang; Yeh, Ming-Kung; Chiang, Chiao-Hsi

    2014-09-01

    A novel low cytotoxicity and high efficiency transfection reagent, human serum albumin (HSA)-conjugated polyethylenimine (PEI) was prepared to improve the effect of PEI on gene transfection in this study. Transfecting a cell with DNA is a crucial step for DNA vaccination or gene therapy. PEI, a non-viral vector, is one of the popularly used cationic polymers because of its intensive positive charge that condenses DNA as a nano-sized complex, and attaches on the negative-charged cell membrane, triggering cell endocytosis. In this study, we used a zero-length cross-linkage EDC system to chemically conjugate HSA and PEI, and the size of final synthesized product HSA-conjugated PEI (HSA-PEI) was 14 nm with a positive zeta potential 20.8 mV. We also evaluated the characteristics of HSA-PEI in cells. We chose the A549 cell line as our evaluation model because of its GP-60 receptor. Our results showed that HSA-conjugated PEI was easily applied to form a nano-sized complex with plasmid DNA (pDNA) by simply mixing. The functional ligand, HSA, has a large size, much free PEI (or equivalent free PEI effect) and increases the protection of pDNA by stereo-barring, good condensation effect. HSA-PEI also showed good pDNA transfection enhancement in A549 cell lines, and low toxic characteristics.

  17. The pharmacokinetics of albumin conjugates of D-penicillamine in humans.

    PubMed

    Joyce, D A; Day, R O; Murphy, B R

    1991-01-01

    D-penicillamine (D-PEN) is incompletely recovered during short-term balance studies, despite rapid elimination of D-PEN and its low molecular weight metabolites. Urinary excretion of metabolites of D-PEN also persists long after cessation of chronic therapy. A study was performed to determine whether the formation and later breakdown of a stable disulfide between D-PEN and plasma albumin could explain these aspects of D-PEN pharmacokinetics. Five human volunteers received D-penicillamine, 250 mg orally, daily for 21 days. Plasma concentration-time profiles for D-PEN and D-PEN-albumin disulfide (D-PEN-albumin) were determined during the first day and pre-dose concentrations were measured on five further occasions. The pharmacokinetics of D-PEN on the first day were similar to those reported previously. No D-PEN was found in any of the pre-dose specimens. The concentration of D-PEN-albumin rose rapidly during the first day, with an estimated 8.6% of the bioavailable D-PEN being transformed to D-PEN-albumin. Pseudo-steady-state concentrations of D-PEN-albumin were achieved in three subjects at between 14 and 21 days. The mean trough concentration of D-PEN-albumin at 21 days (19.5 microM) exceeded the peak concentration of D-PEN (during the first day) by 5.7-fold. The terminal elimination half-life of D-PEN-albumin was 1.65 +/- 0.29 days, which compared with an elimination half-life of 59 +/- 8.4 min for D-PEN.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Bovine serum albumin-directed synthesis of biocompatible CdSe quantum dots and bacteria labeling.

    PubMed

    Wang, Qisui; Ye, Fangyun; Fang, Tingting; Niu, Wenhan; Liu, Peng; Min, Xinmin; Li, Xi

    2011-03-01

    A simple method was developed for preparing CdSe quantum dots (QDs) using a common protein (bovine serum albumin (BSA)) to sequester QD precursors (Cd(2+)) in situ. Fluorescence (FL) and absorption spectra showed that the chelating time between BSA and Cd(2+), the molar ratio of BSA/Cd(2+), temperature, and pH are the crucial factors for the quality of QDs. The average QD particle size was estimated to be about 5 nm, determined by high-resolution transmission electron microscopy. With FL spectra, Fourier transform infrared spectra, and thermogravimetric analysis, an interesting mechanism was discussed for the formation of the BSA-CdSe QDs. The results indicate that there might be conjugated bonds between CdSe QDs and -OH, -NH, and -SH groups in BSA. In addition, fluorescence imaging suggests that the QDs we designed can successfully label Escherichia coli cells, which gives us a great opportunity to develop biocompatible tools to label bacteria cells.

  19. Improved conjugation and purification strategies for the preparation of protein-polysaccharide conjugates.

    PubMed

    Suárez, N; Massaldi, H; Franco Fraguas, L; Ferreira, F

    2008-12-12

    A glycoconjugate constituted by the Streptococcus pneumoniae serotype 14 capsular polysaccharide (CPS14) and bovine serum albumin (BSA) was prepared, and the unique properties of Sephadex LH-20 were used to separate the conjugate from the unconjugated material. The strength of this approach consists in its capacity to produce pure polysaccharide-protein conjugate in good yield and free from unconjugated material, a common residual contaminant of this type of immunobiologicals. The CPS14-BSA conjugate prepared via an improved 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP)-activation technique was characterized chemically and its immunogenicity was evaluated in mice. The purified conjugate, unlike the corresponding polysaccharide, produced a T-cell-dependent response in this species.

  20. Conjugation of a dipicolyl chelate to polypeptide conjugates increases binding affinities for human serum albumin and survival times in human serum.

    PubMed

    Balliu, Aleksandra; Baltzer, Lars

    2017-03-16

    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 μM affinity for Zn2+, was found by surface plasmon resonance to increase in the presence of 1μM ZnCl2 at physiological pH. The dependence on polypeptide hydrophobicity was found to be minor, 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 suggesting proximity to 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 suggesting that Zn2+ ion chelating agents may provide a general route to increased survival times of peptides in serum in therapeutic and diagnostic applications without significantly increasing their molecular weights.

  1. Interaction study on bovine serum albumin physically binding to silver nanoparticles: Evolution from discrete conjugates to protein coronas

    NASA Astrophysics Data System (ADS)

    Guo, Jun; Zhong, Ruibo; Li, Wanrong; Liu, Yushuang; Bai, Zhijun; Yin, Jun; Liu, Jingran; Gong, Pei; Zhao, Xinmin; Zhang, Feng

    2015-12-01

    The nanostructures formed by inorganic nanoparticles together with organic molecules especially biomolecules have attracted increasing attention from both industries and researching fields due to their unique hybrid properties. In this paper, we systemically studied the interactions between amphiphilic polymer coated silver nanoparticles and bovine serum albumins by employing the fluorescence quenching approach in combination with the Stern-Volmer and Hill equations. The binding affinity was determined to 1.30 × 107 M-1 and the interaction was spontaneously driven by mainly the van der Waals force and hydrogen-bond mediated interactions, and negatively cooperative from the point of view of thermodynamics. With the non-uniform coating of amphiphilic polymer, the silver nanoparticles can form protein coronas which can become discrete protein-nanoparticle conjugates when controlling their molar ratios of mixing. The protein's conformational changes upon binding nanoparticles was also studied by using the three-dimensional fluorescence spectroscopy.

  2. Inhibition effects of protein-conjugated amorphous zinc sulfide nanoparticles on tumor cells growth

    NASA Astrophysics Data System (ADS)

    Cao, Ying; Wang, Hua-Jie; Cao, Cui; Sun, Yuan-Yuan; Yang, Lin; Wang, Bao-Qing; Zhou, Jian-Guo

    2011-07-01

    In this article, a facile and environmentally friendly method was applied to fabricate BSA-conjugated amorphous zinc sulfide (ZnS) nanoparticles using bovine serum albumin (BSA) as the matrix. Transmission electron microscopy analysis indicated that the stable and well-dispersed nanoparticles with the diameter of 15.9 ± 2.1 nm were successfully prepared. The energy dispersive X-ray, X-ray powder diffraction, Fourier transform infrared spectrograph, high resolution transmission electron microscope, and selected area electron diffraction measurements showed that the obtained nanoparticles had the amorphous structure and the coordination occurred between zinc sulfide surfaces and BSA in the nanoparticles. In addition, the inhibition effects of BSA-conjugated amorphous zinc sulfide nanoparticles on tumor cells growth were described in detail by cell viability analysis, optical and electron microscopy methods. The results showed that BSA-conjugated amorphous zinc sulfide nanoparticles could inhibit the metabolism and proliferation of human hepatocellular carcinoma cells, and the inhibition was dose dependent. The half maximal inhibitory concentration (IC50) was 0.36 mg/mL. Overall, this study suggested that BSA-conjugated amorphous zinc sulfide nanoparticles had the application potential as cytostatic agents and BSA in the nanoparticles could provide the modifiable site for the nanoparticles to improve their bioactivity or to endow them with the target function.

  3. Preparation, characterization, and in vitro targeted delivery of folate-conjugated 2-methoxyestradiol-loaded bovine serum albumin nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Nan; Xia, Yadan; Guo, Xiaojing; Wang, Pei; Yan, Shujuan; Lu, Chunyun; Cao, Danhua; Zhang, Zhenzhong

    2014-05-01

    The aim of this study was to prepare a novel targeting nano drug delivery system of 2-methoxyestradiol (2-ME) based on the folic acid-modified bovine serum albumin, in order to improve the clinical application disadvantages and antitumor effect of 2-ME. In this study, 2-methoxyestradiol-loaded albumin nanoparticles (2-ME-BSANPs) were prepared by desolvation method, and then the activated folic acid was conjugated to 2-ME-BSANPs by covalent attachment (2-ME-FA-BSANPs). The size and zeta potential of 2-ME-FA-BSANPs were about 208.8 ± 5.1 nm and -32.70 ± 1.01 mV, respectively. 2-ME loading efficiency and loading amount of the nanoparticles were 80.49 ± 3.80 and 10.25 ± 1.59 %, respectively. SEM images indicated that 2-ME-FA-BSANPs were of a round shape, similar uniform size, and smooth surface. Studies on drug release indicated that 2-ME-FA-BSANPs had the properties of sustained and controlled release, which provided them with the ability to fight continually against cancer cells. Internalization analysis demonstrated that 2-ME-FA-BSANPs-targeting drug delivery system could get efficiently transferred into the cells through the folic acid-mediated endocytosis, leading to higher apoptosis and affording higher antitumor efficacy against SMMC-7721 cells in vitro compared with 2-ME alone. Furthermore, the cell-cycle arrest of 2-ME-FA-BSANPs on the SMMC-7721 cells occurred at G2/M phase, and 2-ME-FA-BSANPs did not change the inhibition of the tumor mechanisms of 2-ME. Based on these results, it was concluded that albumin nanoparticles could be the promising nano carrier for 2-ME, and 2-ME-FA-BSANPs-targeting drug delivery system may be promising candidate for providing high treatment efficacy with minimal side effects in future cancer therapy.

  4. Preparation and Self-Assembly Mechanism of Bovine Serum Albumin-Citrus Peel Pectin Conjugated Hydrogel: A Potential Delivery System for Vitamin C.

    PubMed

    Peng, Hailong; Chen, Sha; Luo, Mei; Ning, Fangjian; Zhu, Xuemei; Xiong, Hua

    2016-10-05

    In this study, a novel hydrogel (BSA-pectin hydrogel, BPH) was prepared via a self-assembly method by using the natural polymers of bovine serum albumin (BSA) and citrus peel pectin (pectin). The rheological properties and gel conformational structures were determined and showed that electrostatic and covalent interactions between BSA and pectin were the main mechanisms for the formation of BPH. The morphological characteristics of BPH included a stable and solid three-dimensional network structure with a narrow size distribution (polydispersity index <0.06). BPH was used as a delivery system to load the functional agent vitamin C (Vc). The encapsulation efficiency (EE) and release properties of Vc from BPH were also investigated. The results revealed that the EE of Vc into BPH was approximately 65.31%, and the in vitro Vc release from BPH was governed by two distinct stages (i.e., burst release and sustained release) in different pH solutions, with release mechanisms involving diffusion, swelling, and erosion. Meanwhile, the stability results showed that BPH was a stable system with an enhanced Vc retention (73.95%) after 10 weeks of storage. Thus, this three-dimensional network system of BPH may be a potential delivery system to improve the stability and bioavailability of functional agents in both food and non-food fields.

  5. The establishment of a highly sensitive ELISA for detecting bovine serum albumin (BSA) based on a specific pair of monoclonal antibodies (mAb) and its application in vaccine quality control.

    PubMed

    Zhang, Kui; Song, Chaojun; Li, Qi; Li, Yongming; Sun, Yuanjie; Yang, Kun; Jin, Boquan

    2010-08-01

    A highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for quantifying BSA was established, based on two mAbs that recognize different epitopes on a BSA molecule. Our ELISA system was used to detect BSA concentrations in several vaccines, such as the MMR (measles, mumps and rubella) vaccine, hepatitis A vaccine, and hepatitis B vaccine. Moreover, we compared the mAb ELISA and the present pAb ELISA by detecting BSA standards and bovine serum samples. The results showed that our ELISA system was in good accordance with the pAb ELISA system. A pair of mAbs (FMU-BSA NO.6 and FMU-BSA NO.11) from 11 murine hybridomas secreting BSA-specific mAbs was selected for the development of the sandwich ELISA. The detection limit of this quantitative assay reaches 0.38 μg/L, which is 10-fold more sensitive than those previously reported. The quantitative range of BSA concentration is from 0.5 to 40 μg/L, which is comparable to the currently used polyclonal antibody (pAb) ELISA. Intra-assay and inter-assay coefficient variations are both lower than 10% at the three concentrations used (10, 20, and 40 μg/L). Thus, the mAb sandwich ELISA developed herein may provide a stable, precise, and highly sensitive method for quantifying BSA, which is very useful in the quality control of some vaccines.

  6. Biotin/Folate-decorated Human Serum Albumin Nanoparticles of Docetaxel: Comparison of Chemically Conjugated Nanostructures and Physically Loaded Nanoparticles for Targeting of Breast Cancer.

    PubMed

    Nateghian, Navid; Goodarzi, Navid; Amini, Mohsen; Atyabi, Fatemeh; Khorramizadeh, Mohammad Reza; Dinarvand, Rassoul

    2016-01-01

    Docetaxel (DTX) is a widely used chemotherapeutic agent with very low water solubility. Conjugation of DTX to human serum albumin (HSA) is an effective way to increase its water solubility. Attachment of folic acid (FA) or biotin as targeting moieties to DTX-HSA conjugates may lead to active targeting and specific uptake by cancer cells with overexpressed FA or biotin receptors. In this study, FA or biotin molecules were attached to DTX-HSA conjugates by two different methods. In one method, FA or biotin molecules were attached to remaining NH2 residues of HSA in DTX-HSA conjugate by covalent bonds. In the second method, HSA-FA or HSA-biotin conjugates were synthesized separately and then combined by DTX-HSA conjugate in proper ratio to prepare nanoparticles containing DTX-HSA plus HSA-FA or HSA-biotin. Cell viability of different nanoparticle was evaluated on MDA-MB-231 (folate receptor positive), A549 (folate receptor negative), and 4T1 (biotin receptor positive) and showed superior cytotoxicity compared with free docetaxel (Taxotere). In vivo studies of DTX-HSA-FA and DTX-HSA-biotin conjugates in BULB/c mice, tumorized by 4T1 cell line, showed the conjugates prepared in this study were more powerful in the reduction in tumor size and increasing the survival rate when compared to free docetaxel.

  7. Detailed Study of BSA Adsorption on Micro- and Nanocrystalline Diamond/β-SiC Composite Gradient Films by Time-Resolved Fluorescence Microscopy.

    PubMed

    Handschuh-Wang, Stephan; Wang, Tao; Druzhinin, Sergey I; Wesner, Daniel; Jiang, Xin; Schönherr, Holger

    2017-01-24

    The adsorption of bovine serum albumin (BSA) on micro- and nanocrystalline diamond/β-SiC composite films synthesized using the hot filament chemical vapor deposition (HFCVD) technique has been investigated by confocal fluorescence lifetime imaging microscopy. BSA labeled with fluorescein isothiocyanate (FITC) was employed as a probe. The BSA(FITC) conjugate was found to preferentially adsorb on both O-/OH-terminated microcrystalline and nanocrystalline diamond compared to the OH-terminated β-SiC, resulting in an increasing amount of BSA adsorbed to the gradient surfaces with an increasing diamond/β-SiC ratio. The different strength of adsorption (>30 times for diamond with a grain size of 570 nm) coincides with different surface energy parameters and differing conformational changes upon adsorption. Fluorescence data of the adsorbed BSA(FITC) on the gradient film with different diamond coverage show a four-exponential decay with decay times of 3.71, 2.54, 0.66, and 0.13 ns for a grain size of 570 nm. The different decay times are attributed to the fluorescence of thiourea fluorescein residuals of linked FITC distributed in BSA with different dye-dye and dye-surface distances. The longest decay time was found to correlate linearly with the diamond grain size. The fluorescence of BSA(FITC) undergoes external dynamic fluorescence quenching on the diamond surface by H- and/or sp(2)-defects and/or by amorphous carbon or graphite phases. An acceleration of the internal fluorescence concentration quenching in BSA(FITC) because of structural changes of albumin due to adsorption, is concluded to be a secondary contributor. These results suggest that the micro- and nanocrystalline diamond/β-SiC composite gradient films can be utilized to spatially control protein adsorption and diamond crystallite size, which facilitates systematic studies at these interesting (bio)interfaces.

  8. Characterization of covalent protein conjugates using solid-state sup 13 C NMR spectroscopy

    SciTech Connect

    Garbow, J.R.; Fujiwara, Hideji; Sharp, C.R.; Logusch, E.W. )

    1991-07-23

    Cross-polarization magic-angle spinning (CPMAS) {sup 13}C NMR spectroscopy has been used to characterize covalent conjugates of alachlor, an {alpha}-chloroacetamide hapten, with glutathione (GSH) and bovine serum albumin (BSA). The solid-state NMR method demonstrates definitively the covalent nature of these conjugates and can also be used to characterize the sites of hapten attachment to proteins. Three different sites of alachlor binding are observed in the BSA system. Accurate quantitation of the amount of hapten covalently bound to GSH and BSA is reported. The solid-state {sup 13}C NMR technique can easily be generalized to study other small molecule/protein conjugates and can be used to assist the development and refinement of synthetic methods needed for the successful formation of such protein alkylation products.

  9. Orthogonal assembly of a designed ankyrin repeat protein-cytotoxin conjugate with a clickable serum albumin module for half-life extension.

    PubMed

    Simon, Manuel; Frey, Raphael; Zangemeister-Wittke, Uwe; Plückthun, Andreas

    2013-11-20

    The generation of drug conjugates for safe and effective tumor targeting requires binding proteins tolerant to functionalization by rational engineering. Here, we show that Designed Ankyrin Repeat Proteins (DARPins), a novel class of binding proteins not derived from antibodies, can be used as building blocks for facile orthogonal assembly of bioconjugates for tumor targeting with tailored properties. DARPin Ec1, which targets the Epithelial Cell Adhesion Molecule (EpCAM), was genetically modified with a C-terminal cysteine for conjugation of the small molecule cytotoxin monomethylauristatin F (MMAF). In addition, it was N-terminally functionalized by metabolic introduction of the non-natural amino acid azidohomoalanine to enable linkage of site-specifically dibenzocyclooctyne-modified mouse serum albumin (MSA) for half-life extension using Cu(I)-free click chemistry. The conjugate MSA-Ec1-MMAF was assembled to obtain high yields of a pure and stable drug conjugate as confirmed by various analytical methods and in functional assays. The orthogonality of the assembly led to a defined reaction product and preserved the functional properties of all modules, including EpCAM-specific binding and internalization, FcRn binding mediated by MSA, and cytotoxic potency. Linkage of MMAF to the DARPin increased receptor-specific uptake of the drug while decreasing nonspecific uptake, and further coupling of the conjugate to MSA enhanced this effect. In mice, albumin conjugation increased the serum half-life from 11 min to 17.4 h, resulting in a more than 22-fold increase in the area-under-the-curve (AUC). Our data demonstrate the promise of the DARPin format for facile modular assembly of drug conjugates with improved pharmacokinetic performance for tumor targeting.

  10. Esterase activity of BSA-ZnO nanoparticle complex

    NASA Astrophysics Data System (ADS)

    Bhogale, A.; Nair, A.; Patel, N.; Miotello, A.; Kothari, D. C.

    2014-04-01

    The effect of Zinc Oxide Nanoparticles (ZnO NPs) on functional properties of Bovine Serum Albumin (BSA) protein was studied. ZnO NPs were synthesized with average size of ˜7.5 nm as obtained from TEM analysis. The catalytic conversion of p-nitrophenylacetate (PNPA) to p-nitrophenol in the presence of BSA attached with ZnO NPs was examined by UV-Vis spectroscopy at room temperature. The result suggests that esterase activity of BSA is significantly enhanced (6 times) due to the ground state BSA-ZnO complex formation.

  11. Chemically modified cellulose strips with pyridoxal conjugated red fluorescent gold nanoclusters for nanomolar detection of mercuric ions.

    PubMed

    Bothra, Shilpa; Upadhyay, Yachana; Kumar, Rajender; Ashok Kumar, S K; Sahoo, Suban K

    2017-04-15

    One-pot approach was adopted for the synthesis of highly luminescent near-infrared (NIR)-emitting gold nanoclusters (AuNCs) using bovine serum albumin (BSA) as a protecting agent. The vitamin B6 cofactor pyridoxal was conjugated with the luminescent BSA-AuNCs through the free amines of BSA and then employed for the nanomolar detection of Hg(2+) in aqueous medium via selective fluorescence quenching of AuNCs. This nano-assembly was successfully applied for the real sample analysis of Hg(2+) in fish, tap water and river water. The study also presents chemically-modified cellulosic paper strips with the pyridoxal conjugated BSA-AuNCs for detecting Hg(2+) ion up to 1nM.

  12. Structural determination of the conjugate of human serum albumin with a mitomycin C derivative, KW-2149, by matrix-assisted laser desorption/ionization mass spectrometry.

    PubMed

    Yasuzawa, T; Tomer, K B

    1997-01-01

    A new mitomycin C derivative, KW-2149, is known to form a covalent conjugate with human serum albumin (HSA). This conjugate exhibits 1/20 of the anticellular activity of unconjugated KW-2149. Structural studies of this conjugate were carried out using a combination of enzymatic digestion, high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The tryptic peptide T5 (residues 21-41) was the only peptide found to be modified by KW-2149 moieties, the [(gamma-L-glutamylamino)ethyl]thio group or the (2-aminoethyl)thio group, through a disulfide bond. Although the latter peptide lost its mitomycin C moiety in the course of tryptic digestion, these data strongly suggest that KW-2149 was bound to Cys-34, the only free cysteine on HSA.

  13. Synthesis of 5-Fluorouracil conjugated LaF3:Tb3+/PEG-COOH nanoparticles and its studies on the interaction with bovine serum albumin: spectroscopic approach

    NASA Astrophysics Data System (ADS)

    Mangaiyarkarasi, Rajendiran; Chinnathambi, Shanmugavel; Aruna, Prakasarao; Ganesan, Singaravelu

    2015-03-01

    The luminescent lanthanide-doped nanoparticles have gathered considerable attention in many fields especially in biomedicine. In this work, the lanthanum fluoride-doped terbium nanoparticles (LaF3:Tb3+ NPs) via simple chemical precipitation method has been synthesized and functionalized with polyethylene glycol. The size and the shape of the nanoparticles are confirmed using X-ray diffraction and transmission electron microscopy. The conjugation of 5-Fluorouracil (5-FU) and thus synthesized nanoparticles (NPs) were confirmed using various spectroscopic methods such as UV-Visible spectroscopy, fluorescence steady state, and excited state spectroscopy studies. The enhancement in fluorescence emission ( λ = 543 nm) of drug-conjugated nanoparticles confirms the Vander Waals force of attraction due to F-F bonding between the drug and the nanoparticles. Further, the effects of 5FU-NPs in carrier protein were investigated using bovine serum albumin as a protein model. The 5FU-LaF3:Tb3+ nanoparticles binding is illustrated with binding constant and number of binding sites. The structural change of bovine serum albumin has been studied using circular dichroism and Fourier transform infrared spectroscopy analysis.

  14. Size-Tunable Gd2O3@Albumin Nanoparticles Conjugating Chlorin e6 for Magnetic Resonance Imaging-Guided Photo-Induced Therapy

    PubMed Central

    Zhou, Lijuan; Yang, Tao; Wang, Junxing; Wang, Qiaoli; Lv, Xiaoyan; Ke, Hengte; Guo, Zhengqing; Shen, Junkang; Wang, Yong; Xing, Chungen; Chen, Huabing

    2017-01-01

    Protein nanoparticles as nanocarriers are of particular interest in the field of cancer therapy. Nevertheless, so far a facile fabrication of theranostic protein nanoparticles have been explored with limited success for cancer imaging and therapy. In this work, we demonstrate the controllable synthesis of size-tunable Gd2O3@albumin conjugating photosensitizer (PS) (GA-NPs) using hollow albumin as the nanoreactor for magnetic resonance imaging (MRI)-guided photo-induced therapy. The growth of Gd2O3 nanocrystals within the hollow nanoreactors is well regulated through reaction time, and a typical PS (e.g. chlorin e6) is further conjugated with the protein corona of the nanoreactor through facile chemical coupling, followed by the formation of theranostic GA-NPs. GA-NPs exhibit good longitudinal relaxivity, ideal photostability, enhanced cellular uptakes, and preferable size-dependent tumor accumulation. Moreover, GA-NPs effectively generate remarkable photothermal effect, intracellular reactive oxygen species from Ce6, and subsequent cytoplasmic drug translocation, thereby leading to severe synergistic photothermal and photodynamic cell damages. Consequently, GA-NPs exhibit an in vivo size-dependent MRI capacity with enhanced imaging contrast for effective tumor localization, and also generate a potent synergistic photodynamic therapy/photothermal therapy efficacy under irradiation owing to their enhanced tumor accumulation and strong photo-induced cytotoxicity. These results suggest that GA-NPs can act as a promising theranostic protein nanoplatform for cancer imaging and photo-induced therapy. PMID:28255365

  15. Morphological Analysis and Interaction of Chlorophyll and BSA

    PubMed Central

    Gorza, Filipe D. S.; Pedro, Graciela C.; Trescher, Tarquin F.; da Silva, Romário J.; Silva, Josmary R.; de Souza, Nara C.

    2014-01-01

    Interactions between proteins and drugs, which can lead to formation of stable drug-protein complexes, have important implications on several processes related to human health. These interactions can affect, for instance, free concentration, biological activity, and metabolism of the drugs in the blood stream. Here, we report on the UV-Visible spectroscopic investigation on the interaction of bovine serum albumin (BSA) with chlorophyll (Chl) in aqueous solution under physiological conditions. Binding constants at different temperatures—obtained by using the Benesi-Hildebrand equation—were found to be of the same order of magnitude (~104 M−1) indicating low affinity of Chl with BSA. We have found a hyperchromism, which suggested an interaction between BSA and Chl occurring through conformational changes of BSA caused by exposition of tryptophan to solvent. Films from BSA and Chl obtained at different Chl concentrations showed fractal structures, which were characterized by fractal dimension calculated from microscopic image analysis. PMID:24963490

  16. Preparation for aflatoxin B(1)-cationized bovine serum albumin based on Mannich-type reaction.

    PubMed

    Zhou, Youxiang; Wu, Jiajia; Yu, Wei; Xu, Ying; Wang, Ping; Xie, Bijun; Chen, Fusheng

    2007-12-01

    Aflatoxin B(1) (AFB(1)), which is commonly found in agricultural commodities, is one of the most potent carcinogenic mycotoxins. To ensure food safety, rapid and low-cost immunological methods have been applied to detect AFB(1) worldwide. A key step in these immunological methods is coupling AFB(1) to carrier proteins; AFB(1) is usually deviated to AFB(1)-oxime and coupled to carrier proteins to form the AFB(1)-oxime-protein conjugate. In the current research, AFB(1) was directly coupled with cationized bovine serum albumin (cBSA) using a method based on Mannich-type principles. The coupling effects were investigated with different initial molar ratios of AFB(1) to cBSA. The conjugate molar ratio was 6.4:1 when the initial molar ratio was 40:1. The cationized proteins and their conjugates were identified by UV-Vis and FT-IR spectra, which showed the characteristic bands of the ethylendiamine group and AFB(1), respectively. After BALB/c mice were immunized with AFB(1)-cBSA, a quicker immunological response and a similar sensitivity of antisera against AFB(1) were observed, compared with immunization by AFB(1)-oxime-BSA. This suggests that the Mannich-type reaction might be an alternative method of preparation for AFB(1)-protein.

  17. Synthesis and characterization of collagen grafted poly(hydroxybutyrate-valerate) (PHBV) scaffold for loading of bovine serum albumin capped silver (Ag/BSA) nanoparticles in the potential use of tissue engineering application.

    PubMed

    Bakare, Rotimi A; Bhan, Chandra; Raghavan, Dharmaraj

    2014-01-13

    The objective of this study is to synthesize and characterize collagen grafted poly(3-hydroxylbutyrate-co-3-hydroxylvalerate) (PHBV) film for loading of BSA capped silver (Ag/BSA) nanoparticles. Thermal radical copolymerization and aminolysis methods were used to functionalize macroporous PHBV, followed by collagen grafting so as to formulate collagen-g-poly(hydroxyethylmethyl acrylate)-g-poly(3-hydroxylbutyrate-co-3-hydroxylvalerate) [collagen-g-PHEMA-g-PHBV] and collagen-g-aminated-poly(3-hydroxylbutyrate-co-3-hydroxylvalerate) [collagen-g-NH2-PHBV] films, respectively. Spectroscopic (FTIR, XPS), physical (SEM), and thermal (TGA) techniques were used to characterize the functionalized PHBV films. The amount of collagen present on grafted PHBV film was quantified by the Bradford method. The Ag/BSA nanoparticles were then loaded on collagen grafted and untreated PHBV films, and the nanoparticles loading were determined by atomic absorption spectrometry. The amount of nanoparticles loaded on collagen grafted PHBV film was found to be significantly greater than that on the untreated PHBV film. The nanoparticles loaded PHBV film can potentially serve as a scaffold to promote the growth of bone cells while inhibiting the bacterial growth.

  18. Fluorescence resonance energy transfer between ZnSe ZnS quantum dots and bovine serum albumin in bioaffinity assays of anticancer drugs

    NASA Astrophysics Data System (ADS)

    Shu, Chang; Ding, Li; Zhong, Wenying

    2014-10-01

    In the current work, using ZnSe ZnS quantum dots (QDs) as representative nanoparticles, the affinities of seven anticancer drugs for bovine serum albumin (BSA) were studied using fluorescence resonance energy transfer (FRET). The FRET efficiency of BSA-QD conjugates can reach as high as 24.87% by electrostatic interaction. The higher binding constant (3.63 × 107 L mol-1) and number of binding sites (1.75) between ZnSe ZnS QDs and BSA demonstrated that the QDs could easily associate to plasma proteins and enhance the transport efficacy of drugs. The magnitude of binding constants (103-106 L mol-1), in the presence of QDs, was between drugs-BSA and drugs-QDs in agreement with common affinities of drugs for serum albumins (104-106 L mol-1) in vivo. ZnSe ZnS QDs significantly increased the affinities for BSA of Vorinostat (SAHA), Docetaxel (DOC), Carmustine (BCNU), Doxorubicin (Dox) and 10-Hydroxycamptothecin (HCPT). However, they slightly reduced the affinities of Vincristine (VCR) and Methotrexate (MTX) for BSA. The recent work will not only provide useful information for appropriately understanding the binding affinity and binding mechanism at the molecular level, but also illustrate the ZnSe ZnS QDs are perfect candidates for nanoscal drug delivery system (DDS).

  19. Fluorescence resonance energy transfer between ZnSe ZnS quantum dots and bovine serum albumin in bioaffinity assays of anticancer drugs.

    PubMed

    Shu, Chang; Ding, Li; Zhong, Wenying

    2014-10-15

    In the current work, using ZnSe ZnS quantum dots (QDs) as representative nanoparticles, the affinities of seven anticancer drugs for bovine serum albumin (BSA) were studied using fluorescence resonance energy transfer (FRET). The FRET efficiency of BSA-QD conjugates can reach as high as 24.87% by electrostatic interaction. The higher binding constant (3.63×10(7)Lmol(-1)) and number of binding sites (1.75) between ZnSe ZnS QDs and BSA demonstrated that the QDs could easily associate to plasma proteins and enhance the transport efficacy of drugs. The magnitude of binding constants (10(3)-10(6)Lmol(-1)), in the presence of QDs, was between drugs-BSA and drugs-QDs in agreement with common affinities of drugs for serum albumins (10(4)-10(6)Lmol(-1)) in vivo. ZnSe ZnS QDs significantly increased the affinities for BSA of Vorinostat (SAHA), Docetaxel (DOC), Carmustine (BCNU), Doxorubicin (Dox) and 10-Hydroxycamptothecin (HCPT). However, they slightly reduced the affinities of Vincristine (VCR) and Methotrexate (MTX) for BSA. The recent work will not only provide useful information for appropriately understanding the binding affinity and binding mechanism at the molecular level, but also illustrate the ZnSe ZnS QDs are perfect candidates for nanoscal drug delivery system (DDS).

  20. Conjugation of biogenic and synthetic polyamines with serum proteins: A comprehensive review.

    PubMed

    Chanphai, P; Thomas, T J; Tajmir-Riahi, H A

    2016-11-01

    We have reviewed the conjugation of biogenic polyamines spermine (spm), spermidine (spmd) and synthetic polyamines 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333) with human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (b-LG) in aqueous solution at physiological pH. The results of multiple spectroscopic methods and molecular modeling were analysed here and correlations between polyamine binding mode and protein structural changes were estabilished. Polyamine-protein bindings are mainly via hydrophilic and H-bonding contacts. BSA forms more stable conjugates than HSA and b-LG. Biogenic polyamines form more stable complexes than synthetic polyamines except in the case of b-LG, where the protein shows more hydrophobic character than HSA and BSA. The loading efficacies were 40-52%. Modeling showed the presence of several H-bonding systems, which stabilized polyamine-protein conjugates. Polyamine conjugation induced major alterations of serum protein conformations. The potential application of serum proteins in delivery of polyamines is evaluated here.

  1. Caveolae-mediated albumin transcytosis is enhanced in dengue-infected human endothelial cells: A model of vascular leakage in dengue hemorrhagic fever

    PubMed Central

    Chanthick, Chanettee; Kanlaya, Rattiyaporn; Kiatbumrung, Rattanaporn; Pattanakitsakul, Sa-nga; Thongboonkerd, Visith

    2016-01-01

    Vascular leakage is a life-threatening complication of dengue virus (DENV) infection. Previously, association between “paracellular” endothelial hyperpermeability and plasma leakage had been extensively investigated. However, whether “transcellular” endothelial leakage is involved in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) remained unknown. We thus investigated effects of DENV (serotype 2) infection on transcellular transport of albumin, the main oncotic plasma protein, through human endothelial cell monolayer by Western blotting, immunofluorescence staining, fluorescence imaging, and fluorometry. The data showed that Alexa488-conjugated bovine serum albumin (Alexa488-BSA) was detectable inside DENV2-infected cells and its level was progressively increased during 48-h post-infection. While paracellular transport could be excluded using FITC-conjugated dextran, Alexa488-BSA was progressively increased and decreased in lower and upper chambers of Transwell, respectively. Pretreatment with nystatin, an inhibitor of caveolae-dependent endocytic pathway, significantly decreased albumin internalization into the DENV2-infected cells, whereas inhibitors of other endocytic pathways showed no significant effects. Co-localization of the internalized Alexa488-BSA and caveolin-1 was also observed. Our findings indicate that DENV infection enhances caveolae-mediated albumin transcytosis through human endothelial cells that may ultimately induce plasma leakage from intravascular compartment. Further elucidation of this model in vivo may lead to effective prevention and better therapeutic outcome of DHF/DSS. PMID:27546060

  2. Effect of temperature on the methotrexate BSA interaction: Spectroscopic study

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Maciążek, M.; Równicka, J.; Bojko, B.; Pentak, D.; Sułkowski, W. W.

    2007-05-01

    Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory illness which affects about one percent of the world's population. Methotrexate (4-amino-10-methylfolic acid) (MTX) also known as amethopterin is commonly used to treat rheumatoid arthritis (RA). It is transported in the circulary system as a complex with serum albumin. The aim of this study was to investigate the interactions of MTX with transporting protein with the use of spectroscopic methods. The binding of MTX to bovine serum albumin (BSA) was studied by monitoring the changes in the emission fluorescence spectra of protein in the presence of MTX at excitation wavelength of 280 nm and 295 nm. The quenching of protein fluorescence at temperature range from 298 K to 316 K was observed. Energy transfer between methotrexate and fluorophores contained in the serum albumin structure was found at the molar ratio MTX:BSA 7.5:1. The relative fluorescence intensity of BSA decreases with increase of temperature. Similar results were observed for BSA excited with 280 nm and 295 nm at the same temperature range. The presence of MTX seems to prevent these changes. Temperature dependence of the binding constant has been presented. The binding and quenching constants for equilibrium complex were calculated using Scatchard and Stern-Volmer method, respectively. The results show that MTX forms π-π complex with aromatic amino acid residues of BSA. The binding site for MTX on BSA was found to be situated in the hydrophobic IIA or IB subdomain where the Trps were located. The spontaneity of MTX-BSA complex formation in the temperature range 298-316 K was ascertained.

  3. Effective reduction of non-specific binding by bovine serum albumin modified quantum dot surface for cell targeted imaging

    NASA Astrophysics Data System (ADS)

    Wang, Qian; Zhang, Min; Wang, Ling; Gu, Yueqing

    2014-09-01

    Exploiting the bright and colorful photophysical properties of semiconductor quantum dots (QDs) is an onward trend in biotechnology and QDs have been widely used as fluorescent probes in cell-targeted imaging. However, nonspecific binding to cellular membranes has been a major challenge. In this study, high quality cadmium telluride (CdTe) quantum dots with different particle sizes were prepared via hydrothermal method. The surface of the QDs was modified with the chemically reduced bovine serum albumin (BSA) for effective reduction of nonspecific binding in cell targeting. Here,the as-prepared QDs exhibits tunable photoluminescence (PL) emission between 525nm and 620 nm.BSA-coated QDs which also provide reaction sites for conjugation of targeting ligands is mainly achieved by multiple mercapto groups in BSA macromolecules as multidentate ligands and partially by ligand exchange interaction between BSA and QDs. The BSA-coated QDs, with an overwhelming majority of hydrodynamic diameter size of 15nm ,are found to exhibit strong fluorescent intensities. The cellular uptake and localization of QDs was studied using laser confocal scanning microscopy. The results indicated that the nonspecific cellular binding is effectively reduced by BSA-coated QDs, compared with the N-acetyl-L-cysteine (NAC) -coated CdTe QDs.

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

    PubMed Central

    Taheri, Azade; Dinarvand, Rassoul; Atyabi, Fatemeh; Ahadi, Fatemeh; Nouri, Farank Salman; Ghahremani, Mohammad Hossein; Ostad, Seyed Nasser; Borougeni, Atefeh Taheri; Mansoori, Pooria

    2011-01-01

    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. PMID:21845098

  5. Application of conjugated heparin-albumin microparticles with laser-balloon angioplasty: a potential method for reducing adverse biologic reactivity after angioplasty

    NASA Astrophysics Data System (ADS)

    Kundu, Sourav K.; McMath, Linda P.; Zaidan, Jonathan T.; Spears, J. Richard

    1991-05-01

    Laser-balloon angioplasty (LBA) may potentially be used for local application of pharmacologically active agents which will reduce thrombogenic and proliferative responses after the angioplasty. In this study, the feasibility of applying covalently conjugated heparin- albumin microparticles onto arterial luminal surface was demonstrated. The covalent linkages were formed by reaction with 1-ethyl-3-dimethyl-aminopropyl-carbodiimide (EDC), and the resultant conjugates were used for preparation of microparticles by employing standard emulsification and heat-crosslinking techniques. The heparin release rate from the microparticles was found to be dependent upon the degree of crosslinking. When a thin coagulum of a suspension of microparticles was formed with heat on a glass surface, the treated surface demonstrated resistance to clot formation in contact with non-anticoagulated blood. A suspension of the microparticles applied during laser-balloon angioplasty onto the luminal surface of dog carotid and femoral arteries showed persistence for up to one week without thrombus formation or occlusion of the vessel. Since the rate of biodegradation is primarily dictated by the extent of crosslinking, an optimal degree of thermal denaturation will permit longer persistence of the carrier while allowing adequate release of the entrapped pharmacologic agent. A variety of antithrombotic and antiinflammatory agents are being considered as candidate bioprotective materials for local application after angioplasty.

  6. Comparison of tryptophan interactions to free and grafted BSA protein.

    PubMed

    Garnier, F; Randon, J; Rocca, J L

    2000-04-28

    The binding of d- and l-tryptophan molecules to bovine serum albumin (BSA) protein has been studied using liquid chromatography and ultrafiltration in the pH range from 7 to 11. A hydrophobic interaction between tryptophan and BSA has been observed at pH 7.0 on BSA grafted chromatographic column. However, this interaction is negligible at higher pH for which the interaction to the stereospecific site was predominant. For both grafted and free proteins, the complexation mechanism was a competitive binding of d- and l-enantiomers on a single site. The apparent complexation constants for both d- and l-tryptophan show a maximum in the pH range 9-10. The variations of the apparent complexation constants versus pH were the result of the protonation of both the amino acid and a single site of the protein assuming that the complexation occurs between the zwitter-ionic amino acid form and the unprotonated BSA site. The apparent pK(BSA) is slightly shifted from 8.3 for grafted BSA protein to 9.4 for free BSA protein. This shift is presumably as a result of the different protein conformation.

  7. Encapsulation of catechin and epicatechin on BSA NPS improved their stability and antioxidant potential

    PubMed Central

    Yadav, Ramdhan; Kumar, Dharmesh; Kumari, Avnesh; Yadav, Sudesh Kumar

    2014-01-01

    Nanoencapsulation of antioxidant molecules on protein nanoparticles (NPs) could be an advanced approach for providing stable, better food nutraceuticals and anticancer drugs. The bioavailability and stability of catechin (CAT) and epicatechin (ECAT) were very poor. In the present study, the CAT and ECAT were loaded on bovine serum albumin (BSA) NPs following desolvation method. The transmission electron microscope (TEM) and atomic force microscope (AFM) recorded size of CAT-BSA NPs and ECAT-BSA NPs were 45 ± 5 nm and 48 ± 5 nm respectively. The encapsulation efficiency of CAT and ECAT on BSA NPs was found to be 60.5 and 54.5 % respectively. CAT-BSA NPs and ECAT-BSA NPs show slow and sustained in vitro release. The CAT-BSA NPs and ECAT-BSA NPs were stable in solution at various temperatures 37 °C, 47 °C and 57 °C. DPPH assay revealed that CAT and ECAT maintained their functional activity even after encapsulation on BSA NPs. Furthermore, the efficacy of CAT-BSA NPs and ECAT-BSA NPs determined against A549 cell lines was found to be improved. CAT and ECAT aptly encapsulated in BSA NPs, showed satisfactory sustained release, maintained antioxidant potential and found improved efficacy. This has thus suggested their more effective use in food and nutraceuticals as well as in medical field. PMID:26417264

  8. Combination of UV-vis spectroscopy and chemometrics to understand protein-nanomaterial conjugate: a case study on human serum albumin and gold nanoparticles.

    PubMed

    Wang, Yong; Ni, Yongnian

    2014-02-01

    Study of the interactions between proteins and nanomaterials is of great importance for understanding of protein nanoconjugate. In this work, we choose human serum albumin (HSA) and citrate-capped gold nanoparticles (AuNPs) as a model of protein and nanomaterial, and combine UV-vis spectroscopy with multivariate curve resolution by an alternating least squares (MCR-ALS) algorithm to present a new and efficient method for comparatively comprehensive study of evolution of protein nanoconjugate. UV-vis spectroscopy coupled with MCR-ALS allows qualitative and quantitative extraction of the distribution diagrams, spectra and kinetic profiles of absorbing pure species (AuNPs and AuNPs-HSA conjugate are herein identified) and undetectable species (HSA) from spectral data. The response profiles recovered are converted into the desired thermodynamic, kinetic and structural parameters describing the protein nanoconjugate evolution. Analysis of these parameters for the system gives evidence that HSA molecules are very likely to be attached to AuNPs surface predominantly as a flat monolayer to form a stable AuNPs-HSA conjugate with a core-shell structure, and the binding process takes place mainly through electrostatic and hydrogen-bond interactions between the positively amino acid residues of HSA and the negatively carboxyl group of citrate on AuNPs surface. The results obtained are verified by transmission electron microscopy, zeta potential, circular dichroism spectroscopy and Fourier transform infrared spectroscopy, showing the potential of UV-vis spectroscopy for study of evolution of protein nanoconjugate. In parallel, concentration evolutions of pure species resolved by MCR-ALS are used to construct a sensitive spectroscopic biosensor for HSA with a linear range from 1.8 nM to 28.1 nM and a detection limit of 0.8 nM.

  9. Purification and Characterization of Bovine Serum Albumin Using Chromatographic Method

    PubMed Central

    Balkani, Sanaz; Shamekhi, Sara; Raoufinia, Ramin; Parvan, Reza; Abdolalizadeh, Jalal

    2016-01-01

    Purpose: Albumin is an abundant protein of blood and has many biopharmaceutical applications. The aim of this study was to purify bovine serum albumin (BSA) using produced rabbit anti-BSA antibody. Methods: The polyclonal antibody was produced against the BSA in rabbits. Then, the pure BSA was injected to three white New Zealand rabbits. ELISA test was done to evaluate antibody production. After antibody purification,the purified antibody was attached to CNBr-activated sepharose and finally it was used for purification of albumin from bovine serum. Western blotting analysis was used for functional assessment of immunoaffinity purified BSA. Results: The titer of anti-bovine albumin determined by ELISA was obtained 1: 256000. The SDS-PAGE showed up to 98% purity of isolated BSA and western blotting confirmed the BSA functionality. Purified bovine serum albumin by affinity chromatography showed a single band with molecular weight of 66 KDa. Conclusion: Affinity chromatography using produced rabbit anti-BSA antibody would be an economical and safe method for purification of BSA. PMID:28101473

  10. An Intact Reducing Glycan Promotes the Specific Immune Response to Lacto-N-neotetraose-BSA Neoglycoconjugates

    PubMed Central

    Prasanphanich, Nina S.; Song, Xuezheng; Heimburg-Molinaro, Jamie; Luyai, Anthony E.; Lasanajak, Yi; Cutler, Christopher E.; Smith, David F.; Cummings, Richard D.

    2015-01-01

    The mammalian immune system responds to eukaryotic glycan antigens during infections, cancer, and autoimmune disorders, but the immunological bases for such responses are unclear. Conjugate vaccines containing bacterial polysaccharides linked to carrier proteins (neoglycoconjugates) have proven successful, but these often contain repeating epitopes and the reducing end of the glycan is less important, unlike typical glycan determinants in eukaryotes, which are shorter in length and may include the reducing end. Here we have compared the effects of two linkage methods, one that opens the ring at the reducing end of the glycan, and one that leaves the reducing end closed, on the glycan specificity of the vaccine response in rabbits and mice. We immunized rabbits and mice with bovine serum albumin (BSA) conjugates of synthetic open- and closed-ring forms (OR versus CR) of a simple tetrasaccharide lacto-N-neo-tetraose (LNnT, Galβ1-4GlcNAcβ1-3Galβ1-4Glc), and tested reactivity to the immunogens and several related glycans in both OR and CR versions on glycan microarrays. We found that in rabbits the immune response to the CR conjugate was directed toward the glycan, whereas the OR conjugate elicited antibodies to the reducing end of the glycan and linker region but not specifically to the glycan itself. Unexpectedly, mice did not generate a glycan-specific response to the CR conjugate. Our findings indicate that the reducing end of the sugar is crucial for generation of a glycan-specific response to some eukaryotic vaccine epitopes, and that there are species-specific differences in the ability to make a glycan-specific response to some glycoconjugates. These findings warrant further investigation with regard to rational design of glycoconjugate vaccines. PMID:25671348

  11. Evaluating interaction forces between BSA and rabbit anti-BSA in sulphathiazole sodium, tylosin and levofloxacin solution by AFM

    NASA Astrophysics Data System (ADS)

    Wang, Congzhou; Wang, Jianhua; Deng, Linhong

    2011-11-01

    Protein-protein interactions play crucial roles in numerous biological processes. However, it is still challenging to evaluate the protein-protein interactions, such as antigen and antibody, in the presence of drug molecules in physiological liquid. In this study, the interaction between bovine serum albumin (BSA) and rabbit anti-BSA was investigated using atomic force microscopy (AFM) in the presence of various antimicrobial drugs (sulphathiazole sodium, tylosin and levofloxacin) under physiological condition. The results show that increasing the concentration of tylosin decreased the single-molecule-specific force between BSA and rabbit anti-BSA. As for sulphathiazole sodium, it dramatically decreased the specific force at a certain critical concentration, but increased the nonspecific force as its concentration increasing. In addition, the presence of levofloxacin did not greatly influence either the specific or nonspecific force. Collectively, these results suggest that these three drugs may adopt different mechanisms to affect the interaction force between BSA and rabbit anti-BSA. These findings may enhance our understanding of antigen/antibody binding processes in the presence of drug molecules, and hence indicate that AFM could be helpful in the design and screening of drugs-modulating protein-protein interaction processes.

  12. SANS study of interaction of silica nanoparticles with BSA protein and their resultant structure

    SciTech Connect

    Yadav, Indresh Aswal, V. K.; Kohlbrecher, J.

    2014-04-24

    Small angle neutron scattering (SANS) has been carried out to study the interaction of anionic silica nanoparticles (88 Å) with globular protein Bovine Serum Albumin (BSA) (M.W. 66.4 kD) in aqueous solution. The measurements have been carried out on fixed concentration (1 wt %) of Ludox silica nanoparticles with varying concentration of BSA (0–5 wt %) at pH7. Results show that silica nanoparticles and BSA coexist as individual entities at low concentration of BSA where electrostatic repulsive interactions between them prevent their aggregation. However, as the concentration of BSA increases (≥ 0.5 wt %), it induces the attractive depletion interaction among nanoparticles leading to finally their aggregation at higher BSA concentration (2 wt %). The aggregates are found to be governed by the diffusion limited aggregation (DLA) morphology of fractal nature having fractal dimension about 2.4.

  13. CdSe/ZnS quantum dots based electrochemical immunoassay for the detection of phosphorylated bovine serum albumin

    SciTech Connect

    Pinwattana, Kulwadee; Wang, Jun; Lin, Chiann Tso; Wu, Hong; Du, Dan; Lin, Yuehe; Chailapakul, Orawon

    2010-11-15

    A CdSe/ZnS quantum dot (QD) based electrochemical immunoassay of phosphorylated bovine serum albumin as a protein biomarker is presented. The QDs were used as labels and were conjugated with the secondary anti-phosphoserine antibody in a heterogeneous sandwich immunoassay. First, the primary BSA antibody was immobilized on polystyrene microwells, followed by the addition of BSA-OP. After that, the QD-labeled anti-phosphoserine antibody was added into microwells for immunorecognition. Finally, the bound QD was dissolved in an acid-dissolution step and was detected by electrochemical stripping analysis. The measured current responses were proportional to the concentration of BSA-OP. Under optimal conditions, the voltammetric response was linear over the range of 0.5 - 500 ng mL-1 of BSA-OP, with a detection limit of 0.5 ng mL-1 at a deposition potential of -1.2 V for 120 s. It also shows good reproducibility with a relative standard deviation of 8.6% of six times determination of 25 ng mL-1 of BSA-OP. This QD-based electrochemical immunoassay offers great promise for simple and cost-effective analysis of protein biomarkers.

  14. Spectroscopic, biological, and molecular modeling studies on the interactions of [Fe(III)-meloxicam] with G-quadruplex DNA and investigation of its release from bovine serum albumin (BSA) nanoparticles.

    PubMed

    Ebrahimi, Malihe; Khayamian, Taghi; Hadadzadeh, Hassan; Sayed Tabatabaei, Badraldin Ebrahim; Jannesari, Zahra; Khaksar, Ghazale

    2015-01-01

    The guanine-rich sequence, specifically in DNA, telomeric DNA, is a potential target of anticancer drugs. In this work, a mononuclear Fe(III) complex containing two meloxicam ligands was synthesized as a G-quadruplex stabilizer. The interaction between the Fe(III) complex and G-quadruplex with sequence of 5'-G3(T2AG3)3-3' (HTG21) was investigated using spectroscopic methods, molecular modeling, and polymerase chain reaction (PCR) assays. The spectroscopic methods of UV-vis, fluorescence, and circular dichroism showed that the metal complex can effectively induce and stabilize G-quadruplex structure in the G-rich 21-mer sequence. Also, the binding constant between the Fe(III) complex and G-quadruplex was measured by these methods and it was found to be 4.53(±0.30) × 10(5) M(-1)). The PCR stop assay indicated that the Fe(III) complex inhibits DNA amplification. The cell viability assay showed that the complex has significant antitumor activities against Hela cells. According to the UV-vis results, the interaction of the Fe(III) complex with duplex DNA is an order of magnitude lower than G-quadruplex. Furthermore, the release of the complex incorporated in bovine serum albumin nanoparticles was also investigated in physiological conditions. The release of the complex followed a bi-phasic release pattern with high and low releasing rates at the first and second phases, respectively. Also, in order to obtain the binding mode of the Fe(III) complex with G-quadruplex, molecular modeling was performed. The molecular docking results showed that the Fe(III) complex was docked to the end-stacked of the G-quadruplex with a π-π interaction, created between the meloxicam ligand and the guanine bases of the G-quadruplex.

  15. A novel method for determination of aflatoxin B1 mediated by FCLA + BSA

    NASA Astrophysics Data System (ADS)

    Chen, WenLi; Xing, Da

    2005-02-01

    As a chemiluminescence (CL) probe, 3,7-dihydro-6-{4-{2-(N"-(5-fluoresceinyl) thioureido)ethoxy}phenyl}-2-met -hylimi-dazo{1,2-a}pyrazin-3-one dosium salt (FCLA) can sensitively and specifically react with singlet oxygen (1O2 ) and superoxide(O2""). BSA (Bovine Serum Albumin) can enlarge the CL intensity of FCLA to 860%. This report presents a novel method for determination of Aflatoxin B1 (AfB1) mediated by FCLA+BSA. The concentration of AFB1 showed an obvious positive correlation with the CL intensity mediated by FCLA+BSA. This method could measure accurately ng/ml of AfB1 concentration. At the same time, the fluorescence spectrum of FCLA+BSA and FCLA+BSA+AfB1 were measured respectively, which showed that the fluorescence intensity of FCLA+BSA+AfB1 was higher than FCLA+BSA. Comparing the peak value of FCLA, FCLA+BSA and FCLA+BSA+AfB1 had a 6nm Einstein shift (red shift). The study suggested that CL method mediated by FCLA+BSA might be applicable to the determination of AfB1 concentration.

  16. Poly(amidoamine) Dendrimer-Drug Conjugates with Disulfide Linkages for Intracellular Drug Delivery

    PubMed Central

    Kurtoglu, Yunus E.; Navath, Raghavendra S.; Wang, Bing; Kannan, Sujatha; Romero, Robert; Kannan, Rangaramanujam M.

    2009-01-01

    Understanding and improving drug release kinetics from dendrimer-drug conjugates is a key step to improving their in vivo efficacy. N-Acetylcysteine (NAC) is an anti-inflammatory agent with significant potential for clinical use in the treatment of neuroinflammation, stroke and cerebral palsy. There is a need for delivery of NAC which can enhance its efficacy, reduce dosage and prevent it from binding plasma proteins. For this purpose, a poly(amidoamine) dendrimer-NAC conjugate that contains a disulfide linkage was synthesized and evaluated for its release kinetics in the presence of glutathione (GSH), Cysteine (Cys), and bovine serum albumin (BSA) at both physiological and lysosomal pH. The results indicate that the prepared conjugate can deliver ~60% of its NAC payload within 1 hour at intracellular GSH concentrations at physiological pH, whereas the conjugate did not release any drug at plasma GSH levels. The stability of the conjugate in the presence of bovine serum albumin at plasma concentrations was also demonstrated. The efficacy of the dendrimer-NAC conjugate was measured in activated microglial cells (target cells in vivo) using the reactive oxygen species (ROS) assay. The conjugates showed an order of magnitude increase in anti-oxidant activity compared to free drug. When combined with intrinsic and ligand-based targeting with dendrimers, these types of GSH sensitive nanodevices can lead to improved drug release profiles and in vivo efficacy. PMID:19171376

  17. Binding sites of retinol and retinoic acid with serum albumins.

    PubMed

    Belatik, A; Hotchandani, S; Bariyanga, J; Tajmir-Riahi, H A

    2012-02-01

    Retinoids are effectively transported in the bloodstream via serum albumins. We report the complexation of bovine serum albumin (BSA) with retinol and retinoic acid at physiological conditions, using constant protein concentration and various retinoid contents. FTIR, CD and fluorescence spectroscopic methods and molecular modeling were used to analyze retinoid binding site, the binding constant and the effects of complexation on BSA stability and secondary structure. Structural analysis showed that retinoids bind BSA via hydrophilic and hydrophobic interactions with overall binding constants of K(Ret)(-BSA) = 5.3 (±0.8) × 10(6) M(-1) and K(Retac-BSA) = 2.3 (±0.4) × 10(6) M(-1). The number of bound retinoid molecules (n) was 1.20 (±0.2) for retinol and 1.8 (±0.3) for retinoic acid. Molecular modeling showed the participation of several amino acids in retinoid-BSA complexes stabilized by H-bonding network. The retinoid binding altered BSA conformation with a major reduction of α-helix from 61% (free BSA) to 36% (retinol-BSA) and 26% (retinoic acid-BSA) with an increase in turn and random coil structures indicating a partial protein unfolding. The results indicate that serum albumins are capable of transporting retinoids in vitro and in vivo.

