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Sample records for albumin bsa lysozyme

  1. 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.

  2. Forced Desorption of Bovine Serum Albumin and Lysozyme from Graphite: Insights from Molecular Dynamics Simulation.

    PubMed

    Mücksch, Christian; Urbassek, Herbert M

    2016-08-18

    We use molecular dynamics (MD) simulation to study the adsorption and desorption of two widely different proteins, bovine serum albumin (BSA) and lysozyme, on a graphite surface. The adsorption is modeled using accelerated MD to allow the proteins to find optimum conformations on the surface. Our results demonstrate that the "hard protein" lysozyme retains much of its secondary structure during adsorption, whereas BSA loses it almost completely. BSA has a considerably larger adsorption energy compared to that of lysozyme, which does not scale with chain length. Desorption simulations are carried out using classical steered MD. The BSA molecule becomes fully unzipped during pull-off, whereas several helices survive this process in lysozyme. The unzipping process shows up in the force-distance curve of BSA as a series of peaks, whereas only a single or few, depending on protein orientation, force peaks occur for lysozyme. The maximum desorption force is larger for BSA than for lysozyme, but only by a factor of about 2.3.

  3. 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.

  4. Size-dependent interaction of silica nanoparticles with lysozyme and bovine serum albumin proteins

    NASA Astrophysics Data System (ADS)

    Yadav, Indresh; Aswal, Vinod K.; Kohlbrecher, Joachim

    2016-05-01

    The interaction of three different sized (diameter 10, 18, and 28 nm) anionic silica nanoparticles with two model proteins—cationic lysozyme [molecular weight (MW) 14.7 kDa)] and anionic bovine serum albumin (BSA) (MW 66.4 kDa) has been studied by UV-vis spectroscopy, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The adsorption behavior of proteins on the nanoparticles, measured by UV-vis spectroscopy, is found to be very different for lysozyme and BSA. Lysozyme adsorbs strongly on the nanoparticles and shows exponential behavior as a function of lysozyme concentration irrespective of the nanoparticle size. The total amount of adsorbed lysozyme, as governed by the surface-to-volume ratio, increases on lowering the size of the nanoparticles for a fixed volume fraction of the nanoparticles. On the other hand, BSA does not show any adsorption for all the different sizes of the nanoparticles. Despite having different interactions, both proteins induce similar phase behavior where the nanoparticle-protein system transforms from one phase (clear) to two phase (turbid) as a function of protein concentration. The phase behavior is modified towards the lower concentrations for both proteins with increasing the nanoparticle size. DLS suggests that the phase behavior arises as a result of the nanoparticles' aggregation on the addition of proteins. The size-dependent modifications in the interaction potential, responsible for the phase behavior, have been determined by SANS data as modeled using the two-Yukawa potential accounting for the repulsive and attractive interactions in the systems. The protein-induced interaction between the nanoparticles is found to be short-range attraction for lysozyme and long-range attraction for BSA. The magnitude of attractive interaction irrespective of protein type is enhanced with increase in the size of the nanoparticles. The total (attractive+repulsive) potential leading to two-phase formation is found to be

  5. Size-dependent interaction of silica nanoparticles with lysozyme and bovine serum albumin proteins.

    PubMed

    Yadav, Indresh; Aswal, Vinod K; Kohlbrecher, Joachim

    2016-05-01

    The interaction of three different sized (diameter 10, 18, and 28 nm) anionic silica nanoparticles with two model proteins-cationic lysozyme [molecular weight (MW) 14.7 kDa)] and anionic bovine serum albumin (BSA) (MW 66.4 kDa) has been studied by UV-vis spectroscopy, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The adsorption behavior of proteins on the nanoparticles, measured by UV-vis spectroscopy, is found to be very different for lysozyme and BSA. Lysozyme adsorbs strongly on the nanoparticles and shows exponential behavior as a function of lysozyme concentration irrespective of the nanoparticle size. The total amount of adsorbed lysozyme, as governed by the surface-to-volume ratio, increases on lowering the size of the nanoparticles for a fixed volume fraction of the nanoparticles. On the other hand, BSA does not show any adsorption for all the different sizes of the nanoparticles. Despite having different interactions, both proteins induce similar phase behavior where the nanoparticle-protein system transforms from one phase (clear) to two phase (turbid) as a function of protein concentration. The phase behavior is modified towards the lower concentrations for both proteins with increasing the nanoparticle size. DLS suggests that the phase behavior arises as a result of the nanoparticles' aggregation on the addition of proteins. The size-dependent modifications in the interaction potential, responsible for the phase behavior, have been determined by SANS data as modeled using the two-Yukawa potential accounting for the repulsive and attractive interactions in the systems. The protein-induced interaction between the nanoparticles is found to be short-range attraction for lysozyme and long-range attraction for BSA. The magnitude of attractive interaction irrespective of protein type is enhanced with increase in the size of the nanoparticles. The total (attractive+repulsive) potential leading to two-phase formation is found to be

  6. 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

    2015-01-01

    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. PMID:26378511

  7. 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.