  18. Interaction of amphiphilic drugs with human and bovine serum albumins

    NASA Astrophysics Data System (ADS)

    Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd. Sajid; Khan, Rizwan Hasan; Kabir-ud-Din

    2012-11-01

    To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (kq) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes.

  19. Interaction of amphiphilic drugs with human and bovine serum albumins.

    PubMed

    Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd Sajid; Khan, Rizwan Hasan; Kabir-Ud-Din

    2012-11-01

    To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (k(q)) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes.

  20. Binding of several benzodiazepines to bovine serum albumin: Fluorescence study

    NASA Astrophysics Data System (ADS)

    Machicote, Roberta G.; Pacheco, María E.; Bruzzone, Liliana

    2010-10-01

    The interactions of lorazepam, oxazepam and bromazepam with bovine serum albumin (BSA) were studied by fluorescence spectrometry. The Stern-Volmer quenching constants and corresponding thermodynamic parameters Δ H, Δ G and Δ S were calculated. The binding constants and the number of binding sites were also investigated. The distances between the donor (BSA) and the acceptors (benzodiazepines) were obtained according to fluorescence resonance energy transfer and conformational changes of BSA were observed from synchronous fluorescence spectra.

  1. Calcium inhibits diacylglycerol uptake by serum albumin.

    PubMed

    Ahyayauch, Hasna; Arana, Gorka; Sot, Jesús; Alonso, Alicia; Goñi, Félix M

    2009-03-01

    Serum albumin is an abundant protein in blood plasma, that is well-known for its ability to transport hydrophobic biomolecules and drugs. Recent hypotheses propose that serum albumin plays a role in the regulation of lipid metabolism in addition to its lipid transport properties. The present work explores the capacity of bovine serum albumin (BSA) to extract diacylglycerols (DAG) from phospholipid bilayers, and the inhibition of such interaction by divalent cations. Quantitative measurements using radioactive DAG and morphological evidence derived from giant unilamellar vesicles examined by confocal microscopy provide concurrent results. BSA extracts DAG from vesicles consisting of phosphatidylinositol/DAG. Long, saturated DAG species are incorporated more readily than the shorter-chain or unsaturated ones. Divalent cations hinder DAG uptake by BSA. For Ca(2+), the concentration causing half-maximal inhibition is approximately 10 muM; 90% inhibition is caused by 100 muM Ca(2+). Sr(2+) requires concentrations one order of magnitude higher, while Mg(2+) has virtually no effect. As an example on how DAG uptake by BSA, and its inhibition by Ca(2+), could play a regulating role in lipid metabolism, a PI-specific phospholipase C has been assayed in the presence of BSA and/or Ca(2+). BSA activates the enzyme by removing the end-product DAG, but the activation is reverted by Ca(2+) that inhibits DAG uptake.

  2. A selective, long-lived deep-red emissive ruthenium(II) polypyridine complexes for the detection of BSA.

    PubMed

    Babu, Eththilu; Muthu Mareeswaran, Paulpandian; Singaravadivel, Subramanian; Bhuvaneswari, Jayaraman; Rajagopal, Seenivasan

    2014-09-15

    A selective, label free luminescence sensor for bovine serum albumin (BSA) is investigated using ruthenium(II) complexes over the other proteins. Interaction between BSA and ruthenium(II) complexes has been studied using absorption, emission, excited state lifetime and circular dichroism (CD) spectral techniques. The luminescence intensity of ruthenium(II) complexes (I and II), has enhanced at 602 and 613 nm with a large hypsochromic shift of 18 and 5 nm respectively upon addition of BSA. The mode of binding of ruthenium(II) complexes with BSA has analyzed using computational docking studies.

  3. Spectroscopic studies on the interaction between phycocyanin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Kathiravan, A.; Chandramohan, M.; Renganathan, R.; Sekar, S.

    2009-02-01

    Bluish phycocyanin was obtained from the cyanobacteria namely Spirulina sp. (marine form). The interaction between phycocyanin and bovine serum albumin (BSA) was studied by using absorption, FT-IR, steady-state, time resolved and synchronous fluorescence spectroscopy. Phycocyanin effectively quenched the intrinsic fluorescence of BSA. The number of binding sites ( n) and binding constant ( K) was measured by fluorescence quenching method. The interaction between phycocyanin and BSA occurs through static quenching and conformational changes of BSA were observed.

  4. Fluorescence resonance energy transfer between bovine serum albumin and fluoresceinamine.

    PubMed

    Bai, Zhijun; Liu, Yushuang; Zhang, Ping; Guo, Jun; Ma, Yuxing; Yun, Xiaoling; Zhao, Xinmin; Zhong, Ruibo; Zhang, Feng

    2016-05-01

    Physical binding-mediated organic dye direct-labelling of proteins could be a promising technology for bio-nanomedical applications. Upon binding, it was found that fluorescence resonance energy transfer (FRET) occurred between donor bovine serum albumin (BSA; an amphiphilic protein) and acceptor fluoresceinamine (FA; a hydrophobic fluorophore), which could explain fluorescence quenching found for BSA. FRET efficiency and the distance between FA and BSA tryptophan residues were determined to 17% and 2.29 nm, respectively. Using a spectroscopic superimposition method, the saturated number of FAs that bound to BSA was determined as eight to give a complex formula of FA8-BSA. Finally, molecular docking between BSA and FA was conducted, and conformational change that occurred in BSA upon binding to FA molecules was also studied by three-dimensional fluorescence microscopy.

  5. Effect of albumin on the kinetics of ascorbate oxidation.

    PubMed

    Lozinsky, E; Novoselsky, A; Shames, A I; Saphier, O; Likhtenshtein, G I; Meyerstein, D

    2001-04-03

    The fluorescence intensity of the fluorophore in dansyl piperidine-nitroxide is intramolecularly quenched by the nitroxyl fragment. Therefore, the oxidation of ascorbic acid by the fluorophore-nitroxide (FN) probe can be monitored by two independent methods: steady-state fluorescence and electron paramagnetic resonance. Bovine serum albumin (BSA) affects the rate of this reaction. The influence of BSA on the rate is attributed to the adsorption of both ascorbate and the probe to BSA. Adsorption of ascorbate to BSA is confirmed by NMR relaxation experiments. The spatial distribution of the molecules on the BSA surface changes the availability of ascorbate and FN to each other. The results also point out that, in the presence of BSA, the autoxidation of ascorbate is significantly slowed down. The effect is studied at different pH values and explained in terms of the electrostatic interaction between the ascorbate anion and the BSA molecule.

  6. Binding of Sulpiride to Seric Albumins.

    PubMed

    da Silva Fragoso, Viviane Muniz; de Morais Coura, Carla Patrícia; Hoppe, Luanda Yanaan; Soares, Marília Amável Gomes; Silva, Dilson; Cortez, Celia Martins

    2016-01-04

    The aim of this work was to study the interaction of sulpiride with human serum albumin (HSA) and bovine serum albumin (BSA) through the fluorescence quenching technique. As sulpiride molecules emit fluorescence, we have developed a simple mathematical model to discriminate the quencher fluorescence from the albumin fluorescence in the solution where they interact. Sulpiride is an antipsychotic used in the treatment of several psychiatric disorders. We selectively excited the fluorescence of tryptophan residues with 290 nm wavelength and observed the quenching by titrating HSA and BSA solutions with sulpiride. Stern-Volmer graphs were plotted and quenching constants were estimated. Results showed that sulpiride form complexes with both albumins. Estimated association constants for the interaction sulpiride-HSA were 2.20 (±0.08) × 10⁴ M(-1), at 37 °C, and 5.46 (±0.20) × 10⁴ M(-1), at 25 °C. Those for the interaction sulpiride-BSA are 0.44 (±0.01) × 10⁴ M(-1), at 37 °C and 2.17 (±0.04) × 10⁴ M(-1), at 25 °C. The quenching intensity of BSA, which contains two tryptophan residues in the peptide chain, was found to be higher than that of HSA, what suggests that the primary binding site for sulpiride in albumin should be located next to the sub domain IB of the protein structure.

  7. Binding of Sulpiride to Seric Albumins

    PubMed Central

    da Silva Fragoso, Viviane Muniz; de Morais Coura, Carla Patrícia; Hoppe, Luanda Yanaan; Soares, Marília Amável Gomes; Silva, Dilson; Cortez, Celia Martins

    2016-01-01

    The aim of this work was to study the interaction of sulpiride with human serum albumin (HSA) and bovine serum albumin (BSA) through the fluorescence quenching technique. As sulpiride molecules emit fluorescence, we have developed a simple mathematical model to discriminate the quencher fluorescence from the albumin fluorescence in the solution where they interact. Sulpiride is an antipsychotic used in the treatment of several psychiatric disorders. We selectively excited the fluorescence of tryptophan residues with 290 nm wavelength and observed the quenching by titrating HSA and BSA solutions with sulpiride. Stern-Volmer graphs were plotted and quenching constants were estimated. Results showed that sulpiride form complexes with both albumins. Estimated association constants for the interaction sulpiride–HSA were 2.20 (±0.08) × 104 M−1, at 37 °C, and 5.46 (±0.20) × 104 M−1, at 25 °C. Those for the interaction sulpiride-BSA are 0.44 (±0.01) × 104 M−1, at 37 °C and 2.17 (±0.04) × 104 M−1, at 25 °C. The quenching intensity of BSA, which contains two tryptophan residues in the peptide chain, was found to be higher than that of HSA, what suggests that the primary binding site for sulpiride in albumin should be located next to the sub domain IB of the protein structure. PMID:26742031

  8. Competitive interactions between glucose and lactose with BSA: which sugar is better for children?

    PubMed

    Zhang, Qiulan; Ni, Yongnian; Kokot, Serge

    2016-04-07

    The interactions of the sugars glucose and lactose with the transport protein bovine serum albumin (BSA) were investigated using fluorescence, FT-IR and circular dichroism (CD) techniques. The results indicated that glucose could be bonded and transported by BSA, mainly involving hydrogen bonds and van der Waals interactions (ΔH = -86.13 kJ mol(-1)). The obtained fluorescence data from the binding of sugar and BSA were processed by the multivariate curve resolution-alternating least squares (MCR-ALS) method, and the extracted concentration profiles showed that the equilibrium constant, rglucose:BSA, was about 7. However, the binding of lactose to BSA did not quench the fluorescence significantly, and this indicated that lactose could not be directly transported by BSA. The binding experiments were further performed using the fluorescence titration method in the presence of calcium and BSA. Calcium was added so that the calcium/BSA reactions could be studied in the presence or absence of glucose, lactose or hydrolysis products. The results showed that hydrolyzed lactose seemed to enhance calcium absorption in bovine animals. It would also appear that for children, lactose provides better nutrition; however, glucose is better for adults.

  9. BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates.

    PubMed

    Yang, Bin; Wyman, Charles E

    2006-07-05

    Cellulase and bovine serum albumin (BSA) were added to Avicel cellulose and solids containing 56% cellulose and 28% lignin from dilute sulfuric acid pretreatment of corn stover. Little BSA was adsorbed on Avicel cellulose, while pretreated corn stover solids adsorbed considerable amounts of this protein. On the other hand, cellulase was highly adsorbed on both substrates. Adding a 1% concentration of BSA to dilute acid pretreated corn stover prior to enzyme addition at 15 FPU/g cellulose enhanced filter paper activity in solution by about a factor of 2 and beta-glucosidase activity in solution by about a factor of 14. Overall, these results suggested that BSA treatment reduced adsorption of cellulase and particularly beta-glucosidase on lignin. Of particular note, BSA treatment of pretreated corn stover solids prior to enzymatic hydrolysis increased 72 h glucose yields from about 82% to about 92% at a cellulase loading of 15 FPU/g cellulose or achieved about the same yield at a loading of 7.5 FPU/g cellulose. Similar improvements were also observed for enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated corn stover and Douglas fir treated by SO(2) steam explosion and for simultaneous saccharification and fermentation (SSF) of BSA pretreated corn stover. In addition, BSA treatment prior to hydrolysis reduced the need for beta-glucosidase supplementation of SSF. The results are consistent with non-specific competitive, irreversible adsorption of BSA on lignin and identify promising strategies to reduce enzyme requirements for cellulose hydrolysis.

  10. Spectroscopic identification of interactions of Pb2+ with bovine serum albumin.

    PubMed

    Liu, Yihong; Zhang, Lijun; Liu, Rutao; Zhang, Pengjun

    2012-01-01

    The effect of Pb(2+) targeted to bovine serum albumin (BSA) in vitro was investigated by fluorescence, synchronous fluorescence, UV absorption and circular dichroism (CD) spectrophotometry. The characteristic fluorescence of BSA was quenched, which indicated that Pb(2+) changed the skeleton of BSA and caused the gradual exposure of aromatic amino acid residues (Trp, Tyr, Phe) in the internal hydrophobic region of BSA. When the concentration of Pb(2+) was higher than 1 × 10(-4) mol/L, the BSA was completely denatured. The excess lead ion interacted with the aromatic amino acid residues of BSA exposed to the solution, which decreased the fluorescence of BSA further. According to the experiment results, we found that a lead-BSA complex was formed following static quenching and the binding site was calculated approximately equal to 1. This work reflected the interaction mechanism of BSA and Pb(2+) from the perspective of spectroscopy.

  11. Albumin Test

    MedlinePlus

    ... may also be ordered to evaluate a person's nutritional status. ^ Back to top When is it ordered? An ... albumin test to check or monitor a person's nutritional status. However, since albumin concentrations respond to a variety ...

  12. Bovine serum albumin promotes IL-1beta and TNF-alpha secretion by N9 microglial cells.

    PubMed

    Zhao, Tian-zhi; Xia, Yong-zhi; Li, Lan; Li, Jian; Zhu, Gang; Chen, Shi; Feng, Hua; Lin, Jiang-kai

    2009-10-01

    Bovine serum albumin (BSA) is generally used in biomedical experiments. In the solution of some reagents, BSA is necessary to maintain the stability and concentration of the effective component. Therefore, the potential impact of BSA on experimental results should not be neglected when BSA is used. In this study, we observed that BSA induced significant upregulation of mRNA expression and release of pro-inflammatory cytokines, IL-1beta, and TNF-alpha, by N9 microglial cells. Our results suggest that the effects of BSA should be taken into account in experiments on microglia or the central nervous system when BSA is used. In light of the high similarity and homology among mammalian albumins, our findings also indicate that serum albumin may be a potent trigger of cytokine release by microglia.

  13. Production of BSA-poly(ethyl cyanoacrylate) nanoparticles as a coating material that improves wetting property

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alkyl cyanoacrylates have long been used for the synthesis of colloidal nanoparticles. In the involved polymerization reaction, OH- ions derived from dissociation of water have been used as an initiator. In the current research, an animal protein, bovine serum albumin (BSA) molecules were utilized a...

  14. Radioimmunoassay for medroxyprogesterone acetate (Provera) using the 11alpha-hydroxy succinyl conjugate.

    PubMed

    Royer, M E; Ko, H; Campbell, J A; Murray, H C; Evans, J S; Kaiser, D G

    1974-05-01

    The development of a radioimmunoassay for medroxyprogesterone acetate (MPA) employing rabbit antibodies made against a bovine serum albumin (BSA) conjugate of the hemisuccinate ester of 11alpha-hydroxy MPA are described. The 11alpa-hydroxyl group was introduced into MPA by a series of chemical and microbiological transformations. The acid succinate MPA was coupled to BSA by reacting it with N,N'-carbonyldiimidazole. Cross-reactivities of several MPA analogs were compared suing rabbit antisera developed against the C-11 conjugate of MPA and goat antiserum developed against a C-3 conjugate of MPA. Antibodies formed against the C-11 conjugate showed increased specificity to steroid analogs which changes in the C-21 side chain. The profiles of serum MPA levels vs time, measured with both the C-3 and C-11 antisera, after oral drug administration to the monkey were similar. After intramuscular drug administration to dogs, serum MPA levels measured with the C-3 antisera were consistently greater as compared with those with C-11 antisera. Factors affecting precipitation of the antibody-antigen complex, assay precision, and assay sensitivity were evaluated.

  15. Albumin holograms

    NASA Astrophysics Data System (ADS)

    Ordóñez-Padilla, M. J.; Olivares-Pérez, A.; Vega-Criollo, R.; Berriel-Valdos, L. R.; Mejias-Brizuela, N. Y.

    2011-02-01

    A Characterization is made with performance analysis of new photosensitive films of albumin to certain conditions for holographic recording based on interferometric array. We carried out the photo-oxidation of gallus gallus albumin albumin chemically combining powdered sugar (Glass ®) to an aqueous solution of ammonium dichromate. It was the analysis of the behavior of diffraction efficiency parameter through the intensity diffraction pattern produced by the gratings made with albumin.

  16. Preparation and investigation of Ulex europaeus agglutinin I-conjugated liposomes as potential oral vaccine carriers.

    PubMed

    Li, KeXin; Chen, DaWei; Zhao, XiuLi; Hu, HaiYang; Yang, ChunRong; Pang, DaHai

    2011-11-01

    We prepared and optimized Ulex europaeus agglutinin I (UEAI)-modified Bovine serum albumin (BSA)-encapsulating liposomes (UEAI-LIP) as oral vaccine carriers and examined the feasibility of inducing systemic and mucosal immune responses by oral administration of UEAILIP. The prepared systems were characterized in vitro for their average size, zeta potential, encapsulation efficiency (EE%) and conjugation efficiency (CE%). In vitro release studies indicated that the presence of UEAI around the optimized liposomes was able to prevent a burst release of loaded BSA and provide sustained release of the encapsulated protein. In vivo immune-stimulating results in KM mice showed that BSA given intramuscularly generated systemic response only but both systemic and mucosal immune responses could be induced simultaneously in the groups in which BSA-loaded liposomes (LIP) and UEAI-LIP were administered intragastrically. Furthermore, the modification of UEAI on the surface of liposomes could further enhance the IgA and IgG levels obviously. In conclusion, this study demonstrated the high potential of lectin-modified liposomes containing the antigen as carriers for oral vaccine.

  17. Chemiluminescence and fluorescence spectrum methods for determination of Aflatoxin B1 mediated by FCLA + BSA

    NASA Astrophysics Data System (ADS)

    Chen, WenLi; Xing, Da

    2005-04-01

    BSA (Bovine Serum Albumin) can enlarge the CL intensity of FCLA(3,7-dihydro-6-{4-{2-(N'-(5-fluoresceinyl) thioureido)ethoxy}phenyl}-2-methylimi-dazo{1,2-a}pyrazin-3-one dosium salt) to 763%. This report presents novel methods for determination of Aflatoxin B1 (AfB1) mediated by FCLA+BSA. The concentration of AFB1 showed an obvious positive correlation with the chemiluminescence (CL) intensity mediated by FCLA+BSA, correlative coefficient R@0.94. This method could measure accurately ng/ml of AfB1 concentration. 365nm as excitated wavelength, 440nm and 520nm-two fluorescence peaks of FCLA+BSA+AfB1 were found. The fluorescence intensity of peak at 440nm showed an obvious positive correlation with the concentration of AFB1, R@0.97; the fluorescence intensity of peak at 520nm showed a positive correlation with the concentration of AFB1, R@0.90. Comparing the peak of FCLA, FCLA+BSA and FCLA+BSA+AfB1 had a 6nm Einstein shift (red shift). The study suggested that CL and fluorescence spectrum methods mediated by FCLA+BSA might be applicable to the determination of AfB1 concentration.

  18. Complexation of serum albumins and triton X-100: Quenching of tryptophan fluorescence and analysis of the rotational diffusion of complexes

    NASA Astrophysics Data System (ADS)

    Vlasova, I. M.; Vlasov, A. A.; Saletskii, A. M.

    2016-07-01

    The polarized and nonpolarized fluorescence of bovine serum albumin and human serum albumin in Triton X-100 solutions is studied at different pH values. Analysis of the constants of fluorescence quenching for BSA and HSA after adding Triton X-100 and the hydrodynamic radii of BSA/HSA-detergent complexes show that the most effective complexation between both serum albumins and Triton X-100 occurs at pH 5.0, which lies near the isoelectric points of the proteins. Complexation between albumin and Triton X-100 affects the fluorescence of the Trp-214 residing in the hydrophobic pockets of both BSA and HSA.

  19. Interaction of potassium mono and di phosphates with bovine serum albumin studied by fluorescence quenching method.

    PubMed

    Bakkialakshmi, S; Shanthi, B; Chandrakala, D

    2011-03-01

    The interactions between potassium mono and di phosphates and bovine serum albumin (BSA) were studied using fluorescence spectroscopy (FS) and ultraviolet spectroscopy (UV). The experimental results showed that the potassium mono and di phosphates could insert into the BSA and quench the inner fluorescence of BSA by forming the potassium mono phosphate-BSA and pottassium di phosphate-BSA complexes. It was found that the static quenching was the main reason leading to the fluorescence quenching. It was conformed by XRD and SEM techniques.

  20. Folate-bovine serum albumin functionalized polymeric micelles loaded with superparamagnetic iron oxide nanoparticles for tumor targeting and magnetic resonance imaging.

    PubMed

    Li, Huan; Yan, Kai; Shang, Yalei; Shrestha, Lochan; Liao, Rufang; Liu, Fang; Li, Penghui; Xu, Haibo; Xu, Zushun; Chu, Paul K

    2015-03-01

    Polymeric micelles functionalized with folate conjugated bovine serum albumin (FA-BSA) and loaded with superparamagnetic iron oxide nanoparticles (SPIONs) are investigated as a specific contrast agent for tumor targeting and magnetic resonance imaging (MRI) in vitro and in vivo. The SPIONs-loaded polymeric micelles are produced by self-assembly of amphiphilic poly(HFMA-co-MOTAC)-g-PEGMA copolymers and oleic acid modified Fe3O4 nanoparticles and functionalized with FA-BSA by electrostatic interaction. The FA-BSA modified magnetic micelles have a hydrodynamic diameter of 196.1 nm, saturation magnetization of 5.5 emu/g, and transverse relaxivity of 167.0 mM(-1) S(-1). In vitro MR imaging, Prussian blue staining, and intracellular iron determination studies demonstrate that the folate-functionalized magnetic micelles have larger cellular uptake against the folate-receptor positive hepatoma cells Bel-7402 than the unmodified magnetic micelles. In vivo MR imaging conducted on nude mice bearing the Bel-7402 xenografts after bolus intravenous administration reveals excellent tumor targeting and MR imaging capabilities, especially at 24h post-injection. These findings suggest the potential of FA-BSA modified magnetic micelles as targeting MRI probe in tumor detection.

  1. Complexes of photosensitizer and CdSe/ZnS quantum dots passivated with BSA: optical properties and intracomplex energy transfer

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Vera; Orlova, Anna; Martynenko, Irina; Kundelev, Evgeny; Maslov, Vladimir; Fedorov, Anatoly; Baranov, Alexander; Gun'ko, Yurii

    2016-04-01

    Here we report our investigations of the formation conditions and photophysical properties of complexes between luminescent semiconducting nanoparticles (quantum dots, QDs) and the photosensitizer chlorin e6, which is widely used for the photodynamic therapy. In our complexes, bovine serum albumin (BSA), the most abundant protein in blood serum, was used as a linker between QDs and chlorin e6 molecules. The influence of BSA on the optical properties of Ce6 and QDs in complexes was properly examined using spectral-luminescent methods. It was found that BSA passivated QD surface and substantially QD quantum yield of luminescence was increased. In addition, BSA prevented the aggregation of chlorin e6 molecules in complexes with QDs. We demonstrated that the use of BSA as a linker allows to create functional QD-chlorin e6 complexes with effective photoexcitation energy transfer from QDs to the molecules.

  2. Ultrastable BSA-capped gold nanoclusters with a polymer-like shielding layer against reactive oxygen species in living cells

    NASA Astrophysics Data System (ADS)

    Zhou, Wenjuan; Cao, Yuqing; Sui, Dandan; Guan, Weijiang; Lu, Chao; Xie, Jianping

    2016-05-01

    The prevalence of reactive oxygen species (ROS) production and the enzyme-containing intracellular environment could lead to the fluorescence quenching of bovine serum albumin (BSA)-capped gold nanoclusters (AuNCs). Here we report an efficient strategy to address this issue, where a polymer-like shielding layer is designed to wrap around the Au core to significantly improve the stability of AuNCs against ROS and protease degradation. The key of our design is to covalently incorporate a thiolated AuNC into the BSA-AuNC via carbodiimide-activated coupling, leading to the formation of a AuNC pair inside the cross-linked BSA molecule. The as-designed paired AuNCs in BSA (or BSA-p-AuNCs for short) show improved performances in living cells.The prevalence of reactive oxygen species (ROS) production and the enzyme-containing intracellular environment could lead to the fluorescence quenching of bovine serum albumin (BSA)-capped gold nanoclusters (AuNCs). Here we report an efficient strategy to address this issue, where a polymer-like shielding layer is designed to wrap around the Au core to significantly improve the stability of AuNCs against ROS and protease degradation. The key of our design is to covalently incorporate a thiolated AuNC into the BSA-AuNC via carbodiimide-activated coupling, leading to the formation of a AuNC pair inside the cross-linked BSA molecule. The as-designed paired AuNCs in BSA (or BSA-p-AuNCs for short) show improved performances in living cells. Electronic supplementary information (ESI) available: Detailed experimental materials, apparatus, experimental procedures and characterization data. See DOI: 10.1039/c6nr02178f

  3. Mycobacterial cell-wall skeleton as a universal vaccine vehicle for antigen conjugation.

    PubMed

    Paik, Tae-Hyun; Lee, Ji-Sook; Kim, Ki-Hye; Yang, Chul-Su; Jo, Eun-Kyeong; Song, Chang-Hwa

    2010-11-23

    Mycobacterial cell-wall skeleton (CWS) is an immunoactive and biodegradable particulate adjuvant and has been used for immunotherapy in patients with cancer. The CWS of Mycobacterium bovis bacillus Calmette-Guérin (BCG-CWS) was studied as a universal vaccine vehicle for antigen conjugation, to develop potentially effective and safe vaccines. Here, we describe experiments in which protein antigens, such as keyhole limpet haemocyanin (KLH), ovalbumin (OVA) and bovine serum albumin (BSA) were highly efficiently coupled to 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS)-activated carboxyl groups of BCG-CWS, and tested the immunogenicity of OVA-conjugated BCG-CWS vaccine. We found that a strong immune response was induced in mice immunised with OVA-conjugated BCG-CWS, which was similar to the enhancement of the immune responses in mice immunised with OVA and complete Freund's adjuvant. Covalent conjugation of OVA to BCG-CWS was essential for Th1-skewed immune responses, with prominent expression of IFN-γ. Furthermore, antigen-conjugated BCG-CWS vaccine is simple to manufacture, safe, and easy to use. Our results suggest that mycobacterial CWS as a universal vaccine vehicle for conjugation of a wide variety of antigens constitutes a breakthrough for development of the most promising vaccines for infections, allergic diseases, and cancer.

  4. Concentration of BSA using a superabsorbent polymer: process evaluation.

    PubMed

    Prazeres, D M

    1995-04-15

    A commercially available super absorbent polymer from Hoechst (Sanwet IM-5000-SG) was tested for the concentration of dilute solutions of bovine serum albumin (BSA). A systematic study was undertaken in order to evaluate the possibility of scaling-up the process. The polymer was first characterized by determining the swelling ratio (or mass increase) in aqueous solution as a function of time, temperature, pH, salt and polymer concentration. The swelling ratio was found to be independent of the polymer concentration, temperature (range 15-50 degree C), and pH (range 4-10), but decreased significantly with an increase in NaCL concentration. The polymer was capable of absorbing as much as 300-times its own weight in water, when using the most favorable conditions (0 mM NaCL). BSA was concentrated up to 3.5-times when using the appropriate polymer concentration. The recovery of protein was around 100% for concentration factors below 2.0, but decreased for higher concentration factors. As expected from the characterization results, higher amounts of polymer were needed to concentrate BSA solutions with higher salt concentrations. The performance of the process improved when using lower concentration BSA solutions (0.15 to 0.5 mg ml-1). The initial volume (10 to 500 ml) had a slight effect on the process due to a decrease in the rate of the absorption process. The concentration factor was predicted from the NaCL and polymer concentrations through a semi empirical model.

  5. Quenching interaction of BSA with DTAB is dynamic in nature: A spectroscopic insight

    NASA Astrophysics Data System (ADS)

    Das, Nirmal Kumar; Pawar, Lavanya; Kumar, Naveen; Mukherjee, Saptarshi

    2015-08-01

    The role of electrostatic interactions between the protein, Bovine Serum Albumin (BSA) and the cationic surfactant, dodecyltrimethylammonium bromide (DTAB) has been substantiated using spectroscopic approaches. The primary mechanism of fluorescence quenching of the tryptophan of BSA is most probably dynamic in nature as the complex formation resulting in a protein-surfactant assembly is not very spontaneous. The weak interaction buries the tryptophan amino acid residue inside the protein scaffolds which have been quantitatively proved by our acrylamide quenching studies. The loss in the secondary structure of the protein as a result of interaction with DTAB has been elucidated by CD spectroscopy.

  6. Symmetrical and asymmetrical cyanine dyes. Synthesis, spectral properties, and BSA association study.

    PubMed

    Pisoni, Diego S; Todeschini, Letícia; Borges, Antonio César A; Petzhold, Cesar L; Rodembusch, Fabiano S; Campo, Leandra F

    2014-06-20

    New cyanines were prepared by an efficient and practical route with satisfactory overall yield from low-cost starting materials. The photophysical behavior of the cyanines was investigated using UV-vis and steady-state fluorescence in solution, as well as their association with bovine serum albumin (BSA) in phosphate buffer solution (PBS). No cyanine aggregation was observed in organic solvents or in phosphate buffer solution. The alkyl chain length in the quaternized nitrogen was shown to be fundamental for BSA detection in PBS in these dyes.

  7. Structures of bovine, equine and leporine serum albumin.

    PubMed

    Bujacz, Anna

    2012-10-01

    Serum albumin first appeared in early vertebrates and is present in the plasma of all mammals. Its canonical structure supported by a conserved set of disulfide bridges is maintained in all mammalian serum albumins and any changes in sequence are highly correlated with evolution of the species. Previous structural investigations of mammalian serum albumins have only concentrated on human serum albumin (HSA), most likely as a consequence of crystallization and diffraction difficulties. Here, the crystal structures of serum albumins isolated from bovine, equine and leporine blood plasma are reported. The structure of bovine serum albumin (BSA) was determined at 2.47 Å resolution, two crystal structures of equine serum albumin (ESA) were determined at resolutions of 2.32 and 2.04 Å, and that of leporine serum albumin (LSA) was determined at 2.27 Å resolution. These structures were compared in detail with the structure of HSA. The ligand-binding pockets in BSA, ESA and LSA revealed different amino-acid compositions and conformations in comparison to HSA in some cases; however, much more significant differences were observed on the surface of the molecules. BSA, which is one of the most extensively utilized proteins in laboratory practice and is used as an HSA substitute in many experiments, exhibits only 75.8% identity compared with HSA. The higher resolution crystal structure of ESA highlights the binding properties of this protein because it includes several bound compounds from the crystallization solution that provide additional structural information about potential ligand-binding pockets.

  8. Improved dermal delivery of FITC-BSA using a combination of passive and active methods.

    PubMed

    Wang, Qing; Jaimes-Lizcano, Yuly A; Lawson, Louise B; John, Vijay T; Papadopoulos, Kyriakos D

    2011-11-01

    This work presents results on the in vitro penetration of a model macromolecule [fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA)] through porcine skin, mediated with a microneedle skinroller (200-µm-length needle) and different novel formulations. After perforating the porcine skin with a microneedle skinroller, the efficiency of delivering FITC-BSA via different novel formulations was evaluated and compared. Formulations, including l-α-phosphatidylcholine (PC) liposomes, double emulsions, and double-encapsulation formulations were used. High-resolution cryo-scanning electron microscopy was used to visualize surface morphology and cross-section of perforated porcine skin. By the use of confocal microscopy, the penetration pathway and penetration depth of FITC-BSA through the perforated porcine skin under different formulations were analyzed. FITC-BSA was extracted from stratum corneum and viable skin, and analyzed by fluorimetry, indicating that there is no significant difference in the amount of FITC-BSA delivered to viable skin by PC-liposome suspension (12.90 ± 1.25 µg/cm(2)) versus double-encapsulation formulations (10.47 ± 0.80 µg/cm(2)); however, both formulations showed a significant increase as compared with an aqueous solution of FITC-BSA. In this work, double-encapsulation formulations were used in dermal delivery for the first time and combined with microneedle skinroller treatment, the results showed a high efficiency in delivering macromolecules.

  9. Evaluation of BSA protein release from hollow hydroxyapatite microspheres into PEG hydrogel

    PubMed Central

    Fu, Hailuo; Rahaman, Mohamed N.; Brown, Roger F.; Day, Delbert E.

    2013-01-01

    Implants that simultaneously function as an osteoconductive matrix and as a device for local drug or growth factor delivery could provide an attractive system for bone regeneration. In our previous work, we prepared hollow hydroxyapatite (abbreviated HA) microspheres with a high surface area, mesoporous shell wall and studied the release of a model protein, bovine serum albumin (BSA), from the microspheres into phosphate-buffered saline (PBS). The present work is an extension of our previous work to study the release of BSA from similar HA microspheres into a biocompatible hydrogel, poly(ethylene glycol) (PEG). BSA-loaded HA microspheres were placed in a PEG solution which was rapidly gelled using ultraviolet radiation. The BSA release rate into the PEG hydrogel, measured using a spectrophotometric method, was slower than into PBS, and it was dependent on the initial BSA loading and on the microstructure of the microsphere shell wall. A total of 35–40% of the BSA initially loaded into the microspheres was released into PEG over ~14 days. The results indicate that these hollow HA microspheres have promising potential as an osteoconductive device for local drug or growth factor delivery in bone regeneration and in the treatment of bone diseases. PMID:23498254

  10. Synthesis of fluorescent BSA-Au NCs for the detection of Hg2+ ions

    NASA Astrophysics Data System (ADS)

    Chen, Po-Cheng; Chiang, Cheng-Kang; Chang, Huan-Tsung

    2013-01-01

    In this study, we present a simple heating approach for preparation of gold nanoclusters (Au NCs) using bovine serum albumin (BSA) as a template. At 70 °C, the reaction for the preparation of BSA-Au NCs is completed within 20 min. By conducting matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), we have found that the main product is BSA-Au20 NCs that emit at 660 nm when excited at 330 nm due to "molecular-like" behavior. The X-ray photoelectron spectroscopy data reveal that there are Au+ ions and Au atoms coexisting in the BSA-Au NCs. The as-prepared Au NCs show excellent stability over a wide pH range (2.0-10.0). The fluorescence and MALDI-MS data reveal that the changes in their fluorescence properties are due to the formation of various sizes of BSA-Au NCs for different periods of reaction time. The as-prepared BSA-Au NCs are selective and sensitive (limit of detection of 4 nM at a signal-to noise ratio 3) for the detection of Hg2+ ions through the d10-d10 metallophilic interaction of Au+ and Hg2+ that leads to a decrease in fluorescence. The present assay has been validated for the detection of Hg2+ ions in real water samples, with a result being in good agreement with that from inductively coupled plasma mass spectrometry.

  11. Effect of temperature on the metronidazole BSA interaction: Multi-spectroscopic method

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Jiang, Xin Yu; Chen, Xiao Qing; Chen, Yue

    2008-03-01

    The interaction between metronidazole and bovine serum albumin (BSA) was investigated using fluorescence spectroscopy (FS) and resonance light scattering spectroscopy (RLS). The apparent binding constants ( Ka) between metronidazole and BSA were 3.42 × 10 4 (20 °C), 5.78 × 10 4 (30 °C) and 8.23 × 10 4 L mol -1 (40 °C), and the binding sites values ( n) were 1.48 ± 0.03. The experimental results showed that the metronidazole could be inserted into the BSA, quenching the inner fluorescence by forming the metronidazole-BSA complex. The addition of increasing metronidazole to BSA solution leads to the gradual enhancement in RLS intensity, exhibiting the formation of the aggregate in solution. It was found that both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching. The entropy change and enthalpy change were positive, which indicated that the interaction of metronidazole and BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative.

  12. Nitidine chloride-assisted bio-functionalization of reduced graphene oxide by bovine serum albumin for impedimetric immunosensing.

    PubMed

    Li, Yu; Zhang, Zhao; Zhang, Yuting; Deng, Dongmei; Luo, Liqiang; Han, Baosan; Fan, Chunhai

    2016-05-15

    A novel protocol of label-free electrochemical impedance immunosensor based on bovine serum albumin-nitidine chloride-reduced graphene oxide (BSA-NC-rGO) nanocomposite was proposed for quantitative determination of carcino-embryonic antigen (CEA). BSA was anchored to rGO via the aromatic plane of NC by π-stacking interaction to realize bio-functionalization of rGO, and then gold nanoparticles (AuNPs) were electrodeposited onto the surface of BSA-NC-rGO nanocomposite. The morphology, conductivity and interaction of different nanocomposites were characterized by scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and UV-vis spectrum. CEA monoclonal antibody (anti-CEA) was conjugated to AuNPs via gold-thiol chemistry to construct electrochemical immunosensing platform, and the specific immunoreaction between CEA and anti-CEA was monitored by EIS. Under optimum conditions, CEA could be quantified in a wide range of 0.1-200 ng mL(-1) (R=0.9948) with low detection limit of 0.067 ng mL(-1). The proposed immunosensor exhibited great potential for detecting blood samples.

  13. The effect of different desolvating agents on BSA nanoparticle properties and encapsulation of curcumin

    NASA Astrophysics Data System (ADS)

    Sadeghi, R.; Moosavi-Movahedi, A. A.; Emam-jomeh, Z.; Kalbasi, A.; Razavi, S. H.; Karimi, M.; Kokini, J.

    2014-09-01

    The desolvation method was successfully used to prepare nanoparticles from bovine serum albumin (BSA) using ethanol, acetone, and their mixtures (70:30 and 50:50, respectively). Ethanol and mixtures of ethanol and acetone led to the most spherical nanoparticles, while using pure acetone resulted in a mixture of spherical and rod shape nanoparticle. Acetone was the solvent with higher encapsulation efficiency equal to 99.2 ± 0.36 %. The polydispersity values of BSA NPs in this study were 0.045 ± 0.007, 0.065 ± 0.013, 0.091 ± 0.012, and 0.120 ± 0.016 for ethanol (100) 4×, Et:Ac (70:30) 4×, Et:Ac (50:50) 4×, and acetone (100) 3×, respectively. Encapsulation efficiencies of curcumin inside BSA NPs were 19.4 ± 2.2 and 19.8 ± 1.6 % for 1.0 and 1.5 molar ratios of curcumin to BSA, respectively. Crosslinking using glutaraldehyde improved the stability of BSA NPs and curcumin-loaded BSA NPs and both groups of nanoparticles were stable for 1 month; the lyophilized curcumin-loaded BSA NPs were able to redisperse in water. The particle size and polydispersity index of redispersed NPs were higher than the original NPs before lyophilization. The size distribution study shows that after 10 s of sonication most nanoparticles were well dispersed; however, a small but significant fraction formed aggregates. Sonication for 10 s decreased the effective diameter and polydispersity of the redispersed nanoparticles, while increasing the sonication time to 20 s did not show significant changes. In vitro release study of curcumin from BSA NPs showed that these biocompatible nanoparticles have the ability to be used as a carrier to improve controlled release of curcumin.

  14. Study on the interactions of mapenterol with serum albumins using multi-spectroscopy and molecular docking.

    PubMed

    Bi, Shuyun; Zhao, Tingting; Wang, Yu; Zhou, Huifeng

    2016-03-01

    The interactions of mapenterol with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated systematically using fluorescence spectroscopy, absorption spectroscopy, circular dichroism (CD) and molecular docking techniques. Mapenterol has a strong ability to quench the intrinsic fluorescence of BSA and HSA through static quenching procedures. At 291 K, the binding constants, Ka, were 1.93 × 10(3) and 2.73 × 10(3) L/mol for mapenterol-BSA and mapenterol-HAS, respectively. Electrostatic forces and hydrophobic interactions played important roles in stabilizing the mapenterol-BSA/has complex. Using site marker competitive studies, mapenterol was found to bind at Sudlow site I on BSA/HSA. There was little effect of K(+), Ca(2+), Cu(2+), Zn(2+) and Fe(3+) on the binding. The conformation of BSA/HSA was changed by mapenterol, as seen from the synchronous fluorescence spectra. The CD spectra showed that the binding of mapenterol to BSA/HSA changed the secondary structure of BSA/HSA. Molecular docking further confirmed that mapenterol could bind to Sudlow site I of BSA/HSA. According to Förster non-radiative energy transfer theory (FRET), the distances r0 between the donor and acceptor were calculated as 3.18 and 2.75 nm for mapenterol-BSA and mapenterol-HAS, respectively.

  15. Rotational diffusion of bovine serum albumin denaturated by sodium dodecylsulfate, According to data from tryptophan fluorescence

    NASA Astrophysics Data System (ADS)

    Vlasova, I. M.; Zhuravleva, V. V.; Saletskii, A. M.

    2014-03-01

    The rotational diffusion of bovine serum albumin (BSA) molecules in solutions with different concentrations of the anionic detergent sodium dodecylsulfate (SDS) at different pH values is investigated, yielding information on the denaturation of BSA under the action of SDS. It is found from the increased degree of polarization in the tryptophan fluorescence of BSA and the registered parameters for the rotational diffusion of BSA molecules that the denaturation of BSA under the action of SDS at pH values less than the isoelectric point (pI) of BSA (4-9) is a two-stage process. It is shown that the first stage of BSA denaturation common for all pH values is the decondensation of BSA globules, while the second stage of BSA denaturation at pH greater than the pI of BSA is the unfolding of the protein's amino acid chain. It is concluded that the denaturation of BSA under the action of SDS proceeds more deeply at pH values greater than the pI of BSA.

  16. A Redox-Sensitive Micelle-Like Nanoparticle Self-Assembled from Amphiphilic Adriamycin-Human Serum Albumin Conjugates for Tumor Targeted Therapy

    PubMed Central

    Chen, Lin; Chen, Feng; Zhao, Mengxin; Zhu, Xiandi; Ke, Changhong; Yu, Jiangming; Yan, Zhiqiang; Zhang, Fulei; Sun, Yun; Chen, Di; Jiang, Cheng; Zhao, Xianxian; Gao, Yong; Guo, Shangjing; Li, Wei

    2015-01-01

    The application of chemotherapeutic drug adriamycin (ADR) in cancer therapy is limited by its side effects like high toxicity and insolubility. Nanomedicine offers new hope for overcoming the shortcomings. But how to increase in vivo stability and to control intracellular drug release is a key issue for nano-based formulations. Herein, the hydrophobic ADR was successfully linked to the biocompatible human serum albumin (HSA) by disulfide bond 3-(2-pyridyldithio) propionyl hydrazide (PDPH), resulting in amphiphilic HSA-ADR. The novel ADR-HSA micellar NPs which were thus assembled exhibited a well-defined stable core shell structure with glutathione (GSH) sensitive linkers. The stable PDPH linkers at extracellular level were broken by GSH at intracellular level with a controlled ADR release profile. The in vitro cytotoxicity against gastric cancer cells (NCI-N87) was obviously enhanced by such redox-sensitive ADR-HSA NPs. Additionally, as observed by IVIS Lumina II Imaging System (Xenogen), the intratumor accumulation of ADR-HSA NPs was much higher than that of HSA/ADR NPs due to its high stability. Consequently, the in vivo tumor inhibition was significantly promoted after intravenous administration to the Balb/c nude mice bearing gastric tumors. These in vitro/vivo results indicated that disulfide-bond-containing ADR-HSA NPs were an effective nanodrug delivery system for cancer therapy. PMID:26075280

  17. Denaturation of bovine serum albumin under the action of cetyltrimethylammonium bromide, according to data from fluorescence analysis

    NASA Astrophysics Data System (ADS)

    Vlasova, I. M.; Zhuravleva, V. V.; Saletskii, A. M.

    2013-06-01

    The tryptophan fluorescence of bovine serum albumin (BSA) in solutions with different concentrations of cationic detergent cetyltrimethylammonium bromide (CTAB) at different pH is investigated, providing information on BSA denaturation under the action of CTAB. It is found that BSA denaturation under the action of CTAB at all of the investigated pH values (3.5-8.0) is a single-stage process, as determined by BSA tryptophan fluorescence quenching, by an increased degree of the BSA tryptophan fluorescence polarization, and by the values of the parameters for the rotational diffusion of BSA molecules in CTAB solutions. It is shown that the cationic detergent CTAB is more efficient for BSA denaturation at pH values higher than the BSA isoelectric point (4.9).

  18. Bioactivity of albumins bound to silver nanoparticles.

    PubMed

    Mariam, Jessy; Sivakami, S; Kothari, D C; Dongre, P M

    2014-06-01

    The last decade has witnessed a tremendous rise in the proposed applications of nanomaterials in the field of medicine due to their very attractive physiochemical properties and novel actions such as the ability to reach previously inaccessible targets such as brain. However biological activity of functional molecules bound to nanoparticles and its physiological consequences is still unclear and hence this area requires immediate attention. The functional properties of Human Serum Albumin (HSA) and Bovine Serum Albumin (BSA) bound to silver nanoparticles (~60 nm) have been studied under physiological environment. Esterase activity, binding of drugs (warfarin and ibuprofen), antioxidant activity and copper binding by albumins was evaluated. The catalytic efficiencies of HSA and BSA diminished upon binding to silver nanoparticles. Perturbation in binding of warfarin and ibuprofen, loss of free sulphydryls, antioxidant activity and enhancement of copper binding were observed in albumins bound to nanoparticles. These alterations in functional activity of nanoparticle bound albumins which will have important consequences should be taken into consideration while using nanoparticles for diagnostic and therapeutic purposes.

  19. Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro

    PubMed Central

    SUZUKI, Chie; SAKAGUCHI, Yosuke; HOSHI, Hiroyoshi; YOSHIOKA, Koji

    2015-01-01

    The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and β-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin. PMID:26582048

  20. Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro.

    PubMed

    Suzuki, Chie; Sakaguchi, Yosuke; Hoshi, Hiroyoshi; Yoshioka, Koji

    2016-01-01

    The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and β-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin.

  1. BSA adsorption on bimodal PEO brushes.

    PubMed

    Bosker, W T E; Iakovlev, P A; Norde, W; Cohen Stuart, M A

    2005-06-15

    BSA adsorption onto bimodal PEO brushes at a solid surface was measured using optical reflectometry. Bimodal brushes consist of long (N=770) and short (N=48) PEO chains and were prepared on PS surfaces, applying mixtures of PS(29)-PEO(48) and PS(37)-PEO(770) block copolymers and using the Langmuir-Blodgett technique. Pi-A isotherms of (mixtures of) the block copolymers were measured to establish the brush regime. The isotherms of PS(29)-PEO(48) show hysteresis between compression and expansion cycles, indicating aggregation of the PS(29)-PEO(48) upon compression. Mixtures of PS(29)-PEO(48) and PS(37)-PEO(770) demonstrate a similar hysteresis effect, which eventually vanishes when the ratio of PS(37)-PEO(770) to PS(29)-PEO(48) is increased. The adsorption of BSA was determined at brushes for which the grafting density of the long PEO chains was varied, while the total grafting density was kept constant. BSA adsorption onto monomodal PEO(48) and PEO(770) brushes was determined for comparison. The BSA adsorption behavior of the bimodal brushes is similar to the adsorption of BSA at PEO(770) monomodal brushes. The maximum of BSA adsorption at low grafting density of PEO(770) can be explained by ternary adsorption, implying an attraction between BSA and PEO. The contribution of primary adsorption to the total adsorbed amount is negligible.

  2. Photothermal treatment of liver cancer with albumin-conjugated gold nanoparticles initiates Golgi Apparatus-ER dysfunction and caspase-3 apoptotic pathway activation by selective targeting of Gp60 receptor.

    PubMed

    Mocan, Lucian; Matea, Cristian; Tabaran, Flaviu A; Mosteanu, Ofelia; Pop, Teodora; Mocan, Teodora; Iancu, Cornel

    2015-01-01

    We present a method of enhanced laser thermal ablation of HepG2 cells based on a simple gold nanoparticle (GNP) carrier system such as serum albumin (Alb), and demonstrate its selective therapeutic efficacy compared with normal hepatocyte cells. HepG2 or hepatocytes were treated with Alb-GNPs at various concentrations and various incubation times, and further irradiated using a 2 W, 808 nm laser. Darkfield microscopy and immunochemical staining was used to demonstrate the selective internalization of Alb-GNPs inside the HepG2 cells via Gp60 receptors targeting. The postirradiation apoptotic rate of HepG2 cells treated with Alb-GNPs ranged from 25.8% (for 5 μg/mL) to 48.2% (for 50 μg/mL) at 60 seconds, while at 30 minutes the necrotic rate increased from 35.7% (5 μg/mL) to 52.3% (50 μg/mL), P-value <0.001. Significantly lower necrotic rates were obtained when human hepatocytes were treated with Alb-GNPs in a similar manner. We also showed by means of immunocytochemistry that photothermal treatment of Alb-conjugated GNPs in liver cancer initiates Golgi apparatus-endoplasmic reticulum dysfunction with consequent caspase-3 apoptotic pathway activation and cellular apoptosis. The presented results may become a new method of treating cancer cells by selective therapeutic vectors using nanolocalized thermal ablation by laser heating.

  3. A comparison of the physical properties of ultrasonically synthesized lysozyme- and BSA-shelled microbubbles.

    PubMed

    Vong, Fiona; Son, Younggyu; Bhuiyan, Sadia; Zhou, Meifang; Cavalieri, Francesca; Ashokkumar, Muthupandian

    2014-01-01

    Ultrasonic technique has been used for synthesising protein microspheres possessing specific physical and functional properties. Various proteins have been used as shell materials under different experimental conditions. In previous studies, thermal or chemical denaturation of the proteins was used to obtain stable bovine-serum albumin (BSA) and lysozyme microbubbles (MBs), respectively. It is ideal to establish a generic procedure to synthesise microspheres irrespective of the nature of the protein. In order to see if a generic procedure can be established, ultrasonic synthesis of lysozyme and BSA MBs was carried out under similar experimental conditions and their properties were evaluated. The size, size distribution and the stability of the MBs were significantly different for the lysozyme and BSA MBs. The size and size distribution of the lysozyme coated MBs were larger than BSA bubbles. The mechanical strength of MBs against the shear forces, generated when irradiated by high frequency ultrasound, was studied using pulsed-sonoluminescence (SL). This study indicated that lysozyme MBs were significantly more stable than BSA MBs. An increase in mechanical strength of the MBs may lead to an increase in their storage lifetime and stability against gas diffusion. Possible reasons for such observations have been discussed.

  4. Multi-spectroscopic and molecular modeling studies of bovine serum albumin interaction with sodium acetate food additive.

    PubMed

    Mohammadzadeh-Aghdash, Hossein; Ezzati Nazhad Dolatabadi, Jafar; Dehghan, Parvin; Panahi-Azar, Vahid; Barzegar, Abolfazl

    2017-08-01

    Sodium acetate (SA) has been used as a highly effective protectant in food industry and the possible effect of this additive on the binding to albumin should be taken into consideration. Therefore, for the first time, the mechanism of SA interaction with bovine serum albumin (BSA) has been investigated by multi-spectroscopic and molecular modeling methods under physiological conditions. Stern-Volmer fluorescence quenching analysis showed an increase in the fluorescence intensity of BSA upon increasing the amounts of SA. The high affinity of SA to BSA was demonstrated by a binding constant value (1.09×10(3) at 310°K). The thermodynamic parameters indicated that hydrophobic binding plays a main role in the binding of SA to Albumin. Furthermore, the results of UV-vis spectra confirmed the interaction of this additive to BSA. In addition, molecular modeling study demonstrated that A binding sites of BSA play the main role in the interaction with acetate.

  5. FBS or BSA Inhibits EGCG Induced Cell Death through Covalent Binding and the Reduction of Intracellular ROS Production

    PubMed Central

    Zhang, Yin; Xu, Yu-Ying; Sun, Wen-Jie; Zhang, Mo-Han; Zheng, Yi-Fan; Shen, Han-Ming; Yang, Jun

    2016-01-01

    Previously we have shown that (−)-epigallocatechin gallate (EGCG) can induce nonapoptotic cell death in human hepatoma HepG2 cells only under serum-free condition. However, the underlying mechanism for serum in determining the cell fate remains to be answered. The effects of fetal bovine serum (FBS) and its major component bovine serum albumin (BSA) on EGCG-induced cell death were investigated in this study. It was found that BSA, just like FBS, can protect cells from EGCG-induced cell death in a dose-dependent manner. Detailed analysis revealed that both FBS and BSA inhibited generation of ROS to protect against toxicity of EGCG. Furthermore, EGCG was shown to bind to certain cellular proteins including caspase-3, PARP, and α-tubulin, but not LC3 nor β-actin, which formed EGCG-protein complexes that were inseparable by SDS-gel. On the other hand, addition of FBS or BSA to culture medium can block the binding of EGCG to these proteins. In silico docking analysis results suggested that BSA had a stronger affinity to EGCG than the other proteins. Taken together, these data indicated that the protective effect of FBS and BSA against EGCG-induced cell death could be due to (1) the decreased generation of ROS and (2) the competitive binding of BSA to EGCG. PMID:27830147

  6. Suppressing the cytotoxicity of CuO nanoparticles by uptake of curcumin/BSA particles

    NASA Astrophysics Data System (ADS)

    Zhang, Wenjing; Jiang, Pengfei; Chen, Ying; Luo, Peihua; Li, Guanqun; Zheng, Botuo; Chen, Wei; Mao, Zhengwei; Gao, Changyou

    2016-05-01

    The adverse effects of metal-based nanoparticles on human beings and the environment have received extensive attention recently. It is urgently required to develop a simple and effective method to suppress the toxicity of metal-based nanomaterials. In this study, a hydrophobic antioxidant and a chelation agent curcumin (CUR) were encapsulated into bovine serum albumin (BSA) particles by a simple co-precipitation method, and followed by glutaraldehyde cross-linking. The CUR/BSA particles had an average size of 300 nm in diameter with a negatively charged surface and sustained curcumin release properties. The cellular uptake and cytotoxicity of CUR/BSA particles were followed on A549 cells, HepG2 cells and RAW264.7 cells. The CUR/BSA particles had higher intracellular accumulation and lower cytotoxicity compared with the free curcumin at the same drug concentration. The CUR/BSA particles could suppress the cytotoxicity generated by CuO nanoparticles as a result of decrease of both the intracellular reactive oxygen species (ROS) level and Cu2+ concentration, while the free curcumin did not show any obvious detoxicating effect. The detoxicating effects of CUR/BSA particles were further studied in an intratracheal instillation model in vivo, demonstrating significant reduction of toxicity and inflammatory response in rat lungs induced by CuO nanoparticles. The concept-proving study demonstrates the potential of the CUR/BSA particles in suppressing cytotoxicity of metal-based nanomaterials, which is a paramount requirement for the safe application of nanotechnology.

  7. Spectroscopic Studies on Binding of Lotus Seedpod Oligomeric Procyanidins to Bovine Serum Albumin

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Li, Sh.; Fu, X.; Yang, T.; Chen, H.; Guan, Y.; Xie, B.; Sun, Zh.

    2014-01-01

    The binding of lotus seedpod oligomeric procyanidins (LSOPC) and catechin (a major constituent unit of LSOPC) to bovine serum albumin (BSA) was studied by a fluorescence quenching technique. The results revealed that LSOPC could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure, but catechin could not. The Stern-Volmer quenching constant, K SV, and corresponding thermodynamic parameters, Δ G 0, Δ H 0 and Δ S 0, were calculated. The results of synchronous fluorescence and circular dichroism studies showed that LSOPC could cause a conformational change in BSA. In addition, glucose and metal ions could affect the interaction between LSOPC and BSA.

  8. Photophysical investigations of squaraine and cyanine dyes and their interaction with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Saikiran, M.; Sato, D.; Pandey, S. S.; Kato, T.

    2016-04-01

    A model far-red sensitive symmetrical squaraine dye (SQ-3) and unsymmetrical near infra-red sensitive cyanine dye (UCD-1) bearing direct-COOH functionalized indole ring were synthesized, characterized and subjected to photophysical investigations including their interaction with bovine serum albumin (BSA) as a model protein in phosphate buffer solution (PBS). Both of the dyes exhibit strong interaction with BSA in phosphate buffer with high apparent binding constant. A judicious tuning of hydrophobic main backbone with reactive functionality for associative interaction with active site of BSA has been found to be necessary for BSA detection in PBS.

  9. Spectroscopic studies of the interaction between tetra-substituted aluminum phthalocyanines and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    He, Yipeng; Zheng, Liqin; Huang, Yide; Lin, Pingping; Yang, Hongqin; Peng, Yiru

    2014-11-01

    Serum albumin, the most abundant plasma protein in mammalian blood, shows significant effects on delivery and therapeutic efficacy of drugs, therefore, the investigation of binding interaction between serum albumin and drugs is vital and necessary. In the present study, the binding interaction of two aluminum (III) phthalocyanine (AlPc) derivatives, tetrasulfonate- and tetra-(p-sulfoazophenyl-4-aminosulfonyl)-substituted AlPc (complexes 1 and 2), with bovine serum albumin (BSA) was investigated by UV-Vis and fluorescence spectroscopy. Adding BSA to the Pc complexes in water caused remarkable changes in the Q-band of the Pc complexes, indicating an altered aggregation behavior. When titrating these AlPcs with BSA in PBS, the intrinsic fluorescence of BSA was significantly quenched through a static quenching process. The binding of Pc complexes to BSA might change its conformation, evidenced by the red shift of maximum emission wavelength. Furthermore, binding constants and binding sites were obtained and binding ability between the Pc complexes and BSA was assessed. Our results suggest that complexes 1 and 2 readily interact with BSA whereas the latter shows more affinity (with higher binding constant value) to BSA, implying the stretched amphiphilic substituents of complex 2 may contribute to their transportation in the blood.

  10. Spectral and Fluorescent Studies of the Interaction of an Anionic Oxacarbocyanine Dye with Bovine Serum Albumin

    NASA Astrophysics Data System (ADS)

    Pronkin, P. G.; Tatikolov, A. S.

    2017-01-01

    The influence of the formation of noncovalent intermolecular complexes with bovine serum albumin (BSA) on the spectral and fluorescent properties of the anionic oxacarbocyanine dye 3,3'-di-(γ-sulfopropyl)-5,5'-diphenyl-9-ethyloxacarbocyanine betaine (OCC) was studied. Binding of OCC to BSA increased significantly the dye fluorescence. Changes in the absorption and fluorescence spectra of OCC upon interaction with BSA argued in favor of a shift of the dye cis-trans equilibrium in the complex. The effects of adding albumin-denaturing compounds (urea, sodium dodecyl sulfate) on the spectral and fluorescent properties of the dye in the OCC-BSA complex were studied. It was concluded that OCC can act as a probe for albumins and can be used to study protein denaturing.

  11. [The entrapped efficiency of BSA liposome].

    PubMed

    Hou, Dong-Zhi; Liu, Chang-Ke; Ping, Qi-Neng; Liang, Xiao-Hui

    2007-05-01

    BSA liposomes were prepared with approximately 100 nm mean particle size under rather gentle experiment conditions, and two-colorimetric coomassie brilliant blue protein was employed to measure the free drug in the entrapped efficiency (EE%) determination of BSA liposomes. Gel filtration was used to measure the EE%, and several Sephadex gels were examined by the separation of liposomes and free drug. To determine the free drug, three methods were compared on two-colorimetric UV spectrophotography, Bradford and two-colorimetric coomassie brilliant blue, separately. Two-colorimetric coomassie brilliant blue process increased the accuracy and improved the sensitivity of the assay about 20-fold comparing with the Bradford method. Two-colorimetric coomassie brilliant blue assay appeared to be more sensitive and showed broader dynamic range to measure the free BSA in the EE% determination of BSA liposome.

  12. Chemical conversion of benzo(e)pyrene by aqueous serum albumin to pyrene-like product: fluorescence method

    SciTech Connect

    Srinivasan, B.N.; Fujimori, E.

    1980-01-01

    The interaction of benzo(e)pyrene, an atmospheric pollutant formed during the burning of organic materials, and bovine serum albumin (BSA) was studied to determine a pyrene-type metabolite is formed. (ACR)

  13. In vitro evaluation of potential complexation between bovine insulin and bovine serum albumin.

    PubMed

    Al-Domi, Hayder; Alzweiri, Muhammed; Hamdan, Imad; Jaradat, Ziad

    2014-03-01

    The objective of this study was to examine the possible binding of bovine insulin (BI) with bovine serum albumin (BSA) to form a new potential diabetogenic irreversible complex protein. Several preparations of BSA and BI were prepared. Both capillary electrophoresis and spectrophotometric analysis were undertaken to test the possibility of complexation between BI and BSA. HPLC was used to test whether the potential complex of BI and BSA is reversible or irreversible. The optimum deviation between the real and calculated absorbances was observed at a BI/BSA ratio of 2. Moreover, the migration time of BI decreased substantially with increasing ratio of BI to BSA until it became almost constant at equal molar ratio of BI/BSA. While the majority of the 2:1 BI-BSA sample detached during the HPLC analysis, which confirms the reversible character of BI-BSA binding, the HPLC chromatogram also emphasizes the formation of an irreversible complexation between the two proteins. This study provides evidence of the formation of reversible and irreversible new BI-BSA complexes under physiological conditions. This highlights the importance of examining the possible diabetogenicity of BI-BSA complex in genetically susceptible people.

  14. Ribosylation of bovine serum albumin induces ROS accumulation and cell death in cancer line (MCF-7).

    PubMed

    Khan, Mohd Shahnawaz; Dwivedi, Sourabh; Priyadarshini, Medha; Tabrez, Shams; Siddiqui, Maqsood Ahmed; Jagirdar, Haseeb; Al-Senaidy, Abdulrahman M; Al-Khedhairy, Abdulaziz A; Musarrat, Javed

    2013-12-01

    Formation of advanced glycation end products (AGE) is crucially involved in the several pathophysiologies associated with ageing and diabetes, for example arthritis, atherosclerosis, chronic renal insufficiency, Alzheimer's disease, nephropathy, neuropathy, and cataracts. Because of devastating effects of AGE and the significance of bovine serum albumin (BSA) as a transport protein, this study was designed to investigate glycation-induced structural modifications in BSA and their functional consequences in breast cancer cell line (MCF-7). We incubated D-ribose with BSA and monitored formation of D-ribose-glycated BSA by observing changes in the intensity of fluorescence at 410 nm. NBT (nitro blue tetrazolium) assay was performed to confirm formation of keto-amine during glycation. Absorbance at 540 nm (fructosamine) increased markedly with time. Furthermore, intrinsic protein and 8-anilino-1-naphthalenesulfonate (ANS) fluorescence revealed marked conformational changes in BSA upon ribosylation. In addition, a fluorescence assay with thioflavin T (ThT) revealed a remarkable increase in fluorescence at 485 nm in the presence of glycated BSA. This suggests that glycation with D-ribose induced aggregation of BSA into amyloid-like deposits. Circular dichroism (CD) study of native and ribosylated BSA revealed molten globule formation in the glycation pathway of BSA. Functional consequences of ribosylated BSA on cancer cell line, MCF-7 was studied by MTT assay and ROS estimation. The results revealed cytotoxicity of ribosylated BSA on MCF-7 cells.

  15. Facilitation by serum albumin of renal tubular secretion of organic anions.

    PubMed

    Besseghir, K; Mosig, D; Roch-Ramel, F

    1989-03-01

    The role of albumin in tubular secretion of the organic anions p-aminohippurate (PAH, 21% albumin-bound at 1 microM) and methotrexate (MTX, 55% bound at 1 microM), and of the organic cation N1-methylnicotinamide (NMN, not bound), was investigated in isolated rabbit S2 proximal tubules. PAH or MTX secretory rates were low in the absence of colloids or in the presence of 1 g/dl dextran 40, and were reversibly two- to sevenfold stimulated by either 1 g/dl bovine (BSA, either regular, defatted, and/or dialyzed) or rabbit serum albumin, or by dialyzed native rabbit plasma. NMN secretion was not stimulated by either dextran or albumin. Luminal BSA had no effect, but stimulation of PAH secretion was observed when albumin was present in both lumen and bath. This secretion was BSA concentration-dependent up to a 1 g/dl BSA. Saturation experiments suggested that 1 g/dl BSA may increase PAH apparent affinity for secretion, with no change in its maximum velocity. Albumin appears therefore to facilitate organic anion proximal secretion by an effect unrelated to oncotic pressure or to the extent of organic anion binding.

  16. Investigation of Cu(II) Binding to Bovine Serum Albumin by Potentiometry with an Ion Selective Electrode

    ERIC Educational Resources Information Center

    Jie Liu

    2004-01-01

    A laboratory project that investigates Cu(II) bind to bovine serum albumin (BSA) in an aqueous solution is developed to assist undergraduate students in gaining better understanding of the interaction of ligands with biological macromolecule. Thus, students are introduced to investigation of Cu(II) binding to BSA by potentiometry with the Cu(II)…

  17. Bromophenol blue binding to mammalian albumins and displacement of albumin-bound bilirubin.

    PubMed

    Kim, B Boon; Abdul Kadir, H; Tayyab, S

    2008-10-15

    Interaction of bromophenol blue (BPB) with serum albumins from different mammalian species, namely, human (HSA), bovine (BSA), goat (GSA), sheep (SSA), rabbit (RbSA), porcine (PSA) and dog (DSA) was studied using absorption and absorption difference spectroscopy. BPB-albumin complexes showed significant differences in the spectral characteristics, i.e., extent of bathochromic shift and hypochromism relative to the spectral features of free BPB. Absorption difference spectra of these complexes also showed variations in the position of maxima and absorption difference (deltaAbs.) values. Absorption difference spectra of different bilirubin (BR)-albumin complexes showed a significant blue shift accompanied by decrease in deltaAbs. values in presence of BPB which were indicative of the displacement of bound BR from its binding site in BR-albumin complexes. These changes in the difference spectral characteristics of BR-albumin complexes were more marked at higher BPB concentration. However, the extent of these changes was different for different BR-albumin complexes. Taken together, all these results suggest that BPB partially shares BR binding site on albumin and different mammalian albumins show differences in the microenvironment of the BR/BPB binding site.

  18. Intermolecular forces in bovine serum albumin solutions exhibiting solidlike mechanical behaviors.

    PubMed

    Ikeda, S; Nishinari, K

    2000-01-01

    Mechanical properties of bovine serum albumin (BSA) solutions were analyzed to gain information on intermolecular forces that stabilize the system under normal physiological conditions. BSA solutions showed unexpectedly large zero shear viscosity values under steady shear flows but responded like solids to sinusoidal linear strains: the storage shear moduli were always larger than the loss shear moduli in the frequency range 1-100 rad/s. These results suggest that BSA solutions are so-called colloidal crystals in which colloidal particles are ordered in an array due to strong repulsive forces among particles. However, the pair potential between BSA molecules predicted based on the conventional Derjaguin-Landau-Verwey-Overbeek theory failed to explain these remarkable mechanical properties of BSA solutions. Additional repulsive forces other than electrostatic must be introduced to explain stability of BSA aqueous dispersions.

  19. Spectrometric studies on the interaction of fluoroquinolones and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Ni, Yongnian; Su, Shaojing; Kokot, Serge

    2010-02-01

    The interaction between fluoroquinolones (FQs), ofloxacin and enrofloxacin, and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis spectroscopy. It was demonstrated that the fluorescence quenching of BSA by FQ is a result of the formation of the FQ-BSA complex stabilized, in the main, by hydrogen bonds and van der Waals forces. The Stern-Volmer quenching constant, KSV, and the corresponding thermodynamic parameters, Δ H, Δ S and Δ G, were estimated. The distance, r, between the donor, BSA, and the acceptor, FQ, was estimated from fluorescence resonance energy transfer (FRET). The effect of FQ on the conformation of BSA was analyzed with the aid of UV-vis absorbance spectra and synchronous fluorescence spectroscopy. Spectral analysis showed that the two FQs affected the conformation of the BSA but in a different manner. Thus, with ofloxacin, the polarity around the tryptophan residues decreased and the hydrophobicity increased, while for enrofloxacin, the opposite effect was observed.

  20. Interaction between pirenoxine and bovine serum albumin in aqueous solution

    NASA Astrophysics Data System (ADS)

    Liao, Zhixi; Yu, Xianyong; Yao, Qing; Yi, Pinggui

    2014-08-01

    This work concerns the interaction of prenoxine sodium (PRX) and bovine serum albumin (BSA), which was conducted by spectroscopic means: fluorescence spectra, ultraviolet-visible spectra (UV-vis) and circular dichroism spectra (CD spectra) in physiological conditions. The results revealed the PRX can quench the fluorescence of BSA remarkably in aqueous solution. The quench mechanism has been obtained after corrected the fluorescence intensities for inner filter effects. The binding constants (Ka) were calculated according to the relevant fluorescence data at different temperatures. Moreover, from a series of analyses, we have obtained the binding sites, the binding distance and binding force. The effect of PRX on the conformation of BSA has been analyzed using synchronous fluorescence under experimental conditions. In addition, the CD spectra proved that the secondary structure of BSA changed in the presence of PRX in aqueous solution.

  1. Interaction between pirenoxine and bovine serum albumin in aqueous solution.

    PubMed

    Liao, Zhixi; Yu, Xianyong; Yao, Qing; Yi, Pinggui

    2014-08-14

    This work concerns the interaction of prenoxine sodium (PRX) and bovine serum albumin (BSA), which was conducted by spectroscopic means: fluorescence spectra, ultraviolet-visible spectra (UV-vis) and circular dichroism spectra (CD spectra) in physiological conditions. The results revealed the PRX can quench the fluorescence of BSA remarkably in aqueous solution. The quench mechanism has been obtained after corrected the fluorescence intensities for inner filter effects. The binding constants (Ka) were calculated according to the relevant fluorescence data at different temperatures. Moreover, from a series of analyses, we have obtained the binding sites, the binding distance and binding force. The effect of PRX on the conformation of BSA has been analyzed using synchronous fluorescence under experimental conditions. In addition, the CD spectra proved that the secondary structure of BSA changed in the presence of PRX in aqueous solution.

  2. [Interaction of new pyridylporphyrins with bovine serum albumin].

    PubMed

    Karapetian, N G; Madakian, V N

    2004-01-01

    The interaction of meso-tetra(4-N-hydroxyethylpyridyl)porphyrin, meso-tetra(3-N-hydroxyethylpyridyl)porphyrin, and their zinc complexes with bovine serum albumin (BSA) was studied by electronic spectroscopy, CD, and equilibrium dialysis at pH 7.2. The titration of the porphyrins with BSA was accompanied by a decrease in light absorption and a bathochromic shift of the Soret band, as well as by the appearance of an isobestic point. The porphyrin interaction with BSA also led to the induction of positive CD spectra in the visible region, which is explained by the porphyrin sorption on the protein globule. The equilibrium dialysis helped in determining the stoichiometry of binding and the binding constants of the porphyrins under study with BSA using Scatchard plots. This interaction is nonspecific and reversible. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 2; see also http://www.maik.ru.

  3. Elucidation of structural and functional properties of albumin bound to gold nanoparticles.

    PubMed

    Mariam, Jessy; Sivakami, S; Dongre, P M

    2017-02-01

    Nanoparticle-albumin complexes are being designed for targeted drug delivery and imaging. However, the changes in the functional properties of albumin due to adsorption on nanoparticles remain elusive. Thus, the objective of this work was to elucidate the structural and functional properties of human and bovine serum albumin bound to negatively charged gold nanoparticles (GNPs). Fluorescence data demonstrated static quenching of albumin by GNP with the quenching of buried as well as surface tryptophan in BSA. The binding process was enthalpy and entropy-driven in HSA and BSA, respectively. At lower concentrations of GNP there was a higher affinity for tryptophan, whereas at higher concentrations both tryptophan and tyrosine participated in the interaction. Synchronous fluorescence spectra revealed that the microenvironment of tryptophan in HSA turned more hydrophilic upon exposure to GNP. The α-helical content of albumin was unaltered by GNP. Approximately 37 and 23% reduction in specific activity of HSA and BSA was observed due to GNP binding. In presence of warfarin and ibuprofen the binding constants of albumin-GNP complexes were altered. A very interesting observation not reported so far is the retained antioxidant activity of albumin in presence of GNP i.e. we believe that GNPs did not bind to the free sulfhydryl groups of albumin. However enhanced levels of copper binding were observed. We have also highlighted the differential response in albumin due to gold and silver nanoparticles which could be attributed to differences in the charge of the nanoparticle.

  4. Determination of Conjugation Efficiency of Antibodies and Proteins to the Superparamagnetic Iron Oxide Nanoparticles by Capillary Electrophoresis with Laser-Induced Fluorescence Detection

    NASA Astrophysics Data System (ADS)

    Wang, Fu-Hua; Yoshitake, Takashi; Kim, Do-Kyung; Muhammed, Mamoun; Bjelke, Börje; Kehr, Jan

    2003-04-01

    The method based on capillary electrophoresis with laser-induced fluorescence detection (CE/LIF) was developed for determination of magnetic iron oxide nanoparticles (hydrodynamic diameters of 100 nm) functionalized with molecules containing primary amino groups. The magnetic nanoparticles with carboxylic or aminopropyl-trimethoxysilane groups at their surface were conjugated to the model proteins (bovine serum albumin, BSA; streptavidin or goat anti-rabbit immunoglobulin G, IgG) using carbodiimide as a zero-length cross-linker. The nanoparticle-protein conjugates (hydrodynamic diameter 163-194 nm) were derivatized with naphthalene-2,3-dicarboxaldehyde reagent and separated by CE/LIF with a helium-cadmium laser (excitation at 442 nm, emission at 488 nm). The separations were carried out by using a fused-silica capillary (effective length 48 cm, inner diameter 75 um) and 100 mM sodium borate buffer (pH 9.2), the potential was 30 kV. The detection limit for BSA-conjugate was 1.3 pg/10 nl, i.e. about 20 amol. The present method provides an efficient and fast tool for sensitive determination of the efficacy of biomolecular functionalization of magnetic nanoparticles. The CE/LIF technique requires only negligible sample volumes for analysis, which is especially suitable for controlling the process of preparation of functionalized nanoparticles with unique properties aimed to be used for diagnostic or therapeutic purposes.

  5. Elucidating the influence of gold nanoparticles on the binding of salvianolic acid B and rosmarinic acid to bovine serum albumin.

    PubMed

    Peng, Xin; Qi, Wei; Huang, Renliang; Su, Rongxin; He, Zhimin

    2015-01-01

    Salvianolic acid B and rosmarinic acid are two main water-soluble active ingredients from Salvia miltiorrhiza with important pharmacological activities and clinical applications. The interactions between salvianolic acid B (or rosmarinic acid) and bovine serum albumin (BSA) in the presence and absence of gold nanoparticles (Au NPs) with three different sizes were investigated by using biophysical methods for the first time. Experimental results proved that two components quenched the fluorescence of BSA mainly through a static mechanism irrespective of the absence or presence of Au NPs. The presence of Au NPs decreased the binding constants of salvianolic acid B with BSA from 27.82% to 10.08%, while Au NPs increased the affinities of rosmarinic acid for BSA from 0.4% to 14.32%. The conformational change of BSA in the presence of Au NPs (caused by a noncompetitive binding between Au NPs and drugs at different albumin sites) induced changeable affinity and binding distance between drugs and BSA compared with no Au NPs. The competitive experiments revealed that the site I (subdomain IIA) of BSA was the primary binding site for salvianolic acid B and rosmarinic acid. Additionally, two compounds may induce conformational and micro-environmental changes of BSA. The results would provide valuable binding information between salvianolic acid B (or rosmarinic acid) and BSA, and also indicated that the Au NPs could alter the interaction mechanism and binding capability of drugs to BSA, which might be beneficial to understanding the pharmacokinetics and biological activities of the two drugs.

  6. BSA-directed synthesis of CuS nanoparticles as a biocompatible photothermal agent for tumor ablation in vivo.

    PubMed

    Zhang, Cai; Fu, Yan-Yan; Zhang, Xuejun; Yu, Chunshui; Zhao, Yan; Sun, Shao-Kai

    2015-08-07

    Photothermal therapy as a physical therapeutic approach has greatly attracted research interest due to its negligible systemic effects. Among the various photothermal agents, CuS nanoparticles have been widely used due to their easy preparation, low cost, high stability and strong absorption in the NIR region. However, the ambiguous biotoxicity of CuS nanoparticles limited their bio-application. So it is highly desirable to develop biocompatible CuS photothermal agents with the potential of clinical translation. Herein, we report a novel method to synthesize biocompatible CuS nanoparticles for photothermal therapy using bovine serum albumin (BSA) as a template via mimicking biomaterialization processes. Owing to the inherent biocompatibility of BSA, the toxicity assays in vitro and in vivo showed that BSA-CuS nanoparticles possessed good biocompatibility. In vitro and in vivo photothermal therapies were performed and good results were obtained. The bulk of the HeLa cells treated with BSA-CuS nanoparticles under laser irradiation (808 nm) were killed, and the tumor tissues of mice were also successfully eliminated without causing any obvious systemic damage. In summary, a novel strategy for the synthesis of CuS nanoparticles was developed using BSA as the template, and the excellent biocompatibility and efficient photothermal therapy effects of BSA-CuS nanoparticles show great potential as an ideal photothermal agent for cancer treatment.

  7. Sensitive detection of cyanide using bovine serum albumin-stabilized cerium/gold nanoclusters.

    PubMed

    Wang, Chia-Wei; Chen, Ya-Na; Wu, Bo-Yi; Lee, Cheng-Kai; Chen, Ying-Chieh; Huang, Yu-Huei; Chang, Huan-Tsung

    2016-01-01

    A simple, sensitive, and selective fluorescence assay for the detection of CN(-) has been demonstrated using bovine serum albumin-stabilized cerium/gold nanoclusters (BSA-Ce/Au NCs). When excited at 325 nm, BSA-Ce/Au NCs have two fluorescence bands centered at 410 and 658 nm, which are assigned to BSA-Ce/Au complexes and Au NCs, respectively. Each BSA-Ce/Au NC contains 22 Au atoms and 8 Ce ions. Through etching of the Au core in BSA-Ce/Au NCs by CN(-), the fluorescence at 658 nm is quenched, while that at 410 nm enhances during the formation of complexes among BSA, Ce(4+), and [Au(CN)2](-). The circular dichroism spectra reveal that relative to BSA-Au NCs, BSA-Ce/Au NCs have looser structures of the BSA templates. As a result, it is easier for CN(-) to access the Au cores in BSA-Ce/Au NCs, allowing faster (within 15 min) etching of the Au cores by CN(-). At pH 12.0, this assay allows the detection of CN(-) down to 50 nM, with linearity over 0.1-15 μM. This assay has been applied to the determination of the concentrations of CN(-) in spiked drinking water and pond water samples.

  8. A comparison study on the binding of hesperetin and luteolin to bovine serum albumin by spectroscopy

    NASA Astrophysics Data System (ADS)

    Tang, Lin; Jia, Wanteng

    2013-02-01

    Binding mechanism of luteolin (LUT) and hesperetin (HES) to bovine serum albumin (BSA) was investigated at 288,298,310 K and pH = 7.40 by UV absorption spectroscopy, fluorescence quenching and synchronous fluorescence spectroscopy. Under simulated physiological conditions, the fluorescence data indicated that hesperetin binding to BSA mainly occurs through a static mechanism. In contrast, binding of luteolin to BSA is a combined quenching process while static quenching is prevailing. Linear interval of the Stern-Volmer plot of LUT-BSA for the concentration ratio of LUT to BSA ranged from 0.5 to 1.25 was obtained. The thermodynamic parameters obtained from the Van't Hoff equation indicated that electrostatic force was the predominant force in the LUT-BSA and HES-BSA complex. The inner filter effect was eliminated to get accurate data. The conformational changes of BSA caused by LUT and HES were observed in the UV absorption. Results of fluorescence quenching and synchronous fluorescence showed that degree of luteolin-BSA quenching was higher than hesperetin-BSA quenching, which indicated that the 4'-hydroxide radical was more helpful to the ligand binding to proteins than 4'-methoxyl group for flavones.

  9. Binding interaction of sorafenib with bovine serum albumin: Spectroscopic methodologies and molecular docking.

    PubMed

    Shi, Jie-Hua; Chen, Jun; Wang, Jing; Zhu, Ying-Yao; Wang, Qi

    2015-01-01

    The binding interaction of sorafenib with bovine serum albumin (BSA) was studied using fluorescence, circular dichrosim (CD) and molecular docking methods. The results revealed that there was a static quenching of BSA induced by sorafenib due to the formation of sorafenib-BSA complex. The binding constant and number of binding site of sorafenib with BSA under simulated physiological condition (pH=7.4) were 6.8×10(4) M(-1) and 1 at 310 K, respectively. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH(0)=-72.2 kJ mol(-1) and ΔS(0)=-140.4J mol(-1) K(-1)) and the results of molecular docking, it could be suggested that the binding process of sorafenib and BSA was spontaneous and the main interaction forces of sorafenib with BSA were van der Waals force and hydrogen bonding interaction. From the results of site marker competitive experiments and molecular docking, it could be deduced that sorafenib was inserted into the subdomain IIA (site I) of BSA and leads to a slight change of the conformation of BSA. And, the significant change of conformation of sorafenib occurred in the binding process with BSA to increase the stability of the sorafenib-BSA system, implying that the flexibility of sorafenib played an important role in the binding process.

  10. Interactions and effects of BSA-functionalized single-walled carbon nanotubes on different cell lines

    NASA Astrophysics Data System (ADS)

    Muzi, Laura; Tardani, Franco; La Mesa, Camillo; Bonincontro, Adalberto; Bianco, Alberto; Risuleo, Gianfranco

    2016-04-01

    Functionalized carbon nanotubes (CNTs) have shown great promise in several biomedical contexts, spanning from drug delivery to tissue regeneration. Thanks to their unique size-related properties, single-walled CNTs (SWCNTs) are particularly interesting in these fields. However, their use in nanomedicine requires a clear demonstration of their safety in terms of tissue damage, toxicity and pro-inflammatory response. Thus, a better understanding of the cytotoxicity mechanisms, the cellular interactions and the effects that these materials have on cell survival and on biological membranes is an important first step for an appropriate assessment of their biocompatibility. In this study we show how bovine serum albumin (BSA) is able to generate homogeneous and stable dispersions of SWCNTs (BSA-CNTs), suggesting their possible use in the biomedical field. On the other hand, this study wishes to shed more light on the impact and the interactions of protein-stabilized SWCNTs with two different cell types exploiting multidisciplinary techniques. We show that BSA-CNTs are efficiently taken up by cells. We also attempt to describe the effect that the interaction with cells has on the dielectric characteristics of the plasma membrane and ion flux using electrorotation. We then focus on the BSA-CNTs’ acute toxicity using different cellular models. The novel aspect of this work is the evaluation of the membrane alterations that have been poorly investigated to date.

  11. Tracing the conformational changes in BSA using FRET with environmentally-sensitive squaraine probes

    NASA Astrophysics Data System (ADS)

    Govor, Iryna V.; Tatarets, Anatoliy L.; Obukhova, Olena M.; Terpetschnig, Ewald A.; Gellerman, Gary; Patsenker, Leonid D.

    2016-06-01

    A new potential method of detecting the conformational changes in hydrophobic proteins such as bovine serum albumin (BSA) is introduced. The method is based on the change in the Förster resonance energy transfer (FRET) efficiency between protein-sensitive fluorescent probes. As compared to conventional FRET based methods, in this new approach the donor and acceptor dyes are not covalently linked to protein molecules. Performance of the new method is demonstrated using the protein-sensitive squaraine probes Square-634 (donor) and Square-685 (acceptor) to detect the urea-induced conformational changes of BSA. The FRET efficiency between these probes can be considered a more sensitive parameter to trace protein unfolding as compared to the changes in fluorescence intensity of each of these probes. Addition of urea followed by BSA unfolding causes a noticeable decrease in the emission intensities of these probes (factor of 5.6 for Square-634 and 3.0 for Square-685), and the FRET efficiency changes by a factor of up to 17. Compared to the conventional method the new approach therefore demonstrates to be a more sensitive way to detect the conformational changes in BSA.

  12. Interaction of coffee compounds with serum albumins. Part II: Diterpenes.

    PubMed

    Guercia, Elena; Forzato, Cristina; Navarini, Luciano; Berti, Federico

    2016-05-15

    Cafestol and 16-O-methylcafestol are diterpenes present in coffee, but whilst cafestol is found in both Coffea canephora and Coffea arabica, 16-O-methylcafestol (16-OMC) was reported to be specific of only C. canephora. The interactions of such compounds, with serum albumins, have been studied. Three albumins have been considered, namely human serum albumin (HSA), fatty acid free HSA (ffHSA) and bovine serum albumin (BSA). The proteins interact with the diterpenes at the interface between Sudlow site I and the fatty acid binding site 6 in a very peculiar way, leading to a significant change in the secondary structure. The diterpenes do not displace reference binding drugs of site 2, but rather they enhance the affinity of the site for the drugs. They, therefore, may alter the pharmacokinetic profile of albumin - bound drugs.

  13. Interaction of sulpiride and serum albumin: Modeling from spectrofluorimetric data

    NASA Astrophysics Data System (ADS)

    Fragoso, Viviane Muniz da Silva; Silva, Dilson

    2015-12-01

    We have applied the fluorescence quenching modeling to study the process of interaction of sulpiride with human serum albumin (HSA) and bovine (BSA). Albumin is more abundant protein in blood and it emits fluorescence when excited by 260-295 nm. Sulpiride is an atypical antipsychotic used in the treatment of many psychiatric disorders. As sulpiride is fluorescent, we developed a mathematical model to analyzing the interaction of two fluorescent substances. This model was able to separate the albumin fluorescence from the quencher fluorescence. Results have shown that sulpiride quenches the fluorescence of both albumins by a static process, due to the complex formation drugalbumin. The association constants calculated for sulpiride-HSA was 2.20 (± 0.08) × 104 M-1 at 37° C, and 5.46 (± 0.20) × 104 M-1, 25 ° C, and the primary binding site to sulpiride in the albumin is located closer to the subdomain IB.

  14. Spectroscopic approach of the interaction study of amphiphilic drugs with the serum albumins.

    PubMed

    Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd Sajid; Khan, Rizwan Hasan; Kabir-ud Din

    2011-10-15

    The interaction of the amphiphilic drugs, i.e., amitriptyline hydrochloride (AMT) and promethazine hydrochloride (PMT), with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), has been examined by the various spectroscopic techniques, like fluorescence, UV-vis, and circular dichroism (CD). Fluorescence results indicate that in case of HSA-drug complexes the quenching of fluorescence intensity at 280 nm is less effective as compared to at 295 nm while in case of BSA-drug complexes both have almost same effect and for most of drug-serum albumin complexes there is only one independent class of binding. For all drug-serum albumin complexes the quenching rate constant (K(q)) values suggest the static quenching procedure. The UV-vis results show that the change in protein conformation of PMT-serum albumin complexes was more prominent as compared to AMT-serum albumin complexes. The CD results also explain the conformational changes in the serum albumins on binding with drugs. The increase in α-helical structure for AMT-serum albumin complexes is found to be more as compared to PMT-serum albumin complexes. Hence, the various spectroscopic techniques provide a quantitative understanding of the binding of amphiphilic drugs with serum albumins.

  15. Terbium(III)/gold nanocluster conjugates: the development of a novel ratiometric fluorescent probe for mercury(II) and a paper-based visual sensor.

    PubMed

    Qi, Yan-Xia; Zhang, Min; Zhu, Anwei; Shi, Guoyue

    2015-08-21

    In this work, a novel ratiometric fluorescent probe was developed for rapid, highly accurate, sensitive and selective detection of mercury(II) (Hg(2+)) based on terbium(III)/gold nanocluster conjugates (Tb(3+)/BSA-AuNCs), in which bovine serum albumin capped gold nanoclusters (BSA-AuNCs) acted as the signal indicator and terbium(III) (Tb(3+)) was used as the build-in reference. Our proposed ratiometric fluorescent probe exhibited unique specificity toward Hg(2+) against other common environmentally and biologically important metal ions, and had high accuracy and sensitivity with a low detection limit of 1 nM. In addition, our proposed probe was effectively employed to detect Hg(2+) in the biological samples from the artificial Hg(2+)-infected rats. More significantly, an appealing paper-based visual sensor for Hg(2+) was designed by using filter paper embedded with Tb(3+)/BSA-AuNC conjugates, and we have further demonstrated its feasibility for facile fluorescent sensing of Hg(2+) in a visual format, in which only a handheld UV lamp is used. In the presence of Hg(2+), the paper-based visual sensor, illuminated by a handheld UV lamp, would undergo a distinct fluorescence color change from red to green, which can be readily observed with naked eyes even in trace Hg(2+) concentrations. The Tb(3+)/BSA-AuNC-derived paper-based visual sensor is cost-effective, portable, disposable and easy-to-use. This work unveiled a facile approach for accurate, sensitive and selective measuring of Hg(2+) with self-calibration.

  16. Synthesis, X-Ray Crystallographic Analysis and BSA Interaction of a New α-Aminophosphonate

    NASA Astrophysics Data System (ADS)

    Wang, Q.-M.; Gao, W.; Song, J.-L.; Liu, Y.; Qi, H.; Tang, X.-H.

    2016-09-01

    A new α-aminophosphonate ( 1) was synthesized and its composition and structure were established by EA, FT-IR, ESI-MS, NMR (1H, 13C, and 31P), and X-ray crystallography. Compound 1 crystallizes in a monoclinic system with space group C2/c. The interaction between α-aminophosphonate ( 1) and bovine serum albumin (BSA) at three different temperatures (298, 303, and 310 K) under simulated physiological condition were studied by fluorescence spectroscopy. The results showed that the fluorescence quenching mechanism between 1 and BSA was a static quenching procedure. The binding constant (Ka) and binding sites (n) were obtained. The corresponding thermodynamic parameters (ΔH, ΔS, and ΔG) of the interaction system were calculated at different temperatures. The results revealed that the binding process was spontaneous; hydrogen bonds and van der Waals forces were the main forces that stabilize the complex.

  17. Albumin extravasation rates in tissues of anesthetized and unanesthetized rats

    SciTech Connect

    Renkin, E.M.; Joyner, W.L.; Gustafson-Sgro, M.; Plopper, G.; Sibley, L.

    1989-05-01

    Bovine serum albumin (BSA) labeled with /sup 131/I was injected intravenously in chronically prepared, unanesthetized rats and into pentobarbital-anesthetized rats that had received 2 ml 5% BSA to help sustain plasma volume. Initial uptake rates (clearances) in skin, skeletal muscles, diaphragm, and heart (left ventricle) were measured over 1 h. BSA labeled with /sup 125/I was injected terminally to correct for intravascular /sup 131/I-BSA. Observed clearances were in the following order in both groups of animals: heart much greater than diaphragm approximately equal to skin greater than resting skeletal muscles. Differences between unanesthetized and anesthetized animals were small and inconsistently directed. Our results suggest that the lower albumin clearances reported in the literature for anesthetized rats are not the result of their immobility or any direct effect of anesthesia on albumin transport in these tissues. The lower transport rates appear to result indirectly from changes produced by anesthesia and/or surgery in controllable parameters such as plasma volume and intravascular protein mass.

  18. Insight in the role of bovine serum albumin for promoting the in situ surface growth of polyhydroxybutyrate (PHB) on patterned surfaces via enzymatic surface-initiated polymerization.

    PubMed

    Niamsiri, Nuttawee; Bergkvist, Magnus; Delamarre, Soazig C; Cady, Nathan C; Coates, Geoffrey W; Ober, Christopher K; Batt, Carl A

    2007-10-15

    Polyhydroxyalkanoates (PHAs) are a family of aliphatic polyesters produced by a variety of microorganisms as a reserve of carbon and energy. Enzymes involved in the synthesis of PHAs can be utilized to produce polymers in vitro, both in bulk and on solid surfaces. Here, site-specific attachment of the key catalytic enzyme, PHA synthase, on lithographically patterned surfaces and subsequent addition of (R)-3-hydroxybutyryl-CoA substrate allowed us to fabricate spatially ordered polyhydroxybutyrate (PHB) polymeric structures via an in situ enzymatic surface-initiated polymerization (ESIP). By varying the reaction conditions, we enhanced the growth of PHB on solid surfaces and analyzed the resulting structures by fluorescence microscopy, atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and gel permeation chromatography (GPC). We found that stabilization of smaller PHB granule structures by an addition of bovine serum albumin (BSA) was the most important factor for a successful synthesis of a PHB layer up to 1mum in thickness, consisting mainly of larger cluster assemblies of PHB granules that cover the entire patterned area. Immunofluorescence detection and surface contact angle analysis revealed that BSA was physically bound to the PHB polymer all through the cluster, and reduced the overall hydrophobicity of the polymer surface. Based on information obtained from AFM, kinetic measurements and various polymer characterization methods, a plausible model for roles of BSA in the enhancement of PHB formation on surfaces is discussed. Furthermore, by using biotinylated BSA conjugates, we were able to incorporate biotin groups into the PHB polymer matrix, thus generating a bioactive surface that can be used for displaying other functional biomolecules through streptavidin-biotin interaction on the PHB structures. Because of its versatility, our fabrication strategy is expected to be a useful surface

  19. The Effect of Albumin on MRP2 and BCRP in the Vesicular Transport Assay

    PubMed Central

    Kidron, Heidi

    2016-01-01

    The ABC transporters multidrug resistance associated protein 2 (MRP2) and breast cancer resistance protein (BCRP) are of interest in drug development, since they affect the pharmacokinetics of several drugs. Membrane vesicle transport assays are widely used to study interactions with these proteins. Since albumin has been found to affect the kinetics of metabolic enzymes in similar membrane preparations, we investigated whether albumin affects the kinetic parameters of efflux transport. We found that albumin increased the Vmax of 5(6)-carboxy-2’,7’-dichlorofluorescein (CDCF) and estradiol-17-β-D-glucuronide uptake into MRP2 vesicles in the presence of 0.1% bovine serum albumin (BSA) by 2 and 1.5-fold, respectively, while BSA increased Lucifer yellow uptake by 30% in BCRP vesicles. Km values increased slightly, but the change was not statistically significant. The effect of BSA on substrate uptake was dependent on the vesicle amount, while increasing BSA concentration did not significantly improve substrate uptake. These results indicate a minor effect of albumin on MRP2 and BCRP, but it should be considered if albumin is added to transporter assays for example as a solubilizer, since the effect may be substrate or transporter specific. PMID:27706255

  20. Elevation of CSF albumin in old sheep: relations to CSF turnover and albumin extraction at blood-CSF barrier.

    PubMed

    Chen, Ruo-Li; Chen, Carl Pai-Chu; Preston, Jane Elizabeth

    2010-06-01

    Albumin is the most abundant protein in both CSF and plasma, and albumin quotient is often used to assess the functions of brain barriers especially that of the blood-CSF barrier [i.e. the choroid plexus (CP) which also secretes CSF]. In this study, we took albumin as a model molecule to investigate ageing-related alterations in the CSF-CP system in sheep. We found significant ageing-related increases in the weight of lateral CP [122.4 +/- 14.0 mg in the young, 198.6 +/- 35.4 mg in the middle aged, 286.1 +/- 25.1 mg in the old (p < 0.05)], in the CSF albumin as well as the albumin quotient. Albumin protein spots in old CSF displayed wider on 2D western immunoblotting images, and had higher densities on images of 2D large gels stained with Pro-Q Emerald 488 compared to the young samples, suggesting ageing-related post-translational modification in the albumin. CSF secretion was reduced with age: 0.148 +/- 0.013 mL/min/g in the young, 0.092 +/- 0.02 mL/min/g in the middle aged, 0.070 +/- 0.013 mL/min/g in the old (p < 0.05). The (125)I-BSA extraction was not different among the sheep groups, nor was altered by temperature reduction, monensin, nocodazole, anti-transforming growth factor beta receptor II antibody, as well as unlabelled albumins. In conclusion, elevation of albumin in old CSF is associated with reduced CSF secretion by the CP, which size increases with age. (125)I-BSA extract, reflecting the extracellular space rather than the active albumin uptake in the CP, is not different between ages. These early changes in health ageing may result in the accumulation and modifications of CSF proteins leading to neurotoxicity.

  1. Study on the interaction of sulforaphane with human and bovine serum albumins.

    PubMed

    Abassi, Parvane; Abassi, Farzane; Yari, Faramarz; Hashemi, Mehrdad; Nafisi, Shohreh

    2013-05-05

    Sulforaphane; [1-isothiocyanato-4-(methylsulfinyl) butane], (SFN) is an isothiocyanate derived from glucoraphanin present in cruciferous vegetables and has a variety of potential chemopreventive actions. This study was designed to examine the interaction of sulforaphane with HSA and BSA. FTIR, UV-Vis spectroscopic methods as well as molecular modeling were used to determine the drug binding mode, binding constant and the effect of drug complexation on serum albumins stability and conformation. Structural analysis showed that SFN bind HSA and BSA via polypeptide polar groups with overall binding constants of KSFN-HSA=6.54×10(4) and KSFN-BSA=8.55×10(4) M(-1). HSA and BSA conformations were altered by a major reduction of α-helix upon SFN interaction. These results suggest that serum albumins might act as carrier proteins for SFN in delivering them to target tissues.

  2. Studies on binding interactions between clenbuterol hydrochloride and two serum albumins by multispectroscopic approaches in vitro.

    PubMed

    Wang, Qin; Zhang, Shengrui

    2014-08-01

    In this study, binding properties of clenbuterol hydrochloride (CL) with human serum albumin (HSA) and bovine serum albumin (BSA) were examined using constant protein concentrations and various CL contents under physiological conditions. The binding parameters were confirmed using fluorescence quenching spectroscopy at various temperatures. The experimental results confirmed that the quenching mechanisms of CL and HSA/BSA were both static quenching processes. The thermodynamic parameters, namely, enthalpy change (ΔH) and entropy change (ΔS), were calculated according to the van't Hoff equation, which suggested that the electrostatic interactions were the predominant intermolecular forces in stabilizing the CL-HSA complex, and hydrogen bonds and van der Waals force were the predominant intermolecular forces in stabilizing the CL-BSA complex. Furthermore, the conformational changes of HSA/BSA in the presence of CL were determined using the data obtained from three-dimensional fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy and circular dichroism spectroscopy.

  3. β-Carotene and astaxanthin with human and bovine serum albumins.

    PubMed

    Li, Xiangrong; Wang, Gongke; Chen, Dejun; Lu, Yan

    2015-07-15

    β-Carotene and astaxanthin are two carotenoids with powerful antioxidant properties. In this study, the interaction of these two carotenoids with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions was investigated using several spectroscopic techniques. The experimental results indicate the quenching mechanism of HSA/BSA, by the two carotenoids, is a static process. The binding constants and number of binding sites were evaluated at different temperatures. Thermodynamic investigations revealed the interaction between the two carotenoids and HSA/BSA is synergistically driven by enthalpy and entropy, and hydrophobic forces and electrostatic attraction have a significant role in the reactions. Binding site I was found to be the primary binding site for β-carotene and astaxanthin. In addition, as shown by synchronous fluorescence spectroscopy and FT-IR, the two carotenoids may induce conformational and micro-environmental changes in HSA/BSA.

  4. Adsorption of albumin on prosthetic materials: implication for tribological behavior.

    PubMed

    Serro, A P; Gispert, M P; Martins, M C L; Brogueira, P; Colaço, R; Saramago, B

    2006-09-01

    The orthopedic prosthesis used to substitute damaged natural joints are lubricated by a pseudosynovial fluid that contains biological macromolecules with potential boundary lubrication properties. Proteins are some of those macromolecules whose role in the lubrication process is not yet completely understood. In a previous work, we investigated the influence of the presence of albumin, the major synovial protein, upon the tribological behavior of three of the most used pairs of artificial joint materials: ultra high molecular weight polyethylene (UHMWPE) against counterfaces of alumina, CoCrMo alloy, and 316L stainless steel. Albumin was found to cause a significant decrease in the friction coefficient when the counterfaces were metallic because transfer of UHMWPE was avoided, but this effect was much weaker in the case of alumina. The objective of the present work was to look for an explanation for these differences in tribological behavior in terms of albumin adsorption. With this goal, studies on adsorption of bovine serum albumin (BSA) on the counterface materials, from a biological model fluid (Hanks' balanced salt solution), were carried out using radiolabeled albumin ((125)I-BSA), X-ray photoelectron spectroscopy, and atomic force microscopy. The conclusion from all techniques is that the driving force for albumin adsorption is higher on the metals than on alumina. These results confirm that the greater the amount of protein adsorbed on the counterface, the more efficient is the protection against the transfer of polymeric film to the counterface.

  5. Estimating the relative position of risperidone primary binding site in Sera Albumins. Modeling from spectrofluorimetric data

    NASA Astrophysics Data System (ADS)

    Cortez, Celia Martins; Fragoso, Viviane Muniz S.; Silva, Dilson

    2014-10-01

    In this work, we used a mathematical model to study the interaction of risperidone with human and bovine serum albumins estimating the relative position of the primary binding site, based on the fluorescence quenching theory. Results have shown that the model was able to demonstrate that primary binding site for risperidone in HSA and BSA is very close to the position where is tryptophan 134 of BSA, possibly in domain 1B.

  6. Enzyme biosensor based on the immobilization of HRP on SiO₂/BSA/Au composite nanoparticles.

    PubMed

    Yuan, Shirong; Yuan, Ruo; Chai, Yaqin; Zhuo, Ying; Yang, Xia; Yuan, Yali

    2010-12-01

    In this work, an enzyme biosensor based on the immobilization of horseradish peroxidase (HRP) on SiO₂/BSA/Au/thionine/nafion-modified gold electrode was fabricated successfully. Firstly, nafion was dropped on the surface of the gold electrode to form a nafion film followed by chemisorption of thionine (Thi) as an electron mediator via the ion-exchange interaction between the Thi and nafion. Subsequently, the SiO₂/BSA/Au composite nanoparticles were assembled onto Thi film through the covalent bounding with the amino groups of Thi. Finally, HRP was immobilized on the SiO₂/BSA/Au composite nanoparticles due to the covalent conjugation to construct an enzyme biosensor. The surface topographies of the SiO₂/BSA/Au composite nanoparticles were investigated by using scanning electronic microscopy. The stepwise self-assemble procedure of the biosensor was further characterized by means of cyclic voltammetry and chronoamperometry. The enzyme biosensor showed high sensitivity, good stability and selectivity, a wide linear response to hydrogen peroxide (H₂O₂) in the range of 8.0 x 10⁻⁶  ~3.72 x 10⁻³ mol/L, with a detection limit of 2.0 x 10⁻⁶ mol/L. The Michaelies-Menten constant K(app)(M) value was estimated to be 2.3 mM.

  7. Polymers for the stabilization and delivery of proteins topically and per os to the insect hemocoel through conjugation with aliphatic polyethylene glycol.

    PubMed

    Jeffers, Laura A; Shen, Hongyan; Bissinger, Brooke W; Khalil, Sayed; Gunnoe, T Brent; Roe, R Michael

    2014-10-01

    Co-feeding of aliphatic polyethylene glycol (PEG), phospholipase A2, anionic and ionic detergents, and amphipathic glycoside with bovine serum albumin (BSA) as a model protein to fourth stadium tobacco budworms, Heliothis virescens, did not affect the levels of BSA in the hemolymph. Covalent conjugation of small proteins like the decapeptide trypsin modulating oostatic factor (TMOF) to polyethylene glycol was previously shown to protect the peptide from protease attack and enhance its accumulation in the insect hemocoel. Whether this polymer chemistry could do the same for larger proteins was examined. The chemistry for the synthesis of polydispersed aliphatic PEG350-insulin and monodispersed aliphatic PEG333-insulin are described herein. Insulin was used for this synthesis and not BSA to better control conjugation among the available free amine groups. When PEGylated insulin or free insulin were fed in artificial diet to fifth stadium budworms, greater concentrations of insulin using the PEGylated variants were found in the hemolymph than when free insulin was used (a 6.7 and 7.3-fold increase for the PEG350 and PEG333 conjugates, respectively). When insulin is topically applied to the dorsum of H. virescens, no insulin is found in the hemolymph. However, after topical application of the PEGylated insulins, PEG350-insulin and PEG333-insulin were detected in the hemolymph. After injections of insulin into the hemocoel of fourth stadium H. virescens, insulin is completely cleared from the hemolymph in 120min. In comparison, PEG350-insulin and PEG333-insulin were present in the hemolymph for 300 and 240min after injection, respectively, translating to a 3.3 and 2.7-fold increase in the length of time insulin remains in the hemolymph after injection.

  8. Gd (III) complex conjugate of low-molecular-weight chitosan as a contrast agent for magnetic resonance/fluorescence dual-modal imaging.

    PubMed

    Huang, Yan; Boamah, Peter Osei; Gong, Jianbo; Zhang, Qi; Hua, Mingqing; Ye, Yuzhen

    2016-06-05

    The fusion of molecular and anatomical modalities facilitates more reliable and accurate detection in clinic. In this work, we prepared gadolinium (III) complex Gd-DTPA-FITC-CS11 with magnetic resonance (MR) and fluorescence dual-modal imaging modalities. Gd-DTPA-FITC-CS11 consisted of fluorescein isothiocyanate and low-molecular-weight chitosan (CS11) units conjugated with gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). Gd-DTPA-FITC-CS11 exhibited a higher longitudinal relaxivity (14.09 mM(-1)s(-1)) than the clinical Gd-DTPA (3.85 mM(-1)s(-1)). T1-weighted MR contrast enhancement was also demonstrated the comparability to Gd-DTPA at lower dosage. The binding with bovine serum albumin (BSA) was investigated. The fluorescence of BSA in the presence of Gd-DTPA-FITC-CS11 was weakened due to static quenching mechanism. The conformation of BSA was slightly changed but α-helix was dominant. The binding was entropy-driven and spontaneous and the main contribution was hydrophobic interaction. Our results suggested the potential of Gd-DTPA-FITC-CS11 as an MR/fluorescence dual-modal imaging contrast agent in improving the diagnostic sensitivity and accuracy.

  9. [Effect of tobacco combustion on the immunochemical properties of albumin].

    PubMed

    Martínez, R D; Chávez, R

    1997-01-01

    During tobacco burning smoker to run up substances to contain smoke as far as pulmonary tissue that is damage. In cigarette 600 degrees C are in ignition extreme, but in the other side, in contact with edge of the mouth smoker, the temperature is lower. Smoke could be delivery tobacco products until respiratory tract when temperature gradients occur in cigarette burn. For demonstration of the immunoreactive substances in tobacco smoke condense (TSC) we used a model with two cigarette arrangements: several concentrations of bovine seric albumin (BSA) applied to experimental group of cigarettes and phosphate-saline solution (PBS), 0.15 M pH 7.5 without protein to control cigarettes. Both series, experimental and control, remained at 20 degrees C during 48 h, soon afterward TSC was obtained. Higher protein concentration was observe in the experimental TSC of cigarettes expose to more elevated quantities of BSA, this was identify with polyclonal antibodies toward BSA employing counter-immunoelectrophoresis, immunoelectrophoresis, radial immunodiffusion and hemagglutination inhibition test. In summary: TSC of treat cigarettes had a little quantity of protein (BSA), but immunochemical properties of BSA in TSC were preserve because polyclonal antibodies against BSA bind to this protein. In habitual smoker some compounds present in cigarette smoke could be induce an immune response due to immunogen in tobacco substances.

  10. Interaction of glutathione with bovine serum albumin: Spectroscopy and molecular docking.

    PubMed

    Jahanban-Esfahlan, Ali; Panahi-Azar, Vahid

    2016-07-01

    This study aims to investigate the interaction between glutathione and bovine serum albumin (BSA) using ultraviolet-visible (UV-vis) absorption, fluorescence spectroscopies under simulated physiological conditions (pH 7.4) and molecular docking methods. The results of fluorescence spectroscopy indicated that the fluorescence intensity of BSA was decreased considerably upon the addition of glutathione through a static quenching mechanism. The fluorescence quenching obtained was related to the formation of BSA-glutathione complex. The values of KSV, Ka and Kb for the glutathione and BSA interaction were in the order of 10(5). The thermodynamic parameters including enthalpy change (ΔH), entropy change (ΔS) and also Gibb's free energy (ΔG) were determined using Van't Hoff equation. These values showed that hydrogen bonding and van der Waals forces were the main interactions in the binding of glutathione to BSA and the stabilization of the complex. Also, the interaction of glutathione and BSA was spontaneous. The effects of glutathione on the BSA conformation were determined using UV-vis spectroscopy. Moreover, glutathione was docked in BSA using ArgusLab as a molecular docking program. It was recognized that glutathione binds within the sub-domain IIA pocket in domain II of BSA.

  11. Effect of phosphorylated organic compound on the adsorption of bovine serum albumin by hydroxyapatite.

    PubMed

    Shimabayashi, S; Tanizawa, Y; Ishida, K

    1991-09-01

    The amount of adsorption of bovine serum albumin (BSA) by hydroxyapatite (HAP) increased with a concentration of CaCl2 due to the bridging effect of Ca2+ between adsorbate BSA and adsorbent HAP. On the other hand, it decreased remarkably with a concentration of K2HPO4. This was explained in terms of the effects of ionic strength and competitive adsorption between inorganic phosphate anion (Pi) and BSA, because BSA is in negatively charged over the examined pHs. A similar effect was observed in the presence of phosphorylated compounds such as phosphoserine, phytate, and phosphorylated polyvinylalcohol. The inhibiting effect of these compounds was stronger than that of their mother compounds (serine, inositol, and polyvinylalcohol). This result shows that phosphate groups bound to the mother compounds interfere with the adsorption of BSA by HAP in the same manner that Pi does. Although the adsorption of BSA was almost irreversible with respect to dilution with water, desorption was performed when these organic phosphorylated compounds were added after the accomplishment of the adsorption of BSA. However, the effective concentration of the phosphorylated compounds for the desorption of BSA was fairly higher than that for the competitive inhibition against the BSA adsorption.

  12. Chemical Composition Study of Vanadium Pentoxide Xerogels Doped by Bovine Albumin

    NASA Astrophysics Data System (ADS)

    Sereika, R.; Kaciulis, S.; Mezzi, A.; Brucale, M.

    2016-06-01

    Metal-bioorganic compounds of vanadium pentoxide and bovine serum albumin (BSA) (Fraction V) were obtained by using sol-gel method. Series of the samples (BSA)xV2O5ṡnH2O, where x=0, 0.01 and 0.001, were originally produced by the synthesis of vanadium pentoxide xerogels and subsequent blending with water-dissolved BSA in appropriate molar ratios. It was evident that the gelation process does not occur for x>0.01. For the X-ray photoelectron spectroscopy (XPS) studies, the thin layers of these materials were prepared by drying the gel onto the glass and mica substrates. The surface morphology of the samples was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. It follows from the analysis of experimental XPS spectra of (BSA)xV2O5ṡnH2O that the nitrogen ions in pure albumin and in (BSA)0.01V2O5ṡnH2O are present in imine, amine and protonated amine groups. The additional protonated amine arises when the concentration of albumin in (BSA)xV2O5ṡnH2O is low (x=0.001). Increasing the amount of albumin results in decrease of the number of oxygen ions bonded to vanadium. At the same time (with increase of albumin), the component of oxygen bounded to carbon and nitrogen is increasing. In the samples with greater amount of albumin, the reduction of vanadium ions occurs. This means that the trivalent and tetravalent vanadium ions are present together with pentavalent ones.

  13. Optical, structural and thermodynamic properties of the interaction between tradimefon and serum albumin

    NASA Astrophysics Data System (ADS)

    Zhang, Hua-xin; Mei, Ping; Yang, Xi-xiong

    2009-04-01

    The biological toxicity of a chloric pesticide, tradimefon to bovine serum albumin (BSA) were studied by fluorescence and absorption spectroscopy. The fluorescence quenching mechanism analysis indicates the quenching of BSA by TDF was caused by BSA-TDF complex formation and electrostatic interaction played major role in the reaction. The number of binding sites n and observed binding constant Kb was measured by fluorescence quenching method. The thermodynamic parameters Δ Hθ, Δ Gθ, Δ Sθ at different temperatures were calculated, and the distance r between donor (BSA) and acceptor (TDF) was obtained according to Förster theory of non-radiation energy transfer. Three-dimensional fluorescence spectra, circular dichroism (CD) spectra and synchronous fluorescence spectra were used to investigate the structural change of BSA molecules with addition of TDF and the mechanism of binding reaction was analyzed at molecular level.

  14. Impact of condensed tannin size as individual and mixed polymers on bovine serum albumin precipitation.

    PubMed

    Harbertson, James F; Kilmister, Rachel L; Kelm, Mark A; Downey, Mark O

    2014-10-01

    Condensed tannins composed of epicatechin from monomer to octamer were isolated from cacao (Theobroma cacao, L.) seeds and added to bovine serum albumin (BSA) individually and combined as mixtures. When added to excess BSA the amount of tannin precipitated increased with tannin size. The amount of tannin required to precipitate BSA varied among the polymers with the trimer requiring the most to precipitate BSA (1000 μg) and octamer the least (50 μg). The efficacy of condensed tannins for protein precipitation increased with increased degree of polymerisation (or size) from trimers to octamers (monomers and dimers did not precipitate BSA), while mixtures of two sizes primarily had an additive effect. This study demonstrates that astringent perception is likely to increase with increasing polymer size. Further research to expand our understanding of astringent perception and its correlation with protein precipitation would benefit from sensory analysis of condensed tannins across a range of polymer sizes.

  15. New insight into the binding interaction of hydroxylated carbon nanotubes with bovine serum albumin.

    PubMed

    Guan, Yonghui; Zhang, Hongmei; Wang, Yanqing

    2014-04-24

    In order to understand the effects of carbon nanotubes on the structural stability of proteins, the ligand-binding ability, fibrillation, and chemical denaturation of bovine serum albumin in the presence of a multi-walled hydroxylated carbon nanotubes (HO-MWCNTs) was characterized by UV-vis, circular dichroism, fluorescence spectroscopy and molecule modeling methods at the molecular level. The experiment results indicated that the fluorescence intensity of BSA was decreased obviously in presence of HO-MWCNTs. The binding interaction of HO-MWCNTs with BSA led to the secondary structure changes of BSA. This interaction could not only affect the ligand-binding ability of BSA, but also change the rate of fibrillation and denaturation of BSA. This work gave us some important information about the structures and properties of protein induced by carbon nanotubes.

  16. Spectroscopic analyses on interaction of bovine serum albumin with novel spiro[cyclopropane-pyrrolizin].

    PubMed

    Yu, Xianyong; Liao, Zhixi; Jiang, Bingfei; Hu, Xiaolian; Li, Xiaofang

    2015-02-25

    The interaction between novel spiro[cyclopropane-pyrrolizin] (NSCP) and bovine serum albumin (BSA) was analyzed by fluorescence and ultraviolet-visible (UV-Vis) spectroscopy at 298 K, 304 K and 310 K under simulative physiological conditions. The results showed that NSCP can effectively quench the intrinsic fluorescence of BSA via static quenching. The binding constants, binding sites of NSCP with BSA were calculated. Hydrogen binds and van der Waals force played a major role in stabilizing the complex and the binding reaction were spontaneous. According to the Förster non-radiation energy transfer theory, the average binding distances between NSCP and BSA were obtained. What is more, the synchronous fluorescence spectra indicated that the conformation of BSA has been changed.

  17. Study on the interaction between Besifloxacin and bovine serum albumin by spectroscopic techniques.

    PubMed

    Yu, Xianyong; Jiang, Bingfei; Liao, Zhixi; Jiao, Yue; Yi, Pinggui

    2015-01-01

    The interaction between Besifloxacin (BFLX) and bovine serum albumin (BSA) was investigated by spectroscopic (fluorescence, UV-Vis absorption and circular dichroism) techniques under imitated physiological conditions. The experiments were conducted at different temperatures (298, 304 and 310 K) and the results showed that the BFLX caused the fluorescence quenching of BSA through a static quenching procedure. The binding constant (Ka), binding sites (n) were obtained. The corresponding thermodynamic parameters (ΔH, ΔS and ΔG) of the interaction system were calculated at different temperatures. The results revealed that the binding process was spontaneous and the acting force between BFLX and BSA were mainly electrostatic forces. According to Förster non-radiation energy transfer theory, the binding distance between BFLX and BSA was calculated to be 4.96 nm. What is more, both synchronous fluorescence and circular dichroism spectra confirmed conformational changes of BSA.

  18. Interaction between melamine and bovine serum albumin: Spectroscopic approach and density functional theory

    NASA Astrophysics Data System (ADS)

    Yan, Hua; Wu, Junyong; Dai, Guoliang; Zhong, Aiguo; Yang, Jianguo; Liang, Huading; Pan, Fuyou

    2010-04-01

    Spectroscopic approach and density functional theory (DFT) have been employed to investigate the interaction between melamine (MA) and bovine serum albumin (BSA). The UV absorption difference spectra show the MA-BSA complexes can form under physiological conditions. Furthermore, the B3LYP/6-311++G(d,p) calculations indicate that the protonated melamine (MAH +) bond to Asp, Glu, Asn, Gln, Ser, Thr amino acid residues or peptide groups via N sbnd H(MAH +)…O dbnd C(BSA) or N sbnd H(MAH +)…O sbnd C(BSA) hydrogen bonds, in agreement with the results of UV absorption difference spectra, and the interaction energies of them decrease in the order Asp, Glu > Pep > Asn, Gln > Ser, Thr. The fluorescence spectra, synchronous fluorescence spectra and FT-IR spectra demonstrate that this interaction has no obvious effect on the secondary structure of BSA.

  19. Behaviour of liposomes loaded with bovine serum albumin during in vitro digestion.

    PubMed

    Liu, Weilin; Ye, Aiqian; Liu, Wei; Liu, Chengmei; Han, Jianzhong; Singh, Harjinder

    2015-05-15

    This study examined the stability of liposomes loaded with negatively charged protein (bovine serum albumin, BSA) during in vitro digestion. Zeta-potential and morphology measurements confirmed that BSA-loaded liposomes were successfully prepared, with an encapsulation efficiency of around 34%. The encapsulated BSA and the integrity of the liposomes remained unchanged with time when the liposomes were digested in a simulated gastric environment, suggesting that the liposomal membrane protected the entrapped BSA from pepsin hydrolysis. BSA-loaded liposomes exhibited lower stability in simulated intestinal fluid, as shown by damaged membranes and the release of free fatty acids. Also, lipolysis kinetics revealed that bile salts and ionic strength could facilitate a high level of free fatty acid release. This work further supplemented our knowledge about the effects of gastrointestinal digestion conditions on liposomal properties and provided valuable information for the design of liposome formulations for the food and health care industries.

  20. Investigation on the interaction of pyrene with bovine serum albumin using spectroscopic methods.

    PubMed

    Xu, Chengbin; Gu, Jiali; Ma, Xiping; Dong, Tian; Meng, Xuelian

    2014-05-05

    This paper was designed to investigate the interaction of pyrene with bovine serum albumin (BSA) under physiological condition by spectroscopic methods. Spectroscopic analysis of the emission quenching revealed that the quenching mechanism of BSA by pyrene was static. The binding sites and constants of pyrene-BSA complex were observed to be 1.20 and 2.63×10(6) L mol(-1) at 298 K, respectively. The enthalpy change (ΔH) and entropy change (ΔS) revealed that van der Waals forces and hydrogen bonds stabilized the pyrene-BSA complex. Energy transfer from tryptophan to pyrene occurred by a FRET (fluorescence resonance energy transfer) mechanism, and the distance (r=2.72 nm) had been determined. The results of synchronous, three-dimensional fluorescence, and circular dichroism spectra showed that the pyrene induced conformational changes of BSA.

  1. Interaction of bovine serum albumin protein with self assembled monolayer of mercaptoundecanoic acid

    NASA Astrophysics Data System (ADS)

    Poonia, Monika; Agarwal, Hitesh; Manjuladevi, V.; Gupta, R. K.

    2016-05-01

    Detection of proteins and other biomolecules in liquid phase is the essence for the design of a biosensor. The sensitivity of a sensor can be enhanced by the appropriate functionalization of the sensing area so as to establish the molecular specific interaction. In the present work, we have studied the interaction of bovine serum albumin (BSA) protein with a chemically functionalized surface using a quartz crystal microbalance (QCM). The gold-coated quartz crystals (AT-cut/5 MHz) were functionalized by forming self-assembled monolayer (SAM) of 11-Mercaptoundecanoic acid (MUA). The adsorption characteristics of BSA onto SAM of MUA on quartz crystal are reported. BSA showed the highest affinity for SAM of MUA as compared to pure gold surface. The SAM of MUA provides carboxylated surface which enhances not only the adsorption of the BSA protein but also a very stable BSA-MUA complex in the liquid phase.

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

    PubMed Central

    Xu, Hongliang; Yao, Nannan; Xu, Haoran; Wang, Tianshi; Li, Guiying; Li, Zhengqiang

    2013-01-01

    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. PMID:23839090

  3. Probing the binding of (+)-catechin to bovine serum albumin by isothermal titration calorimetry and spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Li, Xiangrong; Hao, Yongbing

    2015-07-01

    In this study, the interaction between (+)-catechin and bovine serum albumin (BSA) was investigated using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy, UV-vis absorption spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy. Thermodynamic investigations reveal that the electrostatic interaction and hydrophobic interaction are the major binding forces in the binding of (+)-catechin to BSA. The binding of (+)-catechin to BSA is synergistically driven by enthalpy and entropy. Fluorescence experiments suggest that (+)-catechin can quench the fluorescence of BSA through a static quenching mechanism. The obtained binding constants and the equilibrium fraction of unbound (+)-catechin show that (+)-catechin can be stored and transported from the circulatory system to reach its target organ. Binding site I is found to be the primary binding site for (+)-catechin. Additionally, as shown by the UV-vis absorption, synchronous fluorescence spectroscopy and FT-IR, (+)-catechin may induce conformational and microenvironmental changes of BSA.

  4. Effects of oxidation on changes of compressibility of bovine serum albumin.

    PubMed

    Hianik, T; Rybár, P; Benediktyová, Z; Svobodová, L; Hermetter, A

    2003-12-01

    The methods of ultrasound velocity and density measurements were used to study the adiabatic compressibility of bovine serum albumin (BSA) during its oxidation by the prooxidants Cu2+ and 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH). We did not find changes of compressibility of BSA in the presence of copper ions at rather high molar ratio Cu2+/BSA = 0.66 mol/mol. This can be explained by binding of the Cu2+ to the binding site of BSA and thus protecting the prooxidant action of the copper. However, AAPH-mediated oxidation of BSA resulted in an increase of its apparent specific compressibility (psik/beta0). These changes could be caused by the fragmentation of the protein.

  5. Study on the interaction of silver(I) complex with bovine serum albumin by spectroscopic techniques.

    PubMed

    Shahabadi, Nahid; Maghsudi, Maryam; Ahmadipour, Zeinab

    2012-06-15

    The interaction of silver(I) complex, [Ag (2,9-dimethyl-1,10-phenanthroline)(2)](NO(3))·H(2)O, and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorimetry and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the complex was a static procedure. Various binding parameters were evaluated. The negative value of ΔH, negative value of ΔS and the negative value of ΔG indicated that van der Waals force and hydrogen bonding play major roles in the binding of the complex and BSA. Based on Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (Ag(I) complex) was evaluated. The results of CD and UV-vis spectroscopy showed that the binding of this complex could bind to BSA and be effectively transported and eliminated in the body.

  6. Study on the interaction between bovine serum albumin and starch nanoparticles prepared by isoamylolysis and recrystallization.

    PubMed

    Ji, Na; Qiu, Chao; Li, Xiaojing; Xiong, Liu; Sun, Qingjie

    2015-04-01

    The current study primarily investigated the interaction of bovine serum albumin (BSA) with starch nanoparticles (SNPs) prepared by isoamylolysis and recrystallization using UV-vis, fluorescence, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and circular dichroism (CD). The enhanced absorbance observed by UV-vis spectroscopy and decreased intensity of fluorescence spectroscopy suggested that BSA could bind to SNPs and form a BSA-SNP complex. The synchronous fluorescence spectra revealed that the emission maximum of Tyr residue (at Δλ=15nm) was red-shifted at the investigated concentrations range, indicating that the conformation of BSA was changed. Quenching parameters showed that the quenching effect of SNPs was static quenching. TEM images showed that the SNPs were surrounded by protein coronae, indicating that nanoparticle-protein complexes had formed. The FTIR and CD characterization indicated that the SNPs induced structural changes in the secondary structure of BSA.

  7. Binding of Catalpol to Bovine Serum albumin in vitro Examined by Spectroscopy and Molecular Modeling

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Chen, L.; Hu, W.; Li, J.; Liu, X.

    2016-11-01

    This paper explores the interaction mechanisms between catalpol and bovine serum albumin (BSA) in vitro using the methods of fluorescence quenching, UV-vis absorption, synchronous fluorescence spectroscopy, and molecular modeling. The fluorescence quenching mechanism of BSA by catalpol was confirmed to be a dynamic process. In addition, the UV-vis absorption spectra of BSA in the absence and presence of catalpol provided further evidence for the quenching. Synchronous fluorescence spectra showed that the addition of catalpol did not obviously affect the microenvironment in BSA. This could be explained by the distance between catalpol and Trp residues in protein, which was deduced from the subsequent molecular docking. The theoretical results were further verified by molecular docking analysis. It showed that not only the hydrophobic force but also hydrogen bonds played a role in the interaction of catalpol with BSA.

  8. Peptide-derivatized albumins that inhibit fibrin polymerization.

    PubMed

    Watson, Joseph W; Doolittle, Russell F

    2011-11-15

    Synthetic peptides patterned on sequences that appear during thrombin proteolysis of fibrinogen are known to influence fibrin formation in very different ways. A-Knob sequences (GPR-) inhibit polymerization, but B-knob sequences (GHR-) can actually enhance the process. We now report that when such peptides are attached to albumin carriers, both knob conjugates inhibit fibrin formation. In contrast, the 2-aminoethylthiol-albumin conjugate control enhances the polymerization to the same degree as albumin. The peptide AHRPam, which is known to bind exclusively to the βC holes of fibrinogen/fibrin, nullifies the inhibitory effects of the GHRPYGGGCam-albumin conjugate on fibrin polymerization, indicating that the inhibition was exclusively due to interactions with βC holes. AHRPam was much less effective in countering inhibition by the GPRPGGGGCam-albumin conjugate, suggesting that the observed effects with this conjugate involve mainly the γC holes of fibrin/fibrinogen. This study demonstrates that peptides modeled on fibrin polymerization knobs tethered to albumin retain their capacity to interact with fibrinogen/fibrin and may prove useful as inhibitors of clotting in vivo.

  9. Investigations on the binding of mercury ions to albumins employing differential pulse voltammetry.

    PubMed

    Castro, Clarissa Silva Pires de; SouzaDe, Jurandir Rodrigues; Bloch, Carlos

    2003-04-01

    Binding of mercury to BSA and Ovalbumin was investigated by Differential Pulse Voltammetry. The method relies on the direct monitoring of peak current variation due to mercury oxidation in the presence of these two albumins. Linear calibration graphs were obtained for both BSA and Ovalbumin in concentrations ranging from 2.49 x 10(-9) to 19.6 x 10(-9) mol L(-1). The acquired data was used to quantify these two proteins independently and to calculate the dissociation constants of Hg-BSA and Hg-Ovalbumin complexes.

  10. Fluorescent analysis of interaction of flavonols with hemoglobin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Sentchouk, V. V.; Bondaryuk, E. V.

    2007-09-01

    We have studied the fluorescent properties of flavonols (quercetin, fisetin, morin, rutin) with the aim of studying possible interaction with hemoglobin and bovine serum albumin (BSA). We observed an increase in the intensity of intrinsic fluorescence for all the flavonols except rutin in the presence of BSA. From the changes in the fluorescence spectra, we concluded that tautomeric forms are formed on interaction with hemoglobin. We determined the interconnection between the structure of related flavonols and their fluorescent properties on interaction with proteins, and we determined the binding constants for binding with BSA and hemoglobin.

  11. EPR study of the effect of terahertz radiation on the albumin conformation dynamics

    NASA Astrophysics Data System (ADS)

    Nemova, Eugenia F.; Cherkasova, Olga P.; Fedorov, Vyacheslav I.

    2010-09-01

    Effect of the preliminary irradiation of bovine serum albumin (BSA) in the terahertz spectral range on the conformation changes revealed with the help of EPR spectroscopy was investigated using the spin probing technique. The formation of the spin probe occurs directly in the aqueous solution of BSA from a nitrone compound (dihydropyrazine dioxide). It was shown that irradiation causes changes in the parameters of the EPR spectrum of the spin probe. An approach to linking the observed changes with the structural characteristics of reaction centres - the functional groups of amino acids comprising BSA - was outlined.

  12. Effect of the sugar and polyol additives on the aggregation kinetics of BSA in the presence of N-cetyl-N,N,N-trimethyl ammonium bromide.

    PubMed

    Sharma, Anurag; Pasha, Javeed M; Deep, Shashank

    2010-10-01

    The kinetics of the aggregation of bovine serum albumin (BSA) in the presence of N-cetyl-N,N,N-trimethyl ammonium bromide (CTAB) was studied by monitoring turbidity as a function of time. BSA-CTAB aggregation exhibits an exponential growth, with a pronounced lag phase and a subsequent rapid growth of the aggregates. On the addition of sugars and polyols to BSA-CTAB solution, there is an increase in the lag time and decrease in the rate constant of growth phase indicating that the inhibitors affect both the pre- and post-nucleation processes. The concentration dependence studies of lag time of BSA-CTAB aggregation in the presence of additives points towards the involvement of more number of monomers in the nucleus/start aggregate. The increase in the stability of BSA in the presence of these additives indicates probable role of activation energy in the aggregation. However, the temperature dependence of lag time of BSA-CTAB aggregation shows that the hindrance to molecular collisions, as indicated by decrease in the pre-exponential factor, due to increased viscosity in the presence of additives is the main factor responsible for their inhibitory action. Similarly, higher viscosity of sucrose makes it a much better inhibitor of the heat and surfactant induced aggregation of BSA-CTAB than mannitol.

  13. Surface Plasmon Resonance Assay of Binding Properties of Antisense Oligonucleotides to Serum Albumins and Lipoproteins.

    PubMed

    Onishi, Reina; Watanabe, Ayahisa; Nakajima, Mado; Sekiguchi, Mitsuaki; Kugimiya, Akira; Kinouchi, Hiroki; Nihashi, Yoichiro; Kamimori, Hiroshi

    2015-01-01

    In the present study, we developed an assay to evaluate the kinetic binding properties of the unconjugated antisense oligonucleotide (ASO) and lipophilic and hydrophilic ligands conjugated ASOs to mouse and human serum albumin, and lipoproteins using surface plasmon resonance (SPR). The lipophilic ligands conjugated ASOs showed clear affinity to the albumins and lipoproteins, while the unconjugated and hydrophilic ligand conjugated ASOs showed no interaction. The SPR method showed reproducible immobilization of albumins and lipoproteins as ligands on the sensor chip, and reproducible affinity kinetic parameters of interaction of ASOs conjugated with the ligands could be obtained. The kinetic binding data of these ASOs to albumin and lipoproteins by SPR were related with the distributions in the whole liver in mice after administration of these conjugated ASOs. The results demonstrated that our SPR method could be a valuable tool for predicting the mechanism of the properties of delivery of conjugated ASOs to the organs.

  14. Interaction of tetramethylpyrazine with two serum albumins by a hybrid spectroscopic method

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengjun

    The interactions of tetramethylpyrazine (TMPZ) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by various spectroscopic techniques. Fluorescence tests showed that TMPZ could bind to BSA/HSA to form complexes. The binding constants of TMPZ-BSA and TMPZ-HSA complexes were observed to be 1.442 × 104 and 3.302 × 104 M-1 at 298 K, respectively. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TMPZ-HSA was mainly depended on hydrophobic interaction, and yet the binding of TMPZ-BSA might involve hydrophobic interaction strongly and electrostatic interaction. The results of synchronous fluorescence, three-dimensional fluorescence, UV-vis absorption, FT-IR and CD spectra showed that the conformations of both BSA and HSA altered with the addition of TMPZ. The binding average distance between TMPZ and BSA/HSA was evaluated according to Föster non-radioactive energy transfer theory. In addition, with the aid of site markers (such as, phenylbutazone, ibuprofen and digitoxin), TMPZ primarily bound to tryptophan residues of BSA/HSA within site I (sub-domain II A).

  15. Effects of perfluorooctane sulfonate on the conformation and activity of bovine serum albumin.

    PubMed

    Wang, Yanqing; Zhang, Hongmei; Kang, Yijun; Cao, Jian

    2016-06-01

    Perfluorooctane sulfonate (PFOS) is among the most prominent contaminates in human serum and has been reported to possess potential toxicity to the human body. In this study, the effects of PFOS on the conformation and activity of bovine serum albumin (BSA) were investigated in vitro. The results indicated that the binding interaction of PFOS with BSA destroyed the tertiary and secondary structures of protein with the loss of α-helix structure and the increasing of hydrophobic microenvironment of the Trp or Tyr residues. During the thermal denaturation protein, PFOS increases the protein stability of BSA. The proportion of α-helix decreased on increasing the PFOS concentration and the microenvironment of the Trp or Tyr residues becomes more hydrophobic. The results from molecular modeling indicated that BSA had not only one possible binding site to bind with PFOS by the polar interaction, hydrogen bonds and hydrophobic forces. In addition, the BSA relative activities were decreased with the increase of PFOS concentration. Such loss of BSA activity in the presence of PFOS indicated that one of the binding sites in BSA is located in subdomain IIIA, which is in good agreement with the fluorescence spectroscopic experiments and molecular modeling results. This study offers a comprehensive picture of the interactions of PFOS with serum albumin and provides insights into the toxicological effect of perfluoroalkylated substances.

  16. Long-Term Toxicity of 213Bi-Labelled BSA in Mice

    PubMed Central

    Dorso, Laëtitia; Bigot-Corbel, Edith; Abadie, Jérôme; Diab, Maya; Gouard, Sébastien; Bruchertseifer, Frank; Morgenstern, Alfred; Maurel, Catherine; Chérel, Michel; Davodeau, François

    2016-01-01

    Background Short-term toxicological evaluations of alpha-radioimmunotherapy have been reported in preclinical assays, particularly using bismuth-213 (213Bi). Toxicity is greatly influenced not only by the pharmacokinetics and binding specificity of the vector but also by non-specific irradiation due to the circulating radiopharmaceutical in the blood. To assess this, an acute and chronic toxicity study was carried out in mice injected with 213Bi-labelled Bovine Serum Albumin (213Bi-BSA) as an example of a long-term circulating vector. Method Biodistribution of 213Bi-BSA and 125I-BSA were compared in order to evaluate 213Bi uptake by healthy organs. The doses to organs for injected 213Bi-BSA were calculated. Groups of nude mice were injected with 3.7, 7.4 and 11.1 MBq of 213Bi-BSA and monitored for 385 days. Plasma parameters, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine, were measured and blood cell counts (white blood cells, platelets and red blood cells) were performed. Mouse organs were examined histologically at different time points. Results Haematological toxicity was transient and non-limiting for all evaluated injected activities. At the highest injected activity (11.1 MBq), mice died from liver and kidney failure (median survival of 189 days). This liver toxicity was identified by an increase in both ALT and AST and by histological examination. Mice injected with 7.4 MBq of 213Bi-BSA (median survival of 324 days) had an increase in plasma BUN and creatinine due to impaired kidney function, confirmed by histological examination. Injection of 3.7 MBq of 213Bi-BSA was safe, with no plasma enzyme modifications or histological abnormalities. Conclusion Haematological toxicity was not limiting in this study. Liver failure was observed at the highest injected activity (11.1 MBq), consistent with liver damage observed in human clinical trials. Intermediate injected activity (7.4 MBq) should be

  17. Species-dependent stereoselective drug binding to albumin: a circular dichroism study.

    PubMed

    Pistolozzi, Marco; Bertucci, Carlo

    2008-03-01

    Drug binding to albumins from different mammalian species was investigated to disclose evidence of species-dependent stereoselectivity in drug-binding processes and affinities. This aspect is important for evaluating the reliability of extrapolating distribution data among species. The circular dichroism (CD) signal induced by drug binding to the albumins [human serum albumin (HSA), bovine serum albumin (BSA), rat serum albumin (RSA), and dog serum albumin (DSA)] were measured and analyzed. The binding of selected drugs and metabolites to HSA significantly differed from the binding to the other albumins in terms of affinity and conformation of the bound ligands. In particular, phenylbutazone, a marker of site one on HSA, showed a higher affinity for binding to BSA with respect to RSA, HSA, and DSA, respectively. In the case of diazepam, a marker of site two on HSA, the affinity decreased in order from HSA to DSA, RSA, and BSA. The induced CD spectra were similar in terms of energy and band signs, suggesting almost the same conformation for the bound drug to the different albumins. Stereoselectivity was high for the binding of ketoprofen to HSA and RSA. A different sign was observed for the CD spectra induced by the drug to the two albumins because of the prevalence of a different conformation of the bound drug. Interestingly, the same induced CD spectra were obtained using either the racemic form or the (S)-enantiomer. Finally, significant differences were observed in the affinity of bilirubin, being highest for BSA, then decreasing for RSA, HSA, and DSA. A more complex conformational equilibrium was observed for bound bilirubin.

  18. Caveolae may enable albumin to enter human renal glomerular endothelial cells.

    PubMed

    Moriyama, Takahito; Takei, Takashi; Itabashi, Mitsuyo; Uchida, Keiko; Tsuchiya, Ken; Nitta, Kosaku

    2015-06-01

    Caveolae on human renal glomerular endothelial cells (HRGECs) are increased in glomerular disease and correlate with the degree of albuminuria. To assess the mechanism by which caveolae contribute to albuminuria, we investigated whether albumin enters into HRGECs through caveolae. HRGECs were incubated with Alexa Fluor 488 labeled BSA or transferrin, followed by immunofluorescence localization with antibody to caveolin-1 (Cav-1), the main structural protein of caveolae, or clathrin, the major structural protein of clathrin coated pits, to assess whether BSA colocalized with Cav-1. HRGECs were also incubated with albumin and caveolae disrupting agents, including methyl beta cyclodextrin (MBCD) and nystatin, to determine whether disrupting caveolae interfered with albumin endocytosis into HRGECs. HRGECs were also incubated with albumin after transfection with Cav-1 small interfering RNAs (siRNAs). Labeled BSA colocalized with Cav-1, but not with clathrin. In contrast, labeled transferrin colocalized with clathrin, but not with Cav-1. Incubation of HRGECs with MBCD or nystatin, or transfection with Cav-1 siRNA, significantly reduced the intracellular amounts of albumin and Cav-1, relative to normal HRGECs, as shown by western blotting and immunofluorescence. These findings indicate that albumin enters HRGECs through the caveolae, suggesting that caveolae play an important role in the pathogenesis of albuminuria by providing a pathway through which albumin can enter glomerular endothelial cells.

  19. [Spectroscopic study on interaction of rodenticide brodifacoum with bovine serum albumin].

    PubMed

    Duan, Yun-Qing; Lei, Huan-Gui; Min, Shun-Geng; Duan, Zhi-Qing

    2009-11-01

    The mutual interaction of bovine serum albumin (BSA) with brodifacoum (3-[3-(4'-bromophenyl-4) 1,2,3,4-tetralin-10]-4-hydroxyl-coumarin), an anticoagulant rodenticide, was investigated by ultra-violet spectroscopy, flurorescence spectroscopy and synchronous fluorescence spectroscopy under physiological conditions. It was proved that the intrinsic fluorescence quenching of BSA by brodifacoum was the result of the formation of brodifacoum-BSA complex. And this quenching is mainly due to static fluorescence quenching. The quenching rate constant (K(sv)), binding site number (n) and binding constant (KA) at different temperatures were calculated from the double reciprocal Lineweaver-Burk plots and the quenching function of lg[(F0 - F)/F] - lg[Q] plots. The thermodynamic parameters indicated that the process of binding was a spontaneous molecular interaction and the hydrophobic force played a major role in stabilizing the brodifacoum BSA complex. The binding distance r between brodifacoum and BSA was 2.84 and 2.87 nm at 20 and 30 degrees C, respectively, which was obtained based on Forster theory of non-radiation energy transfer. The synchronous spectroscopy of BSA and brodifacoum-BSA revealed that the BSA conformation had changed in the presence of brodifacoum. The binding mode and interaction mechanism were suggested as follows: brodifacoum molecules are closed with amino acid residues with electric charge on the hydrophobic cavities of BSA by electrostatic interaction, and binded to the Trp212 residues inside of BSA hydrophobic cavities by hydrophobic interaction force, thereby changed the microenvironment around the Trp residues. The interaction prevented the energy transfer between Tyr and Trp residues, moreover, caused to a non-radiation energy transfer from Trp residues in BSA to brodifacoum, and finally leaded of the quenching the intrinsic fluorescence of BSA.

  20. Albumin's Influence on Carprofen Enantiomers-Hymecromone Interaction.

    PubMed

    Tang, Mingjie; Guo, Yanjie; Gao, Youshui; Tang, Chao; Dang, Xiaoqian; Zhou, Zubin; Sun, Yuqiang; Wang, Kunzheng

    2016-03-01

    Hymecromone is an important coumarin drug, and carprofen is one of the most important nonsteroidal antiinflammatory drugs (NSAIDs). The present study aims to determine the influence of bovine serum albumin (BSA) on the carprofen-hymecromone interaction. The inhibition of carprofen enantiomers on the UDP-glucuronosyltransferase (UGT) 2B7-catalyzed glucuronidation of hymecromone was investigated in the UGTs incubation system with and without BSA. The inhibition capability of increased by 20% (P < 0.001) of (R)-carprofen after the addition of 0.5% BSA in the incubation mixture. In contrast, no significant difference was observed for the inhibition of (S)-carprofen on UGT2B7 activity in the absence or presence of 0.5% BSA in the incubation system. The Lineweaver-Burk plot showed that the intersection point was located in the vertical axis, indicating the competitive inhibition of (R)-carprofen on UGT2B7 in the incubation system with BSA, which is consistent with the inhibition kinetic type of (R)-carprofen on UGT2B7 in the incubation system without BSA. Furthermore, the second plot using the slopes from the Lineweaver-Burk versus the concentrations of (R)-carprofen showed that the fitting equation was y=39.997x+50. Using this equation, the inhibition kinetic parameter was calculated to be 1.3 μM. For (S)-carprofen, the intersection point was located in the horizontal axis in the Lineweaver-Burk plot for the incubation system with BSA, indicating the noncompetitive inhibition of (S)-carprofen on the activity of UGT2B7. The fitting plot of the second plot was y=24.6x+180, and the inhibition kinetic parameter was 7.3 μM. In conclusion, the present study gives a short summary of BSA's influence on the carprofen enantiomers-hymecromone interaction, which will guide the clinical application of carprofen and hymecromone.

  1. Increased atherosclerosis and glomerulonephritis in cynomolgus monkeys (Macaca fascicularis) given injections of BSA over an extended period of time.

    PubMed Central

    Stills, H. F.; Bullock, B. C.; Clarkson, T. B.

    1983-01-01

    A study was conducted to compare the effects of experimental immune complex disease on the development of glomerulonephritis and aortic and coronary artery atherosclerosis. Fourteen adult male macaques (Macaca fascicularis) were fed a mildly atherogenic diet. Ten of these animals were given repeated intravenous injections of bovine serum albumin (BSA), and the remaining 4 were given similar injections of saline. Three of the monkeys given BSA responded with a high antibody titer, 4 with a moderate titer, and 3 with a low level titer to BSA. In all 4 monkeys with the moderate antibody response glomerulonephritis developed, characterized by increased glomerular cellularity, electron-dense deposits in the glomerular capillary basal lamina, and deposits of IgG, IgM, C3, C4, and BSA. Glomerulonephritis was not seen in the other 6 monkeys given BSA or the 4 control monkeys. Aortic lesions seen at necropsy consisted of a few fatty intimal streaks with no differences between test monkeys (given BSA) and control monkeys (given saline). There was no correlation between total serum cholesterol concentration, high-density lipoprotein cholesterol concentration, or BSA antibody levels and the degree of aortic atherosclerosis. Immunochemical stains for immunoglobulins and complement components revealed increased intimal staining when intimal thickness increased. Medial staining for immunoglobulin and complement components appeared to be slightly increased in monkeys with moderately high-level titers of BSA. The extent of atherosclerosis in the coronary arteries of monkeys given BSA was greater than in the control animals. Differences in the extent and severity of the atherosclerotic lesions were most pronounced in the proximal portions of the main coronary arteries, suggesting an increased susceptibility of this site to immune-complex-exacerbated atherosclerosis. In addition to the increased lesion severity in monkeys given BSA, there were numerous granulocytes seen within

  2. Adsorption of polyethylene-glycolated bovine serum albumin on macroporous and polymer-grafted anion exchangers.

    PubMed

    Zhu, Mimi; Carta, Giorgio

    2014-01-24

    The chromatographic and adsorptive properties of BSA and BSA conjugated with 10 and 30kDa PEG polymers are determined for a macroporous anion exchanger (UNOsphere™ Diol Q) and for a polymer-grafted material having the same backbone matrix (Nuvia Q™). Chromatographic retention, adsorption capacity, and adsorption kinetics are enhanced in the polymer-grafted resin for both BSA and 10kDa PEG-BSA as a result of interactions with the grafted polymers. However, the difference between the two resins diminishes for 30kDa PEG-BSA indicating that size exclusion effects strongly affect binding in the polymer-grafted material for this larger conjugate. Images of intraparticle concentration profiles obtained by confocal scanning laser microscopy show that the transport mechanisms of both BSA and PEGylated BSA are very different in the two resins. The protein binding kinetics are dominated by ordinary pore diffusion and are essentially independent of the direction of transport for UNOsphere Diol Q as a result of its large pore size. Thus, for this material, displacement of PEGylated BSA by BSA is clearly evident at the intraparticle scale. On the other hand, the protein binding kinetics in Nuvia Q are consistent with a solid diffusion mechanism driven by the adsorbed protein concentration. For this material, protein transport is very fast for one component or two-component co-adsorption of BSA and PEGylated BSA but slows down dramatically for sequential adsorption of these species as a result of heightened diffusional hindrance when the two components counterdiffuse within the resin.

  3. Location and binding mechanism of an ESIPT probe 3-hydroxy-2-naphthoic acid in unsaturated fatty acid bound serum albumins.

    PubMed

    Ghorai, Shyamal Kr; Tripathy, Debi Ranjan; Dasgupta, Swagata; Ghosh, Sanjib

    2014-02-05

    The binding site and the binding mechanism of 3-hydroxy-2-naphthoic acid (3HNA) in oleic acid (OA) bound serum albumins (bovine serum albumin (BSA) and human serum albumin (HSA)) have been determined using steady state and time resolved emission of tryptophan residues (Trp) in proteins and the ESIPT emission of 3HNA. Time resolved anisotropy of the probe 3HNA and low temperature phosphorescence of Trp residues of BSA in OA bound BSA at 77K reveals a drastic change of the binding site of 3HNA in the ternary system compared to that in the free protein. 3HNA binds near Trp213 in the ternary system whereas 3HNA binds near Trp134 in the free protein. The structure of OA bound BSA generated using docking methodology exhibits U-bend configuration of all bound OA. The docked pose of 3HNA in the free protein and in OA bound albumins (ternary systems) and the concomitant perturbation of the structure of proteins around the binding region of 3HNA corroborate the enhanced ESIPT emission of 3HNA and the energy transfer efficiency from the donor Trp213 of BSA to 3HNA acceptor in 3HNA-OA-BSA system.

  4. Quantitative and qualitative evaluation of adsorption/desorption of bovine serum albumin on hydrophilic and hydrophobic surfaces.

    PubMed

    Jeyachandran, Y L; Mielczarski, E; Rai, B; Mielczarski, J A

    2009-10-06

    We studied the adsorption of bovine serum albumin (BSA) from phosphate-buffered saline (pH 7.4) to hydrophilic and hydrophobic surfaces. Attenuated total reflection Fourier transform infrared spectroscopy, supported by spectral simulation, allowed us to determine with high precision the amount of BSA adsorbed (surface coverage) and its structural composition. The adsorbed BSA molecules had an alpha-helical structure on both hydrophobic and hydrophilic surfaces but had different molecular conformations and adsorption strengths on the two types of surface. Adsorption of BSA was saturated at around 50% surface coverage on the hydrophobic surface, whereas on the hydrophilic surface the adsorption reached 95%. The BSA molecules adsorbed to the hydrophilic surface with a higher interaction strength than to the hydrophobic surface. Very little adsorbed BSA could be desorbed from the hydrophilic surface, even using 0.1 M sodium dodecyl sulfate, a strong detergent solution. The formation of BSA-phosphate surface complexes was observed under different BSA adsorption conditions on hydrophobic and hydrophilic surfaces. The formation of these complexes correlated with the more efficient blocking of nonspecific interactions by the adsorbed BSA layer. Results from the molecular modeling of BSA interactions with hydrophobic and hydrophilic surfaces support the spectroscopic findings.

  5. Characterization of intermolecular interaction between cyanidin-3-glucoside and bovine serum albumin: spectroscopic and molecular docking methods.

    PubMed

    Shi, Jie-hua; Wang, Jing; Zhu, Ying-yao; Chen, Jun

    2014-08-01

    The intermolecular interaction between cyanidin-3-glucoside (Cy-3-G) and bovine serum albumin (BSA) was investigated using fluorescence, circular dichroism and molecular docking methods. The experimental results revealed that the fluorescence quenching of BSA at 338 nm by Cy-3-G resulted from the formation of Cy-3-G-BSA complex. The number of binding sites (n) for Cy-3-G binding on BSA was approximately equal to 1. The experimental and molecular docking results revealed that after binding Cy-3-G to BSA, Cy-3-G is closer to the Tyr residue than the Trp residue, the secondary structure of BSA almost not change, the binding process of Cy-3-G with BSA is spontaneous, and Cy-3-G can be inserted into the hydrophobic cavity of BSA (site II') in the binding process of Cy-3-G with BSA. Moreover, based on the sign and magnitude of the enthalpy and entropy changes (ΔH(0)  = - 29.64 kcal/mol and ΔS(0)  = - 69.51 cal/mol K) and the molecular docking results, it can be suggested that the main interaction forces of Cy-3-G with BSA are Van der Waals and hydrogen bonding interactions.

  6. Interaction of two imidazolium gemini surfactants with two model proteins BSA and HEWL.

    PubMed

    Gospodarczyk, W; Kozak, M

    Gemini surfactants and their interactions with proteins have gained considerable scientific interest, especially when amyloidogenic proteins are taken into account. In this work, the influence of two selected dicationic (gemini) surfactants (3,3'-[1,8-(2,7-dioxaoctane)]bis(1-dodecylimidazolium) chloride and 3,3'-[1,12-(2,11-dioxadodecane)]bis(1-dodecylimidazolium) chloride) on two model proteins, bovine serum albumin (BSA) and hen egg white lysozyme (HEWL), have been investigated. A pronounced and sophisticated influence on BSA structure has been revealed, including a considerable change of protein radius of gyration as well as substantial alteration of its secondary structure. Radius of gyration has been found to rise significantly with addition of surfactants and to fall down for high surfactants concentration. Similarly, a remarkable fall of secondary structure (α-helix content) has been observed, followed by its partial retrieval for high surfactants concentration. A strong aggregation of BSA has been observed for a confined range of surfactants concentrations as well. In case of HEWL-gemini system, on the other hand, the protein-surfactant interaction was found to be weak. Molecular mechanisms explaining such behaviour of protein-surfactant systems have been proposed. The differences of properties of both studied surfactants have also been discussed.

  7. Modeling the accessibility of the interaction of clonazepan to albumins

    NASA Astrophysics Data System (ADS)

    Valdez, Ethel Celene Narvaez; Paulino, Erica Tex; de Morais e Coura, Carla Patrícia; Cortez, Celia Martins; da Silva Fragoso, Viviane Muniz

    2016-12-01

    This paper shows results obtained from the clonazepam (CNZP) interaction with human and bovine serum albumin study, seeking data on the pharmacokinetics and the binding site for the anxiolytic by comparing the responses of these two proteins to this drug. The quenching response of this experiment show a huge interaction between CNZP and the albumins, that confirm the literature information relative to the high affinity of CNZP with the plasma protein, a long plasma half-life and that the single binding site for this drug can be found in or close to subdomain IB of HSA and BSA.

  8. Tyrosine fluorescence probing of conformational changes in tryptophan-lacking domain of albumins.

    PubMed

    Zhdanova, N G; Maksimov, E G; Arutyunyan, A M; Fadeev, V V; Shirshin, E A

    2017-03-05

    We addressed the possibility of using tyrosine (Tyr) fluorescence for monitoring conformational changes of proteins which are undetectable via tryptophan (Trp) fluorescence. The model objects, human (HSA) and bovine (BSA) serum albumins, contain one and two Trp residues, respectively, while Tyr is more uniformly distributed over their structure. The results of the investigation of albumins interaction with ethanol using intrinsic Trp and Tyr steady-state and time-resolved picosecond fluorescence indicated the presence of an intermediate at 10% (v/v) of ethanol in solution, that was supported by the results of extrinsic fluorescence measurements with the Nile Red dye. Based on the comparison of HSA and BSA Trp and Tyr fluorescence, it was suggested that conformational changes at low ethanol concentration are located in the domain III of albumins, which lacks tryptophan residues. The sensitivity of Tyr fluorescence to domain III alterations was further verified by studying albumins interaction with GdnHCl.

  9. Spectroscopic analysis of the riboflavin—serum albumins interaction on silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Voicescu, Mariana; Angelescu, Daniel G.; Ionescu, Sorana; Teodorescu, Valentin S.

    2013-04-01

    Spectrophotometric behavior of riboflavin (RF) adsorbed on silver nanoparticles as well as its interaction with two serum albumins, BSA and HSA, respectively, has been evidenced. The time evolution of the plasmonic features of the complexes formed by RF/BSA/HSA and Ag(0) nanoparticles having an average diameter of 10.0 ± 2.0 nm have been investigated by UV-Vis absorption spectroscopy. Using steady-state and time-resolved fluorescence spectroscopy, the structure, stability, and dynamics of the serum albumins have been studied. The efficiency of energy transfer process between RF and serum albumins on silver nanoparticles has been estimated. A reaction mechanism of RF with silver nanoparticles is also proposed and the results are discussed with relevance to the involvement of the silver nanoparticles to the redox process of RF and to the RF-serum albumins interaction into a silver nanoparticles complex.

  10. Tyrosine fluorescence probing of conformational changes in tryptophan-lacking domain of albumins

    NASA Astrophysics Data System (ADS)

    Zhdanova, N. G.; Maksimov, E. G.; Arutyunyan, A. M.; Fadeev, V. V.; Shirshin, E. A.

    2017-03-01

    We addressed the possibility of using tyrosine (Tyr) fluorescence for monitoring conformational changes of proteins which are undetectable via tryptophan (Trp) fluorescence. The model objects, human (HSA) and bovine (BSA) serum albumins, contain one and two Trp residues, respectively, while Tyr is more uniformly distributed over their structure. The results of the investigation of albumins interaction with ethanol using intrinsic Trp and Tyr steady-state and time-resolved picosecond fluorescence indicated the presence of an intermediate at 10% (v/v) of ethanol in solution, that was supported by the results of extrinsic fluorescence measurements with the Nile Red dye. Based on the comparison of HSA and BSA Trp and Tyr fluorescence, it was suggested that conformational changes at low ethanol concentration are located in the domain III of albumins, which lacks tryptophan residues. The sensitivity of Tyr fluorescence to domain III alterations was further verified by studying albumins interaction with GdnHCl.

  11. Comparison of photoluminescence properties of HSA-protected and BSA-protected Au25 nanoclusters

    NASA Astrophysics Data System (ADS)

    Tsukamoto, Masato; Kawasaki, Hideya; Saitoh, Tadashi; Inada, Mitsuru; Kansai Univ. Collaboration

    Gold nanoclusters (NCs) have attracted great interest for a wide range of applications. In particular, red light-emitting Au25 NCs have been prepared with various biological ligands. It has been shown that Au25 NCs have Au13-core/6Au2(SR)3-semiring structure. The red luminescence thought to be originated from both core (670 nm) and semiring (625 nm). It is important to reveal a structure of Au25 NCs to facilitate the progress of applications. However, the precise structure of Au25 NCs has not been clarified. There is a possibility of obtaining structural information about Au25 NCs to compare optical properties of the NCs that protected by slightly different molecules. Bovine and human serum albumin (BSA, HSA) are suitable one for this purpose. It has been suggested that rich tyrosine and cysteine residues in these molecules are important to produce the thiolate-protected Au NCs. If Au25 NCs have core/shell structure, only the luminescence of the semiring will be affected by the difference of the albumin molecules. We carefully compared PL characteristics of BSA- and HSA- protected Au25 NCs. As a result, there was no difference in the PL at 670 nm (core), while differences were observed in the PL at 625 nm (semiring). The results support that Au25 NCs have core/semiring structure.

  12. Albumin and multiple sclerosis.

    PubMed

    LeVine, Steven M

    2016-04-12

    Leakage of the blood-brain barrier (BBB) is a common pathological feature in multiple sclerosis (MS). Following a breach of the BBB, albumin, the most abundant protein in plasma, gains access to CNS tissue where it is exposed to an inflammatory milieu and tissue damage, e.g., demyelination. Once in the CNS, albumin can participate in protective mechanisms. For example, due to its high concentration and molecular properties, albumin becomes a target for oxidation and nitration reactions. Furthermore, albumin binds metals and heme thereby limiting their ability to produce reactive oxygen and reactive nitrogen species. Albumin also has the potential to worsen disease. Similar to pathogenic processes that occur during epilepsy, extravasated albumin could induce the expression of proinflammatory cytokines and affect the ability of astrocytes to maintain potassium homeostasis thereby possibly making neurons more vulnerable to glutamate exicitotoxicity, which is thought to be a pathogenic mechanism in MS. The albumin quotient, albumin in cerebrospinal fluid (CSF)/albumin in serum, is used as a measure of blood-CSF barrier dysfunction in MS, but it may be inaccurate since albumin levels in the CSF can be influenced by multiple factors including: 1) albumin becomes proteolytically cleaved during disease, 2) extravasated albumin is taken up by macrophages, microglia, and astrocytes, and 3) the location of BBB damage affects the entry of extravasated albumin into ventricular CSF. A discussion of the roles that albumin performs during MS is put forth.

  13. The albumin controversy.

    PubMed

    Uhing, Michael R

    2004-09-01

    There are relatively few studies of albumin use in neonates and children, with most showing no consistent benefit compared with the use of crystalloid solutions. Certainly, albumin treatment is not indicated for treatment of hypoalbuminemia alone. Studies also show that albumin is not indicated in neonates for the initial treatment of hypotension, respiratory distress, or partial exchange transfusions. In adults, albumin is not considered to be the initial therapy for hypovolemia, burn injury, or nutritional supplementation. Based on the evidence, albumin should be used rarely in the neonatal ICU. Albumin may be indicated in the treatment of hypovolemia only after crystalloid infusion has failed. In patients with acute hemorrhagic shock, albumin may be used with crystalloids when blood products are not available immediately. Inpatients with acute or continuing losses of albumin and normal capillary permeability and lymphatic function, such as during persistent thoracostomy tube or surgical site drainage, albumin supplementation will prevent the development of hypoalbuminemia, and possibly edema formation. This has not been studied systematically, however. In patients with hypoalbuminemia and increased capillary permeability, albumin supplementation often leads to greater albumin leakage across the capillary membrane, contributing to edema formation without improvement in outcome. As the disease process improves and capillary permeability normalizes, albumin supplementation may accelerate recovery, but long-term benefits of albumin treatment usually cannot be demonstrated. These patients will recover whether or not albumin is administered.

  14. Numb Protects Human Renal Tubular Epithelial Cells From Bovine Serum Albumin-Induced Apoptosis Through Antagonizing CHOP/PERK Pathway.

    PubMed

    Ding, Xuebing; Ma, Mingming; Teng, Junfang; Shao, Fengmin; Wu, Erxi; Wang, Xuejing

    2016-01-01

    In recent studies, we found that Numb is involved in oxidative stress-induced apoptosis of renal proximal tubular cells; however, its function on ER stress-induced apoptosis in proteinuric kidney disease remains unknown. The objective of the present study is to explore the role of Numb in urinary albumin-induced apoptosis of human renal tubular epithelial cells (HKCs). In this study, we demonstrate that incubation of HKCs with bovine serum albumin (BSA) resulted in caspase three-dependent cell death. Numb expression was down-regulated by BSA in a time- and dose-dependent manner. Knockdown of Numb by siRNA sensitized HKCs to BSA-induced apoptosis, whereas overexpression of Numb protected HKCs from BSA-induced apoptosis. Moreover, BSA activated CHOP/PERK signaling pathway in a time- and dose-dependent manner as indicated by increased expression of CHOP, PERK, and P-PERK. Furthermore, knockdown of CHOP or PERK significantly attenuated the promoting effect of Numb on BSA-induced apoptosis, while overexpression of CHOP impaired the protective effect of Numb on BSA-induced apoptosis. Taken together, our findings demonstrate that Numb plays a protective role on BSA-induced apoptosis through inhibiting CHOP/PERK signaling pathway in human renal tubular epithelial cells. Therefore, the results from this study provides evidence that Numb is a new target of ER-associated apoptotic signaling networks and Numb may serve as a promising therapeutic target for proteinuric diseases.

  15. Characterization of the interaction between cationic Erbium (III)-porphyrin complex with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Lu, Xi-Liang; Fan, Jian-Jun; Liu, Yi; Hou, An-Xin

    2009-09-01

    The interaction of cationic Erbium (III)-porphyrin complex (Er-Porp) with bovine serum albumin (BSA) has been investigated by fluorescence quenching spectra, UV-vis absorbance, circular dichroism (CD) and three-dimensional (3D) fluorescence spectra. It is proved that the fluorescence quenching of BSA by Er-Porp was mainly for the formation of Er-Porp-BSA complex. The Stern-Volmer quenching constants KSV and corresponding thermodynamic parameters ΔH, ΔG and ΔS were estimated by fluorescence quenching method. The results indicated that the electrostatic and hydrophobic interactions were the predominant intermolecular forces in stabilizing the complex. The binding distance was obtained according to Förster's non-radiative energy transfer theory. Displacement experiment and the number of binding sites calculation show that the cationic Er-Porp ring can inset in site-I (in subdomain IIA) of BSA. The effect of Er-Porp on the conformation of BSA was observed using CD, UV and 3D fluorescence spectra methods. The results show that the conformation of BSA was changed dramatically in the presence of Er-Porp by binding to the Trp residues of BSA. The interaction between BSA and Er-Porp can be used as a model for drug design and pharmaceutical research.

  16. Binding of anti-inflammatory drug cromolyn sodium to bovine serum albumin.

    PubMed

    Hu, Yan-Jun; Liu, Yi; Sun, Ting-Quan; Bai, Ai-Min; Lü, Jian-Quan; Pi, Zhen-Bang

    2006-11-15

    Fluorescence spectroscopy in combination with circular dichroism (CD) and UV-vis absorption spectroscopy were employed to investigate the binding of anti-inflammatory drug cromolyn sodium (Intal) to bovine serum albumin (BSA) under the physiological conditions with Intal concentrations of 0-6.4 x 10(-5)mol L(-1). In the mechanism discussion, it was proved that the fluorescence quenching of BSA by Intal is a result of the formation of Intal-BSA complex. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between Intal and BSA. The thermodynamic parameters Delta G, Delta H, Delta S at different temperatures (298, 304, and 310 K) were calculated and the results indicate the electrostatic interactions play a major role in Intal-BSA association. Binding studies concerning the number of binding sites (n=1) and apparent binding constant K(b) were performed by fluorescence quenching method. Utilizing fluorescence resonant energy transfer (FRET) the distance R between the donor (BSA) and acceptor (Intal) has been obtained. Furthermore, CD and synchronous fluorescence spectrum were used to investigate the structural change of BSA molecules with addition of Intal, the results indicate that the secondary structure of BSA molecules was changed in the presence of Intal.

  17. Study on the interaction characteristics of cefamandole with bovine serum albumin by spectroscopic technique.

    PubMed

    Wang, Qian; Liu, Xuyang; Su, Ming; Shi, Zhihong; Sun, Hanwen

    2015-02-05

    The interaction of cefamandole with bovine serum albumin (BSA) was studied by fluorescence quenching in combination with UV-Vis spectroscopic method under near physiological conditions. The fluorescence quenching rate constants and binding constants for BSA-cefamandole system were determined at different temperatures. The fluorescence quenching of BSA by cefamandole is due to static quenching and energy transfer. The results of thermodynamic parameters, ΔH (-268.0 kJ mol(-1)), ΔS (-810.0 J mol(-1) K(-1)) and ΔG (-26.62 to -8.52 kJ mol(-1)), indicated that van der Waals interaction and hydrogen bonding played a major role for cefamandole-BSA association. The competitive experiments demonstrated that the primary binding site of cefamandole on BSA was located at site III in sub-domain IIIA of BSA. The distance between cefamandole and a tryptophane unit was estimated to be 1.18 nm based on the Förster resonance energy transfer theory. The binding constant (KA) of BSA-cefamandole at 298 K was 2.239×10(4) L mol(-1). Circular dichroism spectra, synchronous fluorescence and three-dimensional fluorescence studies showed that the presence of cefamandole could change the conformation of BSA during the binding process.

  18. Investigation on the interactions of clenbuterol to bovine serum albumin and lysozyme by molecular fluorescence technique.

    PubMed

    Bi, Shuyun; Pang, Bo; Wang, Tianjiao; Zhao, Tingting; Yu, Wang

    2014-01-01

    Clenbuterol interacting with bovine serum albumin (BSA) or lysozyme (LYS) in physiological buffer (pH 7.4) was investigated by the fluorescence spectroscopy and UV-vis absorption spectroscopy. The results indicated that clenbuterol quenched the intrinsic fluorescence of BSA and LYS via a static quenching procedure. The binding constants of clenbuterol with BSA and LYS were 1.16×10(3) and 1.49×10(3) L mol(-1) at 291 K. The values of ΔH and ΔS implied that hydrophobic and electrostatic interaction played a major role in stabilizing the complex (clenbuterol-BSA or clenbuterol-LYS). In the presence of Fe2+, Fe3+, Cu2+, Mg2+, Ca2+, or Zn2+, the binding constants of clenbuterol to BSA or LYS had no significant differences. The distances between the donor (BSA or LYS) and acceptor (clenbuterol) were 2.61 and 2.19 nm for clenbuterol-BSA and clenbuterol-LYS respectively. Furthermore, synchronous fluorescence spectrometry was used to analyze the conformational changes of BSA and LYS.

  19. Comparative studies on the interactions of dihydroartemisinin and artemisinin with bovine serum albumin using spectroscopic methods.

    PubMed

    Liu, Rong; Cheng, Zhengjun; Jiang, Xiaohui

    2014-12-01

    The interactions of dihydroartemisinin (DHA) and artemisinin (ART) with bovine serum albumin (BSA) have been investigated using fluorescence, UV/vis absorption and Fourier transform infrared (FTIR) spectra under simulated physiological conditions. The binding characteristics of DHA/ART and BSA were determined by fluorescence emission and resonance light scattering (RLS) spectra. The quenching mechanism between BSA and DHA/ART is static. The binding constants and binding sites of DHA/ART-BSA systems were calculated at different temperatures (293, 298, 304 and 310 K). According to Förster non-radiative energy transfer theory, the binding distance of BSA to DHA/ART was calculated to be 1.54/1.65 nm. The effect of DHA/ART on the secondary structure of BSA was analyzed using UV/vis absorption, FTIR, synchronous fluorescence and 3D fluorescence spectra. In addition, the effects of common ions on the binding constants of BSA-DHA and BSA-ART systems were also discussed.

  20. Multilayer Capsules of Bovine Serum Albumin and Tannic Acid for Controlled Release by Enzymatic Degradation.

    PubMed

    Lomova, Maria V; Brichkina, Anna I; Kiryukhin, Maxim V; Vasina, Elena N; Pavlov, Anton M; Gorin, Dmitry A; Sukhorukov, Gleb B; Antipina, Maria N

    2015-06-10

    With the purpose to replace expensive and significantly cytotoxic positively charged polypeptides in biodegradable capsules formed via Layer-by-Layer (LbL) assembly, multilayers of bovine serum albumin (BSA) and tannic acid (TA) are obtained and employed for encapsulation and release of model drugs with different solubility in water: hydrophilic-tetramethylrhodamine-isothiocyanate-labeled BSA (TRITC-BSA) and hydrophobic 3,4,9,10-tetra-(hectoxy-carbonyl)-perylene (THCP). Hydrogen bonding is proposed to be predominant within thus formed BSA/TA films. The TRITC-BSA-loaded capsules comprising 6 bilayers of the protein and polyphenol are benchmarked against the shells composed of dextran sulfate (DS) and poly-l-arginine (PARG) on degradability by two proteolytic enzymes with different cleavage site specificity (i.e., α-chymotrypsin and trypsin) and toxicity for murine RAW264.7 macrophage cells. Capsules of both types possess low cytotoxicity taken at concentrations equal or below 50 capsules per cell, and evident susceptibility to α-chymotrypsin resulted in release of TRITC-BSA. While the BSA/TA-based capsules clearly display resistance to treatment with trypsin, the assemblies of DS/PARG extensively degrade. Successful encapsulation of THCP in the TRITC-BSA/TA/BSA multilayer is confirmed, and the release of the model drug is observed in response to treatment with α-chymotrypsin. The thickness, surface morphology, and enzyme-catalyzed degradation process of the BSA/TA-based films are investigated on a planar multilayer comprising 40 bilayers of the protein and polyphenol deposited on a silicon wafer. The developed BSA/TA-based capsules with a protease-specific degradation mechanism are proposed to find applications in personal care, pharmacology, and the development of drug delivery systems including those intravenous injectable and having site-specific release capability.

  1. Nitrite ion-induced fluorescence quenching of luminescent BSA-Au(25) nanoclusters: mechanism and application.

    PubMed

    Unnikrishnan, Binesh; Wei, Shih-Chun; Chiu, Wei-Jane; Cang, Jinshun; Hsu, Pang-Hung; Huang, Chih-Ching

    2014-05-07

    Fluorescence quenching is an interesting phenomenon which is highly useful in developing fluorescence based sensors. A thorough understanding of the fluorescence quenching mechanism is essential to develop efficient sensors. In this work, we investigate different aspects governing the nitrite ion-induced fluorescence quenching of luminescent bovine serum albumin stabilized gold nanoclusters (BSA-Au NCs) and their application for detection of nitrite in urine. The probable events leading to photoluminescence (PL) quenching by nitrite ions were discussed on the basis of the results obtained from ultraviolet-visible (UV-Vis) absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), fluorescence measurements, circular dichroism (CD) spectroscopy, zeta potential and dynamic light scattering (DLS) studies. These studies suggested that PL quenching mainly occurred through the oxidation of Au(0) atoms to Au(i) atoms in the core of BSA-Au NCs mediated by nitrite ions. The interference caused by certain species such as Hg(2+), Cu(2+), CN(-), S(2-), glutathione, cysteine, etc. during the nitrite determination by fluorescence quenching was eliminated by using masking agents and optimising the conditions. Based on these findings we proposed a BSA-Au NC-modified membrane based sensor which would be more convenient for the real life applications such as nitrite detection in urine samples. The BSA-Au NC-modified nitrocellulose membrane (NCM) enabled the detection of nitrite at a level as low as 100 nM in aqueous solutions. This Au NC-based paper probe was validated to exhibit good performance for nitrite analysis in environmental water and urine samples, which makes it useful in practical applications.

  2. Removal of bovine serum albumin using solid-phase extraction with in-situ polymerized stationary phase in a microfluidic device.

    PubMed

    Lee, Eun Zoo; Huh, Yun Suk; Jun, Young-Si; Won, Hyo Jin; Hong, Yeon Ki; Park, Tae Jung; Lee, Sang Yup; Hong, Won Hi

    2008-04-11

    Serum albumin, one of the most abundant serum proteins, blocks the expression of other important biomarkers. The objective of this study is to remove serum albumin effectively by using solid-phase extraction (SPE) in microfluidic devices. Photo-polymerized adsorbent as a stationary phase of SPE was used to remove bovine serum albumin (BSA). The adsorption capacity was examined with the effect of pH and concentration in BSA solution, and adjustment of monomer concentration such as hydrophilic 2-acrylamido-2-methyl-1-propanesulfonic acid and acrylamide in the adsorbent. The effect of hydrophobic butyl methacylate on BSA adsorption was also studied. Selective removal in a bicomponent with BSA and bovine gamma-globulin was performed by adjusting the pH as required.

  3. Interactions of cephalexin with bovine serum albumin: displacement reaction and molecular docking

    PubMed Central

    Hamishehkar, Hamed; Hosseini, Soheila; Naseri, Abdolhossein; Safarnejad, Azam; Rasoulzadeh, Farzaneh

    2016-01-01

    Introduction: The drug-plasma protein interaction is a fundamental issue in guessing and checking the serious drug side effects related with other drugs. The purpose of this research was to study the interaction of cephalexin with bovine serum albumin (BSA) and displacement reaction using site probes. Methods: The interaction mechanism concerning cephalexin (CPL) with BSA was investigated using various spectroscopic methods and molecular modeling method. The binding sites number, n, apparent binding constant, K, and thermodynamic parameters, ΔG0, ΔH0, and ΔS0 were considered at different temperatures. To evaluate the experimental results, molecular docking modeling was calculated. Results: The distance, r=1.156 nm between BSA and CPL were found in accordance with the Forster theory of non-radiation energy transfer (FRET) indicating energy transfer occurs between BSA and CPL. According to the binding parameters and ΔG0= negative values and ΔS0= 28.275 j mol-1K-1, a static quenching process is effective in the CPL-BSA interaction spontaneously. ΔG0 for the CPL-BSA complex obtained from the docking simulation is -28.99 kj mol-1, which is close to experimental ΔG of binding, -21.349 kj mol-1 that indicates a good agreement between the results of docking methods and experimental data. Conclusion: The outcomes of spectroscopic methods revealed that the conformation of BSA changed during drug-BSA interaction. The results of FRET propose that CPL quenches the fluorescence of BSA by static quenching and FRET. The displacement study showed that phenylbutazon and ketoprofen displaced CPL, indicating that its binding site on albumin is site I and Gentamicin cannot be displaced from the binding site of CPL. All results of molecular docking method agreed with the results of experimental data. PMID:27853676

  4. Spectroscopic characterization of effective components anthraquinones in Chinese medicinal herbs binding with serum albumins

    NASA Astrophysics Data System (ADS)

    Bi, Shuyun; Song, Daqian; Kan, Yuhe; Xu, Dong; Tian, Yuan; Zhou, Xin; Zhang, Hanqi

    2005-11-01

    The interactions of serum albumins such as human serum albumin (HSA) and bovine serum albumin (BSA) with emodin, rhein, aloe-emodin and aloin were assessed employing fluorescence quenching and absorption spectroscopic techniques. The results obtained revealed that there are relatively strong binding affinity for the four anthraquinones with HSA and BSA and the binding constants for the interactions of anthraquinones with HSA or BSA at 20 °C were obtained. Anthraquinone-albumin interactions were studied at different temperatures and in the presence of some metal ions. And the competition binding of anthraquinones with serum albumins was also discussed. The Stern-Volmer curves suggested that the quenching occurring in the reactions was the static quenching process. The binding distances and transfer efficiencies for each binding reactions were calculated according to the Föster theory of non-radiation energy transfer. Using thermodynamic equations, the main action forces of these reactions were also obtained. The reasons of the different binding affinities for different anthraquinone-albumin reactions were probed from the point of view of molecular structures.

  5. Probing the binding sites of antibiotic drugs doxorubicin and N-(trifluoroacetyl) doxorubicin with human and bovine serum albumins.

    PubMed

    Agudelo, Daniel; Bourassa, Philippe; Bruneau, Julie; Bérubé, Gervais; Asselin, Eric; Tajmir-Riahi, Heidar-Ali

    2012-01-01

    We located the binding sites of doxorubicin (DOX) and N-(trifluoroacetyl) doxorubicin (FDOX) with bovine serum albumin (BSA) and human serum albumins (HSA) at physiological conditions, using constant protein concentration and various drug contents. FTIR, CD and fluorescence spectroscopic methods as well as molecular modeling were used to analyse drug binding sites, the binding constant and the effect of drug complexation on BSA and HSA stability and conformations. Structural analysis showed that doxorubicin and N-(trifluoroacetyl) doxorubicin bind strongly to BSA and HSA via hydrophilic and hydrophobic contacts with overall binding constants of K(DOX-BSA) = 7.8 (± 0.7) × 10(3) M(-1), K(FDOX-BSA) = 4.8 (± 0.5)× 10(3) M(-1) and K(DOX-HSA) = 1.1 (± 0.3)× 10(4) M(-1), K(FDOX-HSA) = 8.3 (± 0.6)× 10(3) M(-1). The number of bound drug molecules per protein is 1.5 (DOX-BSA), 1.3 (FDOX-BSA) 1.5 (DOX-HSA), 0.9 (FDOX-HSA) in these drug-protein complexes. Docking studies showed the participation of several amino acids in drug-protein complexation, which stabilized by H-bonding systems. The order of drug-protein binding is DOX-HSA > FDOX-HSA > DOX-BSA > FDOX>BSA. Drug complexation alters protein conformation by a major reduction of α-helix from 63% (free BSA) to 47-44% (drug-complex) and 57% (free HSA) to 51-40% (drug-complex) inducing a partial protein destabilization. Doxorubicin and its derivative can be transported by BSA and HSA in vitro.

  6. Urine Albumin and Albumin/ Creatinine Ratio

    MedlinePlus

    ... that is present in high concentrations in the blood. Virtually no albumin is present in the urine when the kidneys ... on trying to determine if increased levels of albumin in the urine are also indicative of CVD risk in those who do not have diabetes or high blood pressure. ^ Back to ... Proudly sponsored by ... Learn ...

  7. Study of the interaction of kaempferol with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Tian, Jianniao; Liu, Jiaqin; Tian, Xuan; Hu, Zhide; Chen, Xingguo

    2004-03-01

    The binding of kaempferol with bovine serum albumin (BSA) was investigated at three temperatures, 296, 310 and 318 K, by the fluorescence, circular dichroism (CD) and Fourier transform infrared spectroscopy (FT-IR) at pH 7.40. The CD and FT-IR studies indicate that kaempferol binds strongly to BSA. The association constant K was determined by Stern-Volmer equation based on the quenching of the fluorescence BSA in the presence of kaempferol. The thermodynamic parameters were calculated according to the dependence of enthalpy change on the temperature as follows: Δ H0 and Δ S0 possess small negative (-1.694 kJ/mol) and positive values (88.814 J/mol K), respectively. According to the displacement experimental and the thermodynamic results, it is considered that kaempferol binding site II (subdomain III) mainly by hydrophobic interaction. The results studied by FT-IR and CD experiments indicate that the secondary structures of the protein have been changed by the interaction of kaempferol with BSA. The distance between the tryptophan residues in BSA and kaempferol bound to site II was estimated to be 2.78 nm using Foster's equation on the basis of fluorescence energy transfer.

  8. Size exclusion chromatographic analysis of polyphenol-serum albumin complexes.

    PubMed

    Hatano, Tsutomu; Hori, Mami; Hemingway, Richard W; Yoshida, Takashi

    2003-08-01

    Formation of water-soluble polyphenol-protein complexes was investigated by size-exclusion chromatography (SEC). The combination of (-)-epigallocatechin gallate (EGCG) and bovine serum albumin (BSA), which did not form a precipitate after the solutions were mixed, showed an SEC peak due to complex formation 2-24 h after mixing. Peak size of the complex varied with time, suggesting slow change of the conformation of the protein accompanied by complexation. Formation of the complex was substantiated by ultrafiltration of the mixture; the complex did not pass through a membrane with a 100,000 nominal molecular weight limit (NMWL). The SEC profile varied with the combination of compounds. The peaks due to the complexes showed that the apparent value of the number average molecular weight (M(n)) of the EGCG-BSA complex was 2.8x10(5), while that of a pentagalloylglucose (PGG)-BSA complex was 9.5x10(5) under the conditions used. Dimeric hydrolyzable tannins, oenothein B and cornusiin A, also caused changes in the SEC profile of BSA, although the combinations did not show peaks attributable to formation of such large complexes observed for EGCG and PGG. Procyanidin B3 and (+)-catechin did not cause changes in the SEC profile of BSA. With cytochrome c, EGCG did not show any chromatographic changes.

  9. Intermolecular interaction of nickel (ii) phthalocyanine tetrasulfonic acid tetrasodium salt with bovine serum albumin: A multi-technique study.

    PubMed

    Dezhampanah, Hamid; Firouzi, Roghaye; Hasani, Leila

    2017-02-01

    The interaction of nickel (II) phthalocyanine tetrasulfonic acid tetrasodium salt with bovine serum albumin (BSA) has been investigated by combination of fluorescence, UV-vis absorption, Fourier transform infrared (FT-IR), and circular dichorism (CD) spectroscopies as well as through molecular docking. Fluorescence quenching and absorption spectra were investigated as a mean for estimating the binding parameters. Analysis of fluorescence quenching data at different temperatures was performed in order to specify the thermodynamics parameters for interactions of phthalocyanine complex with BSA. According to experimental data it was suggested that phthalocyanine had a significant binding affinity to BSA and the process was entropy driven. Based on the results of molecular docking it was indicated that the main active binding site for this phthalocyanine complex is site I in subdomain IIA of BSA. The results provide useful information for understanding the binding mechanism of anticancer drug-albumin and gives insight into the biological activity and metabolism of the drug in blood.

  10. Albumin - blood (serum) test

    MedlinePlus

    ... protein in the clear liquid portion of the blood. Albumin can also be measured in the urine . How ... Results Mean A lower-than-normal level of blood albumin may be a sign of: Kidney diseases Liver ...

  11. Biophysical influence of isocarbophos on bovine serum albumin: Spectroscopic probing

    NASA Astrophysics Data System (ADS)

    Zhang, Hua-xin; Zhou, Ying; Liu, E.

    Isocarbophos (ICP) is a phosphorous pesticide with high toxicity. It has been detected in several kinds of food and therefore can enter human body. In this paper, spectroscopic approaches including three-dimensional fluorescence (3D-FL) spectroscopy, UV-visible absorption spectroscopy and circular dichroism (CD) spectroscopy were employed to explore the binding of ICP to bovine serum albumin (BSA) at simulated physiological conditions. It was found that the fluorescence quenching of BSA was caused by the formation of ICP-BSA complex at ground state and belonged to static quenching mechanism. The binding constants, the number of binding sites, enthalpy change (ΔHθ), Gibbs free energy change (ΔGθ) and entropy change (ΔSθ) were calculated at four different temperatures according to Scatchard model and thermodynamic equations. To identify the binding location, fluorescence probe techniques were used. The results showed that warfarin, an acknowledged site marker for BSA, could be partially replaced by ICP when ICP was added to warfarin-BSA systems, which demonstrated that ICP primarily bound on Sudlow's site I in domain IIA of BSA molecule. The distance r (3.06 nm) between donor (Trp-212) and acceptor (ICP) was obtained based on Förster's non-radiation fluorescence resonance energy transfer (FRET) theory. Furthermore, the CD spectral results indicated that the secondary structure of BSA was changed in presence of ICP. The study is helpful to evaluating the toxicology of ICP and understanding its effects on the function of protein during the blood transportation process.

  12. Environment sensitive fluorescent analogue of biologically active oxazoles differentially recognizes human serum albumin and bovine serum albumin: Photophysical and molecular modeling studies.

    PubMed

    Maiti, Jyotirmay; Biswas, Suman; Chaudhuri, Ankur; Chakraborty, Sandipan; Chakraborty, Sibani; Das, Ranjan

    2017-03-15

    An environment sensitive fluorophore, 4-(5-(4-(dimethylamino)phenyl)oxazol-2-yl)benzoic acid (DMOBA), that closely mimics biologically active 2,5-disubstituited oxazoles has been designed to probe two homologous serum proteins, human serum albumin (HSA) and bovine serum albumin (BSA) by means of photophysical and molecular modeling studies. This fluorescent analogue exhibits solvent polarity sensitive fluorescence due to an intramolecular charge transfer in the excited state. In comparison to water, the steady state emission spectra of DMOBA in BSA is characterized by a greater blue shift (~10nm) and smaller Stokes' shift (~5980cm(-1)) in BSA than HSA (Stokes'shift~6600cm(-1)), indicating less polar and more hydrophobic environment of the dye in the former than the latter. The dye-protein binding interactions are remarkably stronger for BSA than HSA which is evident from higher value of the association constant for the DMOBA-BSA complex (Ka~5.2×10(6)M(-1)) than the DMOBA-HSA complex (Ka~1.0×10(6)M(-1)). Fӧrster resonance energy transfer studies revealed remarkably less efficient energy transfer (8%) between the donor tryptophans in BSA and the acceptor DMOBA dye than that (30%) between the single tryptophan moiety in HSA and the dye, which is consistent with a much larger distance between the donor (tryptophan)-acceptor (dye) pair in BSA (34.5Å) than HSA (25.4Å). Site specific competitive binding assays have confirmed on the location of the dye in Sudlow's site II of BSA and in Sudlow's site I of HSA, respectively. Molecular modeling studies have shown that the fluorescent analogue is tightly packed in the binding site of BSA due to strong steric complementarity, where, binding of DMOBA to BSA is primarily dictated by the van der Waals and hydrogen bonding interactions. In contrast, in HSA the steric complementarity is less significant and binding is primarily guided by polar interactions and van der Waals interactions appear to be less significant in the

  13. Environment sensitive fluorescent analogue of biologically active oxazoles differentially recognizes human serum albumin and bovine serum albumin: Photophysical and molecular modeling studies

    NASA Astrophysics Data System (ADS)

    Maiti, Jyotirmay; Biswas, Suman; Chaudhuri, Ankur; Chakraborty, Sandipan; Chakraborty, Sibani; Das, Ranjan

    2017-03-01

    An environment sensitive fluorophore, 4-(5-(4-(dimethylamino)phenyl)oxazol-2-yl)benzoic acid (DMOBA), that closely mimics biologically active 2,5-disubstituited oxazoles has been designed to probe two homologous serum proteins, human serum albumin (HSA) and bovine serum albumin (BSA) by means of photophysical and molecular modeling studies. This fluorescent analogue exhibits solvent polarity sensitive fluorescence due to an intramolecular charge transfer in the excited state. In comparison to water, the steady state emission spectra of DMOBA in BSA is characterized by a greater blue shift ( 10 nm) and smaller Stokes' shift ( 5980 cm- 1) in BSA than HSA (Stokes'shift 6600 cm- 1), indicating less polar and more hydrophobic environment of the dye in the former than the latter. The dye-protein binding interactions are remarkably stronger for BSA than HSA which is evident from higher value of the association constant for the DMOBA-BSA complex (Ka 5.2 × 106 M- 1) than the DMOBA-HSA complex (Ka 1.0 × 106 M- 1). Fӧrster resonance energy transfer studies revealed remarkably less efficient energy transfer (8%) between the donor tryptophans in BSA and the acceptor DMOBA dye than that (30%) between the single tryptophan moiety in HSA and the dye, which is consistent with a much larger distance between the donor (tryptophan)-acceptor (dye) pair in BSA (34.5 Å) than HSA (25.4 Å). Site specific competitive binding assays have confirmed on the location of the dye in Sudlow's site II of BSA and in Sudlow's site I of HSA, respectively. Molecular modeling studies have shown that the fluorescent analogue is tightly packed in the binding site of BSA due to strong steric complementarity, where, binding of DMOBA to BSA is primarily dictated by the van der Waals and hydrogen bonding interactions. In contrast, in HSA the steric complementarity is less significant and binding is primarily guided by polar interactions and van der Waals interactions appear to be less significant in the

  14. Chlorpromazine interactions to sera albumins. A study by the quenching of fluorescence

    NASA Astrophysics Data System (ADS)

    Silva, Dilson; Cortez, Célia M.; Louro, Sônia R. W.

    2004-04-01

    Binding of chlorpromazine (CPZ) and hemin (Hmn) to human (HSA) and bovine (BSA) serum albumin was studied by fluorescence quenching technique. Intrinsic fluorescences of BSA and HSA were measured by selectively exciting their tryptophan residues. Gradual quenching was observed by titration of both proteins with CPZ and Hmn. CPZ is a widely used anti-psychosis drug that causes severe side effects and strongly interacts with biomembranes, both in its lipidic and proteic regions. CPZ also interacts with blood components, influences bioavailability, and affects the function of several biomolecules. Albumin plays an important role in the transport and storage of hormones, ions, fatty acids and others substances, including CPZ, affecting the regulation of their plasmatic concentration. Hmn is an important ferric residue of hemoglobin that binds within the hydrophobic region of albumin with great specificity. Hmn added to HSA and BSA solutions at a molar ratio of 1:1 quenched about half of their fluorescence. Stern-Volmer plots obtained from experiments carried out at 25 and 35 °C showed the quenching of fluorescence of HSA and BSA by CPZ to be a collisional phenomenon. Hmn quenches fluorescence by a static process, which specifically indicates the formation of a complex. Our results suggest the prime binding site for CPZ and Hmn on both HSA and BSA to be near tryptophan residues.

  15. Genetically engineered mannosylated-human serum albumin as a versatile carrier for liver-selective therapeutics.

    PubMed

    Hirata, Kenshiro; Maruyama, Toru; Watanabe, Hiroshi; Maeda, Hitoshi; Nakajou, Keisuke; Iwao, Yasunori; Ishima, Yu; Katsumi, Hidemasa; Hashida, Mitsuru; Otagiri, Masaki

    2010-07-01

    Human serum albumin (HSA), a non-glycosylated protein, is widely employed as carrier for drug delivery systems. A series of recombinant, mannosylated-HSA mutants (Man-rHSAs: D63N, A320T and D494N) and their triple mutant (TM-rHSA: D63N/A320T/D494N) were prepared, that can be selectively delivered to the liver via mannose receptor (MR) on the liver non-parenchymal cells. A pharmacokinetic analysis of (111)In-Man-rHSAs in mice showed that they were rapidly cleared from the blood circulation, and were largely taken up by the liver rapidly in the order: TM-rHSA>D494N>A320T=D63N, consistent with their degree of mannosylation. In vivo competition experiments with an excess amount of chemically modified Man-BSA or mannan suggested that the hepatic uptake of TM-rHSA was selectively mediated by MR on Kupffer cells. Lastly, a TM-rHSA-NO conjugate, S-nitrosylated TM-rHSA, effectively delivered NO to the liver and then exhibited a significant inhibitory effect against hepatic ischemia/reperfusion injury model rats, accompanied by the induction of heme oxygenase-1.

  16. Fatty Acid Saturation of Albumin Used in Resuscitation Fluids Modulates Cell Damage in Shock: In Vitro Results Using a Novel Technique to Measure Fatty Acid Binding Capacity.

    PubMed

    Penn, Alexander H; Dubick, Michael A; Torres Filho, Ivo P

    2017-03-21

    The use of albumin for resuscitation has not proven as beneficial in human trials as expected from numerous animal studies. One explanation could be the practice of adding fatty acid (FA) during manufacture of pharmaceutical albumin. During ischemia, unbound free FAs (FFA) in the circulation could potentially induce cellular damage. We hypothesized that albumins with higher available binding capacities (ABC) for FFAs may prevent that damage. Therefore, we developed a technique to measure ABC, determined if pharmaceutical human serum albumin (HSA) has decreased ABC compared to FA-free bovine serum albumin (BSA), and if binding capacity would affect hemolysis when blood is mixed with exogenous FFA at levels similar to those observed in shock. The new assay used exogenous oleic acid (OA), glass fiber filtration, and a FFA assay kit. RBC hemolysis was determined by mixing 0-5 mM OA with PBS, HSA, FA-free BSA, or FA-saturated BSA and measuring plasma hemoglobin after incubation with human blood. 5% HSA contained 4.7±0.2 mM FFA, leaving an ABC of 5.0 ± 0.6 mM, compared to FA-free BSA's ABC of 7.0 ± 1.3 mM (P < 0.024). Hemolysis after OA was reduced with FA-free BSA but increased with FA-saturated BSA. HSA provided intermediate results. 25% solutions of FA-free BSA and HSA were more protective, while 25% FA-saturated BSA was more damaging than 5% solutions. These findings suggest that increased FA saturation may reverse albumin's potential benefit to lessen cellular damage and may explain, at least in part, its failure in human trauma studies.

  17. The effect of Cu2+ on interaction between flavonoids with different C-ring substituents and bovine serum albumin: structure-affinity relationship aspect.

    PubMed

    Zhang, Yuping; Shi, Shuyun; Sun, Xiaorui; Xiong, Xiang; Peng, Mijun

    2011-12-01

    Four flavonoids quercetin (QU), luteolin (LU), taxifolin (TA) and (+)-catechin (CA) with the same A- and B-rings but different C-ring substituents have been investigated for their binding to bovine serum albumin (BSA) in the absence and presence of Cu(2+) by means of various spectroscopic methods such as fluorescence, UV-visible and circular dichroism (CD). The results indicated that hydroxyl group at 3-position increased the binding affinities between flavonoids and BSA. The values of the binding affinities were in the order: QU>CA>TA>LU. The presence of Cu(2+) affected the interactions of flavonoids with BSA significantly. The binding affinities of QU and TA for BSA were decreased about 6.7% and 13.2%. However, the binding affinities of LU and CA for BSA were increased about 43.0% and 20.7%. The formation of Cu(2+)-flavonoid complex and steric hindrance together influenced the binding affinities of QU, LU and TA for BSA, while the conformational change of BSA may be the main reason for the increased binding affinity of CA for BSA. However, the quenching mechanism for QU, LU, TA and CA to BSA was based on static quenching combined with non-radiative energy transfer irrespective of the absence or presence of Cu(2+). The UV-visible results showed the change in BSA conformation and the formation of flavonoid-Cu(2+) complex. The CD results also explained the conformational changes of BSA on binding with flavonoids.

  18. Structural studies of bovine, equine, and leporine serum albumin complexes with naproxen.

    PubMed

    Bujacz, Anna; Zielinski, Kamil; Sekula, Bartosz

    2014-09-01

    Serum albumin, a protein naturally abundant in blood plasma, shows remarkable ligand binding properties of numerous endogenous and exogenous compounds. Most of serum albumin binding sites are able to interact with more than one class of ligands. Determining the protein-ligand interactions among mammalian serum albumins is essential for understanding the complexity of this transporter. We present three crystal structures of serum albumins in complexes with naproxen (NPS): bovine (BSA-NPS), equine (ESA-NPS), and leporine (LSA-NPS) determined to 2.58 Å (C2), 2.42 Å (P61), and 2.73 Å (P2₁2₁2₁) resolutions, respectively. A comparison of the structurally investigated complexes with the analogous complex of human serum albumin (HSA-NPS) revealed surprising differences in the number and distribution of naproxen binding sites. Bovine and leporine serum albumins possess three NPS binding sites, but ESA has only two. All three complexes of albumins studied here have two common naproxen locations, but BSA and LSA differ in the third NPS binding site. None of these binding sites coincides with the naproxen location in the HSA-NPS complex, which was obtained in the presence of other ligands besides naproxen. Even small differences in sequences of serum albumins from various species, especially in the area of the binding pockets, influence the affinity and the binding mode of naproxen to this transport protein.

  19. Prevention of hemodynamic and vascular albumin filtration changes in diabetic rats by aldose reductase inhibitors

    SciTech Connect

    Tilton, R.G.; Chang, K.; Pugliese, G.; Eades, D.M.; Province, M.A.; Sherman, W.R.; Kilo, C.; Williamson, J.R. )

    1989-10-01

    This study investigated hemodynamic changes in diabetic rats and their relationship to changes in vascular albumin permeation and increased metabolism of glucose to sorbitol. The effects of 6 wk of streptozocin-induced diabetes and three structurally different inhibitors of aldose reductase were examined on (1) regional blood flow (assessed with 15-microns 85Sr-labeled microspheres) and vascular permeation by 125I-labeled bovine serum albumin (BSA) and (2) glomerular filtration rate (assessed by plasma clearance of 57Co-labeled EDTA) and urinary albumin excretion (determined by radial immunodiffusion assay). In diabetic rats, blood flow was significantly increased in ocular tissues (anterior uvea, posterior uvea, retina, and optic nerve), sciatic nerve, kidney, new granulation tissue, cecum, and brain. 125I-BSA permeation was increased in all of these tissues except brain. Glomerular filtration rate and 24-h urinary albumin excretion were increased 2- and 29-fold, respectively, in diabetic rats. All three aldose reductase inhibitors completely prevented or markedly reduced these hemodynamic and vascular filtration changes and increases in tissue sorbitol levels in the anterior uvea, posterior uvea, retina, sciatic nerve, and granulation tissue. These observations indicate that early diabetes-induced hemodynamic changes and increased vascular albumin permeation and urinary albumin excretion are aldose reductase-linked phenomena. Discordant effects of aldose reductase inhibitors on blood flow and vascular albumin permeation in some tissues suggest that increased vascular albumin permeation is not entirely attributable to hemodynamic change.

  20. Spectroscopic studies on the interaction between tetrandrine and two serum albumins by chemometrics methods

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengjun; Liu, Rong; jiang, Xiaohui

    2013-11-01

    The binding interactions of tetrandrine (TETD) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by spectroscopic methods. These experimental data were further analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) method, and the concentration profiles and pure spectra for three species (BSA/HSA, TETD and TETD-BSA/HSA) existed in the interaction procedure, as well as, the apparent equilibrium constants Kapp were evaluated. The binding sites number n and the binding constants K were obtained at various temperatures. The binding distance between TETD and BSA/HSA was 1.455/1.451 nm. The site markers competitive experiments indicated that TETD primarily bound to the tryptophan residue of BSA/HSA within site I. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TETD-BSA was mainly depended on the hydrophobic interaction strongly and electrostatic interaction, and yet the binding of TETD-HSA was strongly relied on the hydrophobic interaction. The results of synchronous fluorescence, 3D fluorescence and FT-IR spectra show that the conformation of proteins has altered in the presence of TETD. In addition, the effect of some common ions on the binding constants between TETD and proteins were also discussed.

  1. Spectroscopic studies on the interaction between tetrandrine and two serum albumins by chemometrics methods.

    PubMed

    Cheng, Zhengjun; Liu, Rong; Jiang, Xiaohui

    2013-11-01

    The binding interactions of tetrandrine (TETD) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by spectroscopic methods. These experimental data were further analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) method, and the concentration profiles and pure spectra for three species (BSA/HSA, TETD and TETD-BSA/HSA) existed in the interaction procedure, as well as, the apparent equilibrium constants Kapp were evaluated. The binding sites number n and the binding constants K were obtained at various temperatures. The binding distance between TETD and BSA/HSA was 1.455/1.451nm. The site markers competitive experiments indicated that TETD primarily bound to the tryptophan residue of BSA/HSA within site I. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TETD-BSA was mainly depended on the hydrophobic interaction strongly and electrostatic interaction, and yet the binding of TETD-HSA was strongly relied on the hydrophobic interaction. The results of synchronous fluorescence, 3D fluorescence and FT-IR spectra show that the conformation of proteins has altered in the presence of TETD. In addition, the effect of some common ions on the binding constants between TETD and proteins were also discussed.

  2. Toxic effects of different charged metal ions on the target—Bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Liu, Rutao; Chi, Zhenxing; Gao, Canzhu

    2011-01-01

    In this work, the toxic influence of metallic ions (Na +, Cu 2+, Al 3+) on the serum albumin were studied by fluorescence, resonance light scattering (RLS), synchronous fluorescence, UV-vis absorption and circular dichroism (CD) spectroscopy. The experimental results indicated that ion electric charge is not the main factor affecting the structure of bovine serum albumin (BSA). Na + made the structure of BSA tighter and hydrophobicity enhanced, which improved fluorescence intensity, while Cu 2+ could react with some functional groups of BSA, making the structure of BSA looser, so that the internal hydrophobic groups such as tryptophan (Trp) and other aromatic residues were gradually exposed. When we observed them with fluorescence spectra, we found fluorescence quenching with increasing Cu 2+ dose. Al 3+ is shown as little significant influence on the BSA, but BSA was found to aggregate with the dose of Al 3+ by means of RLS because of the hydrolysis and ion strength effect of Al 3+. The results also proved normal saline could keep lives healthy and good-working as a biological humour, however, heavy metals made harmful effects to the body when they exceeded the minimal effect level (MEL), such as Cu 2+ chosen in our work.

  3. The interaction between cepharanthine and two serum albumins: multiple spectroscopic and chemometric investigations.

    PubMed

    Cheng, Zhengjun; Liu, Rong; Jiang, Xiaohui; Xu, Qianyong

    2014-08-01

    The binding modes of cepharanthine (CEPT) with bovine serum albumin (BSA) and human serum albumin (HSA) have been established by reproducing physiological conditions, which is very important to understand the pharmacokinetics and toxicity of CEPT. These spectral data were further analyzed by the multivariate curve resolution-alternating least squares method. Moreover, the concentration profiles and pure spectra of three species (BSA/HSA, CEPT and CEPT-BSA/HSA) and the apparent equilibrium constants K(app) were evaluated. The experimental results showed that CEPT could quench the fluorescence intensity of BSA/HSA by a combined quenching (static and dynamic) procedure. The binding constant (K), the thermodynamic parameters (ΔG, ΔH and ΔS) and binding subdomain were measured, and indicated that CEPT could spontaneously bind to BSA/HSA on subdomain IIA through the hydrophobic interactions. The effect of CEPT on the secondary structure of proteins has been analyzed by circular dichroism, 3D fluorescence and Fourier transform infrared spectra. The binding distance between CEPT and tryptophan of BSA/HSA was 2.305/1.749 nm, which is based on the Förster resonance energy transfer theory.

  4. In situ measurement of bovine serum albumin interaction with gold nanospheres

    PubMed Central

    Dominguez-Medina, Sergio; McDonough, Steven; Swanglap, Pattanawit; Landes, Christy F.; Link, Stephan

    2012-01-01

    Here we present in situ observations of adsorption of bovine serum albumin (BSA) on citrate-stabilized gold nanospheres. We implemented scattering correlation spectroscopy as a tool to quantify changes in the nanoparticle Brownian motion resulting from BSA adsorption onto the nanoparticle surface. Protein binding was observed as an increase in the nanoparticle hydrodynamic radius. Our results indicate the formation of a protein monolayer at similar albumin concentrations as those found in human blood. Additionally, by monitoring the frequency and intensity of individual scattering events caused by single gold nanoparticles passing the observation volume, we found that BSA did not induce colloidal aggregation, a relevant result from the toxicological viewpoint. Moreover, to elucidate the thermodynamics of the gold nanoparticle-BSA association, we measured an adsorption isotherm which was best described by an anti-cooperative binding model. The number of binding sites based on this model was consistent with a BSA monolayer in its native state. In contrast, experiments using poly-ethylene glycol capped gold nanoparticles revealed no evidence for adsorption of BSA. PMID:22515552

  5. Spectroscopic and molecular modelling studies of binding mechanism of metformin with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Sharma, Deepti; Ojha, Himanshu; Pathak, Mallika; Singh, Bhawna; Sharma, Navneet; Singh, Anju; Kakkar, Rita; Sharma, Rakesh K.

    2016-08-01

    Metformin is a biguanide class of drug used for the treatment of diabetes mellitus. It is well known that serum protein-ligand binding interaction significantly influence the biodistribution of a drug. Current study was performed to characterize the binding mechanism of metformin with serum albumin. The binding interaction of the metformin with bovine serum albumin (BSA) was examined using UV-Vis absorption spectroscopy, fluorescence, circular dichroism, density functional theory and molecular docking studies. Absorption spectra and fluorescence emission spectra pointed out the weak binding of metformin with BSA as was apparent from the slight change in absorbance and fluorescence intensity of BSA in presence of metformin. Circular dichroism study implied the significant change in the conformation of BSA upon binding with metformin. Density functional theory calculations showed that metformin has non-planar geometry and has two energy states. The docking studies evidently signified that metformin could bind significantly to the three binding sites in BSA via hydrophobic, hydrogen bonding and electrostatic interactions. The data suggested the existence of non-covalent specific binding interaction in the complexation of metformin with BSA. The present study will certainly contribute to the development of metformin as a therapeutic molecule.

  6. Interaction of triprolidine hydrochloride with serum albumins: thermodynamic and binding characteristics, and influence of site probes.

    PubMed

    Sandhya, B; Hegde, Ashwini H; Kalanur, Shankara S; Katrahalli, Umesha; Seetharamappa, J

    2011-04-05

    The interaction between triprolidine hydrochloride (TRP) to serum albumins viz. bovine serum albumin (BSA) and human serum albumin (HSA) has been studied by spectroscopic methods. The experimental results revealed the static quenching mechanism in the interaction of TRP with protein. The number of binding sites close to unity for both TRP-BSA and TRP-HSA indicated the presence of single class of binding site for the drug in protein. The binding constant values of TRP-BSA and TRP-HSA were observed to be 4.75 ± 0.018 × 10(3) and 2.42 ± 0.024 × 10(4)M(-1) at 294 K, respectively. Thermodynamic parameters indicated that the hydrogen bond and van der Waals forces played the major role in the binding of TRP to proteins. The distance of separation between the serum albumin and TRP was obtained from the Förster's theory of non-radioactive energy transfer. The metal ions viz., K(+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Mn(2+) and Zn(2+) were found to influence the binding of the drug to protein. Displacement experiments indicated the binding of TRP to Sudlow's site I on both BSA and HSA. The CD, 3D fluorescence spectra and FT-IR spectral results revealed the changes in the secondary structure of protein upon interaction with TRP.

  7. The effect of structural alterations of three mammalian serum albumins on their binding properties

    NASA Astrophysics Data System (ADS)

    Równicka-Zubik, J.; Sułkowski, L.; Maciążek-Jurczyk, M.; Sułkowska, A.

    2013-07-01

    The binding of piroxicam (PIR) to human (HSA), bovine (BSA) and sheep (SSA) serum albumin in native and destabilized/denaturated state was studied by the fluorescence quenching technique. Quenching of the intrinsic fluorescence of three analyzed serum albumins was observed due to selective exciting of tryptophanyl and tyrosil residues at 295 nm and 280 nm. Based on fluorescence emission spectra the quenching (KQ) and binding constants (Ka) were determined. The results showed that PIR is bound mainly in IIA subdomain of HSA and is additionally able to interact with tyrosil groups located in subdomains IB, IIB or IIIA. PIR interacts only with tryptophanyl residues of BSA and SSA [Trp-214, Trp-237 (IIA) and Trp-135, Trp-158 (IB)]. The presence of denaturating factors modified the mechanism of fluorescence quenching of SSA by PIR. Linear Scatchard plots suggest that HSA, BSA and SSA bind PIR in one class of binding sites.

  8. Interaction and oxidative damage of DVDMS to BSA: a study on the mechanism of photodynamic therapy-induced cell death.

    PubMed

    Li, Li; Wang, Huiyu; Wang, Haiping; Li, Lijun; Wang, Pan; Wang, Xiaobing; Liu, Quanhong

    2017-03-02

    Photodynamic therapy (PDT) is a promising method for neoplastic and nonneoplastic diseases. In this study, we utilized sinoporphyrin sodium (DVDMS) as a sensitizer combined with light to investigate its cytotoxic effect on different cell lines. For this purpose, we chose bovine serum albumin (BSA) as a model to explore the mechanism of PDT-induced cell death at a molecular level. Our findings indicated that the combined treatment significantly suppressed cell survival. Fluorescence spectroscopy revealed a strong interaction between DVDMS and BSA molecules in aqueous solution, affecting DVDMS' targeting distribution and metabolism. Spectroscopic analysis and carbonyl content detection indicated that DVDMS-PDT significantly enhanced the damage of BSA at a higher extent than Photofrin II-PDT under similar experimental conditions. Our observations were consistent with the cytotoxicity results. Excessive reactive oxygen species (ROS) were induced by the synergy effect of the sensitizer and light, which played an important role in damaging BSA and tumor cells. These results suggested that the interaction and oxidative damage of protein molecules by DVDMS were the main reasons to cell death and constitute a valuable reference for future DVDMS-PDT investigations.

  9. Fe3O4/BSA particles induce osteogenic differentiation of mesenchymal stem cells under static magnetic field.

    PubMed

    Jiang, Pengfei; Zhang, Yixian; Zhu, Chaonan; Zhang, Wenjing; Mao, Zhengwei; Gao, Changyou

    2016-12-01

    Differentiation of stem cells is influenced by many factors, yet uptake of the magnetic particles with or without magnetic field is rarely tackled. In this study, iron oxide nanoparticles-loaded bovine serum albumin (BSA) (Fe3O4/BSA) particles were prepared, which showed a spherical morphology with a diameter below 200 nm, negatively charged surface, and tunable magnetic property. The particles could be internalized into bone marrow mesenchymal stem cells (MSCs), and their release from the cells was significantly retarded under external magnetic field, resulting in almost twice intracellular amount of the particles within 21 d compared to that of the magnetic field free control. Uptake of the Fe3O4/BSA particles enhanced significantly the osteogenic differentiation of MSCs under a static magnetic field, as evidenced by elevated alkaline phosphatase (ALP) activity, calcium deposition, and expressions of collagen type I and osteocalcin at both mRNA and protein levels. Therefore, uptake of the Fe3O4/BSA particles brings significant influence on the differentiation of MSCs under magnetic field, and thereby should be paid great attention for practical applications.

  10. Interaction and oxidative damage of DVDMS to BSA: a study on the mechanism of photodynamic therapy-induced cell death

    PubMed Central

    Li, Li; Wang, Huiyu; Wang, Haiping; Li, Lijun; Wang, Pan; Wang, Xiaobing; Liu, Quanhong

    2017-01-01

    Photodynamic therapy (PDT) is a promising method for neoplastic and nonneoplastic diseases. In this study, we utilized sinoporphyrin sodium (DVDMS) as a sensitizer combined with light to investigate its cytotoxic effect on different cell lines. For this purpose, we chose bovine serum albumin (BSA) as a model to explore the mechanism of PDT-induced cell death at a molecular level. Our findings indicated that the combined treatment significantly suppressed cell survival. Fluorescence spectroscopy revealed a strong interaction between DVDMS and BSA molecules in aqueous solution, affecting DVDMS’ targeting distribution and metabolism. Spectroscopic analysis and carbonyl content detection indicated that DVDMS-PDT significantly enhanced the damage of BSA at a higher extent than Photofrin II-PDT under similar experimental conditions. Our observations were consistent with the cytotoxicity results. Excessive reactive oxygen species (ROS) were induced by the synergy effect of the sensitizer and light, which played an important role in damaging BSA and tumor cells. These results suggested that the interaction and oxidative damage of protein molecules by DVDMS were the main reasons to cell death and constitute a valuable reference for future DVDMS-PDT investigations. PMID:28252029

  11. Conjugation of organoruthenium(II) 3-(1H-benzimidazol-2-yl)pyrazolo[3,4-b]pyridines and indolo[3,2-d]benzazepines to recombinant human serum albumin: a strategy to enhance cytotoxicity in cancer cells.

    PubMed

    Stepanenko, Iryna N; Casini, Angela; Edafe, Fabio; Novak, Maria S; Arion, Vladimir B; Dyson, Paul J; Jakupec, Michael A; Keppler, Bernhard K

    2011-12-19

    Following our strategy of coupling cyclin-dependent kinase (Cdk) inhibitors with organometallic moieties to improve their physicochemical properties and bioavailability, five organoruthenium complexes (1c-5c) of the general formula [RuCl(η(6)-arene)(L)]Cl have been synthesized in which the arene is 4-formylphenoxyacetyl-η(6)-benzylamide and L is a Cdk inhibitor [3-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines (L1-L3) and indolo[3,2-d]benzazepines (L4 and L5)]. All of the compounds were characterized by spectroscopic and analytical methods. Upon prolonged standing (2-3 months) at room temperature, the dimethyl sulfoxide (DMSO) solutions of 1c and 2c(-HCl) afforded residues, which after recrystallization from EtOH and EtOH/H(2)O, respectively, were shown by X-ray diffraction to be cis,cis-[Ru(II)Cl(2)(DMSO)(2)(L1)]·H(2)O and mer-[Ru(II)Cl(DMSO)(3)(L2-H)]·H(2)O. Compound 5c, with a coordinated amidine unit, undergoes E/Z isomerization in solution. The antiproliferative activities and effects on the cell cycle of the new compounds were evaluated. Complexes 1c-5c are moderately cytotoxic to cancer cells (CH1, SW480, A549, A2780, and A2780cisR cell lines). Therefore, in order to improve their antiproliferative effects, as well as their drug targeting and delivery to cancer cells, 1c-5c were conjugated to recombinant human serum albumin, potentially exploiting the so-called "enhanced permeability and retention" effect that results in the accumulation of macromolecules in tumors. Notably, a marked increase in cytotoxicity of the albumin conjugates was observed in all cases.

  12. Investigation of adsorption behavior of (-)-epigallocatechin gallate on bovine serum albumin surface using quartz crystal microbalance with dissipation monitoring.

    PubMed

    Wang, Xiaoyong; Ho, Chi-Tang; Huang, Qingrong

    2007-06-27

    Quartz crystal microbalance with dissipation monitoring (QCM-D) has been employed to study the interactions between (-)-epigallocatechin gallate (EGCG) and bovine serum albumin (BSA) surface. The adsorbed mass, thickness, and viscoelastic properties of EGCG adlayer on BSA surface at various EGCG concentrations, temperatures, sodium chloride concentrations, and pH values have been determined by QCM-D in combination with the Voigt model. The adsorption isotherm of EGCG on BSA surfaces can be better described by the Freundlich model than the Langmuir model, indicating that EGCG adsorption on BSA surfaces is dominated by nonspecific hydrophobic interactions, as supported by stronger EGCG adsorption at higher temperature. Shifts in the Fourier transform infrared spectra of the BSA surface with and without EGCG adsorption disclose that hydrogen bonding might also be involved in EGCG adsorption on BSA surfaces. The addition of salt and change of pH can also influence the EGCG adsorption on BSA surfaces. Usually, higher EGCG adsorption leads to higher values of viscosity and shear elastic modulus of EGCG adlayer, which can be explained by the aggregation of BSA through EGCG bridges. Compared with EGCG, nongalloylated (+)-catechin shows much lower adsorption capacity on BSA surfaces, suggesting the importance of the galloyl group in polyphenol/protein interactions.

  13. Combined spectroscopies and molecular docking approach to characterizing the binding interaction between lisinopril and bovine serum albumin.

    PubMed

    Jiang, Min; Huang, Chuan-ren; Wang, Qi; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-01

    To further understand the mode of action and pharmacokinetics of lisinopril, the binding interaction of lisinopril with bovine serum albumin (BSA) under imitated physiological conditions (pH 7.4) was investigated using fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD) and molecular docking methods. The results showed that the fluorescence quenching of BSA near 338 nm resulted from the formation of a lisinopril-BSA complex. The number of binding sites (n) for lisinopril binding on subdomain IIIA (site II) of BSA and the binding constant were ~ 1 and 2.04 × 10(4) M(-1), respectively, at 310 K. The binding of lisinopril to BSA induced a slight change in the conformation of BSA, which retained its α-helical structure. However, the binding of lisinopril with BSA was spontaneous and the main interaction forces involved were van der Waal's force and hydrogen bonding interaction as shown by the negative values of ΔG(0), ΔH(0) and ΔS(0) for the binding of lisinopril with BSA. It was concluded from the molecular docking results that the flexibility of lisinopril also played an important role in increasing the stability of the lisinopril-BSA complex.

  14. Folic acid-grafted bovine serum albumin decorated graphene oxide: An efficient drug carrier for targeted cancer therapy.

    PubMed

    Ma, Naxin; Liu, Jing; He, Wenxiu; Li, Zhonghao; Luan, Yuxia; Song, Yunmei; Garg, Sanjay

    2017-03-15

    Targeting drug carrier systems based on graphene oxide (GO) are of great interest, since it can selectively deliver anticancer drugs to tumor cells, and enhance therapeutic activities with minimized side effects. However, direct grafting target molecules on GO usually results in aggregation of physiological fluid, limiting its biomedical applications. Here, we propose a new strategy to construct targeting GO drug carrier using folic acid grafted bovine serum albumin (FA-BSA) as both the stabilizer and targeting agent. FA-BSA decorated graphene oxide-based nanocomposite (FA-BSA/GO) was fabricated by the physical adsorption of FA-BSA on GO, which was developed as a targeting drug delivery carrier. FA-BSA/GO as the drug carrier was associated with anticancer drug doxorubicin (DOX) through π-π and hydrogen-bond interactions, resulting in high drug loading (up to 437.43μgDOX/mgFA-BSA/GO). FA-BSA/GO/DOX systems demonstrated pH responsive and sustained drug release. The hemolysis ratio of FA-BSA/GO was less than 5%, demonstrating its safety as drug carrier for intravenous injection. Moreover, in vitro cell cytotoxicity and cellular uptake analysis suggested that the constructed FA-BSA/GO/DOX nanohybrids could significantly enhance the anticancer activity. The present work has confirmed the potential for fabrication of highly stable and dispersible GO-based targeting delivery systems for efficient cancer therapy.

  15. Polymerized soluble venom--human serum albumin

    SciTech Connect

    Patterson, R.; Suszko, I.M.; Grammer, L.C.

    1985-03-01

    Extensive previous studies have demonstrated that attempts to produce polymers of Hymenoptera venoms for human immunotherapy resulted in insoluble precipitates that could be injected with safety but with very limited immunogenicity in allergic patients. We now report soluble polymers prepared by conjugating bee venom with human serum albumin with glutaraldehyde. The bee venom-albumin polymer (BVAP) preparation was fractionated on Sephacryl S-300 to have a molecular weight range higher than catalase. /sup 125/I-labeled bee venom phospholipase A was almost completely incorporated into BVAP. Rabbit antibody responses to bee venom and bee venom phospholipase A were induced by BVAP. Human antisera against bee venom were absorbed by BVAP. No new antigenic determinants on BVAP were present as evidenced by absorption of antisera against BVAP by bee venom and albumin. BVAP has potential immunotherapeutic value in patients with anaphylactic sensitivity to bee venom.

  16. Study on the interaction between carbonyl-fused N-confused porphyrin and bovine serum albumin by spectroscopic techniques.

    PubMed

    Yu, Xianyong; Liao, Zhixi; Jiang, Bingfei; Zheng, Lingyi; Li, Xiaofang

    2014-12-10

    The interaction between carbonyl-fused N-confused porphyrin (CF-NCP) and bovine serum albumin (BSA) was investigated by fluorescence and ultraviolet-visible (UV-Vis) spectroscopy. The results indicated that CF-NCP has strong ability to quench the intrinsic fluorescence of BSA by forming complexes. The binding constants (Ka), binding sites (n) were obtained. The corresponding thermodynamic parameters (ΔH, ΔS and ΔG) of the interaction system were calculated at three different temperatures. The results revealed that the binding process is spontaneous, and the acting force between CF-NCP and BSA were mainly electrostatic forces. According to Förster non-radiation energy transfer theory, the binding distance between CF-NCP and BSA was calculated to be 4.37nm. What is more, the conformation of BSA was observed from synchronous fluorescence spectroscopy.

  17. Study on the interaction between 21-(Ph-NN)-NCTPP and bovine serum albumin by spectroscopic techniques.

    PubMed

    Yu, Xianyong; Jiang, Bingfei; Liao, Zhixi; Li, Xiaofang

    2015-05-05

    The interaction between 21-(Ph-NN)-NCTPP and bovine serum albumin (BSA) was investigated by fluorescence and ultraviolet-visible (UV-Vis) spectroscopy under imitated physiological conditions. The results showed that the intrinsic fluorescence of BSA was quenched strongly by 21-(Ph-NN)-NCTPP. The binding constants (Ka) and the binding sites (n) were obtained at three different temperatures (298, 304, and 310K). The thermodynamic parameters (ΔH, ΔS and ΔG) of the interaction system were calculated, the results indicated that the binding process was spontaneous and the hydrophobic interaction played a major role in [21-(Ph-NN)-NCTPP]-BSA binding process. Based on the Förster non-radiation energy transfer theory, the binding distance from 21-(Ph-NN)-NCTPP to BSA was estimated to be about 3.51nm. What's more, the synchronous fluorescence spectra indicated that the conformation of BSA has not been changed.

  18. Comparative studies on the interaction of caffeic acid, chlorogenic acid and ferulic acid with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Li, Shuang; Huang, Kelong; Zhong, Ming; Guo, Jun; Wang, Wei-zheng; Zhu, Ronghua

    2010-10-01

    The substitution of the hydrogen on aromatic and esterification of carboxyl group of the phenol compounds plays an important role in their bio-activities. In this paper, caffeic acid (CaA), chlorogenic acid (ChA) and ferulic acid (FA) were selected to investigate the binding to bovine serum albumin (BSA) using UV absorption spectroscopy, fluorescence spectroscopy and synchronous fluorescence spectroscopy. It was found that the methoxyl group substituting for the 3-hydroxyl group of CaA decreased the affinity for BSA and the esterification of carboxyl group of CaA with quinic acid increased the affinities. The affinities of ChA and FA with BSA were more sensitive to the temperature than that of CaA with BSA. Synchronous fluorescence spectroscopy and time-resolved fluorescence indicated that the Stern-Volmer plots largely deviated from linearity at high concentrations and were caused by complete quenching of the tyrosine fluorescence of BSA.

  19. 3,6-diHydroxyflavone/bovine serum albumin interaction in cyclodextrin medium: Absorption and emission monitoring

    NASA Astrophysics Data System (ADS)

    Voicescu, Mariana; Bandula, Rodica

    2015-03-01

    Photophysical properties of a bioactive flavonol which can be used as a model for polyhydroxylated natural flavonols, 3,6-diHydroxyflavone (3,6-diHF) in cyclodextrins (CDs)/bovine serum albumin (BSA) systems have been studied by absorption and fluorescence spectroscopy. The influence of CDs nature and of the different molar ratios BSA/CDs on the fluorescent characteristics of 3,6-diHF, and on the excited - state intramolecular proton transfer (ESIPT) process were studied. Quantitative information on the interaction between 3,6-diHF and BSA in CDs medium, were estimated. The influence of temperature (25-60 °C range) on the intrinsic fluorescence of BSA in 3,6-diHF/BSA/CDs systems, was investigated. The results are discussed with relevance to 3,6-diHF as a potential sensitive fluorescence probe in the systems of biological interest.

  20. Osmotically unresponsive water fraction on proteins: non-ideal osmotic pressure of bovine serum albumin as a function of pH and salt concentration.

    PubMed

    Fullerton, Gary D; Kanal, Kalpana M; Cameron, Ivan L

    2006-01-01

    How much does protein-associated water differ in colligative properties (freezing point, boiling point, vapor pressure and osmotic behavior) from pure bulk water? This question was approached by studying the globular protein bovine serum albumin (BSA), using changes in pH and salt concentration to alter its native structural conformation and state of aggregation. BSA osmotic pressure was investigated experimentally and analyzed using the molecular model of Fullerton et al. [Biochem Cell Biol 1992;70(12):1325]. Analysis yielded both the extent of osmotically unresponsive water (OUW) and the effective molecular weight values of the membrane-impermeable BSA solute. Manipulation of BSA conformation and aggregation by membrane-penetrating cosolutes show that alterations in pH and salt concentration change the amount of bulk water that escapes into BSA from a minimum of 1.4 to a maximum of 11.7 g water per g dry mass BSA.

  1. Effects of pH and metal ions on the conformation of bovine serum albumin in aqueous solution An attenuated total reflection (ATR) FTIR spectroscopic study

    NASA Astrophysics Data System (ADS)

    Qing, Huai; Yanlin, He; Fenlin, Sheng; Zuyi, Tao

    1996-11-01

    The Hummel-Dreyer gel permeation technique has been applied to investigate the binding of bovine serum albumin (BSA) with Zn 2+ and Cd 2+, and has provided evidence for the existence of two different types of binding sites in the BSA molecule. The effects of pH and the presence of metal ions Zn 2- and Cd 2+ on the conformation of BSA were investigated using ATR FTIR Spectroscopy. The results demonstrated that there were different conformational states in BSA at pH 5.0 and 9.0. Furthermore, we observed the spectral changes of BSA in the amide I region and major metal ion (Zn 2+ and Cd 2+) binding sites which were CO and CN groups of BSA.

  2. Catalytic damage of bovine serum albumin by metronidazole under ultrasonic irradiation in the presence of nano-sized TiO2 powder

    NASA Astrophysics Data System (ADS)

    Wang, J.; Wang, Z. G.; Jin, X. D.; Guo, Y. W.; Gao, J. Q.; Li, K.; Wang, B. X.; Li, Y.

    2012-05-01

    In previous work, it was found that the bovine serum albumin (BSA) could obviously be damaged by nano-sized TiO2 powder as a sonocatalyst under ultrasonic irradiation. In this work, metronidazole (MTZ) was adopted as a sensitizer to intensify the damage of BSA molecules. It was found that the damage degree of BSA molecules in the presence of MTZ was more serious than in the absence of MTZ. That is, under ultrasonic irradiation combined with nano-sized TiO2 powder, the addition of MTZ could remarkably aggravate the damage to BSA molecules. Meanwhile, the damage degree was also affected by some influence factors, such as ultrasonic irradiation time, ultrasonic irradiation power, MTZ concentration, solution acidity, ionic strength and solution temperature. In addition, the damage site of BSA molecules was also estimated by synchronous fluorescence spectra. It was found that the damage site of BSA molecules was mainly at tyrosine (Tyr) residue.

  3. Synthesis and biological evaluation of novel benzimidazole derivatives and their binding behavior with bovine serum albumin.

    PubMed

    Zhang, Shao-Lin; Damu, Guri L V; Zhang, Ling; Geng, Rong-Xia; Zhou, Cheng-He

    2012-09-01

    A series of novel benzimidazole derivatives were synthesized and characterized by (1)H NMR, (13)C NMR, MS, IR and HRMS spectra. All the new compounds were screened for their antimicrobial activities in vitro by two-fold serial dilution technique. Bioactive assay manifested that the bis-benzimidazole derivative 11d and its hydrochloride 13b exhibited remarkable antimicrobial activities, which were comparable or even better than the reference drugs Norfloxacin, Chloromycin and Fluconazole. The interaction evaluation of compound 11d with bovine serum albumin (BSA) by Fluorescence and UV-vis absorption spectroscopic method showed that BSA could generate fluorescent quenching under approximately human physiological conditions by the prepared benzimidazole compound 11d as result of the formation of ground-state compound 11d-BSA complex. The thermodynamic parameters indicated that the hydrogen bonds and van der Waals forces played major roles in the strong association of benzimidazole 11d and BSA.

  4. Relief of amplification inhibition in PCR with bovine serum albumin or T4 gene 32 protein

    SciTech Connect

    Kreader, C.A.

    1996-03-01

    The benefits of adding bovine serum albumin (BSA) or T4 gene 32 proteins (gp32) to PCR were evaluated with reaction mixtures containing substances that inhibit amplification. Whereas 10- to 1,000-fold more FeCl{sub 3}, hemin, fulvic acids, humic acids, tannic acids, or extracts from feces, freshwater, or marine water were accommodated in PCR when either 400 ng of BSA per {mu}l was included in the reactions, neither BSA nor gp32 relieved interference significantly when minimum inhibitory levels of bile salts, bilirubin, EDTA, NaCl, sodium dodecyl sulfate, or Triton X-100 were present. Use of BSA and gp32 together offered no more relief of inhibition than either alone at its optimal level, and neither protein had any noticeable effect on amplification in the absence of inhibitors. 21 refs., 3 figs.

  5. Glycation of bovine serum albumin by ascorbate in vitro: Possible contribution of the ascorbyl radical?

    PubMed Central

    Sadowska-Bartosz, Izabela; Stefaniuk, Ireneusz; Galiniak, Sabina; Bartosz, Grzegorz

    2015-01-01

    Ascorbic acid (AA) has been reported to be both pro-and antiglycating agent. In vitro, mainly proglycating effects of AA have been observed. We studied the glycation of bovine serum albumin (BSA) induced by AA in vitro. BSA glycation was accompanied by oxidative modifications, in agreement with the idea of glycoxidation. Glycation was inhibited by antioxidants including polyphenols and accelerated by 2,​2′-​azobis-​2-​methyl-​propanimidamide and superoxide dismutase. Nitroxides, known to oxidize AA, did not inhibit BSA glycation. A good correlation was observed between the steady-state level of the ascorbyl radical in BSA samples incubated with AA and additives and the extent of glycation. On this basis we propose that ascorbyl radical, in addition to further products of AA oxidation, may initiate protein glycation. PMID:26202868

  6. Glycation of bovine serum albumin by ascorbate in vitro: Possible contribution of the ascorbyl radical?

    PubMed

    Sadowska-Bartosz, Izabela; Stefaniuk, Ireneusz; Galiniak, Sabina; Bartosz, Grzegorz

    2015-12-01

    Ascorbic acid (AA) has been reported to be both pro-and antiglycating agent. In vitro, mainly proglycating effects of AA have been observed. We studied the glycation of bovine serum albumin (BSA) induced by AA in vitro. BSA glycation was accompanied by oxidative modifications, in agreement with the idea of glycoxidation. Glycation was inhibited by antioxidants including polyphenols and accelerated by 2,​2'-​azobis-​2-​methyl-​propanimidamide and superoxide dismutase. Nitroxides, known to oxidize AA, did not inhibit BSA glycation. A good correlation was observed between the steady-state level of the ascorbyl radical in BSA samples incubated with AA and additives and the extent of glycation. On this basis we propose that ascorbyl radical, in addition to further products of AA oxidation, may initiate protein glycation.

  7. Assessment of the europium(III) binding sites on albumin using fluorescence spectroscopy.

    PubMed

    Tikhonova, Tatiana N; Shirshin, Evgeny A; Budylin, Gleb S; Fadeev, Victor V; Petrova, Galina P

    2014-06-19

    Intrinsic fluorescence quenching of bovine serum albumin (BSA) and europium(III) luminescence in BSA complexes were investigated. The number of BSA binding sites (n) and equilibrium constant (Keq) values were determined from both measurements provided qualitatively different results. While the modified Stern-Volmer relation for BSA fluorescence quenching gave n = 1 at pH 4.5 and pH 6, two sets of binding sites were determined from Eu(3+) luminescence with n1 = 2, n2 = 4 at pH 6 and n1 = 1, n2 = 2 at pH 4.5. The model explaining the discrepancy between the results obtained by these fluorescent approaches was suggested, and the limitations in application of the "log-log" Stern-Volmer plots in analysis of binding processes were discussed.

  8. Spectroscopic study of the competitive interaction between streptomycin and Evans blue to bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Huang, Jü-qin; Lv, Qing-luan; Wang, Huai You

    2011-12-01

    The mechanism of the competitive interaction of streptomycin and Evans blue (EB) to bovine serum albumin (BSA) has been studied by using both fluorimetry and spectrophtometry. Effects of pH, streptomycin and concentration of EB on the competitive interaction of streptomycin and EB were examined. A static fluorescence quenching process was confirmed in the light of Stern-Volmer plot. The test result showed that there were strong and weak binding sites on BSA molecule and the binding constant of EB-BSA complex and the number of binding site n were obtained. These facts revealed that the competitive interaction was occurred between EB and streptomycin, which can possibly provide useful message in investigation of the interaction of antibiotic with BSA.

  9. Characterization of the binding of 2-mercaptobenzimidazole to bovine serum albumin.

    PubMed

    Teng, Yue; Zou, Luyi; Huang, Ming; Zong, Wansong

    2015-04-01

    2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment is potentially harmful to human health. In this article, the interaction of MBI with bovine serum albumin (BSA) was explored using spectroscopic and molecular docking methods under physiological conditions. The positively charged MBI can spontaneously bind with the negatively charged BSA through electrostatic forces with one binding site. The site marker competition experiments and the molecular docking study revealed that MBI bound into site II (subdomain IIIA) of BSA, which further led to some secondary structure and microenvironmental changes of BSA. This work provides useful information on understanding the toxicological actions of MBI at the molecular level.

  10. Copper Selenide Nanosnakes: Bovine Serum Albumin-Assisted Room Temperature Controllable Synthesis and Characterization

    NASA Astrophysics Data System (ADS)

    Huang, Peng; Kong, Yifei; Li, Zhiming; Gao, Feng; Cui, Daxiang

    2010-06-01

    Herein we firstly reported a simple, environment-friendly, controllable synthetic method of CuSe nanosnakes at room temperature using copper salts and sodium selenosulfate as the reactants, and bovine serum albumin (BSA) as foaming agent. As the amounts of selenide ions (Se2-) released from Na2SeSO3 in the solution increased, the cubic and snake-like CuSe nanostructures were formed gradually, the cubic nanostructures were captured by the CuSe nanosnakes, the CuSe nanosnakes grew wider and longer as the reaction time increased. Finally, the cubic CuSe nanostructures were completely replaced by BSA-CuSe nanosnakes. The prepared BSA-CuSe nanosnakes exhibited enhanced biocompatibility than the CuSe nanocrystals, which highly suggest that as-prepared BSA-CuSe nanosnakes have great potentials in applications such as biomedical engineering.

  11. Copper selenide nanosnakes: bovine serum albumin-assisted room temperature controllable synthesis and characterization.

    PubMed

    Huang, Peng; Kong, Yifei; Li, Zhiming; Gao, Feng; Cui, Daxiang

    2010-04-03

    Herein we firstly reported a simple, environment-friendly, controllable synthetic method of CuSe nanosnakes at room temperature using copper salts and sodium selenosulfate as the reactants, and bovine serum albumin (BSA) as foaming agent. As the amounts of selenide ions (Se2-) released from Na2SeSO3 in the solution increased, the cubic and snake-like CuSe nanostructures were formed gradually, the cubic nanostructures were captured by the CuSe nanosnakes, the CuSe nanosnakes grew wider and longer as the reaction time increased. Finally, the cubic CuSe nanostructures were completely replaced by BSA-CuSe nanosnakes. The prepared BSA-CuSe nanosnakes exhibited enhanced biocompatibility than the CuSe nanocrystals, which highly suggest that as-prepared BSA-CuSe nanosnakes have great potentials in applications such as biomedical engineering.

  12. Self-assembling of poly(aspartic acid) with bovine serum albumin in aqueous solutions.

    PubMed

    Nita, L E; Chiriac, A P; Bercea, M; Asandulesa, M; Wolf, Bernhard A

    2017-02-01

    Macromolecular co-assemblies built up in aqueous solutions, by using a linear polypeptide, poly(aspartic acid) (PAS), and a globular protein, bovine serum albumin (BSA), have been studied. The main interest was to identify the optimum conditions for an interpenetrated complex formation in order to design materials suitable for biomedical applications, such as drug delivery systems. BSA surface possesses several amino- and carboxylic groups available for covalent modification, and/or bioactive substances attachment. In the present study, mixtures between PAS and BSA were investigated at 37°C in dilute aqueous solution by viscometry, dynamic light scattering and zeta potential determination, as well as in solid state by AFM microscopy and dielectric spectroscopy. The experimental data have shown that the interpolymer complex formation occurs for a PAS/BSA molar ratio around 0.541.

  13. Spectroscopic and coarse-grained simulation studies of the BSA and HSA protein adsorption on silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Voicescu, Mariana; Ionescu, Sorana; Angelescu, Daniel G.

    2012-10-01

    The photophysical properties of the bovine serum albumin (BSA) and human serum albumin (HSA) adsorbed on (non) functionalized Ag(0) nanoparticles have been studied by spectroscopic techniques. The surface plasmon resonance kinetic of the BSA/HSA-Ag(0) nanoparticle complexes has been assessed by UV-Vis absorption spectroscopy. Transmission electron microscopy analysis showed that the average size of the particles is 9 nm and the core-shell structure of the protein-Ag(0) nanoparticle complexes has been supported by UV-Vis spectra. The structure, stability, dynamics, and conformation of the proteins have been investigated by steady-state, time-resolved fluorescence, and circular dichroism spectroscopy. Insights of the HSA conformation at the nanoparticle surface were obtained by the Monte Carlo simulations carried out using an appropriate coarse-grained model. The HSA conformation upon adsorption on the nanoparticle surface is distorted so that the Trp fluorescence is quenched and the α-helix content diminished. The adsorbed protein exhibited an extended conformation with Trp residue depleted from the nanoparticle surface and rather located toward the protein boundary. Experimental and simulated experiments were in good agreements and the results are discussed in terms of functional properties of the serum albumins in protein-Ag(0) nanoparticle complex.

  14. Selective inhibition of aggregation/fibrillation of bovine serum albumin by osmolytes: Mechanistic and energetics insights

    PubMed Central

    Dasgupta, Moumita

    2017-01-01

    Bovine serum albumin (BSA) is an important transport protein of the blood and its aggregation/fibrillation would adversely affect its transport ability leading to metabolic disorder. Therefore, understanding the mechanism of fibrillation/aggregation of BSA and design of suitable inhibitor molecules for stabilizing its native conformation, are of utmost importance. The qualitative and quantitative aspects of the effect of osmolytes (proline, hydroxyproline, glycine betaine, sarcosine and sorbitol) on heat induced aggregation/fibrillation of BSA at physiological pH (pH 7.4) have been studied employing a combination of fluorescence spectroscopy, Rayleigh scattering, isothermal titration calorimetry (ITC), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Formation of fibrils by BSA under the given conditions was confirmed from increase in fluorescence emission intensities of Thioflavin T over a time period of 600 minutes and TEM images. Absence of change in fluorescence emission intensities of 8-Anilinonaphthalene-1-sulfonic acid (ANS) in presence of native and aggregated BSA signify the absence of any amorphous aggregates. ITC results have provided important insights on the energetics of interaction of these osmolytes with different stages of the fibrillar aggregates of BSA, thereby suggesting the possible modes/mechanism of inhibition of BSA fibrillation by these osmolytes. The heats of interaction of the osmolytes with different stages of fibrillation of BSA do not follow a trend, suggesting that the interactions of stages of BSA aggregates are osmolyte specific. Among the osmolytes used here, we found glycine betaine to be supporting and promoting the aggregation process while hydroxyproline to be maximally efficient in suppressing the fibrillation process of BSA, followed by sorbitol, sarcosine and proline in the following order of their decreasing potency: Hydroxyproline> Sorbitol> Sarcosine> Proline> Glycine betaine. PMID:28207877

  15. Kinetics and efficiency of a methyl-carboxylated 5-Fluorouracil-bovine serum albumin adduct for targeted delivery.

    PubMed

    Koziol, Michael J; Sievers, Torsten K; Smuda, Kathrin; Xiong, Yu; Müller, Angelika; Wojcik, Felix; Steffen, Axel; Dathe, Margitta; Georgieva, Radostina; Bäumler, Hans

    2014-03-01

    5-Fluorouracil (5-FU) is a clinically well-established anti-cancer drug effectively applied in chemotherapy, mainly for the treatment of breast and colorectal cancer. Substantial disadvantages are adverse effects, arising from serious damage of healthy tissues, and shortcoming pharmacokinetics due to its low molecular weight. A promising approach for improvement of such drugs is their coupling to suitable carriers. Here, a 5-FU adduct, 5-fluorouracil acetate (FUAc) is synthesized and covalently coupled to bovine serum albumin (BSA) as model carrier molecule. On average, 12 molecules FUAc are bound to one BSA. Circular dichriosm (CD)-spectra of BSA and FUAc-BSA are identical, suggesting no significant conformational differences. FUAc-BSA is tested on T-47D and MDA-MB-231 breast cancer cells. Proliferation inhibition of membrane albumin-binding protein (mABP)-expressing T-47D cells by FUAc-BSA is similar to that of 5-FU and only moderate for MDA-MB-231 cells that lack such expression. Therefore, a crucial role of mABP expression in effective cell growth inhibition by FUAc-BSA is assumed.

  16. Elucidating the Influence of Gold Nanoparticles on the Binding of Salvianolic Acid B and Rosmarinic Acid to Bovine Serum Albumin

    PubMed Central

    Peng, Xin; Qi, Wei; Huang, Renliang; Su, Rongxin; He, Zhimin

    2015-01-01

    Salvianolic acid B and rosmarinic acid are two main water-soluble active ingredients from Salvia miltiorrhiza with important pharmacological activities and clinical applications. The interactions between salvianolic acid B (or rosmarinic acid) and bovine serum albumin (BSA) in the presence and absence of gold nanoparticles (Au NPs) with three different sizes were investigated by using biophysical methods for the first time. Experimental results proved that two components quenched the fluorescence of BSA mainly through a static mechanism irrespective of the absence or presence of Au NPs. The presence of Au NPs decreased the binding constants of salvianolic acid B with BSA from 27.82% to 10.08%, while Au NPs increased the affinities of rosmarinic acid for BSA from 0.4% to 14.32%. The conformational change of BSA in the presence of Au NPs (caused by a noncompetitive binding between Au NPs and drugs at different albumin sites) induced changeable affinity and binding distance between drugs and BSA compared with no Au NPs. The competitive experiments revealed that the site I (subdomain IIA) of BSA was the primary binding site for salvianolic acid B and rosmarinic acid. Additionally, two compounds may induce conformational and micro-environmental changes of BSA. The results would provide valuable binding information between salvianolic acid B (or rosmarinic acid) and BSA, and also indicated that the Au NPs could alter the interaction mechanism and binding capability of drugs to BSA, which might be beneficial to understanding the pharmacokinetics and biological activities of the two drugs. PMID:25861047

  17. A combined spectroscopic and molecular docking approach to characterize binding interaction of megestrol acetate with bovine serum albumin.

    PubMed

    Shi, Jie-hua; Zhu, Ying-yao; Wang, Jing; Chen, Jun

    2015-02-01

    The binding interactions between megestrol acetate (MA) and bovine serum albumin (BSA) under simulated physiological conditions (pH 7.4) were investigated by fluorescence spectroscopy, circular dichroism and molecular modeling. The results revealed that the intrinsic fluorescence of BSA was quenched by MA due to formation of the MA-BSA complex, which was rationalized in terms of a static quenching procedure. The binding constant (Kb ) and number of binding sites (n) for MA binding to BSA were 2.8 × 10(5)  L/mol at 310 K and about 1 respectively. However, the binding of MA with BSA was a spontaneous process due to the negative ∆G(0) in the binding process. The enthalpy change (∆H(0) ) and entropy change (∆S(0) ) were - 124.0 kJ/mol and -295.6 J/mol per K, respectively, indicating that the major interaction forces in the binding process of MA with BSA were van der Waals forces and hydrogen bonding. Based on the results of spectroscopic and molecular docking experiments, it can be deduced that MA inserts into the hydrophobic pocket located in subdomain IIIA (site II) of BSA. The binding of MA to BSA leads to a slight change in conformation of BSA but the BSA retained its secondary structure, while conformation of the MA has significant change after forming MA-BSA complex, suggesting that flexibility of the MA molecule supports the binding interaction of BSA with MA.

  18. Mechanism and conformational studies of farrerol binding to bovine serum albumin by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Zhang, Guowen; Wang, Lin; Fu, Peng; Hu, Mingming

    2011-11-01

    The mechanism and conformational changes of farrerol binding to bovine serum albumin (BSA) were studied by spectroscopic methods including fluorescence quenching technique, UV-vis absorption, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that farrerol could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The thermodynamic parameters enthalpy change and entropy change for the binding were calculated to be -29.92 kJ mol -1 and 5.06 J mol -1 K -1 according to the van't Hoff equation, which suggested that the both hydrophobic interactions and hydrogen bonds play major role in the binding of farrerol to BSA. The binding distance r deduced from the efficiency of energy transfer was 3.11 nm for farrerol-BSA system. The displacement experiments of site markers and the results of fluorescence anisotropy showed that warfarin and farrerol shared a common binding site I corresponding to the subdomain IIA of BSA. Furthermore, the studies of synchronous fluorescence, CD and FT-IR spectroscopy showed that the binding of farrerol to BSA induced conformational changes in BSA.

  19. Influence of bovine serum albumin and alginate on silver nanoparticle dissolution and toxicity to Nitrosomonas europaea.

    PubMed

    Ostermeyer, Ann-Kathrin; Kostigen Mumuper, Cameron; Semprini, Lewis; Radniecki, Tyler

    2013-12-17

    Bovine serum albumin (BSA), a model protein, reduced the toxicity of 20 nm citrate silver nanoparticles (AgNP) toward Nitrosomonas europaea, a model ammonia oxidizing bacteria, through a dual-mode protection mechanism. BSA reduced AgNP toxicity by chelating the silver ions (Ag(+)) released from the AgNPs. BSA further reduced AgNP toxicity by binding to the AgNP surface thus preventing NH3-dependent dissolution from occurring. Due to BSA's affinity toward Ag(+) chemisorbed on the AgNP surface, increased concentrations of BSA lead to increased AgNP dissolution rates. This, however, did not increase AgNP toxicity as the dissolved Ag(+) were adsorbed onto the BSA molecules. Alginate, a model extracellular polysaccharide (EPS), lacks strong Ag(+) ligands and was unable to protect N. europaea from Ag(+) toxicity. However, at high concentrations, alginate reduced AgNP toxicity by binding to the AgNP surface and reducing AgNP dissolution rates. Unlike BSA, alginate only weakly interacted with the AgNP surface and was unable to completely prevent NH3-dependent AgNP dissolution from occurring. Based on these results, AgNP toxicity in high protein environments (e.g., wastewater) is expected to be muted while the EPS layers of wastewater biofilms may provide additional protection from AgNPs, but not from Ag(+) that have already been released.

  20. Effects of gene carrier polyethyleneimines on the structure and binding capability of bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Guo, Zhiyong; Kong, Zhijie; Wei, Yanshan; Li, Hua; Wang, Yajing; Huang, Aimin; Ma, Lin

    2017-02-01

    Polyethyleneimine (PEI), one of the most effective non-viral gene carriers, is also cytotoxic, however the molecular basis is poorly understood. Little is known about the effects of PEI on the structure and functions of the biomacromolecules. In this work, fluorescence, UV-vis absorption, circular dichroism (CD) spectroscopy and zeta-potential measurement were conducted to reveal the interaction between PEIs (average molecular weight 25, 10 and 1.8 kDa) and bovine serum albumin (BSA), and to evaluate the effects on the conformation of BSA as long as its binding capability to the model compounds, 8-anilino-1-naphthalenesulfonic acid (ANS) and quercetin. PEIs were found to complex with BSA and induced a conformational change of the protein by a major reduction of α-helix at PEI concentration < 0.2 mg·mL- 1 and an increase at higher PEI concentration. The binding efficacy of ANS and quercetin to BSA was greatly reduced by the competitive binding by PEI and influenced by the conformational change of BSA, which was found to display a similar trend to the change of the α-helix content of the protein. The polymer size played an important role in PEI-BSA interaction. PEI of higher molecular weight was more favorable to interact with BSA and more efficient to perturb the conformation and binding capability of the protein.

  1. Spectroscopic and docking studies on the interaction between pyrrolidinium based ionic liquid and bovine serum albumin.

    PubMed

    Kumari, Meena; Maurya, Jitendra Kumar; Singh, Upendra Kumar; Khan, Abbul Bashar; Ali, Maroof; Singh, Prashant; Patel, Rajan

    2014-04-24

    The interaction of synthesized ionic liquid, 1-butyl-1-methyl-2-oxopyrrolidinium bromide (BMOP) and bovine serum albumin (BSA) was investigated using UV-Vis, FT-IR, steady state and time resolved fluorescence measurements and docking studies. Steady state spectra revealed that BMOP strongly quenched the intrinsic fluorescence of BSA through dynamic quenching mechanism. The corresponding thermodynamic parameters; Gibbs free energy change (ΔG), entropy change (ΔS) and enthalpy change (ΔH) showed that the binding process was spontaneous and entropy driven. It is also indicated that hydrophobic forces play a key role in the binding of BMOP to BSA. The synchronous fluorescence spectroscopy reveals that the conformation of BSA changed in the presence of BMOP. The shift in amide I band of FT-IR spectrum of BSA suggested unfolding of the protein secondary structure upon the addition of BMOP. In addition, the molecular modeling study of BSA-BMOP system shows that BMOP binds with BSA at the interface between two sub domains IIA and IIIA, which is located just above the entrance of the binding pocket of IIA through hydrophobic and hydrogen bond interactions in which hydrophobic interaction are dominated.

  2. Bovine serum albumin nanoparticles for delivery of tacrolimus to reduce its kidney uptake and functional nephrotoxicity.

    PubMed

    Zhao, Lei; Zhou, Yanxia; Gao, Yajie; Ma, Shujin; Zhang, Chao; Li, Jinwen; Wang, Dishi; Li, Xueping; Li, Chengwei; Liu, Yan; Li, Xinru

    2015-04-10

    The purpose of the present study was to develop a new nanoparticulate formulation for delivery of tacrolimus to reduce its kidney distribution and functional nephrotoxicity. Tacrolimus (TAC)-loaded bovine serum albumin (BSA) nanoparticles (TAC-BSA-NPs) were prepared by emulsification-dispersion technique. The obtained TAC-BSA-NPs, with 189.50±7.15 nm of diameter and -20.86±0.45 mV of Zeta potential determined by DLS, were spherical in shape observed by TEM. The drug loading content and encapsulation efficiency were (1.7±0.13)% and (85±3.0)%, respectively. The in vitro release of TAC-BSA-NPs exhibited biphasic drug release pattern with an initial burst release and subsequently sustained release. Pharmacokinetic analysis displayed that TAC-BSA-NPs could enhance the drug blood level and prolong the circulation time in comparison to Prograf(®). Meanwhile, compared with Prograf(®), TAC-BSA-NPs could deliver less TAC to kidney and simultaneously reduce the functional nephrotoxicity of TAC to kidney. In conclusion, BSA nanoparticles might be a more safe carrier for delivery of hydrophobic drug TAC.

  3. The competition of drugs to serum albumin in combination chemotherapy: NMR study

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Bojko, B.; Równicka, J.; Rezner, P.; Sułkowski, W. W.

    2005-06-01

    Combination chemotherapy with cyclophosphamide (CM), metotrexate and 5-fluorouracil (FU) is used in treatment of patients with breast carcinoma. Although clinical toxicity of CM combinated with FU is greater than that of CM, the levels were clinically acceptable. The mechanism of competition of CM and FU to bovine serum albumin (BSA) was examined with the use of 1H and 13C NMR spectroscopy. The chemical shifts and the linewidth of individual proton and carbon resonances of each drug were measured as a function of the drug/BSA molar ratio in order to analyse the drug-protein interaction and the molecular motion of the drug. The effect of the second drug used in the combination chemotherapy on the analysed NMR parameters is discussed. It was found that FU and CM bind to BSA at molar ratio drug/BSA 160 and 330, respectively. The formation of lev-BSA complex was not confirmed. Whereas it was proved that in the presence of both lev and CM the number of FU molecules bound with BSA increases. It was also observed that FU induces the rising of the affinity between lev and BSA.

  4. Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking.

    PubMed

    Wang, Qi; Huang, Chuan-ren; Jiang, Min; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-05

    The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH=7.4) were 1.41 × 10(5) M(-1) and about 1 at 310K, respectively. The values of the enthalpic change (ΔH(0)), entropic change (ΔS(0)) and Gibbs free energy (ΔG(0)) in the binding process of atorvastatin with BSA at 310K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA.

  5. Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Huang, Chuan-ren; Jiang, Min; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-01

    The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH = 7.4) were 1.41 × 105 M- 1 and about 1 at 310 K, respectively. The values of the enthalpic change (ΔH0), entropic change (ΔS0) and Gibbs free energy (ΔG0) in the binding process of atorvastatin with BSA at 310 K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA.

  6. Urea-induced binding between diclofenac sodium and bovine serum albumin: a spectroscopic insight.

    PubMed

    Dohare, Neeraj; Khan, Abbul Bashar; Athar, Fareeda; Thakur, Sonu Chand; Patel, Rajan

    2016-06-01

    We investigated the interaction of diclofenac sodium (Dic.Na) with bovine serum albumin (BSA) in the absence and presence of urea using different spectroscopic techniques. A fluorescence quenching study revealed that the Stern-Volmer quenching constant decreases in the presence of urea, decreasing further at higher urea concentrations. The binding constant and number of binding sites were also evaluated for the BSA-Dic.Na interaction system in the absence and presence of urea using a modified Stern-Volmer equation. The binding constant is greater at high urea concentrations, as shown by the fluorescence results. In addition, for the BSA-Dic.Na interaction system, a static quenching mechanism was observed, which was further confirmed using time-resolved fluorescence spectroscopy. UV-vis spectroscopy provided information about the formation of a complex between BSA and Dic.Na. Circular dichroism was carried out to explain the conformational changes in BSA induced by Dic.Na in the absence and presence of urea. The presence of urea reduced the α-helical content of BSA as the Dic.Na concentration varied. The distance r between the donor (BSA) and acceptor (Dic.Na) was also obtained in the absence and presence of urea, using fluorescence resonance energy transfer. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Effects of serum albumin on the degradation and cytotoxicity of single-walled carbon nanotubes.

    PubMed

    Ding, Yun; Tian, Rong; Yang, Zhen; Chen, Jianfa; Lu, Naihao

    2017-03-01

    Neutrophil myeloperoxidase (MPO) and peroxynitrite (ONOO(-)) can oxidatively biodegrade carboxylated single-walled carbon nanotubes (SWCNTs). The protein-SWCNTs interactions will play an important role in the degradation and cytotoxicity of nanotubes. Here, we investigated the binding of bovine serum albumin (BSA, a common and well-characterized model blood serum protein) to SWCNTs, and found that the hydrophobic and electrostatic interactions might be crucial factors in stabilizing the binding of SWCNTs with BSA. The binding of BSA could impair SWCNTs biodegradation in vitro through the competitive adsorption to nanotube. Both SWCNTs and BSA-SWCNTs were significantly degraded in zymosan-stimulated macrophages, and the degradation degree was more for BSA-SWCNTs. The mechanism for SWCNTs degradation in activated macrophages was further investigated to demonstrate the dominant participation of MPO and ONOO(-)-driven pathways. Moreover, binding of BSA to SWCNTs reduced cytotoxicity and degraded nanotubes induced less cytotoxicity than non-degraded nanotubes. The binding of BSA may be an important determinant for the biodegradation and cytotoxicity of SWCNTs in inflammatory cells, and therefore, provide a new route to mitigate the potential toxicity of nanotubes in future biomedical applications.

  8. Effects of gene carrier polyethyleneimines on the structure and binding capability of bovine serum albumin.

    PubMed

    Guo, Zhiyong; Kong, Zhijie; Wei, Yanshan; Li, Hua; Wang, Yajing; Huang, Aimin; Ma, Lin

    2017-02-15

    Polyethyleneimine (PEI), one of the most effective non-viral gene carriers, is also cytotoxic, however the molecular basis is poorly understood. Little is known about the effects of PEI on the structure and functions of the biomacromolecules. In this work, fluorescence, UV-vis absorption, circular dichroism (CD) spectroscopy and zeta-potential measurement were conducted to reveal the interaction between PEIs (average molecular weight 25, 10 and 1.8kDa) and bovine serum albumin (BSA), and to evaluate the effects on the conformation of BSA as long as its binding capability to the model compounds, 8-anilino-1-naphthalenesulfonic acid (ANS) and quercetin. PEIs were found to complex with BSA and induced a conformational change of the protein by a major reduction of α-helix at PEI concentration <0.2mg·mL(-1) and an increase at higher PEI concentration. The binding efficacy of ANS and quercetin to BSA was greatly reduced by the competitive binding by PEI and influenced by the conformational change of BSA, which was found to display a similar trend to the change of the α-helix content of the protein. The polymer size played an important role in PEI-BSA interaction. PEI of higher molecular weight was more favorable to interact with BSA and more efficient to perturb the conformation and binding capability of the protein.

  9. Comparison of human serum and bovine serum albumins on oxidation dynamics induced by talaporfin sodium photosensitization reaction with albumin rich conditions: solution experiments

    NASA Astrophysics Data System (ADS)

    Kurotsu, Mariko; Nakamura, Tetsuya; Takahashi, Mei; Ogawa, Emiyu; Arai, Tsunenori

    2014-02-01

    In order to understand extracellular-photosensitization reaction (PR) using talaporfin sodium, we studied comparison of oxidation dynamics of albumin and talaporfin sodium in solution system by visible and ultraviolet absorption spectrum measurements. Almost all talaporfin sodium particles may be bound to albumin in interstitial fluid, and this binding would affect the oxidation dynamics during this PR. Bovine serum albumin (BSA) is commonly used in vitro study but its binding characteristics with talaporfin sodium are different from human serum albumin (HSA). PR was operated in a solution composed of 20 μg/ml talaporfin sodium and 1.3 mg/ml HSA or BSA to simulate myocardial extracellular PR condition. Laser radiation of 662 nm was irradiated to this solution with irradiance of 0.29 W/cm2. Absorption spectra of these solutions were measured during the PR. We estimated oxidized ratio by absorption difference around 240 nm before and after the PR. Talaporfin sodium was oxidized 100% with HSA and BSA by the PR of 100 J/cm2 in radiant exposure. On the other hand, HSA and BSA were oxidized 60% and 94%, respectively in this radiant exposure. Q-band absorption peak of talaporfin sodium with HSA was shifted to 1 nm longer wavelength increasing radiant exposure up to 100 J/cm2. This longer wavelength shift would mean binding ratio of non-oxidized talaporfin sodium to non-oxidized HSA was increased with increasing radiant exposure. Therefore it would be possible that PR with talaporfin sodium bound to HSA might present efficient PDT than PR bound to BSA.

  10. Determination of association constants between steroid compounds and albumins by partial-filling ACE.

    PubMed

    Amundsen, Lotta K; Sirén, Heli

    2007-10-01

    ACE is a popular technique for evaluating association constants between drugs and proteins. However, ACE has not previously been applied to study the association between electrically neutral biomolecules and plasma proteins. We studied the affinity between human and bovine serum albumins (HSA and BSA, respectively) and three neutral endogenous steroid hormones (testosterone, epitestosterone and androstenedione) and two synthetic analogues (methyltestosterone and fluoxymesterone) by applying the partial-filling technique in ACE (PF-ACE). From the endocrinological point of view, the distribution of endogenous steroids among plasma components is of great interest. Strong interactions with albumins suppress the biological activity of steroids. Notable differences in the association constants were observed. In the case of the endogenous steroids, the interactions between testosterone and the albumins were strongest, and those between androstenedione and the albumins were substantially weaker. The association constants, K(b), for testosterone, epitestosterone and androstenedione and HSA at 37 degrees C were 32 100 +/- 3600, 21 600 +/- 1500 and 13 300 +/- 1300 M(-1), respectively, while the corresponding values for the steroids and BSA were 18 800 +/- 1500, 14 000 +/- 400 and 7800 +/- 900 M(-1). Methyltestosterone was bound even more strongly than testosterone, while fluoxymesterone was only weakly bound by the albumins. Finally, the steroids were separated by PF-ACE with HSA and BSA used as resolving components.

  11. Buffers more than buffering agent: introducing a new class of stabilizers for the protein BSA.

    PubMed

    Gupta, Bhupender S; Taha, Mohamed; Lee, Ming-Jer

    2015-01-14

    In this study, we have analyzed the influence of four biological buffers on the thermal stability of bovine serum albumin (BSA) using dynamic light scattering (DLS). The investigated buffers include 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES), 4-(2-hydroxyethyl)-1-piperazine-propanesulfonic acid (EPPS), 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid sodium salt (HEPES-Na), and 4-morpholinepropanesulfonic acid sodium salt (MOPS-Na). These buffers behave as a potential stabilizer for the native structure of BSA against thermal denaturation. The stabilization tendency follows the order of MOPS-Na > HEPES-Na > HEPES ≫ EPPS. To obtain an insight into the role of hydration layers and peptide backbone in the stabilization of BSA by these buffers, we have also explored the phase transition of a thermoresponsive polymer, poly(N-isopropylacrylamide (PNIPAM)), a model compound for protein, in aqueous solutions of HEPES, EPPS, HEPES-Na, and MOPS-Na buffers at different concentrations. It was found that the lower critical solution temperatures (LCST) of PNIPAM in the aqueous buffer solutions substantially decrease with increase in buffer concentration. The mechanism of interactions between these buffers and protein BSA was probed by various techniques, including UV-visible, fluorescence, and FTIR. The results of this series of studies reveal that the interactions are mainly governed by the influence of the buffers on the hydration layers surrounding the protein. We have also explored the possible binding sites of BSA with these buffers using a molecular docking technique. Moreover, the activities of an industrially important enzyme α-chymotrypsin (α-CT) in 0.05 M, 0.5 M, and 1.0 M of HEPES, EPPS, HEPES-Na, and MOPS-Na buffer solutions were analyzed at pH = 8.0 and T = 25 °C. Interestingly, the activities of α-CT were found to be enhanced in the aqueous solutions of these investigated buffers. Based upon the Jones-Dole viscosity parameters, the

  12. Fluorescence lifetime measurements of native and glycated human serum albumin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Joshi, Narahari V.; Joshi, Virgina O. d.; Contreras, Silvia; Gil, Herminia; Medina, Honorio; Siemiarczuk, Aleksander

    1999-05-01

    Nonenzymatic glycation, also known as Maillard reaction, plays an important role in the secondary complications of the diabetic pathology and aging, therefore, human serum albumin (HSA) and bovine serum albumin (BSA) were glycated by a conventional method in our laboratory using glucose as the glycating agent. Fluorescence lifetime measurements were carried out with a laser strobe fluorometer equipped with a nitrogen/dye laser and a frequency doubler as a pulsed excitation source. The samples were excited at 295 nm and the emission spectra were recorded at 345 nm. The obtained decay curves were tried for double and triple exponential functions. It has been found that the shorter lifetime increases for glycated proteins as compared with that of the native ones. For example, in the case of glycated BSA the lifetime increased from 1.36 ns to 2.30 ns. Similarly, for HSA, the lifetime increases from 1.58 ns to 2.26 ns. Meanwhile, the longer lifetime changed very slightly for both proteins (from 6.52 ns to 6.72 ns). The increase in the lifetime can be associated with the environmental effect; originated from the attachment of glucose to some lysine residues. A good example is Trp 214 which is in the cage of Lys 225, Lys 212, Lys 233, Lys 205, Lys 500, Lys 199 and Lys 195. If fluorescence lifetime technique is calibrated and properly used it could be employed for assessing glycation of proteins.

  13. Optical spectroscopic exploration of binding of Cochineal Red A with two homologous serum albumins.

    PubMed

    Bolel, Priyanka; Mahapatra, Niharendu; Halder, Mintu

    2012-04-11

    Cochineal Red A is a negatively charged synthetic azo food colorant and a potential carcinogen. We present here the study of binding of Cochineal Red A with two homologous serum albumins, human (HSA) and bovine (BSA), in aqueous pH 7.4 buffer by optical spectroscopic techniques. Protein intrinsic fluorescence quenching by Cochineal Red A occurs through ground-state static interaction and its binding with BSA is stronger than with HSA. The magnitudes of thermodynamic parameters suggest that dye binding occurs principally via electrostatic complexation. Site-marker competitive binding shows that Cochineal Red A binds primarily to site I of serum albumins. Circular dichroic spectra indicate that dye binding results in some conformational modification of serum albumins. Increased ionic strength of the medium results in lowering of binding. This study provides an important insight into possible means of removal of dye toxicity.

  14. Synthesis, purification and mass spectrometric characterisation of a fluorescent Au9@BSA nanocluster and its enzymatic digestion by trypsin

    NASA Astrophysics Data System (ADS)

    Fernández-Iglesias, Nerea; Bettmer, Jörg

    2013-12-01

    Nanoclusters of noble metals like Ag and Au have attracted great attention as they form a missing link between isolated metal atoms and nanoparticles. Their particular properties like luminescence in the visible range and nontoxicity make them attractive for bioimaging and biolabelling purposes, especially with use of proteins as stabilising agents. In this context, this study intends the synthesis of a specific Au nanocluster covered by bovine serum albumin (BSA). It is shown that size-exclusion chromatography is feasible for the purification and isolation of the nanocluster. A mass spectrometric characterisation, preferably by ESI-MS, indicates the presence of an Au9@BSA nanocluster. Enzymatic digestion of the nanocluster with trypsin results in a significant increase of the fluorescence intensity at 650 and 710 nm, whereas complementary MALDI-MS studies are presented for the identification of generated peptides and show a distinctive pattern in comparison to the pure protein. It can be concluded that Au9@BSA might be, in future, an interesting candidate for in vitro studies of protease activities.Nanoclusters of noble metals like Ag and Au have attracted great attention as they form a missing link between isolated metal atoms and nanoparticles. Their particular properties like luminescence in the visible range and nontoxicity make them attractive for bioimaging and biolabelling purposes, especially with use of proteins as stabilising agents. In this context, this study intends the synthesis of a specific Au nanocluster covered by bovine serum albumin (BSA). It is shown that size-exclusion chromatography is feasible for the purification and isolation of the nanocluster. A mass spectrometric characterisation, preferably by ESI-MS, indicates the presence of an Au9@BSA nanocluster. Enzymatic digestion of the nanocluster with trypsin results in a significant increase of the fluorescence intensity at 650 and 710 nm, whereas complementary MALDI-MS studies are presented

  15. Analysis of albumin hologram

    NASA Astrophysics Data System (ADS)

    Ordóñez-Padilla, M. J.; Olivares-Pérez, A.; Berriel-Valdos, L. R.; Ortiz-Gutiérrez, M.; Villa-Manríquez, J. F.

    2012-03-01

    We present the characterizations of the photosensitive film made with albumins gallus gallus and callipepla cali, with the purpose to make holographic recording. Albumin was combined with propylene glycol, to build colloidal systems by adding the ammonium dichromate solution as photosensitive salt at certain concentrations. Hence, we conducted the photo-oxidation process with laser, λ=442nm. Obtaining holograms that allowed the analysis of the diffraction efficiency parameter. One of the objectives of this work was to obtain some mechanical and chemical stability of films made with albumin when prepared with propylene glycol. At once, experimental studies were performed to compare the results of the holographic recording films between chicken albumin and quail albumin film to prove the recording capabilities and to quantify the diffraction efficiency in holographic grating made with each kind of albumin.

  16. Formulation and Characterization of Bovine Serum Albumin-Loaded Niosome.

    PubMed

    Moghassemi, Saeid; Hadjizadeh, Afra; Omidfar, Kobra

    2017-01-01

    Niosomal vesicle, as a unique novel drug delivery system, is synthesized by non-ionic surfactants. Both hydrophilic and lipophilic drugs and also biomacromolecular agents, such as peptides and proteins can be encapsulated in this vesicular particle. Regarding polypeptide-based component loading, and delivery potential of the niosome, some valuable studies have been conducted in recent years. However, exploring the full potential of this approach requires fine tuned optimization and characterization approaches. Therefore, this study was conducted to achieve the following two goals. First, formulation and optimization of bovine serum albumin (BSA) load and release behavior as a function of cholesterol (CH) to sorbitan monostearate (Span 60) molar ratio. Second, investigating a cost- and time-effective polypeptide detecting method via methyl orange (MO) dye. To this aim, BSA-loaded niosomes were prepared by reversed-phase evaporation technique. The effect of CH to Sorbitan monostearate (Span 60) molar ratio on noisome entrapment efficiency (EE%) and release profile of BSA was studied using a ultraviolet (UV) spectrophotometer technique (NanoDrop 2000/2000c).Niosome with a 60% CH content showed the highest BSA EE% and release behavior. Then, BSA was dyed using MO in an acidic solution and used in BSA-niosome formulation. The MO-colored protein, loaded into the vesicles, was successfully assessed by an inverted light microscope, in order to observe the protein location in the vesicle. The results obtained in this study can be useful for various applications in different fields, including pharmaceutical, cosmetics, and drug delivery in biomedical and tissue engineering.

  17. Foam fractionation of binary mixtures of lysozyme and albumin.

    PubMed

    Lockwood, C E; Jay, M; Bummer, P M

    2000-06-01

    A nitrogen gas-based foam fractionation method was employed to separate model proteins, bovine serum albumin (BSA) and hen egg white lysozyme, from each other. Fractionation was characterized by the separation ratio and by recovery of proteins in the retentate as a function of the nominal pore size of the gas dispersion frit and solution conditions (pH and ionic strength). For binary mixtures of the proteins at pH 7.4, and ionic strength (mu) of 0.18 M, the recovery of lysozyme and the separation ratio were both dependent on the frit size employed to generate the foam. At low ionic strength (mu = 0.01 M), separation was only somewhat greater with the small pore size frits, although at values significantly lower than those found for high ionic strength. The diminished separations appear to be due to the only slight changes in recoveries observed for BSA and lysozyme.%Separation ratios of lysozyme from BSA in solutions either of high or low ionic strength were maximal at pH values equal to or less than the isoelectric point (pI) of BSA. Separation ratios were lower when foaming was carried out under low compared with high ionic strength. The recovery of lysozyme was enhanced by foaming from solutions of low pH and high ionic strength. Recoveries of BSA were greatest when the molecule was negatively charged. Electrical interactions between the positively charged lysozyme and negatively charged BSA may explain the diminished separation ratios and enhanced recoveries. Enzyme activity studies of lysozyme remaining in the retentate showed no change from prefoam activity.

  18. Study of the cross-reaction between rabbit anti-bovine serum albumin antibodies and equine serum albumin

    PubMed Central

    Rangel, H.

    1965-01-01

    Cross-reactions between bovine serum albumin and equine serum albumin were studied using heterologous soluble complexes and specifically purified cross-reacting antibody. Experiments with soluble complexes showed that homologous antigen can displace heterologous antigen specifically bound to antibody but heterologous antigen cannot displace homologous antigen. On gel precipitation tests a specific precipitation resulted when heterologous soluble complex reacted with homologous antigen. By using equine serum albumin conjugated to polyaminopolystyrene the cross-reacting antibodies from anti-bovine serum albumin imune sera could be isolated. These are divalent 7S, γ-globulin antibodies. A figure of cross-reaction was obtained when these purified antibodies were tested by double diffusion in agar with bovine and equine serum albumins. The results obtained both with soluble complexes and with purified antibody support the view that cross-reacting antibody is more avid for the homologous than for the heterologous antigen. ImagesFIG. 3FIG. 4FIG. 5 PMID:14245318

  19. Structure-affinity relationship of flavones on binding to serum albumins: effect of hydroxyl groups on ring A.

    PubMed

    Xiao, Jianbo; Cao, Hui; Wang, Yuanfeng; Yamamoto, Koichiro; Wei, Xinlin

    2010-07-01

    Four flavones (flavone, 7-hydroxyflavone, chrysin, and baicalein) sharing the same B- and C-ring structure but a different numbers of hydroxyl groups on the A-ring were studied for their affinities for BSA and HSA. The hydroxylation on ring A of flavones increased the binding constants (K(a)) and the number of binding sites (n) between flavones and serum albumins. The affinities of 7-hydroxyflavone for BSA and HSA were about 800 times and 40 times higher than that of flavone, respectively. It appears that the optimal number of hydroxyl groups introduced to the ring A of flavones is one. As more hydroxyl groups were introduced to positions at C-5, C-6, and/or C-7 of flavones, the affinities for serum albumins decrease. The critical energy transfer distances (R(0)) between the hydroxylated flavones (1-3 OH on the ring A) and serum albumins decreased with the increasing affinities for serum albumins.

  20. Evaluation of DNA, BSA binding, and antimicrobial activity of new synthesized neodymium complex containing 29-dimethyl 110-phenanthroline.

    PubMed

    Moradi, Zohreh; Khorasani-Motlagh, Mozhgan; Rezvani, Ali Reza; Noroozifar, Meissam

    2017-02-21

    In order to evaluate biological potential of a novel synthesized complex [Nd(dmp)2Cl3.OH2] where dmp is 29-dimethyl 110-phenanthroline, the DNA-binding, cleavage, BSA binding, and antimicrobial activity properties of the complex are investigated by multispectroscopic techniques study in physiological buffer (pH 7.2).The intrinsic binding constant (Kb) for interaction of Nd(III) complex and FS-DNA is calculated by UV-Vis (Kb = 2.7 ± 0.07 × 10(5)) and fluorescence spectroscopy (Kb = 1.13 ± 0.03 × 10(5)). The Stern-Volmer constant (KSV), thermodynamic parameters including free energy change (ΔG°), enthalpy change (∆H°), and entropy change (∆S°), are calculated by fluorescent data and Vant' Hoff equation. The experimental results show that the complex can bind to FS-DNA and the major binding mode is groove binding. Meanwhile, the interaction of Nd(III) complex with protein, bovine serum albumin (BSA), has also been studied by using absorption and emission spectroscopic tools. The experimental results show that the complex exhibits good binding propensity to BSA. The positive ΔH° and ∆S° values indicate that the hydrophobic interaction is main force in the binding of the Nd(III) complex to BSA, and the complex can quench the intrinsic fluorescence of BSA remarkably through a static quenching process. Also, DNA cleavage was investigated by agarose gel electrophoresis that according to the results cleavage of DNA increased with increasing of concentration of the complex. Antimicrobial screening test gives good results in the presence of Nd(III) complex system.

  1. Stability of protein-encapsulating DRV liposomes after freeze-drying: A study with BSA and t-PA.

    PubMed

    Ntimenou, Vassiliki; Mourtas, Spyridon; Christodoulakis, Emmanouil V; Tsilimbaris, Miltiadis; Antimisiaris, Sophia G

    2006-01-01

    Stability of protein-encapsulating DRV (dried-rehydrated vesicle) liposomes is evaluated after freeze-drying vesicles in presence (or not) of trehalose. Two proteins, bovine serum albumin (BSA) and tissue-type plasminogen activator (t-PA), are used, and protein-encapsulating liposomes with different lipid compositions are prepared by DRV technique. Encapsulation efficiencies are calculated, after measuring BSA with a fluorescence technique and t-PA's amidolytic activity toward a chromogenic substrate. Experimental results show that encapsulation of BSA in vesicles ranges between 35 and 53% of the protein and is only slightly affected by lipid composition. For t-PA, entrapment efficiencies are lower, ranging between 2 and 16%, while lipid composition has substantial effect on entrapment (cholesterol inclusion is very important). After freeze-drying, some lipid compositions remain stable, retaining most of initially entrapped proteins, while others do not, but they may be stabilized by trehalose. In the case of BSA, liposome behavior cannot be explained based on lipid membrane rigidity (more rigid = more stable). This may be connected with previously demonstrated interactions of BSA with membranes. Oppositely, t-PA behavior is more predictable, meaning that the lipid composition selected for the specific therapeutic application determines the need for cryoprotectant addition before freeze-drying t-PA containing DRV liposomes, perhaps due to the fact that under conditions applying minimum or no interactions between t-PA and lipid membranes occur.Thereby, interactions between proteins and membranes determine not only the encapsulation efficiency but also the need for cryopreservation of liposomal protein formulations.

  2. [Spectrophotometric determination of albumin with acid brown SR].

    PubMed

    Zhao, Chang-Rong; Liu, Bao-Sheng; Zhang, Hong-Yi

    2005-01-01

    A new method for the determination of albumin in human serum and mouse serum has been developed by spectrophotometry coupled with acid brown SR(ASR) as probe molecule. The maximum absorption wavelength of ASR was at 445 nm, while the maximum absorption wavelength of their product was at 610 nm. However, the reaction of ASR with albumin such as BSA or HSA was so strong that parts of their product were undissoluble in water. The addition of gum water into the system effectively eliminated the deposition. Under optimum reaction conditions, the ranges of working lines for BSA and HSA were 0-91.0 mg x L(-1) and 0-95.2 mg x L(-1), respectively. The detection limits were 5.72 mg x L(-1) for BSA and 5.15 mg x L(-1) for HSA. The relative standard derivation and the recovery of the method for the determination of total proteins in 6 human serum samples were 1.8%-4.4% and 93.6% - 109.1%, respectively. The proposed method has been employed in the assay of protein of human serum and mouse serum. The results of this work were in agreement with those obtained by Biuret method.

  3. Albumin/asparaginase capsules prepared by ultrasound to retain ammonia.

    PubMed

    Tinoco, Ana; Ribeiro, Artur; Oliveira, César; Parpot, Pier; Gomes, Andreia; Cavaco-Paulo, Artur

    2016-11-01

    Asparaginase reduces the levels of asparagine in blood, which is an essential amino acid for the proliferation of lymphoblastic malign cells. Asparaginase converts asparagine into aspartic acid and ammonia. The accumulation of ammonia in the bloodstream leads to hyperammonemia, described as one of the most significant side effects of asparaginase therapy. Therefore, there is a need for asparaginase formulations with the potential to reduce hyperammonemia. We incorporated 2 % of therapeutic enzyme in albumin-based capsules. The presence of asparaginase in the interface of bovine serum albumin (BSA) capsules showed the ability to hydrolyze the asparagine and retain the forming ammonia at the surface of the capsules. The incorporation of Poloxamer 407 in the capsule formulation further increased the ratio aspartic acid/ammonia from 1.92 to 2.46 (and 1.10 from the free enzyme), decreasing the levels of free ammonia. This capacity to retain ammonia can be due to electrostatic interactions and retention of ammonia at the surface of the capsules. The developed BSA/asparaginase capsules did not cause significant cytotoxic effect on mouse leukemic macrophage cell line RAW 264.7. The new BSA/asparaginase capsules could potentially be used in the treatment of acute lymphoblastic leukemia preventing hyperammonemia associated with acute lymphoblastic leukemia (ALL) treatment with asparaginase.

  4. Reductive unfolding of serum albumins uncovered by Raman spectroscopy.

    PubMed

    David, Catalina; Foley, Sarah; Mavon, Christophe; Enescu, Mironel

    2008-07-01

    The reductive unfolding of bovine serum albumin (BSA) and human serum albumin (HSA) induced by dithiothreitol (DTT) is investigated using Raman spectroscopy. The resolution of the S-S Raman band into both protein and oxidized DTT contributions provides a reliable basis for directly monitoring the S-S bridge exchange reaction. The related changes in the protein secondary structure are identified by analyzing the protein amide I Raman band. For the reduction of one S-S bridge of BSA, a mean Gibbs free energy of -7 kJ mol(-1) is derived by studying the reaction equilibrium. The corresponding value for the HSA S-S bridge reduction is -2 kJ mol(-1). The reaction kinetics observed via the S-S or amide I Raman bands are identical giving a reaction rate constant of (1.02 +/- 0.11) M(-1) s(-1) for BSA. The contribution of the conformational Gibbs free energy to the overall Gibbs free energy of reaction is further estimated by combining experimental data with ab initio calculations.

  5. Stimuli-Responsive Cucurbit[7]uril-Mediated BSA Nanoassembly for Uptake and Release of Doxorubicin.

    PubMed

    Barooah, Nilotpal; Kunwar, Amit; Khurana, Raman; Bhasikuttan, Achikanath C; Mohanty, Jyotirmayee

    2017-01-03

    We report the construction of a non-toxic nanoassembly of bovine serum albumin (BSA) protein and the cucurbit[7]uril macrocycle as well as its stimuli-responsive breakage with adamantylamine or pH, which restores the protein structure and recognition properties. The assembly showed efficient loading and controlled release of a standard drug, doxorubicin (DOX), and the same was validated in live cells. The cell viability studies documented that the DOX-loaded assembly mask the cytotoxicity of DOX and the toxicity can be revived at the target on demand, triggering its therapeutic activation. This is found to be more effective in the cancer cells. In addition, such host-assisted protein assemblies are also highly promising for stabilizing/protecting the native protein structure, a viable approach to prevent/inhibit protein misfolding and aggregation.

  6. Epitope imprinted polymer coating CdTe quantum dots for specific recognition and direct fluorescent quantification of the target protein bovine serum albumin.

    PubMed

    Yang, Ya-Qiong; He, Xi-Wen; Wang, Yi-Zhi; Li, Wen-You; Zhang, Yu-Kui

    2014-04-15

    A novel epitope molecularly imprinted polymer (EMIP) for specific recognition and direct fluorescent quantification of the target protein bovine serum albumin (BSA) was demonstrated where polymerization was performed on the surface of silica nanospheres embedded CdTe quantum dots (QDs). The synthetic peptide derived from the surface-exposed C-terminus of bovine serum albumin (BSA, residues 599-607) was selected as the template molecule. The resulting EMIP film was able to selectively capture the template peptide and the corresponding target protein BSA via the recognition cavities. Based on the fluorescence quenching, the EMIP-coated QDs (molecular imprinted polymer coating CdTe QDs using epitope as the template) nanospheres were successfully applied to the direct fluorescence quantification of BSA. Compared with BMIP-coated QDs (molecular imprinted polymer coating CdTe QDs using BSA as the template), the imprinting factor and adsorption capacity of EMIP-coated QDs were greatly increased. The prepared EMIP-coated QDs can also discriminate even one mismatched sequences from the original sequences of the epitope of the BSA. The practical analytical performance of the EMIP-coated QDs was examined by evaluating the detection of BSA in the bovine calf serum sample with satisfactory results. In addition, the resulting EMIP-coated QDs nanospheres were also successfully applied to separating BSA from the bovine blood sample.

  7. Recognition and binding of β-lactam antibiotics to bovine serum albumin by frontal affinity chromatography in combination with spectroscopy and molecular docking.

    PubMed

    Li, Qian; Zhang, Tianlong; Bian, Liujiao

    2016-03-01

    Serum albumins are the most abundant carrier proteins in blood plasma and participate in the binding and transportation of various exogenous and endogenous compounds in the body. This work was designed to investigate the recognition and binding of three typical β-lactam antibiotics including penicillin G (Pen G), penicillin V (Pen V) and cefalexin (Cef) with bovine serum albumin (BSA) by frontal affinity chromatography in combination with UV-vis absorption spectra, fluorescence emission spectra, binding site marker competitive experiment and molecular docking under simulated physiological conditions. The results showed that a BSA only bound with one antibiotic molecule in the binding process, and the binding constants for Pen G-BSA, Pen V-BSA and Cef-BSA complexes were 4.22×10(1), 4.86×10(2) and 3.32×10(3) (L/mol), respectively. All the three β-lactam antibiotics were mainly inserted into the subdomain IIA (binding site 1) of BSA by hydrogen bonds and Van der Waals forces. The binding capacity between the antibiotics and BSA was closely related to the functional groups and flexibility of side chains in antibiotics. This study provided an important insight into the molecular recognition and binding interaction of BSA with β-lactam antibiotics, which may be a useful guideline for the innovative clinical medications and new antibiotic designs with effective pharmacological properties.

  8. Comparison of interactions between three food colorants and BSA.

    PubMed

    Li, Tian; Cheng, Zhengjun; Cao, Lijun; Jiang, Xiaohui

    2016-03-01

    Fast Green FCF (FCF), Patent Blue V (PBV) and Acid Blue 1 (AB1) are used as food colorants. Multiple spectroscopic techniques were employed to probe in depth the affinity of FCF/PBV/AB1 with BSA in different pH and/or salt concentrations. The results showed that FCF/PBV/AB1 quenched the intrinsic fluorescence of BSA by a static process, and electrostatic force dominated the formation of BSA-FCF/PBV/AB1 complex which was confirmed by the effects of salt on their interactions. Subdomain IIA was the primary binding site for FCF/PBV/AB1 on BSA in the pH range of 5.5-7.4, while both Trp 212 and Trp 134 residues of BSA might be bound by FCF/PBV/AB1 at pH 4.8. The K values suggested that the binding ability of three food colorants with BSA was FCF>PBV>AB1. The results of UV-vis absorption, synchronous fluorescence, 3D fluorescence and FT-IR spectra proved that the structure of BSA altered by FCF/PBV/AB1.

  9. Modulation of arachidonic acid release and membrane fluidity by albumin in vascular smooth muscle and endothelial cells.

    PubMed

    Beck, R; Bertolino, S; Abbot, S E; Aaronson, P I; Smirnov, S V

    1998-11-02

    Albumin is the major plasma protein circulating in blood. Albumin potently decreases capillary permeability, although the mechanisms are not understood completely. Albumin also effectively binds arachidonic acid (AA), which increases capillary permeability. To investigate the interactions of BSA and AA with the cell membrane, the effect of these substances on [3H]AA release and membrane fluidity was studied in vascular myocytes and endothelial cells. BSA (0.2 and 1 mg . mL-1) stimulated a significant release of [3H]AA from both intact rat aorta and cultured smooth muscle cells. This effect was not mimicked by gamma-globulin or myoglobin (both 1 mg . mL-1) in intact tissue. BSA, but not gamma-globulin and myoglobin, decreased the membrane fluidity (assessed as changes in the steady-state fluorescence anisotropy of 1,6-diphenyl-1,3, 5-hexatriene) in a concentration-dependent manner with a half-maximum concentration between 0.007 and 0.4 mg . mL-1 in both freshly isolated and cultured rat aortic myocytes and human umbilical vein endothelial cells. AA (1 to 200 micromol/L) caused the opposite effect, increasing membrane fluidity and antagonizing the effect of BSA. BSA modified at its arginine residues, which are thought to be important in AA binding, did not stimulate [3H]AA release and was significantly less potent than native BSA in altering the membrane fluidity. The effect of BSA can be explained by a high-affinity binding of AA to the protein and extraction of AA from the cell membrane. The interaction between BSA and AA could play a role in the regulation of vascular permeability.

  10. Treatment with GAD65 or BSA does not protect against diabetes in BB rats.

    PubMed

    Petersen, J S; Mackay, P; Plesner, A; Karlsen, A; Gotfredsen, C; Verland, S; Michelsen, B; Dyrberg, T

    1997-01-01

    The M(r) 65,000 isoform of glutamic acid decarboxylase (GAD65) has been implicated as the initiating islet cell antigen in the pathogenesis of diabetes, primarily based on studies in non-obese diabetic (NOD) mice. To test the role of this islet cell autoantigen in the pathogenesis of spontaneously occurring diabetes in another animal model, purified recombinant human islet GAD65 was injected i.v. at 200 micrograms/animal into 18-day-old diabetes-prone BB rats. For controls, bovine serum albumin (BSA), which has also been implicated in the pathogenesis of diabetes, or buffer alone was injected into age matched BB rats. At 210 days of age there were no differences in diabetes incidence in the 3 groups, i.e. 73% (11 of 15) in the GAD65-treated, 81% (13 of 16) in the BSA-treated and 65% (11 of 17) in the buffer-treated animals, or in the median age at onset of disease, i.e. 79 days (range 65-111), 87 days (range 60-107) and 86 days (range 74-109), respectively. The lack of protection against diabetes following GAD65 treatment could hypothetically be explained by no or by an aberrant expression of GAD in BB-rat islet cells. However, immunohistochemistry of pancreata and immunoblotting analysis of isolated islets showed that the expression of GAD65 and GAD67 was similar in BB and Lewis rats. In conclusion, these data indicate that neither GAD65 nor BSA autoimmunity is important for the development of diabetes in BB rats, in contrast to the situation in NOD mice, and further emphasizes that extrapolation from only one animal model to autoimmune diabetes in general may not be appropriate.

  11. Seeking to shed some light on the binding of fluoroquinolones to albumins.

    PubMed

    Bosca, Francisco

    2012-03-22

    Interactions between serum albumins (HSA, human, and BSA, bovine) and fluoroquinolones (FQs), such as enoxacin, norfloxacin, ciprofloxacin, and ofloxacin, have been studied using the laser flash photolysis technique. Lifetimes and quantum yields of FQs triplet excited states ((3)FQs) are not affected by the presence of albumins, however, the quenching of (3)FQs by tryptophan and tyrosine and the subsequent generation of FQs radical anions and tyrosyl or tryptophanyl radicals were detected. These results, besides agreeing with association constants (K(a)) for FQs binding to albumins lower than 6 × 10(2) M(-1), are highly relevant to understanding the process of photohapten formation, the first event in the onset of photoallergy. The emission of tryptophan within albumin is not affected by the presence of FQs when the inner filter effects (IFE) of these drugs are taken into account, which explains the discrepancies reported in the literature about K(a) of FQs with albumins.

  12. Effect of pH on protein distribution in electrospun PVA/BSA composite nanofibers.

    PubMed

    Tang, Christina; Ozcam, A Evren; Stout, Brendon; Khan, Saad A

    2012-05-14

    We examine the protein distribution within an electrospun polymer nanofiber using polyvinyl alcohol and bovine serum albumin as a model system. We hypothesize that the location of the protein within the nanofiber can be controlled by carefully selecting the pH and the applied polarity of the electric field as the pH affects the net charge on the proteins. Using fluorescently labeled BSA and surface analysis, we observe that the distribution of BSA is affected by the pH of the electrospinning solution. Therefore, we further probe the relevant forces on the protein in solution during electrospinning. The role of hydrodynamic friction was assessed using glutaraldehyde and HCl as a tool to modify the viscosity of the solution during electrospinning. By varying the pH and the polarity of the applied electric field, we evaluated the effects of electrostatic forces and dielectrophoresis on the protein during fiber formation. We surmise that electrostatic forces and hydrodynamic friction are insignificant relative to dielectrophoretic forces; therefore, it is possible to separate species in a blend using polarizability contrast. A coaxial distribution of protein in the core can be obtained by electrospinning at the isoelectric point of the protein, whereas surface enrichment can be obtained when the protein carries a net charge.

  13. Photoinduced electron transfer in a protein-surfactant complex: probing the interaction of SDS with BSA.

    PubMed

    Chakraborty, Anjan; Seth, Debabrata; Setua, Palash; Sarkar, Nilmoni

    2006-08-24

    Photoinduced fluorescence quenching electron transfer from N,N-dimethyl aniline to different 7-amino coumarin dyes has been investigated in sodium dodecyl sulfate (SDS) micelles and in bovine serum albumin (BSA)-SDS protein-surfactant complexes using steady state and picosecond time resolved fluorescence spectroscopy. The electron transfer rate has been found to be slower in BSA-SDS protein-surfactant complexes compared to that in SDS micelles. This observation has been explained with the help of the "necklace-and-bead" structure formed by the protein-surfactant complex due to coiling of protein molecules around the micelles. In the correlation of free energy change to the fluorescence quenching electron transfer rate, we have observed that coumarin 151 deviates from the normal Marcus region, showing retardation in the electron transfer rate at higher negative free energy region. We endeavored to establish that the retardation in the fluorescence quenching electron transfer rate for coumarin 151 at higher free energy region is a result of slower rotational relaxation and slower translational diffusion of coumarin 151 (C-151) compared to its analogues coumarin 152 and coumarin 481 in micelles and in protein-surfactant complexes. The slower rotational relaxation and translational diffusion of C-151 are supposed to be arising from the different location of coumarin 151 compared to coumarin 152 and coumarin 481.

  14. Dynamics in BSA solutions at low ionic strengths as observed by holographic relaxation spectroscopy

    NASA Astrophysics Data System (ADS)

    Barish, Amy O.; Gabriel, Don A.; Johnson, Charles S., Jr.

    1987-09-01

    Holographic relaxation techniques (HRS) were used to study dynamics in solutions of bovine serum albumin (BSA) labeled with azobenzene-p-isothiocyanate (ABITC). The ionic strengths ranged from 0.5 to 100 mM and the protein concentrations were 3 to 50 g/L. A single diffusive component was observed above 25 mM salt, but at lower ionic strengths two components were resolved. Also, electrophoresis combined with holographic relaxation spectroscopy (EHRS) showed two components. A photoionization model, in which the net charge of the BSA-ABITC molecule is altered by the writing laser pulse, is proposed to explain the results. The coupled diffusion problem for the bleached and unbleached macroions and the counter and coions is solved to obtain the concentration and ionic strength dependences of the diffusion coefficients. Also, effective diffusion coefficients for the components in EHRS are obtained. Overall, there is good agreement between this simple model and experiment; however, the macroion charges required in the theory are roughly a factor of two lower than those found by titration and electrolysis.

  15. Albumin adsorption on CoCrMo alloy surfaces

    NASA Astrophysics Data System (ADS)

    Yan, Yu; Yang, Hongjuan; Su, Yanjing; Qiao, Lijie

    2015-12-01

    Proteins can adsorb on the surface of artificial joints immediately after being implanted. Although research studying protein adsorption on medical material surfaces has been carried out, the mechanism of the proteins’ adsorption which affects the corrosion behaviour of such materials still lacks in situ observation at the micro level. The adsorption of bovine serum albumin (BSA) on CoCrMo alloy surfaces was studied in situ by AFM and SKPFM as a function of pH and the charge of CoCrMo alloy surfaces. Results showed that when the specimens were uncharged, hydrophobic interaction could govern the process of the adsorption rather than electrostatic interaction, and BSA molecules tended to adsorb on the surfaces forming a monolayer in the side-on model. Results also showed that adsorbed BSA molecules could promote the corrosion process for CoCrMo alloys. When the surface was positively charged, the electrostatic interaction played a leading role in the adsorption process. The maximum adsorption occurred at the isoelectric point (pH 4.7) of BSA.

  16. Albumin adsorption on CoCrMo alloy surfaces

    PubMed Central

    Yan, Yu; Yang, Hongjuan; Su, Yanjing; Qiao, Lijie

    2015-01-01

    Proteins can adsorb on the surface of artificial joints immediately after being implanted. Although research studying protein adsorption on medical material surfaces has been carried out, the mechanism of the proteins’ adsorption which affects the corrosion behaviour of such materials still lacks in situ observation at the micro level. The adsorption of bovine serum albumin (BSA) on CoCrMo alloy surfaces was studied in situ by AFM and SKPFM as a function of pH and the charge of CoCrMo alloy surfaces. Results showed that when the specimens were uncharged, hydrophobic interaction could govern the process of the adsorption rather than electrostatic interaction, and BSA molecules tended to adsorb on the surfaces forming a monolayer in the side-on model. Results also showed that adsorbed BSA molecules could promote the corrosion process for CoCrMo alloys. When the surface was positively charged, the electrostatic interaction played a leading role in the adsorption process. The maximum adsorption occurred at the isoelectric point (pH 4.7) of BSA. PMID:26673525

  17. Determination of drugs in plasma samples by disposable pipette extraction with C18-BSA phase and liquid chromatography-tandem mass spectrometry.

    PubMed

    Pinto, Mônia Ap Lemos; de Souza, Israel D; Queiroz, Maria Eugênia C

    2017-05-30

    This work describes restricted access material (RAM) constituted of porous octadecylsilane particles with the outer surface covered with bovine serum albumin (C18-BSA) as a stationary phase to extract drugs from plasma samples by disposable pipette extraction (DPX) for further analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The C18-BSA phase simultaneously excluded macromolecules by chemical diffusion barrier (BSA network) and enrichment of the interior phase (C18) with drug traces by sorption. The hydrophilic barrier of the C18-BSA allows small molecules (drugs) to permeate through the hydrophobic part (C18), while at the same time it excludes the macromolecules by chemical diffusion barrier (BSA network). Optimization of the DPX variables (sorption equilibration time, exclusion of endogenous compounds, and elution step) improved the sensitivity and selectivity of the method, which presented a linear range from the lower limit of quantification (0.5-20.0ngmL(-1)) to the upper limit of quantification (32.5-10,500ngmL(-1)), inter- and intra-assay precision with coefficients of variation (CV) lower than 15%, and relative standard error (RSE) of the accuracy ranging from -12% to 11%. The developed method was successfully used to determine five antipsychotics (olanzapine, quetiapine, clozapine, haloperidol, and chlorpromazine) in combination with seven antidepressants (mirtazapine, paroxetine, citalopram, sertraline, imipramine, clomipramine, and fluoxetine), two anticonvulsants (carbamazepine and lamotrigine), and two anxiolytics (diazepam and clonazepam) in plasma samples from schizophrenic patients for therapeutic drug monitoring.

  18. Bovine serum albumin: survival and osmolarity effect in bovine spermatozoa stored above freezing point.

    PubMed

    Nang, C F; Osman, K; Budin, S B; Ismail, M I; Jaffar, F H F; Mohamad, S F S; Ibrahim, S F

    2012-05-01

    Liquid nitrogen preservation in remote farms is a limitation. The goal of this study was to determine optimum temperature above freezing point for bovine spermatozoa preservation using bovine serum albumin (BSA) as a supplementation. Pooled semen sample from three ejaculates was subjected to various BSA concentration (1, 4, 8 and 12 mg ml(-1)), before incubation in different above freezing point temperatures (4, 25 and 37 °C). Viability assessment was carried out against time from day 0 (fresh sample) until all spermatozoa become nonviable. Optimal condition for bovine spermatozoa storage was at 4 °C with 1 mg ml(-1) BSA for almost 7 days. BSA improved bovine spermatozoa viability declining rate to 44.28% at day 4 and 57.59% at day 7 compared to control, with 80.54% and 98.57% at day 4 and 7 respectively. Increase in BSA concentration did not improve sperm viability. Our results also confirmed that there was a strong negative correlation between media osmolarity and bovine spermatozoa survival rate with r = 0.885, P < 0.0001. Bovine serum albumin helps to improve survival rate of bovine spermatozoa stored above freezing point.

  19. Bovine serum albumin-sodium alkyl sulfates bioconjugates as drug delivery systems.

    PubMed

    Benkő, M; Varga, N; Sebők, D; Bohus, G; Juhász, Á; Dékány, I

    2015-06-01

    Precipitation of bovine serum albumin (BSA) by anionic surfactants with alkyl chains of increasing lengths (octyl, decyl, dodecyl sulfates) was studied at room temperature, at pH 3.0, in isotonic sodium chloride solution. The particle size of albumin, the zeta potential, the surface charge and fluorescent properties of BSA-surfactant composites were investigated concerning addition of increasing amount of surfactant. The thermal stability of the systems was monitored by calorimetric analysis (DSC). The formation of the well-ordered structure in the self-assembly process in liquid phase was studied by XRD measurement. The structure of the precipitated BSA-surfactant nanocomposites was characterized by small-angle X-ray scattering (SAXS). Finally, ibuprofen (IBU) molecules were enclosed in BSA-surfactant bioconjugate systems and the release properties of the drug were investigated. It has been found out that, as a consequence to the increasing number of carbon atoms in the alkyl chains of the surfactant, the structure and the fluorescent properties of the aggregates formed can be controlled due to the increase in the hydrophobicity of BSA-surfactant composites. The bioconjugates are well applicable as carrier to realize controlled release of drug molecules.

  20. Spectroscopic study on the interaction of bovine serum albumin with zinc(II) phthalocyanine.

    PubMed

    Li, Yejing; Wang, Yi; Wang, Ao; Lu, Shan; Zhou, Lin; Zhou, Jiahong; Lin, Yun; Wei, Shaohua

    2015-12-01

    The interaction between the photosensitive antitumour drug, 2(3),9(10),16(17),23(24)-tetra-(((2-aminoethylamino)methyl)phenoxy)phthalocyaninato-zinc(II) (ZnPc) and bovine serum albumin (BSA) has been investigated using various spectroscopic methods. This work may provide some useful information for understanding the interaction mechanism of anticancer drug-albumin binding and gain insight into the biological activity and metabolism of the drug in blood. Based on analysis of the fluorescence spectra, ZnPc could quench the intrinsic fluorescence of BSA and the quenching mechanism was static by forming a ground state complex. Meanwhile, the Stern-Volmer quenching constant (KSV), binding constant (Kb), number of binding sites (n) and thermodynamic parameters were obtained. Results showed that the interaction of ZnPc with BSA occurred spontaneously via hydrogen bond and van der Waal's force. According to Foster's non-radioactive energy transfer theory, the energy transfer from BSA to ZnPc occurred with high possibility. Synchronous fluorescence and circular dichroism (CD) spectra also demonstrated that ZnPc induced the secondary structure of and conformation changes in BSA, especially α helix.

  1. Interaction of bovine serum albumin with starch nanoparticles prepared by TEMPO-mediated oxidation.

    PubMed

    Fan, Haoran; Ji, Na; Zhao, Mei; Xiong, Liu; Sun, Qingjie

    2015-01-01

    The objective of this study was to elucidate the interaction of starch nanoparticles prepared through TEMPO oxidation (TEMPO-SNPs) with protein (bovine serum albumin) by various spectroscopic techniques and transmission electron microscopy (TEM). The enhanced absorbance observed by UV spectra and the decrease in fluorescence spectroscopy of bovine serum albumin (BSA) induced by TEMPO-SNPs demonstrated the occurrence of an interaction between BSA and TEMPO-SNPs. The quenching constant was inversely correlated with temperature, showing that the quenching effect of TEMPO-SNPs was static quenching. Electrostatic force had a leading contribution to the binding roles of BSA on TEMPO-SNPs, which was confirmed by negative enthalpy change and positive entropy change. When interacting with TEMPO-SNPs at different concentrations, the content of the α-helix structure in BSA decreased and β-sheet and random coil structures increased, indicating that TEMPO-SNPs had an effect on the secondary conformation of BSA. Furthermore, TEM images suggested that nanoparticle-protein complexes were formed.

  2. The effect of methylamine on the solution structures of human and bovine serum albumins

    NASA Astrophysics Data System (ADS)

    Hamdani, S.; Joly, D.; Carpentier, R.; Tajmir-Riahi, H. A.

    2009-11-01

    Serum albumins are the major soluble protein constituents of the circulatory system and have many physiological functions including transporting a variety of compounds. Methylamine, a monoamine with one positive charge complexes with protein and alters protein secondary structure. The aim of this study was to examine the interactions of human serum albumin (HSA) and bovine serum albumin (BSA) with methylamine at physiological conditions, using constant protein concentration and various monoamine concentrations. FTIR, UV-vis, CD and fluorescence spectroscopic methods were used to analyse methylamine binding mode, the binding constant and the effects of monoamine on HSA and BSA stability and conformations. Structural analysis showed that methylamine binds HSA and BSA via hydrophilic (polypeptide and amine polar groups) and hydrophobic interactions with overall binding constants of Kmet-HSA = 2.42 (±0.5) × 10 2 M -1 and Kmet-BSA = 1.34 (±0.3) × 10 3 M -1 with the number of bound methylamine around one molecule per protein. Methylamine complexation alters protein conformation by major reduction of α-helix and increase in random coil and turn structures indicating a partial protein unfolding.

  3. Optimization and evaluation of a thermoresponsive ophthalmic in situ gel containing curcumin-loaded albumin nanoparticles

    PubMed Central

    Lou, Jie; Hu, Wenjing; Tian, Rui; Zhang, Hua; Jia, Yuntao; Zhang, Jingqing; Zhang, Liangke

    2014-01-01

    This study aimed to optimize and evaluate a thermoresponsive ophthalmic in situ gel containing curcumin-loaded albumin nanoparticles (Cur-BSA-NPs-Gel). Albumin nanoparticles were prepared via a desolvation method, and the gels were prepared via a cold method. The central composite design and response surface method was used to evaluate the effects of varying Pluronic® F127 and Pluronic® F68 concentrations on the sol–gel transition temperature, which is an indicator of optimum formulations. The optimized formulation was a free-flowing liquid below 30.9°C that transformed into a semi-solid gel above 34.2°C after dilution with simulated tear fluid. Results of the in vitro release and erosion behavior study indicated that Cur-BSA-NPs-Gel achieved superior sustained-release effects and that incorporation of albumin nanoparticles exerted minimal effects on the gel structure. In addition, in vivo ophthalmic experiments employing Cur-BSA-NPs-Gel were subsequently performed in rabbits. In vivo eye irritation results showed that Cur-BSA-NPs-Gel might be considered safe for ophthalmic drug delivery. The in vivo study also revealed that the formulation could significantly increase curcumin bioavailability in the aqueous humor. In conclusion, the optimized in situ gel formulation developed in this work has significant potential for ocular application. PMID:24904211

  4. Concentration-dependent reversible self-oligomerization of serum albumins through intermolecular β-sheet formation.

    PubMed

    Bhattacharya, Arpan; Prajapati, Roopali; Chatterjee, Surajit; Mukherjee, Tushar Kanti

    2014-12-16

    Proteins inside a cell remain in highly crowded environments, and this often affects their structure and activity. However, most of the earlier studies involving serum albumins were performed under dilute conditions, which lack biological relevance. The effect of protein-protein interactions on the structure and properties of serum albumins at physiological conditions have not yet been explored. Here, we report for the first time the effect of protein-protein and protein-crowder interactions on the structure and stability of two homologous serum albumins, namely, human serum albumin (HSA) and bovine serum albumin (BSA), at physiological conditions by using spectroscopic techniques and scanning electron microscopy (SEM). Concentration-dependent self-oligomerization and subsequent structural alteration of serum albumins have been explored by means of fluorescence and circular dichroism spectroscopy at pH 7.4. The excitation wavelength (λex) dependence of the intrinsic fluorescence and the corresponding excitation spectra at each emission wavelength indicate the presence of various ground state oligomers of serum albumins in the concentration range 10-150 μM. Circular dichroism and thioflavin T binding assay revealed formation of intermolecular β-sheet rich interfaces at high protein concentration. Excellent correlations have been observed between β-sheet content of both the albumins and fluorescence enhancement of ThT with protein concentrations. SEM images at a concentration of 150 μM revealed large dispersed self-oligomeric states with sizes vary from 330 to 924 nm and 260 to 520 nm for BSA and HSA, respectively. The self-oligomerization of serum albumins is found to be a reversible process; upon dilution, these oligomers dissociate into a native monomeric state. It has also been observed that synthetic macromolecular crowder polyethylene glycol (PEG 200) stabilizes the self-associated state of both the albumins which is contrary to expectations that the

  5. Protections of bovine serum albumin protein from damage on functionalized graphene-based electrodes by flavonoids.

    PubMed

    Sun, Bolu; Gou, Yuqiang; Xue, Zhiyuan; Zheng, Xiaoping; Ma, Yuling; Hu, Fangdi; Zhao, Wanghong

    2016-05-01

    A sensitive electrochemical sensor based on bovine serum albumin (BSA)/poly (diallyldimethylammonium chloride) (PDDA) functionalized graphene nanosheets (PDDA-G) composite film modified glassy carbon electrode (BSA/PDDA-G/GCE) had been developed to investigate the oxidative protein damage and protections of protein from damage by flavonoids. The performance of this sensor was remarkably improved due to excellent electrical conductivity, strong adsorptive ability, and large effective surface area of PDDA-G. The BSA/PDDA-G/GCE displayed the greatest degree of BSA oxidation damage at 40 min incubation time and in the pH 5.0 Fenton reagent system (12.5 mM FeSO4, 50 mM H2O2). The antioxidant activities of four flavonoids had been compared by fabricated sensor based on the relative peak current ratio of SWV, because flavonoids prevented BSA damage caused by Fenton reagent and affected the BSA signal in a solution containing Co(bpy)3(3+). The sensor was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). UV-vis spectrophotometry and FTIR were also used to investigate the generation of hydroxyl radical and BSA damage, respectively. On the basis of results from electrochemical methods, the order of the antioxidant activities of flavonoids is as follows: (+)-catechin>kaempferol>apigenin>naringenin. A novel, direct SWV analytical method for detection of BSA damage and assessment of the antioxidant activities of four flavonoids was developed and this electrochemical method provided a simple, inexpensive and rapid detection of BSA damage and evaluation of the antioxidant activities of samples.

  6. Interaction between bovine serum albumin and equimolarly mixed cationic-anionic surfactants decyltriethylammonium bromide-sodium decyl sulfonate.

    PubMed

    Lu, Run-Chao; Cao, Ao-Neng; Lai, Lu-Hua; Zhu, Bu-Yao; Zhao, Guo-Xi; Xiao, Jin-Xin

    2005-03-25

    The interactions of bovine serum albumin (BSA) with the anionic surfactant sodium decylsulfonate (C10SO3), the cationic surfactant decyltriethylammonium bromide (C10NE) and equimolarly mixed cationic-anionic surfactants C10NE-C10SO3 were investigated by surface tension, viscosity, dynamic light scattering (DLS) and circular dichroism (CD). It was shown that the single ionic surfactant C10SO3 or C10NE has obvious interaction with BSA. The presence of C10SO3 or C10NE modified BSA structure. However, the equimolarly mixed cationic-anionic surfactants C10NE-C10SO3 showed very weak interactions with BSA. The surface tension-log concentration (gamma-logC) plot for the aqueous solutions of C10NE-C10SO3/BSA mixtures coincided with that of C10NE-C10SO3 solutions. Viscometry showed that there is no significant change in the rheological properties for the C10NE-C10SO3/BSA mixed solutions. DLS showed that BSA monomers and mixed aggregates of C10NE-C10SO3 existed in the C10NE-C10SO3/BSA mixed solutions. From CD spectra no obvious modification of BSA structure in the presence of C10NE-C10SO3 mixtures was observed. The weak interactions between BSA and C10NE-C10SO3 might be explained in terms of the very low critical micelle concentration (cmc) of C10NE-C10SO3 mixtures that made the concentration of ionic surfactant monomers much lower than that needed for inducing the modification of BSA structure. In other words, the very strong synergism between oppositely charged cationic and anionic surfactants makes the formation of cationic-anionic surfactant mixed aggregates in the bulk solution a more favorable process than binding to proteins.

  7. Red-blood-cell-like BSA/Zn3(PO4)2 hybrid particles: Preparation and application to adsorption of heavy metal ions

    NASA Astrophysics Data System (ADS)

    Zhang, Baoliang; Li, Peitao; Zhang, Hepeng; Li, Xiangjie; Tian, Lei; Wang, Hai; Chen, Xin; Ali, Nisar; Ali, Zafar; Zhang, Qiuyu

    2016-03-01

    A novel kind of red-blood-cell-like bovine serum albumin (BSA)/Zn3(PO4)2 hybrid particle is prepared at room temperature by a facile and rapid one-step method based on coordination between BSA and zinc ion. The morphology of the monodisperse hybrid particle shows oblate spheroidal type with a one sided single hole on the surface. The hybrid particle is constructed with BSA/Zn3(PO4)2 nanoplates of 35 nm thick. The average particle size of hybrid particle is 2.3 μm, and its BET specific surface area is 146.64 cm2/g. To clarify the evolution of BSA/Zn3(PO4)2 hybrid particle, SEM and elemental analysis as a function of particle growth time are investigated. The formation mechanism of BSA/Zn3(PO4)2 hybrid particle, which can be described as crystallization, coordination and self-assembly process, is illustrated in detail. The as-prepared BSA/Zn3(PO4)2 hybrid particle is used for adsorption of Cu2+. The hybrid particle displayed excellent adsorption properties on Cu2+. The adsorption efficiency of BSA/Zn3(PO4)2 hybrid particles at 5 min and 30 min are 86.33% and 98.9%, respectively. The maximum adsorption capacity is 6.85 mg/g. Thus, this kind of novel adsorbent shows potential application value in ultra-fast and highly efficient removal of Cu2+.

  8. Quarter variation and correlations of colostrum albumin, immunoglobulin G1 and G2 in dairy cows.

    PubMed

    Samarütel, Jaak; Baumrucker, Craig R; Gross, Josef J; Dechow, Chad D; Bruckmaier, Rupert M

    2016-05-01

    A high variation in immunoglobulin G1 (IgG1) concentration in first milked quarter colostrum has been reported, but BSA quarter colostrum variation is not known. The occurrence of serum albumin in milk has been attributed to increased blood-milk barrier penetration. Reports of serum albumin binding to the Fc Receptor of the neonate, the receptor thought to be responsible for IgG1 transcytosis, suggested that a correlation with the appearance of IgG1 in colostrum of dairy cows was likely. The objective of the study was to establish the quarter colostrum concentration and mass of immunoglobulins and serum albumin. First colostrum was quarter collected within 4 h of parturition from healthy udders of 31 multiparous dairy cows. Individual quarter colostrum weight was determined and a sample of each was frozen for subsequent analysis. Concentrations of immunoglobulin G1, G2, and BSA were measured by ELISA and total mass of components was calculated. In addition, colostrum was also analysed for L-lactate dehydrogenase activity. Analysis of concentration and mass of BSA, immunoglobulin G1, G2 established that the quarter variations were different by cow, quarter and quarter within cow. Partial correlations corrected for colostrum weight indicated that BSA and IgG2 concentration and mass are closely correlated while that of BSA and IgG1 concentration and mass exhibited no correlation suggesting that BSA and IgG1 may have different transport mechanisms. Interestingly, immunoglobulin G1 and G2 concentration and mass exhibited strong correlations suggesting that also some unknown mechanism of immunoglobulin G2 appearance in colostrum is occurring. Finally, no measured protein exhibited any correlation with the activity of lactate dehydrogenase in colostrum.

  9. Carbon nanotubes induce secondary structure changes of bovine albumin in aqueous phase.

    PubMed

    Yang, Man; Meng, Jie; Mao, Xiaobo; Yang, Yang; Cheng, Xuelian; Yuan, Hui; Wang, Chen; Xu, Haiyan

    2010-11-01

    Interaction of nanomaterials to protein molecules is one of the most important issues to deeply understand the influences of the nanomaterials upon physiological processes and protein functions. So far most of investigations focused on the protein molecules adsorbed on the nanomaterials surface, less is known about those in the aqueous phase (not absorbed). In this work, luminescent spectroscopy analysis, circular dichroism measurement, atomic force microscopy, matrix-assisted laser desorption/ionization time of flight mass spectrometry, isoelectric focusing and sulfate polyacrylamide gel electrophoresis were used to investigate the influence of oxidized water-soluble multiwalled carbon nanotubes (CNT) dispersing in aqueous solution upon the structures of bovine serum albumin (BSA) through co-incubation. We focused on BSA molecules that stayed in the aqueous phase instead of those adsorbed by CNT. Experimental results show that the fractions of beta-sheet decreased from 33.3% to 29.8% and beta-turn increased from 2% to 5% in reference with native BSA. There was a slight increase of alpha-helix and a slight reduction of random coil. BSA molecules that had been encountered with CNT and were left in the solution formed a loose and flatten morphology on graphite substrates instead of their native tight and round morphology observed by AFM. The value of isoelectric point for BSA after exposed to CNT moved towards to a higher pH position compared with native BSA. All together, it was concluded that the oxidized water-soluble multiwalled carbon nanotubes not only adsorb bovine serum albumin molecules to their surface, but also induces albumin molecules in the aqueous solution undergo secondary structure changes, which lead to a conformation change.

  10. Protein Crystal Serum Albumin

    NASA Technical Reports Server (NTRS)

    1998-01-01

    As the most abundant protein in the circulatory system albumin contributes 80% to colloid osmotic blood pressure. Albumin is also chiefly responsible for the maintenance of blood pH. It is located in every tissue and bodily secretion, with extracellular protein comprising 60% of total albumin. Perhaps the most outstanding property of albumin is its ability to bind reversibly to an incredible variety of ligands. It is widely accepted in the pharmaceutical industry that the overall distribution, metabolism, and efficiency of many drugs are rendered ineffective because of their unusually high affinity for this abundant protein. An understanding of the chemistry of the various classes of pharmaceutical interactions with albumin can suggest new approaches to drug therapy and design. Principal Investigator: Dan Carter/New Century Pharmaceuticals

  11. Advanced Glycation End Products Modulate Structure and Drug Binding Properties of Albumin.

    PubMed

    Awasthi, Saurabh; Murugan, N Arul; Saraswathi, N T

    2015-09-08

    The extraordinary ligand binding properties of albumin makes it a key player in the pharmacokinetics and pharmacodynamics of many vital drugs. Albumin is highly susceptible for nonenzymatic glycation mediated structural modifications, and there is a need to determine structural and functional impact of specific AGEs modifications. The present study was aimed toward determining the AGE mediated structure and function changes, primarily looking into the effect on binding affinity of drugs in the two major drug binding sites of albumin. The impact of the two most predominant AGEs modifications, i.e., carboxyethyllysine (CEL) and argpyrimidine (Arg-P), was studied on the basis of the combination of in vitro and in silico experiments. In vitro studies were carried out by AGEs modification of bovine serum albumin (BSA) for the formation of Arg-P and CEL followed by drug interaction studies. In silico studies involved molecular dynamics (MD) simulations and docking studies for native and AGEs modified BSAs. In particular the side chain modification was specifically carried out for the residues in the drug binding sites, i.e., Arg-194, Arg-196, Arg-198, and Arg-217, and Lys-204 (site I) and Arg-409 and Lys-413 (site II). The equilibrated structures of native BSA (n-BSA) and glycated BSA (G-BSA) as obtained from MD were used for drug binding studies using molecular docking approach. It was evident from the results of both in vitro and in silico drug interaction studies that AGEs modification results in the reduced drug binding affinity for tolbutamide (TLB) and ibuprofen (IBP) in sites I and II. Moreover, the AGEs modification mediated conformational changes resulted in the shallow binding pockets with reduced accessibility for drugs.

  12. Single Particle Dynamic Imaging and Fe3+ Sensing with Bright Carbon Dots Derived from Bovine Serum Albumin Proteins

    PubMed Central

    Yang, Qingxiu; Wei, Lin; Zheng, Xuanfang; Xiao, Lehui

    2015-01-01

    In this work, we demonstrated a convenient and green strategy for the synthesis of highly luminescent and water-soluble carbon dots (Cdots) by carbonizing carbon precursors, i.e., Bovine serum albumin (BSA) nanoparticles, in water solution. Without post surface modification, the as-synthesized Cdots exhibit fluorescence quantum yield (Q.Y.) as high as 34.8% and display superior colloidal stability not only in concentrated salt solutions (e.g. 2 M KCl) but also in a wide range of pH solutions. According to the FT-IR measurements, the Cdots contain many carboxyl groups, providing a versatile route for further chemical and biological functionalization. Through conjugation of Cdots with the transacting activator of transcription (TAT) peptide (a kind of cell penetration peptide (CPP)) derived from human immunodeficiency virus (HIV), it is possible to directly monitor the dynamic interactions of CPP with living cell membrane at single particle level. Furthermore, these Cdots also exhibit a dosage-dependent selectivity toward Fe3+ among other metal ions, including K+, Na+, Mg2+, Hg2+, Co2+, Cu2+, Pb2+ and Al3+. We believed that the Cdots prepared by this strategy would display promising applications in various areas, including analytical chemistry, nanomedicine, biochemistry and so on. PMID:26634992

  13. Single Particle Dynamic Imaging and Fe3+ Sensing with Bright Carbon Dots Derived from Bovine Serum Albumin Proteins.

    PubMed

    Yang, Qingxiu; Wei, Lin; Zheng, Xuanfang; Xiao, Lehui

    2015-12-04

    In this work, we demonstrated a convenient and green strategy for the synthesis of highly luminescent and water-soluble carbon dots (Cdots) by carbonizing carbon precursors, i.e., Bovine serum albumin (BSA) nanoparticles, in water solution. Without post surface modification, the as-synthesized Cdots exhibit fluorescence quantum yield (Q.Y.) as high as 34.8% and display superior colloidal stability not only in concentrated salt solutions (e.g. 2 M KCl) but also in a wide range of pH solutions. According to the FT-IR measurements, the Cdots contain many carboxyl groups, providing a versatile route for further chemical and biological functionalization. Through conjugation of Cdots with the transacting activator of transcription (TAT) peptide (a kind of cell penetration peptide (CPP)) derived from human immunodeficiency virus (HIV), it is possible to directly monitor the dynamic interactions of CPP with living cell membrane at single particle level. Furthermore, these Cdots also exhibit a dosage-dependent selectivity toward Fe(3+) among other metal ions, including K(+), Na(+), Mg(2+), Hg(2+), Co(2+), Cu(2+), Pb(2+) and Al(3+). We believed that the Cdots prepared by this strategy would display promising applications in various areas, including analytical chemistry, nanomedicine, biochemistry and so on.

  14. Single Particle Dynamic Imaging and Fe3+ Sensing with Bright Carbon Dots Derived from Bovine Serum Albumin Proteins

    NASA Astrophysics Data System (ADS)

    Yang, Qingxiu; Wei, Lin; Zheng, Xuanfang; Xiao, Lehui

    2015-12-01

    In this work, we demonstrated a convenient and green strategy for the synthesis of highly luminescent and water-soluble carbon dots (Cdots) by carbonizing carbon precursors, i.e., Bovine serum albumin (BSA) nanoparticles, in water solution. Without post surface modification, the as-synthesized Cdots exhibit fluorescence quantum yield (Q.Y.) as high as 34.8% and display superior colloidal stability not only in concentrated salt solutions (e.g. 2 M KCl) but also in a wide range of pH solutions. According to the FT-IR measurements, the Cdots contain many carboxyl groups, providing a versatile route for further chemical and biological functionalization. Through conjugation of Cdots with the transacting activator of transcription (TAT) peptide (a kind of cell penetration peptide (CPP)) derived from human immunodeficiency virus (HIV), it is possible to directly monitor the dynamic interactions of CPP with living cell membrane at single particle level. Furthermore, these Cdots also exhibit a dosage-dependent selectivity toward Fe3+ among other metal ions, including K+, Na+, Mg2+, Hg2+, Co2+, Cu2+, Pb2+ and Al3+. We believed that the Cdots prepared by this strategy would display promising applications in various areas, including analytical chemistry, nanomedicine, biochemistry and so on.

  15. Enantiomeric separations using bovine serum albumin immobilized on ion-exchange stationary phases

    SciTech Connect

    Jacobson, S.C.; Guiochon, G. |

    1992-07-01

    Bovine serum albumin (BSA) can be readily immobilized on ion-exchange stationary phases by frontal analysis of a proper solution. This provides a simple means of adjusting the amount of BSA contained in the column and of measuring it accurately. Although the immobilization is ionic and not covalent, the columns are stable for extensive periods of time. If needed, they can be easily regenerated by the same frontal analysis procedure. Results for the separation of various organic compounds on these columns are reported. 11 refs., 3 figs., 2 tabs.

  16. Bovine serum albumin detection and quantitation based on capacitance measurements of liquid crystals

    NASA Astrophysics Data System (ADS)

    Lin, Chi-Hao; Lee, Mon-Juan; Lee, Wei

    2016-08-01

    Liquid crystal (LC)-based biosensing is generally limited by the lack of accurate quantitative strategies. This study exploits the unique electric capacitance properties of LCs to establish quantitative assay methods for bovine serum albumin (BSA) biomolecules. By measuring the voltage-dependent electric capacitance of LCs under an alternating-current field with increasing amplitude, positive correlations were derived between the BSA concentration and the electric capacitance parameters of LCs. This study demonstrates that quantitative analysis can be achieved in LC-based biosensing through electric capacitance measurements extensively employed in LCD research and development.

  17. Exploring the binding mechanism of ondansetron hydrochloride to serum albumins: spectroscopic approach.

    PubMed

    B, Sandhya; Hegde, Ashwini H; K C, Ramesh; J, Seetharamappa

    2012-02-01

    The mechanism of interaction of ondansetron hydrochloride (OND) to serum albumins [bovine serum albumin (BSA) and human serum albumin (HSA)] was studied for the first time employing fluorimetric, circular dichroism, FTIR and UV-vis absorption techniques under the simulated physiological conditions. Fluorimetric results were utilized to investigate the binding and conformational characteristics of protein upon interaction with varying concentrations of the drug. Higher binding constant values revealed the strong interaction between the drug and protein while the number of binding sites close to unity indicated single class of binding site for OND in protein. Thermodynamic results revealed that both hydrogen bond and hydrophobic interactions played a major role in stabilizing drug-protein complex. Site marker competitive experiments indicated that the OND bound to albumins at subdomin II A (Sudlow's site I). Further, the binding distance between OND and serum albumin was calculated based on the Förster's theory of non-radioactive energy transfer and found to be 2.30 and 3.41 nm, respectively for OND-BSA and OND-HSA. The circular dichroism data revealed that the presence of OND decreased the α-helix content of serum albumins. 3D-fluorescence results also indicated the conformational changes in protein upon interaction with OND. Further, the effects of some cations have been investigated in the interaction of drug to protein.

  18. Exploring the binding mechanism of ondansetron hydrochloride to serum albumins: Spectroscopic approach

    NASA Astrophysics Data System (ADS)

    Sandhya, B.; Hegde, Ashwini H.; K. C., Ramesh; Seetharamappa, J.

    2012-02-01

    The mechanism of interaction of ondansetron hydrochloride (OND) to serum albumins [bovine serum albumin (BSA) and human serum albumin (HSA)] was studied for the first time employing fluorimetric, circular dichroism, FTIR and UV-vis absorption techniques under the simulated physiological conditions. Fluorimetric results were utilized to investigate the binding and conformational characteristics of protein upon interaction with varying concentrations of the drug. Higher binding constant values revealed the strong interaction between the drug and protein while the number of binding sites close to unity indicated single class of binding site for OND in protein. Thermodynamic results revealed that both hydrogen bond and hydrophobic interactions played a major role in stabilizing drug-protein complex. Site marker competitive experiments indicated that the OND bound to albumins at subdomin II A (Sudlow's site I). Further, the binding distance between OND and serum albumin was calculated based on the Förster's theory of non-radioactive energy transfer and found to be 2.30 and 3.41 nm, respectively for OND-BSA and OND-HSA. The circular dichroism data revealed that the presence of OND decreased the α-helix content of serum albumins. 3D-fluorescence results also indicated the conformational changes in protein upon interaction with OND. Further, the effects of some cations have been investigated in the interaction of drug to protein.

  19. Epicutaneous immunization with DNP-BSA induces CD4+ CD25+ Treg cells that inhibit Tc1-mediated CS.

    PubMed

    Majewska-Szczepanik, Monika; Zemelka-Wiącek, Magdalena; Ptak, Włodzimierz; Wen, Li; Szczepanik, Marian

    2012-09-01

    As we have shown previously that protein antigen applied epicutaneously (EC) in mice inhibits TNP-specific Th1-mediated contact sensitivity (CS), we postulated that the maneuver of EC immunization might also suppress Tc1-dependent CS response. Here we showed that EC immunization of normal mice with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA) applied on the skin in the form of a patch induces a state of subsequent unresponsiveness due to regulatory T cells (Treg) that inhibited sensitization and elicitation of effector T-cell responses. Suppression is transferable in vivo by TCRαβ(+) CD4(+) CD25(+) lymphocytes harvested from lymph nodes (LNs) of skin-patched animals. Flow cytometry revealed that EC immunization with DNP-BSA increased TCRαβ(+) CD4(+) CD25(+) FoxP3(+) lymphocytes in subcutaneous LNs, suggesting that observed suppression was mediated by Treg cells. Further, in vitro experiments showed that EC immunization with DNP-BSA prior to 1-fluoro-2,4-dinitrobenzen sensitization suppressed LN cell proliferation and inhibited production of TNF-α, IL-12 and IFN-γ. Using a transwell system or anti-CTLA-4 mAb, we found that EC induced suppression required direct Treg-effector cell contact and is CTLA-4-dependent.

  20. Nickel(II)-Schiff base complex recognizing domain II of bovine and human serum albumin: Spectroscopic and docking studies

    NASA Astrophysics Data System (ADS)

    Ray, Aurkie; Koley Seth, Banabithi; Pal, Uttam; Basu, Samita

    It has been spectroscopically monitored that a mononuclear nickel(II)-Schiff base complex {[NiL]·CH3OH = NSC} exhibits greater binding affinity for bovine serum albumin (BSA) than that of its human counterpart (HSA). Moreover the modes of binding of NSC with the two serum albumins also differ significantly. Docking studies predict a relatively rare type of 'superficial binding' of NSC at domain IIB of HSA with certain mobility whereas for BSA such phenomena has not been detected. The mobile nature of NSC at domain IIB of HSA has been well correlated with the spectroscopic results. It is to be noted that thermodynamic parameters for the NSC interaction also differ for the two serum albumins. Occurrence of energy transfer between the donor (Trp of BSA and HSA) and acceptor (NSC) has been obtained by means of Förster resonance energy transfer (FRET). The protein stability on NSC binding has also been experimented by the GuHCl-induced protein unfolding studies. Interestingly it has been found that NSC-HSA interaction enhances the protein stability whereas NSC-BSA binding has no such impact. Such observations are indicative of the fact that the conformation of NSC is responsible in recognizing the two serum albumins and selectively enhancing protein stability.

  1. Nickel(II)-Schiff base complex recognizing domain II of bovine and human serum albumin: spectroscopic and docking studies.

    PubMed

    Ray, Aurkie; Seth, Banabithi Koley; Pal, Uttam; Basu, Samita

    2012-06-15

    It has been spectroscopically monitored that a mononuclear nickel(II)-Schiff base complex {[NiL]·CH(3)OH=NSC} exhibits greater binding affinity for bovine serum albumin (BSA) than that of its human counterpart (HSA). Moreover the modes of binding of NSC with the two serum albumins also differ significantly. Docking studies predict a relatively rare type of 'superficial binding' of NSC at domain IIB of HSA with certain mobility whereas for BSA such phenomena has not been detected. The mobile nature of NSC at domain IIB of HSA has been well correlated with the spectroscopic results. It is to be noted that thermodynamic parameters for the NSC interaction also differ for the two serum albumins. Occurrence of energy transfer between the donor (Trp of BSA and HSA) and acceptor (NSC) has been obtained by means of Förster resonance energy transfer (FRET). The protein stability on NSC binding has also been experimented by the GuHCl-induced protein unfolding studies. Interestingly it has been found that NSC-HSA interaction enhances the protein stability whereas NSC-BSA binding has no such impact. Such observations are indicative of the fact that the conformation of NSC is responsible in recognizing the two serum albumins and selectively enhancing protein stability.

  2. Cotton Study: Albumin Binding and its Effect on Elastase Activity in the Chronic Non-healing Wound

    SciTech Connect

    Castro, Nathan J.; Goheen, Steven C.

    2005-12-01

    A comparative examination of two methods, the classical- and chromatographic, commonly used to study adsorption isotherms is presented. Both methods were used to study the solid/liquid interface of two different derivatives of cotton fiber and bovine serum albumin (BSA).

  3. Immunochemistry of bovine serum albumin.

    PubMed

    Habeeb, A F

    1978-01-01

    Two fragments were isolated from BSA one was derived from the first terminal third of the molecule and the second from the last third of the molecule. Each fragment inhibited the reaction of BSA-anti BSA by 90% or better. An immunoabsorbent of each bound 90% of anti BSA. Each fragment bound two antibody molecules per mole of fragment. These results are explained by the concept that BSA contains repeating identical or similar antigenic determinants. Conformational non identity of various batches of BSA was revealed by reactivity of the disulfide bonds at the neutral transition. Trypsin was found to cleave GSA, PSA, and HSA to yield an immunochemically reactive fragment. At least in the case of HSA, the fragment exhibited all the immunochemical reactivity of the native protein.

  4. Spectroscopic studies on the interaction of bovine serum albumin with surfactants and apigenin

    NASA Astrophysics Data System (ADS)

    Zhao, Xu-Na; Liu, Yi; Niu, Li-Yuan; Zhao, Chen-Ping

    The binding of apigenin (Ap) to bovine serum albumin (BSA) has been studied using the methods of fluorescence spectroscopy and UV-vis absorption spectroscopy. The spectroscopic analysis of the quenching mechanism indicates that the quenching constants are inversely correlated with the temperatures and the quenching process could result from a static interaction. The type of interaction force was discussed and the binding site of Ap was in site I (subdomain IIA) of BSA. The thermodynamic parameters ΔH and ΔS are -42.02 kJ mol-1 and -48.31 J mol-1 K-1, respectively and the negative ΔG implying that the binding interaction was spontaneous. The distance r between BSA and Ap was calculated according to Förster's theory and the value is 3.44 nm. The synchronous and three-dimensional fluorescence spectra show that the binding of Ap to BSA could lead to the changes in the conformation and microenvironment of BSA. At the same time, the effects of ionic surfactants on the interaction of Ap and BSA have also been investigated.

  5. Study on the interaction between antibacterial drug and bovine serum albumin: A spectroscopic approach

    NASA Astrophysics Data System (ADS)

    Naik, P. N.; Chimatadar, S. A.; Nandibewoor, S. T.

    2009-09-01

    The binding of sulfamethoxazole (SMZ) to bovine serum albumin (BSA) was investigated by spectroscopic methods viz., fluorescence, FT-IR and UV-vis absorption techniques. The binding parameters have been evaluated by fluorescence quenching method. The thermodynamic parameters, Δ H°, Δ S°and Δ G° were observed to be -58.0 kJ mol -1, -111 J K -1 mol -1 and -24 kJ mol -1, respectively. These indicated that the hydrogen bonding and weak van der Waals forces played a major role in the interaction. Based on the Forster's theory of non-radiation energy transfer, the binding average distance, r, between the donor (BSA) and acceptor (SMZ) was evaluated and found to be 4.12 nm. Spectral results showed the binding of SMZ to BSA induced conformational changes in BSA. The effect of common ions and some of the polymers used in drug delivery for control release was also tested on the binding of SMZ to BSA. The effect of common ions revealed that there is adverse effect on the binding of SMZ to BSA.

  6. Analysis of the hydration water around bovine serum albumin using terahertz coherent synchrotron radiation.

    PubMed

    Bye, Jordan W; Meliga, Stefano; Ferachou, Denis; Cinque, Gianfelice; Zeitler, J Axel; Falconer, Robert J

    2014-01-09

    Terahertz spectroscopy was used to study the absorption of bovine serum albumin (BSA) in water. The Diamond Light Source operating in a low alpha mode generated coherent synchrotron radiation that covered a useable spectral bandwidth of 0.3-3.3 THz (10-110 cm(-1)). As the BSA concentration was raised, there was a nonlinear change in absorption inconsistent with Beer's law. At low BSA concentrations (0-1 mM), the absorption remained constant or rose slightly. Above a concentration of 1 mM BSA, a steady decrease in absorption was observed, which was followed by a plateau that started at 2.5 mM. Using a overlapping hydration layer model, the hydration layer was estimated to extend 15 Å from the protein. Calculation of the corrected absorption coefficient (αcorr) for the water around BSA by subtracting the excluded volume of the protein provides an alternative approach to studying the hydration layer that provides evidence for complexity in the population of water around BSA.

  7. Effects of titania nanotubes with or without bovine serum albumin loaded on human gingival fibroblasts.

    PubMed

    Liu, Xiangning; Zhou, Xiaosong; Li, Shaobing; Lai, Renfa; Zhou, Zhiying; Zhang, Ye; Zhou, Lei

    2014-01-01

    Modifying the surface of the transmucosal area is a key research area because this process positively affects the three functions of implants: attachment to soft tissue, inhibiting bacterial biofilm adhesion, and the preservation of the crestal bone. To exploit the potential of titania nanotube arrays (TNTs) with or without using bovine serum albumin (BSA) to modify the surface of a dental implant in contact with the transmucosal area, BSA was loaded into TNTs that were fabricated by anodizing Ti sheets; the physical characteristics of these arrays, including their morphology, chemical composition, surface roughness, contact angle, and surface free energy (SFE), were assessed. The effect of Ti surfaces with TNTs or TNTs-BSA on human gingival fibroblasts (HGFs) was determined by analyzing cell morphology, early adhesion, proliferation, type I collagen (COL-1) gene expression, and the extracellular secretion of COL-1. The results indicate that early HGF adhesion and spreading behavior is positively correlated with surface characteristics, including hydrophilicity, SFE, and surface roughness. Additionally, TNT surfaces not only promoted early HGF adhesion, but also promoted COL-1 secretion. BSA-loaded TNT surfaces promoted early HGF adhesion, while suppressing late proliferation and COL-1 secretion. Therefore, TNT-modified smooth surfaces are expected to be applicable for uses involving the transmucosal area. Further study is required to determine whether BSA-loaded TNT surfaces actually affect closed loop formation of connective tissue because BSA coating actions in vivo are very rapid.

  8. Locating the binding sites of Pb(II) ion with human and bovine serum albumins.

    PubMed

    Belatik, Ahmed; Hotchandani, Surat; Carpentier, Robert; Tajmir-Riahi, Heidar-Ali

    2012-01-01

    Lead is a potent environmental toxin that has accumulated above its natural level as a result of human activity. Pb cation shows major affinity towards protein complexation and it has been used as modulator of protein-membrane interactions. We located the binding sites of Pb(II) with human serum (HSA) and bovine serum albumins (BSA) at physiological conditions, using constant protein concentration and various Pb contents. FTIR, UV-visible, CD, fluorescence and X-ray photoelectron spectroscopic (XPS) methods were used to analyse Pb binding sites, the binding constant and the effect of metal ion complexation on HSA and BSA stability and conformations. Structural analysis showed that Pb binds strongly to HSA and BSA via hydrophilic contacts with overall binding constants of K(Pb-HSA) = 8.2 (±0.8)×10(4) M(-1) and K(Pb-BSA) = 7.5 (±0.7)×10(4) M(-1). The number of bound Pb cation per protein is 0.7 per HSA and BSA complexes. XPS located the binding sites of Pb cation with protein N and O atoms. Pb complexation alters protein conformation by a major reduction of α-helix from 57% (free HSA) to 48% (metal-complex) and 63% (free BSA) to 52% (metal-complex) inducing a partial protein destabilization.

  9. Binding thermodynamics of synthetic dye Allura Red with bovine serum albumin.

    PubMed

    Lelis, Carini Aparecida; Hudson, Eliara Acipreste; Ferreira, Guilherme Max Dias; Ferreira, Gabriel Max Dias; da Silva, Luis Henrique Mendes; da Silva, Maria do Carmo Hespanhol; Pinto, Maximiliano Soares; Pires, Ana Clarissa Dos Santos

    2017-02-15

    The interaction between Allura Red and bovine serum albumin (BSA) was studied in vitro at pH 7.4. The fluorescence quenching was classified as static quenching due to the formation of AR-BSA complex, with binding constant (K) ranging from 3.26±0.09 to 8.08±0.0610(4)L.mol(-1), at the warfarin binding site of BSA. This complex formation was driven by increasing entropy. Isothermal titration calorimetric measurements also showed an enthalpic contribution. The Allura Red diffusion coefficient determined by the Taylor-Aris technique corroborated these results because it reduced with increasing BSA concentration. Interfacial tension measurements showed that the AR-BSA complex presented surface activity, since interfacial tension of the water-air interface decreased as the colorant concentration increased. This technique also provided a complexation stoichiometry similar to those obtained by fluorimetric experiments. This work contributes to the knowledge of interactions between BSA and azo colorants under physiological conditions.

  10. Characterization of the binding of nevadensin to bovine serum albumin by optical spectroscopic technique

    NASA Astrophysics Data System (ADS)

    Yu, Zhaolian; Li, Daojin; Ji, Baoming; Chen, Jianjun

    2008-10-01

    Binding of nevadensin to bovine serum albumin (BSA) has been studied in detail at 298 and 310 K using spectrophotometric technique. The intrinsic fluorescence of BSA was strongly quenched by the addition of nevadensin and spectroscopic observations are mainly rationalized in terms of a static quenching process at lower concentration of nevadensin ( Cdrug/ CBSA < 1) and a combined quenching process at higher concentration of nevadensin ( Cdrug/ CBSA > 1). The binding parameters for the reaction at a pH above (7.40) or below (3.40) the isoelectric point have been calculated according to the double logarithm regression curve. The thermodynamic parameters Δ H0, Δ G0, Δ S0 at different temperatures and binding mechanism of nevadensin to BSA at pH 7.40 and 3.40 were evaluated. The binding ability of nevadensin to BSA at pH 7.40 was stronger than that at pH 3.40. Steady fluorescence, synchronous fluorescence and circular dichroism (CD) were applied to investigate protein conformation. A value of 2.15 nm for the average distance r between nevadensin (acceptor) and tryptophan residues (Trp) of BSA (donor) was derived from the fluorescence resonance energy transfer. Moreover, influence of pH on the interaction nevadensin with BSA was investigated.

  11. Functionalized polypropylene non-woven fabric membrane with bovine serum albumin and its hemocompatibility enhancement.

    PubMed

    Zhang, Chang; Jin, Jing; Zhao, Jie; Jiang, Wei; Yin, Jinghua

    2013-02-01

    Bovine serum albumin (BSA) was successfully immobilized onto polypropylene non-woven fabric (PP(NWF)) membranes using poly(acrylic acid) (PAA) as a spacer. Firstly, O(2) plasma treatment and UV-irradiated technique were combined to graft PAA onto the membranes. BSA was then immobilized onto the PAA grafted surface through the coupling of amino groups of BSA to the carboxyl groups of PAA. The immobilization of PAA and BSA onto the membrane was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and water contact angle measurement. The water contact angle measurement results revealed that the membrane hydrophilicity improved after modification with PAA and BSA. After BSA immobilization, the amount of protein adsorption and the number of platelet adhesion on the modified membrane significantly decreased, which indicated that hemocompatibility had been considerably improved compared with neat and PAA grafted PP(NWF). The whole blood clotting time measurement showed that the anticoagulant property of the modified membrane was also significantly enhanced.

  12. Fluorescent bovine serum albumin interacting with the antitussive quencher dextromethorphan: a spectroscopic insight.

    PubMed

    Durgannavar, Amar K; Patgar, Manjanath B; Nandibewoor, Sharanappa T; Chimatadar, Shivamurti A

    2016-05-01

    The interaction of dextromethorphan hydrobromide (DXM) with bovine serum albumin (BSA) is studied by using fluorescence spectra, UV-vis absorption, synchronous fluorescence spectra (SFS), 3D fluorescence spectra, Fourier transform infrared (FTIR) spectroscopy and circular dichroism under simulated physiological conditions. DXM effectively quenched the intrinsic fluorescence of BSA. Values of the binding constant, K(A), are 7.159 × 10(3), 9.398 × 10(3) and 16.101 × 10(3)  L/mol; the number of binding sites, n, and the corresponding thermodynamic parameters ΔG°, ΔH° and ΔS° between DXM and BSA were calculated at different temperatures. The interaction between DXM and BSA occurs through dynamic quenching and the effect of DXM on the conformation of BSA was analyzed using SFS. The average binding distance, r, between the donor (BSA) and acceptor (DXM) was determined based on Förster's theory. The results of fluorescence spectra, UV-vis absorption spectra and SFS show that the secondary structure of the protein has been changed in the presence of DXM.

  13. Swelling and mechanical properties of biopolymer hydrogels containing chitosan and bovine serum albumin.

    PubMed

    Butler, Michael F; Clark, Allan H; Adams, Sarah

    2006-11-01

    Experimental and theoretical investigations of the swelling and mechanical properties of hydrogels formed from chitosan, bovine serum albumin (BSA), and chitosan/BSA mixtures cross-linked with genipin were performed. The properties of cross-linked chitosan hydrogels were explained in terms of its polyelectrolyte behavior, which led to a gradual increase in swelling ratio below the pK value, but whereby its swelling ability was eliminated by the presence of salt that screened the charges. Comparison of theoretical and experimental calculations of the swelling ratio, however, indicated that complications arising from wastage of cross-links, and formation of polymerized genipin cross-links must be considered before quantitative prediction can be achieved. Cross-linked BSA hydrogels swelled even in the presence of salt, and a marked increase in swelling was observed below pH = 3 that was explained as the result of an acid induced denaturation of the protein that led to unfolding of the molecule. Swollen BSA hydrogels were mechanically weak, however. Composite gels made from a cross-linked mixture of chitosan and BSA exhibited the swelling behavior of BSA combined with the mechanical properties of chitosan and were therefore considered most suitable for use in a gastric environment.

  14. Characterization of erythrosine B binding to bovine serum albumin and bilirubin displacement.

    PubMed

    Mathavan, Vinodaran M K; Boh, Boon Kim; Tayyab, Saad

    2009-08-01

    The interaction of crythrosine B (ErB), a commonly used dye for coloring foods and drinks, with bovine scrum albumin (BSA) was investigated both in the absence and presence of bilirubin (BR) using absorption and absorption difference spectroscopy. ErB binding to BSA was reflected from a significant red shift of 11 nm in the absorption maximum of ErB (527 nm) with the change in absorbance at lamdamax. Analysis of absorption difference spectroscopic titration results of BSA with increasing concentrations of ErB3 using Benesi-Hildebrand equation gave the association constant, K as 6.9 x 10(4) M(-1). BR displacing action of ErB was revealed by a significant blue shift in the absorption maximum, accompanied by a decrease in absorbance difference at lamdamax in the difference spectrum of BR-BSA complex upon addition of increasing concentrations of ErB. This was further substantiated by fluorescence spectroscopy, as addition of increasing concentrations of ErB to BR-BSA complex caused a significant decrease in fluoresccnce at 510 nm. The results suggest that ErB binds to a site in the vicinity of BR binding site on BSA. Therefore, intake of ErB may increase the risk of hyperbilirubinemia in the healthy subjects.

  15. Effects of titania nanotubes with or without bovine serum albumin loaded on human gingival fibroblasts

    PubMed Central

    Liu, Xiangning; Zhou, Xiaosong; Li, Shaobing; Lai, Renfa; Zhou, Zhiying; Zhang, Ye; Zhou, Lei

    2014-01-01

    Modifying the surface of the transmucosal area is a key research area because this process positively affects the three functions of implants: attachment to soft tissue, inhibiting bacterial biofilm adhesion, and the preservation of the crestal bone. To exploit the potential of titania nanotube arrays (TNTs) with or without using bovine serum albumin (BSA) to modify the surface of a dental implant in contact with the transmucosal area, BSA was loaded into TNTs that were fabricated by anodizing Ti sheets; the physical characteristics of these arrays, including their morphology, chemical composition, surface roughness, contact angle, and surface free energy (SFE), were assessed. The effect of Ti surfaces with TNTs or TNTs-BSA on human gingival fibroblasts (HGFs) was determined by analyzing cell morphology, early adhesion, proliferation, type I collagen (COL-1) gene expression, and the extracellular secretion of COL-1. The results indicate that early HGF adhesion and spreading behavior is positively correlated with surface characteristics, including hydrophilicity, SFE, and surface roughness. Additionally, TNT surfaces not only promoted early HGF adhesion, but also promoted COL-1 secretion. BSA-loaded TNT surfaces promoted early HGF adhesion, while suppressing late proliferation and COL-1 secretion. Therefore, TNT-modified smooth surfaces are expected to be applicable for uses involving the transmucosal area. Further study is required to determine whether BSA-loaded TNT surfaces actually affect closed loop formation of connective tissue because BSA coating actions in vivo are very rapid. PMID:24623977

  16. Investigating the influence of effective parameters on molecular characteristics of bovine serum albumin nanoparticles

    NASA Astrophysics Data System (ADS)

    Rohiwal, S. S.; Satvekar, R. K.; Tiwari, A. P.; Raut, A. V.; Kumbhar, S. G.; Pawar, S. H.

    2015-04-01

    The protein nanoparticles formulation is a challenging task as they are prone to undergo conformational transitions while processing which may affect bioavailability for bioactive compounds. Herein, a modified desolvation method is employed to prepare Bovine Serum Albumin nanoparticles, with controllable particle size ranging from 100 to 300 nm and low polydispersity index. The factors influencing the size and structure of BSA NPs viz. protein concentration, pH and the conditions for purification are well investigated. The structure of BSA NPs is altered due to processing, and may affect the effective binding ability with drugs and bioactive compounds. With that aims, investigations of molecular characteristics of BSA NPs are carried out in detail by using spectroscopic techniques. UV-visible absorption and Fourier Transform Infrared demonstrate the alteration in protein structure of BSA NPs whereas the FT-Raman spectroscopy investigates changes in the secondary and tertiary structures of the protein. The conformational changes of BSA NPs are observed by change in fluorescence intensity and emission maximum wavelength of tryptophan residue by fluorescence spectroscopy. The field emission scanning electron and atomic force microscopy micrographs confirm the size and semi-spherical morphology of the BSA NPs. The effect of concentration and pH on particle size distribution is studied by particle size analyzer.

  17. Pulse radiolytic study of the oxidation reactions of uric acid in presence of bovine serum albumin. Evidence of possible complex formation in the transient state

    NASA Astrophysics Data System (ADS)

    Adhikari, S.; Joshi, R.; Gopinathan, C.

    1997-01-01

    The pulse radiolytic and spectrophotometric study of uric acid in presence of bovine serum albumin (BSA) has been carried out. In the spectrophotometric study there is no evidence for ground state interaction between BSA and uric acid. The oxidation reactions of uric acid in presence and absence of BSA employing CCl 3OO and Br radicals have been carried out. In a composition of equal concentration of uric acid and BSA, the CCl 3OO and Br radicals produce a transient absorption spectrum which show two peaks at 330 and 360 nm. The peak at 360 nm is ascribed due to weak complex formation between semioxidised BSA and uric acid radicals. The rate constant of CCl 3OO . radical with uric acid increases with the increase in BSA concentration which is explained as protection of BSA by uric acid from radical attack. The Br radical attacks uric acid and BSA in a manner similar to CCl 3OO radical. The bimolecular rate constants for the reaction of Br radical with BSA and uric acid have been found as 2.9 × 10 10 dm 3 mol -1 s -1 and 6.33 × 10 9 dm 3 mol -1 s -, respectively.

  18. Structure of Serum Albumin

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; Ho, Joseph X.

    1994-01-01

    Because of its availability, low cost, stability, and unusual ligand-binding properties, serum albumin has been one of the mst extensively studied and applied proteins in biochemistry. However, as a protein, albumin is far from typical, and the widespread interest in and application of albumin have not been balanced by an understanding of its molecular structure. Indeed, for more than 30 years structural information was surmised based solely on techniques such as hydrodynamics, low-angle X-ray scattering, and predictive methods.

  19. Synthesis of a silica-bonded bovine serum albumin s-triazine chiral stationary phase for high-performance liquid chromatographic resolution of enantiomers.

    PubMed

    Zhang, Q; Zou, H; Wang, H; Ni, J

    2000-01-14

    A novel method of synthesizing protein chiral stationary phase (protein-CSP) is proposed with 2,4,6-trichloro-1,3,5-triazine as the activator. The bovine serum albumin (BSA) based chiral columns (150 x 4.6 mm I.D.) were prepared successfully within 8 h. With tryptophan as the probe solute, it was observed that the BSA immobilized by this method had a better ability to distinguish enantiomers than that activated by glutaric dialdehyde. This may be due to the well-maintained BSA conformation and the larger amount of BSA immobilized on the silica gel. The BSA-CSP prepared by this method was relatively stable under experimental conditions, and the resolution of 13 chiral compounds was achieved. The coupling reaction in this method is mild, reliable and reproducible; it is also suitable for the immobilization of various biopolymers in the preparation of bioreactor, biosensor and affinity chromatography columns.

  20. Photodynamic performance of zinc phthalocyanine in HeLa cells: A comparison between DPCC liposomes and BSA as delivery systems.

    PubMed

    M Garcia, Angélica; de Alwis Weerasekera, Hasitha; Pitre, Spencer P; McNeill, Brian; Lissi, Eduardo; Edwards, Ana M; Alarcon, Emilio I

    2016-10-01

    Comparable intracellular concentrations (≈30pmol/10(6) cells) of bovine serum albumin-ZnPc (BSA) adduct outperformed dipalmitoyl-phosphatidyl-choline (DPPC) liposomes containing ZnPc at photodynamic-killing of human cervical cancer cells (HeLa) after only 15min of irradiation using red light (λ>620nm, 30W/cm(2)). This result could not be simply explained in terms of dye aggregation within the carrier, since in the liposomes the dye was considerably less aggregated than in bovine serum albumin, formulation that was capable to induce cell apoptosis upon red light exposure. Thus, using specific organelle staining, our cumulative data points towards intrinsic differences in intra-cellular localization depending on the cargo vehicle used, being ZnPc:BSA preferentially located in the near vicinity of the nucleus and in the Golgi structures, while the liposomal formulation ZnPc:DPPC was preferentially located in cellular membrane and cytoplasm. In addition to those differences, using real-time advanced fluorescence lifetime imaging of HeLa cells loaded with the photosensitizer contained in the different vehicles, we have found that only for the ZnPc:BSA formulation, there was no significant changes in the fluorescence lifetime of the photosensitizer inside the cells. This contrasts with the in situ≈two-fold reduction of the fluorescence lifetime measured for the liposomal ZnPc formulation. Those observations point towards the superiority of the protein to preserve dye aggregation, and its photochemical activity, post-cell uptake, demonstrating the pivotal role of the delivery vehicle at determining the ultimate fate of a photosensitizer.

  1. Enhanced tumor delivery and antitumor response of doxorubicin-loaded albumin nanoparticles formulated based on a Schiff base.

    PubMed

    Li, Fang; Zheng, Chunli; Xin, Junbo; Chen, Fangcheng; Ling, Hua; Sun, Linlin; Webster, Thomas J; Ming, Xin; Liu, Jianping

    2016-01-01

    A novel method was developed here to prepare albumin-based nanoparticles (NPs) for improving the therapeutic and safety profiles of chemotherapeutic agents. This approach involved crosslinking bovine serum albumin (BSA) using a Schiff base-containing vanillin, into NPs and loading doxorubicin (DOX) into the NPs by incubation. The resultant NPs (DOX-BSA-V-NPs) displayed a particle size of 100.5±1.3 nm with a zeta potential of -23.05±1.45 mV and also showed high drug-loading efficiency and excellent stability with respect to storage and temperature. The encapsulation of DOX into the BSA-V-NPs was confirmed by dynamic scanning calorimetry and Raman spectroscopy. DOX-BSA-V-NPs exhibited a significantly faster DOX release at pH 6.5 than pH 7.4, as well as in a solution with a higher glutathione concentration. In vitro studies showed that the cellular uptake of DOX-BSA-V-NPs was time-dependent, concentration-dependent, and faster than free DOX, while the cytotoxicity of DOX-BSA-V-NPs (IC50 value of 3.693 μg/mL) was superior to free DOX (IC50 value of 4.007 μg/mL). More importantly, DOX-BSA-V-NPs showed a longer mean survival time of 24.83 days, a higher tumor inhibition rate of 56.66%, and a decreased distribution in the heart than other DOX formulations in animal studies using a tumor xenograft model. Thus, the vanillin-based albumin NPs were shown here to be a promising carrier for tumor-targeted delivery of chemotherapeutic agents and, thus, should be further studied.

  2. Enhanced tumor delivery and antitumor response of doxorubicin-loaded albumin nanoparticles formulated based on a Schiff base

    PubMed Central

    Li, Fang; Zheng, Chunli; Xin, Junbo; Chen, Fangcheng; Ling, Hua; Sun, Linlin; Webster, Thomas J; Ming, Xin; Liu, Jianping

    2016-01-01

    A novel method was developed here to prepare albumin-based nanoparticles (NPs) for improving the therapeutic and safety profiles of chemotherapeutic agents. This approach involved crosslinking bovine serum albumin (BSA) using a Schiff base-containing vanillin, into NPs and loading doxorubicin (DOX) into the NPs by incubation. The resultant NPs (DOX-BSA-V-NPs) displayed a particle size of 100.5±1.3 nm with a zeta potential of −23.05±1.45 mV and also showed high drug-loading efficiency and excellent stability with respect to storage and temperature. The encapsulation of DOX into the BSA-V-NPs was confirmed by dynamic scanning calorimetry and Raman spectroscopy. DOX-BSA-V-NPs exhibited a significantly faster DOX release at pH 6.5 than pH 7.4, as well as in a solution with a higher glutathione concentration. In vitro studies showed that the cellular uptake of DOX-BSA-V-NPs was time-dependent, concentration-dependent, and faster than free DOX, while the cytotoxicity of DOX-BSA-V-NPs (IC50 value of 3.693 μg/mL) was superior to free DOX (IC50 value of 4.007 μg/mL). More importantly, DOX-BSA-V-NPs showed a longer mean survival time of 24.83 days, a higher tumor inhibition rate of 56.66%, and a decreased distribution in the heart than other DOX formulations in animal studies using a tumor xenograft model. Thus, the vanillin-based albumin NPs were shown here to be a promising carrier for tumor-targeted delivery of chemotherapeutic agents and, thus, should be further studied. PMID:27574421

  3. Antigenic changes in human albumin caused by reactivity with the occupational allergen diphenylmethane diisocyanate

    PubMed Central

    Wisnewski, Adam V.; Liu, Jian; Redlich, Carrie A.

    2010-01-01

    Diphenylmethane diisocyanate (MDI), the chemical commonly used as a cross-linking agent in commercial polyurethane production, is a well-recognized cause of asthma. Reaction products between MDI and “self” proteins are hypothesized to act as antigens capable of inducing airway inflammation and asthma; however, such MDI antigens remain incompletely understood. We used a variety of analytical methods to characterize the range of MDI–albumin reaction products that form under physiological conditions. Sites of MDI conjugation on antigenic MDI–albumin products, as defined by serum immunoglobulin G (IgG) from MDI-exposed workers, were determined by high-performance liquid chromatography (HPLC) followed by tandem mass spectrometry (MS/MS). The data identified 14 MDI conjugation sites (12 lysines and 2 asparagines) on human albumin and highlight reaction specificity for the second lysine in dilysine (KK) motifs, and this may be a common characteristic of “immune-sensitizing” chemicals. Several of the MDI conjugation sites are not conserved in albumin from other species, and this may suggest species differences in epitope specificity for self protein (albumin)–isocyanate conjugates. The study also describes new applications of contemporary proteomic methodology for characterizing and standardizing MDI–albumin conjugates destined for use in clinical research. PMID:20123080

  4. Interactions of aptamers with sera albumins

    NASA Astrophysics Data System (ADS)

    Cortez, Célia Martins; Silva, Dilson; Silva, Camila M. C.; Missailidis, Sotiris

    2012-09-01

    The interactions of two short aptamers to human and bovine serum albumins were studied by fluorescence spectroscopic techniques. Intrinsic fluorescence of BSA and HSA were measured by selectively exciting their tryptophan residues. Gradual quenching was observed by titration of both proteins with aptamers. Aptamers are oligonucleic acid or peptide molecules that bind a specific target and can be used for both biotechnological and clinical purposes, since they present molecular recognition properties like that commonly found in antibodies. Two aptamers previously selected against the MUC1 tumour marker were used in this study, one selected for the protein core and one for the glycosylated MUC1. Stern-Volmer graphs were plotted and quenching constants were estimated. Plots obtained from experiments carried out at 25 °C and 37 °C showed the quenching of fluorescence of by aptamers to be a collisional phenomenon. Stern-Volmer constants estimated for HSA quenched by aptamer A were 1.68 × 105 (±5 × 103) M-1 at 37 °C, and 1.37 × 105 (±103) M-1 at 25 °C; and quenched by aptamer B were 1.67 × 105 (±5 × 103) M-1 at 37 °C, and 1.32 × 105 (±103) M-1 at 25 °C. Results suggest that the primary binding site for aptamers on albumin is close to tryptophan residues in sub domain IIA.

  5. Conformation of adsorbed bovine serum albumin governing its desorption behavior at alumina-water interfaces.

    PubMed

    Urano, H; Fukuzaki, S

    2000-01-01

    The mode of initial adsorption of bovine serum albumin (BSA) onto positively charged Al2O3 particles was studied as a function of surface coverage (theta). The adsorption isotherm of BSA exhibited saturation (theta = 1) and the existence of an inflection point at theta of 0.82. The relative numbers of ionic groups on a BSA molecule interacting with the Al2O3 surface at various theta were monitored by measuring the relative adsorption density of H+ and OH-, ([gamma(H+) - gamma(OH-)]), for BSA-adsorbed Al2O3 using potentiometric titration. The [gamma(H+) - gamma(OH-)] curves for Al2O3, BSA, and BSA-adsorbed Al2O3 at various KNO3 concentrations showed a common intersection point (cip) which was the pH giving the acid-base equivalence point, respectively. Compared with the cip's of Al2O3 (5.6) and BSA (5.2), the cip's of BSA-adsorbed Al2O3 were situated at points corresponding to more alkaline pH values over the theta range of 0.13 to 1.0. These results suggested that negatively charged groups, mainly carboxyl groups, on the BSA molecule electrostatically interacted with the Al2O3 surface. The degree of shift in the cip increased gradually with increasing theta from 0.13 to 0.70, while it decreased markedly over the theta range of 0.82 to 1.0. The variation in the cip reflected the change in the total number of ion pairs formed between BSA molecules and Al2O3. The initial rates of BSA desorption during alkali cleaning were low and almost constant over the theta range of 0.13 to 0.70, but increased markedly at theta higher than 0.82. It is suggested that the conformational changes of BSA adsorbed on Al2O3, involving changes in the relative magnitude of electrostatic interaction forces, occur discretely at theta of approximately 0.8.

  6. Effect of ionic micellar medium on kinetics and mechanism of oxidation of bovine serum albumin: A pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Joshi, Ravi; Mukherjee, Tulsi

    2010-09-01

    Effect of protein-micelle interaction on bovine serum albumin (BSA) oxidation by trichloromethyl peroxyl radical (CCl 3O 2·) in anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethyl ammonium bromide (CTAB) micellar media has been studied using nanosecond pulse radiolysis technique. Viscosity measurement and light scattering studies have suggested that SDS and CTAB micelles produce BSA-micelle aggregates of different sizes and polydispersity. Oxidation kinetics and transients have been affected both by anionic SDS and cationic CTAB micelles but in a different manner. Tryptophanyl-CCl 3O 2· adduct radical to tyrosyl radical transformation in BSA has been observed in anionic SDS micelles but not in cationic CTAB micelles. Similar studies have also been done with tryptophan and tyrosine amino acids, which undergo oxidation in BSA. The study suggests that Coulombic and hydrophobic interactions between micelles and protein affect the structure of the protein to shield its functional amino acids, like tryptophan and tyrosine, to neutral oxidizing radical.

  7. Comprehensive studies on the nature of interaction between carboxylated multi-walled carbon nanotubes and bovine serum albumin.

    PubMed

    Lou, Kai; Zhu, Zhaohua; Zhang, Hongmei; Wang, Yanqing; Wang, Xiaojiong; Cao, Jian

    2016-01-05

    Herein, the interaction between carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) and bovine serum albumin has been investigated by using circular dichroism, UV-vis, and fluorescence spectroscopic methods and molecular modeling in order to better understand the basic behavior of carbon nanotubes in biological systems. The spectral results showed that MWCNTs-COOH bound to BSA and induced the relatively large changes in secondary structure of protein by mainly hydrophobic forces and π-π stacking interactions. Thermal denaturation of BSA in the presence of MWCNTs-COOH indicated that carbon nanotubes acted as a structure destabilizer for BSA. In addition, the putative binding site of MWCNTs-COOH on BSA was near to domain II. With regard to human health, the present study could provide a better understanding of the biological properties, cytotocicity of surface modified carbon nanotubes.

  8. Biomimetic synthesis of hollow calcium carbonate with the existence of the agar matrix and bovine serum albumin.

    PubMed

    Feng, Jianhua; Wu, Gang; Qing, Chengsong

    2016-01-01

    Proteins play important roles in the process of biomineralization. Vaterite and calcite have been synthesized by the reaction of Na2CO3 and CaCl2 in the bovine serum albumin (BSA) and agar system. The samples have been characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The shape of CaCO3 crystal has been analyzed by scanning electronic microscopy (SEM). The results show that calcite is a single product in the absence of BSA, but the product is a mixture of calcite and vaterite in the presence of BSA. The spheral shell of CaCO3 crystal was obtained when the concentration of BSA increased to 9.0mg/mL.

  9. Spectroscopic analyses and studies on respective interaction of cyanuric acid and uric acid with bovine serum albumin and melamine

    NASA Astrophysics Data System (ADS)

    Chen, Dandan; Wu, Qiong; Wang, Jun; Wang, Qi; Qiao, Heng

    2015-01-01

    In this work, the fluorescence quenching was used to study the interaction of cyanuric acid (CYA) and uric acid (UA) with bovine serum albumin (BSA) at two different temperatures (283 K and 310 K). The bimolecular quenching constant (Kq), apparent quenching constant (Ksv), effective binding constant (KA) and corresponding dissociation constant (KD), binding site number (n) and binding distance (r) were calculated by adopting Stern-Volmer, Lineweaver-Burk, Double logarithm and overlap integral equations. The results show that CYA and UA are both able to obviously bind to BSA, but the binding strength order is BSA + CYA < BSA + UA. And then, the interactions of CYA and UA with melamine (MEL) under the same conditions were also studied by using similar methods. The results indicates that both CYA and UA can bind together closely with melamine (MEL). It is wished that these research results would facilitate the understanding the formation of kidney stones and gout in the body after ingesting excess MEL.

  10. Analysis of binding interaction between pegylated puerarin and bovine serum albumin by spectroscopic methods and dynamic light scattering

    NASA Astrophysics Data System (ADS)

    Yu, Meirong; Ding, Zhishan; Jiang, Fusheng; Ding, Xinghong; Sun, Jinyue; Chen, Suhong; Lv, Guiyuan

    2011-12-01

    The interaction between bovine serum albumin (BSA) and pegylated puerarin (Pur) in aqueous solution was investigated by UV-Vis spectroscopy, fluorescence spectroscopy and circular dichroism spectra (CD), as well as dynamic light scattering (DLS). The fluorescence of BSA was strongly quenched by the binding of pegylated Pur to BSA. The binding constants and the number of binding sites of mPEG 5000-Pur with BSA were 2.67 ± 0.12 and 1.37 ± 0.05 folds larger after pegylating, which were calculated from the data obtained from fluorescence quenching experiments. The enthalpy change (Δ H) and entropy change (Δ S) were calculated to be 4.09 kJ mol -1 and 20.01 J mol -1 K -1, respectively, according to Van't Hoff equation, indicating that the hydrophobic force plays a main role in the binding interaction between pegylated Pur and BSA. In addition, the negative sign for Gibbs free energy change (Δ G) implies that the interaction process is spontaneous. Moreover, the results of synchronous fluorescence and CD spectra demonstrated that the microenvironment and the secondary conformation of BSA were changed. Comparing with Pur, all our data collected indicated that pegylated Pur interacted with BSA in the same way as that of Pur, but docked into the hydrophobic pocket of BSA with more accessibility and stronger binding force. DLS measurements showed monomethoxy polyethylene glycol (mPEG) have an effect on BSA conformation, and revealed that changes in BSA size might be due to increases in binding constant and the absolute values of Δ G after Pur pegylation.

  11. Investigation of the association behaviors between bovine serum albumin and 2-(4-methylphenyl)-3-(N-acetyl)-5-(2,4-dichlorophenoxymethyl)-1,3,4-oxodiazoline.

    PubMed

    Huang, Zhenzhong; Wang, Ruiling; Han, Erwei; Xu, Lifan; Song, Yonghai

    2013-07-01

    The study was designed to examine the interaction between 2-(4-methylphenyl)-3-(N-acetyl)-5-(2,4-dichlorophenoxymethyl)-1,3,4-oxodiazoline (MPNDO) and bovine serum albumin (BSA) under physiological conditions by using fluorescence spectroscopy, ultraviolet absorption spectroscopy, FT-IR spectroscopy and circular dichroism spectroscopy and atomic force microscope. Spectroscopic analysis of the fluorescence emission quenching and ultraviolet absorption revealed that the quenching mechanism of bovine serum albumin by MPNDO was static quenching procedure. The binding constant and binding sites number at different temperatures were measured. The average binding distances between donor (BSA) and acceptor (MPNDO) was estimated to be 1.46 nm (301 K), based on the Föster non-radioactive energy transfer theory. An average size of 3.1 nm had a high proportion and these dots might be ascribed to BSA, some other dots with an average size of 6.6 nm might result from BSA-MPNDO bioconjugates while the average diameter of MPNDO was 1.6 nm, which was reasonable to conclude that one BSA-MPNDO bioconjugates consisted of one BSA and one MPNDO. The thermodynamic parameters, enthalpy change (ΔH), entropy change (ΔS) and free energy change (ΔG) were calculated, which indicated that the action force was mainly van der Waals forces. The data collected through synchronous fluorescence, FT-IR spectroscopy and circular dichroism spectroscopy demonstrated that the conformation of BSA was not affected obviously in the presence of MPNDO.

  12. [Structure of fish serum albumins].

    PubMed

    Andreeva, A M

    2010-01-01

    Data are presented about the presence of serum albumins in fishes of different classes and orders inhabiting different ecological conditions, about structure of typical albumins and albumin-like proteins, and about the degree of homology of these proteins to mammalian albumins. There is shown a wide spectrum of structural diversity of albumins in Pisces due to their participation in osmotic, plastic, and transport functions under conditions of environment and of the organism internal media. Detection of similar motifs in the piscine and mammalian albumin genes allows uniting these genes into one superfamily and considering vertebrate albumins the homologous proteins.

  13. Highly sensitive detection of bovine serum albumin based on the aggregation of triangular silver nanoplates.

    PubMed

    Zhang, Ling Ling; Ma, Fang Fang; Kuang, Yang Fang; Cheng, Shu; Long, Yun Fei; Xiao, Qiu Guo

    2016-02-05

    A simple, fast and highly sensitive spectrophotometric method for the determination of bovine serum albumin (BSA) has been developed based on the interactions between triangular silver nanoplates (TAgNPs) and BSA in the presence of Britton-Robison buffer solution (BR). Particularly, the wavelength of absorption maximum (λ(max)) of TAgNPs is red shifted in the presence of BSA together with Britton-Robinson buffer solution (BR, pH=2.56), and the color of the solution changed from blue to light blue. This may be due to the interactions between BSA molecules on the surface of TAgNPs through electrostatic forces, hydrogen bonds, hydrophobic effects and van der Waals forces at pH2.56, which leads to the aggregation of TAgNPs. The determination of BSA was achieved by measuring the change of λ(max) corresponding to localized surface plasmon resonance (LSPR) from UV-visible spectrophotometry. It was found that the shift value in the wavelength of absorption maximum (Δλ, the difference in absorption maxima of the TAgNPs/BSA/BR mixture and the TAgNPs/BR mixture) was proportionate to the concentration of BSA in the range of 1.0 ng mL(-1) to 100.0 ng mL(-1) with the correlation coefficient of r=0.9969. The detection limit (3 σ/k) for BSA was found to be as low as 0.5 ng mL(-1).

  14. Highly sensitive detection of bovine serum albumin based on the aggregation of triangular silver nanoplates

    NASA Astrophysics Data System (ADS)

    Zhang, Ling Ling; Ma, Fang Fang; Kuang, Yang Fang; Cheng, Shu; Long, Yun Fei; Xiao, Qiu Guo

    2016-02-01

    A simple, fast and highly sensitive spectrophotometric method for the determination of bovine serum albumin (BSA) has been developed based on the interactions between triangular silver nanoplates (TAgNPs) and BSA in the presence of Britton-Robison buffer solution (BR). Particularly, the wavelength of absorption maximum (λmax) of TAgNPs is red shifted in the presence of BSA together with Britton-Robinson buffer solution (BR, pH = 2.56), and the color of the solution changed from blue to light blue. This may be due to the interactions between BSA molecules on the surface of TAgNPs through electrostatic forces, hydrogen bonds, hydrophobic effects and van der Waals forces at pH 2.56, which leads to the aggregation of TAgNPs. The determination of BSA was achieved by measuring the change of λmax corresponding to localized surface plasmon resonance (LSPR) from UV-visible spectrophotometry. It was found that the shift value in the wavelength of absorption maximum (Δλ, the difference in absorption maxima of the TAgNPs/BSA/BR mixture and the TAgNPs/BR mixture) was proportionate to the concentration of BSA in the range of 1.0 ng mL- 1 to 100.0 ng mL- 1 with the correlation coefficient of r = 0.9969. The detection limit (3 σ/k) for BSA was found to be as low as 0.5 ng mL- 1.

  15. Expulsion of bovine serum albumin from the air/water interface by a sparingly soluble lecithin lipid.

    PubMed

    Phang, Tze-Lee; Franses, Elias I

    2004-07-15

    Dynamic surface tensiometry, ellipsometry, and infrared reflection-absorption spectroscopy (IRRAS) were used to study the dynamic adsorption and surface tensions of dilauroylphosphatidylcholine (DLPC) in the presence of bovine serum albumin (BSA). Results show that the equilibrium adsorbed layers consist mostly of DLPC, which can produce dynamic surface tensions (1 mN/m) as low as the more successful lung surfactant replacement formulations. When the aqueous surface expands and contracts sinusoidally, BSA can coadsorb and lead to slightly higher dynamic surface tensions than when DLPC is alone. Similar results were obtained with BSA and sodium myristate [McClellan and Franses, Colloids Surf. B 30 (2003) 1]. Expulsion of the BSA in the layer by DLPC can take from 5 to 15 min, depending on relative concentrations and history of solute addition. This is shown by tensiometry measurements on mixtures, and also by injecting aqueous DLPC underneath adsorbed BSA layers and probing the surface layer with ellipsometry and IRRAS. Albumin layers from buffer solutions aged up to 30 h can be expelled by DLPC. In pure water, there is an initial enhancement in protein adsorption after the DLPC is injected. This can be explained by the hypothesis that DLPC molecules bind with BSA molecules to form a hydrophobic lipoprotein complex, which is more hydrophobic than the protein itself. Since DLPC produces lower surface energy than BSA and--being slightly soluble--adsorbs to the surface by a molecular mechanism, it fulfills the thermodynamic and dynamic requirements for expelling the BSA from the surface. The results have implications for minimizing lung surfactant inhibition by serum proteins, as it occurs in the cases of adult or acute respiratory distress syndrome.

  16. Spectroscopic insight into the interaction of bovine serum albumin with imidazolium-based ionic liquids in aqueous solution.

    PubMed

    Satish, Lakkoji; Millan, Sabera; Sahoo, Harekrushna

    2016-11-03

    The study of protein-ionic liquid interactions is very important because of the widespread use of ionic liquids as protein stabilizer in the recent years. In this work, the interaction of bovine serum albumin (BSA) with different imidazolium-based ionic liquids (ILs) such as [1-ethyl-3-methyl-imidazolium ethyl sulfate (EmimESO4 ), 1-ethyl-3-methyl-imidazolium chloride (EmimCl) and 1-butyl-3-methyl-imidazolium chloride (BmimCl)] has been investigated using different spectroscopic techniques. The intrinsic fluorescence of BSA is quenched by ILs by the dynamic mechanism. The thermodynamic analysis demonstrates that very weak interactions exist between BSA and ILs. 8-Anilino-1-naphthalenesulfonic acid (ANS) fluorescence and lifetime measurements reveal the formation of the compact structure of BSA in IL medium. The conformational changes of BSA were monitored by CD analysis. Temperature-dependent ultraviolet (UV) measurements were done to study the thermal stability of BSA. The thermal stability of BSA in the presence of ILs follows the trend EmimESO4  > EmimCl > BmimCl and in the presence of more hydrophobic IL, destabilization increases rapidly as a function of concentration.

  17. Nanogels fabricated from bovine serum albumin and chitosan via self-assembly for delivery of anticancer drug.

    PubMed

    Wang, Yuntao; Xu, Shasha; Xiong, Wenfei; Pei, Yaqiong; Li, Bin; Chen, Yijie

    2016-10-01

    In this study, bovine serum albumin (BSA) and chitosan (CS) were used to prepare BSA-CS nanogels by a simple green self-assembly technique. Then the nanogels were successfully used to entrap doxorubicin hydrochloride (DOX) with an entrapment ratio of 46.3%, aiming to realize the slow-release effect and lower the cytotoxicity of DOX. The IC50 values of DOX-loaded BSA-CS (DOX-BSA-CS) and free DOX obtained by MTT assay in SGC7901 cells were 0.22 and 0.05μg/mL, respectively. The cytotoxicity of DOX significantly decreased within 24h after encapsulation by the nanogels, indicating that the loaded drug could slowly release within 24h and the BSA-CS was a good slow release system. The cellular uptake experiments indicated DOX-BSA-CS diffused faster into the cancer cell than the bare drug. The flow cytometry and TUNEL assay proved DOX-BSA-CS could induce a larger apoptosis proportion of gastric cancer cells 7901 than the bare drug and it is promising to be used for curing gastric cancer.

  18. Bovine serum albumin bioconjugated graphene oxide: Red blood cell adhesion and hemolysis studied by QCM-D

    NASA Astrophysics Data System (ADS)

    Cai, Bing; Hu, Kebang; Li, Chunming; Jin, Jing; Hu, Yuexin

    2015-11-01

    Graphene oxide (GO) had great potential in various applications especial biomedical materials. In this study, we improved the hemocompatibility especial hemolysis properties of GO nanosheets by grafting bovine serum albumin (BSA). The hemocompatibility of GO-g-BSA was improved. The hemolysis ratio of GO-g-BSA was lower than 0.2% and no visible hemoglobin release was observed. In a flowed condition, the interaction between GO and RBC was monitored real time by quartz crystal microbalance with dissipation (QCM-D) and the hemolysis rates of eluted RBC solution was determined. The balance between the adsorption and degradation of RBC on the surface of GO was a linear process. The GO-g-BSA surface decreased the adhesion of RBC in a flowed condition, maintained the morphology of RBC and reduced the hemolysis rate in the most effective manner. The inert of BSA resisted GO interacting with the lipid bilayers of RBC and the negative charge on the surface of BSA repelled the approach of negative charged RBC. The excellent hemocompatibility of the BSA modified GO might confer its great potentials for various biomedical applications.

  19. The interaction of the phosphorothioate insecticides chlorpyrifos and parathion and their oxygen analogues with bovine serum albumin.

    PubMed

    Sultatos, L G; Basker, K M; Shao, M; Murphy, S D

    1984-07-01

    The distribution and subsequent toxicity of hazardous chemicals can be influenced by their interactions with plasma proteins. In the present study reversible binding of the phosphorothioate insecticides chlorpyrifos and parathion to fatty acid-free bovine serum albumin (BSA) was examined using the technique of equilibrium dialysis. Computer analyses of the binding data revealed that chlorpyrifos and parathion each bound reversibly to a single class of binding sites on BSA, with apparent KD values of 3.4 +/- 0.1 and 11.1 +/- 0.3 microM, respectively. Additionally, the maximal number of binding sites for each insecticide per molecule of BSA was one. Displacement studies using both chlorpyrifos and parathion indicated that each was a competitive inhibitor of the other's binding, suggesting that they were bound to the same site. Incubation of chlorpyrifos oxon or paraoxon with a 1% solution of BSA resulted in limited, EDTA-insensitive formation of 3,5,6-trichloro-2-pyridinol or p-nitrophenol, respectively. Pretreatment of BSA with 5 mM paraoxon, chlorpyrifos oxon, or 1 mM diisopropylfluorophosphate did not alter this activity, suggesting that these reactions resulted from an esterase-like capacity of BSA, and not from phosphorylation of BSA by these oxons.

  20. Effects of bovine serum albumin on boar sperm quality during liquid storage at 17°C.

    PubMed

    Zhang, X-G; Yan, G-J; Hong, J-Y; Su, Z-Z; Yang, G-S; Li, Q-W; Hu, J-H

    2015-04-01

    This study aimed to investigate the effects of bovine serum albumin (BSA) on boar sperm quality during liquid storage at 17°C. Boar semen samples were collected and diluted with Modena containing different concentrations (0, 1, 2, 3, 4, 5 and 6 g/l) of BSA, and sperm motility, plasma membrane integrity, acrosome integrity, total antioxidative capacity (T-AOC) activity and malondialdehyde (MDA) content were measured and analysed. The results showed that Modena supplemented with 3, 4 and 5 g/l BSA could improve boar sperm motility, effective survival time and plasma membrane integrity (p < 0.05), decrease MDA content (p < 0.05), while no statistical difference was observed for sperm acrosome integrity and T-AOC activity among these three groups (p > 0.05). The semen sample diluted with Modena containing 4 g/l BSA could achieve optimum effect, and sperm survival time was 7.5 days. After 7 days preservation, sperm motility, plasma membrane integrity and acrosome integrity were 54%, 49% and 78%, respectively. T-AOC activity and MDA content were 1.03 U/ml and 17.5 nmol/ml, respectively. In conclusion, Modena supplemented with BSA reduced the oxidative stress and improved the sperm quality of boar semen during liquid storage at 17°C, and 4 g/l BSA was the optimum concentration. Further studies are required to obtain more concrete results on the determination of antioxidant capacities of BSA in liquid preserved boar semen.

  1. Chemical treatment and chitosan coating of yeast cells to improve the encapsulation and controlled release of bovine serum albumin.

    PubMed

    Shi, Guorong; Liu, Yating; He, Zijun; Zhou, Jihen

    2016-08-10

    We investigate the encapsulation of bovine serum albumin (BSA) in chemical-treated and chitosan-coated yeast cells, Saccharomyces cerevisiae (S. cerevisiae), for the controlled release of BSA. The chemical treatment can sufficiently enlarge the small-sized cell-wall cavities and/or break the integrity for the entrance of BSA to the interior of yeast cells, and the additional chitosan coating can well prevent the rapid release of encapsulated BSA from the yeast-derived microcapsules. The sodium hydroxide pretreated S. cerevisiae gives a maximum encapsulation yield of (10.1 ± 0.2)% for BSA. An additional coating of S. cerevisiae with chitosan can reduce the initial burst release of BSA and extend the release period from 24 h in the chitosan-free case to 48 h in phosphate buffer at pH 7.4. The prepared microcapsules can well keep the shapes and sizes of yeast cells and thus show uniform sizes of 3.85 ± 0.81 μm. The encapsulated BSA well retains its pristine ultraviolet spectroscopic and chromatographic behaviors. The present microencapsulation protocol has the advantages of convenient and mild operation, high encapsulation efficiency, and organic solvent-free nature, which is of reference value for establishing high-performance controllable biomacromolecule-delivery systems.

  2. In vitro inhibition of human neutrophil elastase by oleic acid albumin formulations from derivatized cotton wound dressings.

    PubMed

    Edwards, J Vincent; Howley, Phyllis; Cohen, I Kelman

    2004-10-13

    Human neutrophil elastase (HNE) is elevated in chronic wounds. Oleic acid albumin formulations that inhibit HNE may be applicable to treatment modalities for chronic wounds. Oleic acid/albumin formulations with mole ratios of 100:1, 50:1, and 25:1 (oleic acid to albumin) were prepared and found to have dose response inhibition properties against HNE. The IC50 values for inhibition of HNE with oleic acid/albumin formulations were 0.029-0.049 microM. Oleic acid/albumin (BSA) formulations were bound to positively and negatively charged cotton wound dressings and assessed for elastase inhibition using a fiber bound formulation in an assay designed to mimic HNE inhibition in the wound. Cotton derivatized with both carboxylate and amine functional groups were combined with oleic acid/albumin formulations at a maximum loading of 0.030 mg oleic acid + 0.14 mg BSA/mg fiber. The IC50 values for inhibition of HNE with oleic acid/albumin formulations bound to derivatized cotton were 0.26-0.42 microM. Release of the oleic acid/albumin formulation from the fiber was measured by measuring oleic acid levels with quantitative GC analysis. Approximately, 35-50% of the fiber bound formulation was released into solution within the first 15 min of incubation. Albumin was found to enhance the rate of elastase hydrolysis of the substrate within a concentration range of 0.3-50 g/L. The acceleration of HNE substrate hydrolysis by albumin required increased concentration of inhibitor in the formulation to obtain complete inhibition of HNE. Oleic acid formulations prepared with albumin enable transport, solubility and promote dose response inhibition of HNE from derivatized cotton fibers under aqueous conditions mimicking the chronic wound.

  3. Biophysical influence of coumarin 35 on bovine serum albumin: Spectroscopic study

    NASA Astrophysics Data System (ADS)

    Bayraktutan, Tuğba; Onganer, Yavuz

    2017-01-01

    The binding mechanism and protein-fluorescence probe interactions between bovine serum albumin (BSA) and coumarin 35 (C35) was investigated by using UV-Vis absorption and fluorescence spectroscopies since they remain major research topics in biophysics. The spectroscopic data indicated that a fluorescence quenching process for BSA-C35 system was occurred. The fluorescence quenching processes were analyzed using Stern-Volmer method. In this regard, Stern-Volmer quenching constants (KSV) and binding constants were calculated at different temperatures. The distance r between BSA (donor) and C35 (acceptor) was determined by exploiting fluorescence resonance energy transfer (FRET) method. Synchronous fluorescence spectra were also studied to observe information about conformational changes. Moreover, thermodynamics parameters were calculated for better understanding of interactions and conformational changes of the system.

  4. Quenching of tryptophan fluorescence of bovine serum albumin under the effect of ions of heavy metals

    NASA Astrophysics Data System (ADS)

    Plotnikova, O. A.; Mel'nikov, A. G.; Mel'nikov, G. V.; Gubina, T. I.

    2016-01-01

    The interaction of heavy metals with bovine serum albumin (BSA) has been studied using data of quenching of intrinsic fluorescence of the protein by the ions of the heavy metals. Under the assumption of static quenching with formation of nonfluorescent complexes of fluorophores of BSA with heavy metals, conclusions have been drawn on the peculiarities of binding of the heavy metals to the protein. The values of the Stern-Volmer constants of association and those of the constants of BSA binding to the heavy metals decrease in the order Cu(II) > Pb(II) > Cd(II). It has been experimentally found that the copper ions have greater capacity to bind to the protein with the formation of the nonfluorescent complexes, which results in a significant decrease in the fluorescence intensity of the protein.

  5. Reactions of trimethylphosphine analogues of auranofin with bovine serum albumin

    SciTech Connect

    Isab, A.A.; Shaw, C.F. III; Hoeschele, J.D.; Locke, J.

    1988-10-05

    The reactions of bovine serum albumin (BSA) with (trimethylphosphine)(2,3,4,6-tetra-O-acetyl-1-thio-..beta..-D-glucopyranosato-S)gold(I), Me/sub 3/PAuSAtg, and its chloro analogue, Me/sub 3/PAuCl, were studied to develop insights into the role of the phosphine ligand in the serum chemistry of the related antiarthritic drug auranofin (triethylphosphine)(2,3,4,6-tetra-O-acetyl-1-thio-..beta..-D-glucopyranosato-S)gold(I). /sup 31/P NMR spectroscopy, protein modification, and gel-exclusion chromatography methods were employed. Comparison of the reactions of the methyl derivatives to the previously reported reactions of auranofin and Et/sub 3/PAuCl with BSA demonstrated that similar chemical species are formed but revealed three major differences. Despite these differences, the results for the methyl analogues provide important confirmation for previously developed chemical models of auranofin reactions in serum. Me/sub 3/PO was not observed in reaction mixtures lacking tetraacetylthioglucose (AtgSH); this result affirms the role of AtgSH, displaced by the reaction of Me/sub 3/PAuSAtg at Cys-34, in the generation of the phosphine oxide (an important metabolite in vivo). The weak binding sites on albumin react with Me/sub 3/PAuCl, but not Me/sub 3/PAuSAtg, demonstrating the importance of the strength and reactivity of the anionic ligand-gold bond on the reactions of auranofin analogues. The gold binding capacity of albumin is enhanced after Me/sub 3/PO is formed, consistent with reductive cleavage of albumin disulfide bonds by trimethylphosphine. 24 references, 2 figures, 3 tables.

  6. The role of nanoparticles in the albumin-cytarabine and albumin-methotrexate interactions.

    PubMed

    Pentak, Danuta; Maciążek-Jurczyk, Małgorzata; Zawada, Zygmunt H

    2017-04-01

    Understanding the interactions which occur between nanomaterials and biomolecules is one of the most important issues in nanotechnology. Determining the properties of nanoparticles obtained through the use of novel methods and defining the scope of their application as drug carriers has important practical significance. Nanoparticles containing methotrexate and cytarabine obtained by a modified reverse-phase evaporation method (mREV) were characterized through the use of the UV/Vis and NMR methods. Obtained results confirmed high degree of analysed drugs encapsulation. The encapsulation efficiencies of cytarabine (AraC) and methotrexate (MTX) in LDPPC/AraC/MTX were found to be 86.30% (AraC) and 86.00% (MTX). The increased permeability of the phospholipid membranes, resulting from physico-chemical properties and the location of the drug, as well as from the physico-chemical properties of the phospholipids themselves, has been confirmed by increase in the length of the T1 relaxation time of protons in the N(+)(CH3)3 group. The study of analysed drugs release process from the liposomes has been made for bovine serum albumin, both in the absence (dBSA) and in the presence of fatty acid (BSA). Moreover two types of kinetic models (Bhaskar equation and Rigter-Peppas equation) have been used. Based on the study it has been concluded that mathematical modelling of drug release can be very helpful in speeding up product development and in better understanding the mechanisms controlling drug release from advanced delivery systems.

  7. Structural and immunologic characterization of bovine, horse, and rabbit serum albumins.

    PubMed

    Majorek, Karolina A; Porebski, Przemyslaw J; Dayal, Arjun; Zimmerman, Matthew D; Jablonska, Kamila; Stewart, Alan J; Chruszcz, Maksymilian; Minor, Wladek

    2012-10-01

    Serum albumin (SA) is the most abundant plasma protein in mammals. SA is a multifunctional protein with extraordinary ligand binding capacity, making it a transporter molecule for a diverse range of metabolites, drugs, nutrients, metals and other molecules. Due to its ligand binding properties, albumins have wide clinical, pharmaceutical, and biochemical applications. Albumins are also allergenic, and exhibit a high degree of cross-reactivity due to significant sequence and structure similarity of SAs from different organisms. Here we present crystal structures of albumins from cattle (BSA), horse (ESA) and rabbit (RSA) sera. The structural data are correlated with the results of immunological studies of SAs. We also analyze the conservation or divergence of structures and sequences of SAs in the context of their potential allergenicity and cross-reactivity. In addition, we identified a previously uncharacterized ligand binding site in the structure of RSA, and calcium binding sites in the structure of BSA, which is the first serum albumin structure to contain metal ions.

  8. Structural and immunologic characterization of bovine, horse, and rabbit serum albumins

    PubMed Central

    Majorek, Karolina A.; Porebski, Przemyslaw J.; Dayal, Arjun; Zimmerman, Matthew D.; Jablonska, Kamila; Stewart, Alan J.; Chruszcz, Maksymilian; Minor, Wladek

    2012-01-01

    Serum albumin (SA) is the most abundant plasma protein in mammals. SA is a multifunctional protein with extraordinary ligand binding capacity, making it a transporter molecule for a diverse range of metabolites, drugs, nutrients, metals and other molecules. Due to its ligand binding properties, albumins have wide clinical, pharmaceutical, and biochemical applications. Albumins are also allergenic, and exhibit a high degree of cross-reactivity due to significant sequence and structure similarity of SAs from different organisms. Here we present crystal structures of albumins from cattle (BSA), horse (ESA) and rabbit (RSA) serums. The structural data are correlated with the results of immunological studies of SAs. We also analyze the conservation or divergence of structures and sequences of SAs in the context of their potential allergenicity and cross-reactivity. In addition, we identified a previously uncharacterized ligand binding site in the structure of RSA, and calcium binding sites in the structure of BSA, which is the first serum albumin structure to contain metal ions. PMID:22677715

  9. Coupling of albumin flux to volume flow in skin and muscles of anesthetized rats

    SciTech Connect

    Renkin, E.M.; Gustafson-Sgro, M.; Sibley, L.

    1988-09-01

    Bovine serum albumin (BSA) labeled with /sup 131/I or /sup 125/I was injected intravenously in pentobarbital sodium-anesthetized rats, and tracer clearances into leg skin and muscles were measured over 30, 60, and 120 min. BSA labeled with the alternate tracer was used as vascular volume reference. Two minutes before injection of the tracer, a ligature was tied around one femoral vein to occlude outflow partially and raise capillary pressure in that leg. The unoccluded leg served as control. Skin and muscles of the occluded leg had variably and substantially higher water contents (delta W) than paired control tissues and slightly but consistently increased albumin clearances (CA). The delta CA/delta W, equivalent to the albumin concentration of capillary filtrate relative to plasma determined by linear regression, were as follows: leg skin 0.004 (95% confidence limits -0.001 to +0.009), muscle biceps femoris 0.005 (0.001-0.010), muscle gastrocnemius 0.011 (0.004-0.019), muscle tibialis anterior 0.016 (0.012-0.021). All these values are significantly less than 0.10, which corresponds to a reflection coefficient for serum albumin (sigma A) of 0.90. Convective coupling of albumin flux to volume flux in skin and muscles of intact, anesthetized rats is low, with sigma AS in the range 0.98 to greater than 0.99.

  10. Probing the binding sites and the effect of berbamine on the structure of bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Cheng, Xiao-Xia; Lui, Yi; Zhou, Bo; Xiao, Xiao-He; Liu, Yi

    2009-06-01

    Berbamine, a naturally occurring isoquinoline alkaloid extracted from Berberis sp., is the active constituent of some Chinese herbal medicines and exhibits a variety of pharmacological activities. The effects of berbamine on the structure of bovine serum albumin