  8. 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. PMID:27419617

  9. 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.

  10. 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.

  11. 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.

  12. 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 Central

    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

    2008-01-01

    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°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. PMID:18458031

  13. The studies of density, apparent molar volume, and viscosity of bovine serum albumin, egg albumin, and lysozyme in aqueous and RbI, CsI, and DTAB aqueous solutions at 303.15 K.

    PubMed

    Singh, Man; Chand, Hema; Gupta, K C

    2005-06-01

    Density (rho), apparent molar volume (V(phi)), and viscosity (eta) of 0.0010 to 0.0018% (w/v) of bovine serum albumin (BSA), egg albumin, and lysozyme in 0.0002, 0.0004, and 0.0008 M aqueous RbI and CsI, and (dodecyl)(trimethyl)ammonium bromide (DTAB) solutions were obtained. The experimental data were regressed against composition, and constants are used to elucidate the conformational changes in protein molecules. With salt concentration, the density of proteins is found to decrease, and the order of the effect of additives on density is observed as CsI > RbI > DTAB. The trend of apparent molar volume of proteins is found as BSA > egg-albumin > lysozyme for three additives. In general, eta values of BSA remain higher for all compositions of RbI than that of egg-albumin for CsI and DTAB. These orders of the data indicate the strength of intermolecular forces between proteins and salts, and are helpful for understanding the denaturation of proteins.

  14. Hepatoma-Targeted Radionuclide Immune Albumin Nanospheres: (131)I-antiAFPMcAb-GCV-BSA-NPs.

    PubMed

    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 ((131)I-antiAFPMcAb-GCV-BSA-NPs). In vitro as well as in vivo targeting of (131)I-antiAFPMcAb-GCV-BSA-NPs to AFP-positive hepatoma was examined. In cultured HepG2 cells, the uptake and retention rates of (131)I-antiAFPMcAb-GCV-BSA-NPs were remarkably higher than those of (131)I alone. As well, the uptake rate and retention ratios of (131)I-antiAFPMcAb-GCV-BSA-NPs in AFP-positive HepG2 cells were also significantly higher than those in AFP-negative HEK293 cells. Compared to (131)I alone, (131)I-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 (131)I-antiAFPMcAb-GCV-BSA-NPs are promising for further effective radiation-gene therapy of hepatoma.

  15. 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

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

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    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 ( 1O 2) and hydroxyl radicals ( rad OH) were generated.

  17. Small-angle neutron scattering study of differences in phase behavior of silica nanoparticles in the presence of lysozyme and bovine serum albumin proteins

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    The differences in phase behavior of anionic silica nanoparticles (88 Å) in the presence of two globular proteins [cationic lysozyme (molecular weight (MW) 14.7 kD) and anionic bovine serum albumin (BSA) (MW 66.4 kD)] have been studied by small-angle neutron scattering. The measurements were carried out on a fixed concentration (1 wt %) of Ludox silica nanoparticles with varying concentrations of proteins (0-5 wt %) at pH = 7. It is found that, despite having different natures (opposite charges), both proteins can render to the same kind of aggregation of silica nanoparticles. However, the concentration regions over which the aggregation is observed are widely different for the two proteins. Lysozyme with very small amounts (e.g., 0.01 wt %) leads to the aggregation of silica nanoparticles. On the other hand, silica nanoparticles coexist with BSA as independent entities at low protein concentrations and turn to aggregates at high protein concentrations (>1 wt %). In the case of lysozyme, the charge neutralization by the protein on the nanoparticles gives rise to the protein-mediated aggregation of the nanoparticles. The nanoparticle aggregates coexist with unaggregated nanoparticles at low protein concentrations, whereas, they coexist with a free protein at higher protein concentrations. For BSA, the nonadsorbing nature of the protein produces the depletion force that causes the aggregation of the nanoparticles at higher protein concentrations. The evolution of the interaction is modeled by the two Yukawa potential, taking account of both attractive and repulsive terms of the interaction in these systems. The nanoparticle aggregation is found to be governed by the short-range attraction for lysozyme and the long-range attraction for BSA. The aggregates are characterized by the diffusion limited aggregate type of mass fractal morphology.

  18. 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.

  19. 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.

  20. 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. PMID:26799950

  1. 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.

  2. 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. PMID:26555641

  3. Effect of grafted PEG chain conformation on albumin and lysozyme adsorption: A combined study using QCM-D and DPI.

    PubMed

    Jin, Jing; Han, Yuanyuan; Zhang, Chang; Liu, Jingchuan; Jiang, Wei; Yin, Jinghua; Liang, Haojun

    2015-12-01

    In this study, elucidation of protein adsorption mechanism is performed using dual polarization interferometry (DPI) and quartz crystal microbalance with dissipation (QCM-D) to study adsorption behaviors of bovine serum albumin (BSA) and lysozyme (LYZ) on poly (ethylene glycol) (PEG) layers. From the analysis of DPI, PEG2000 and PEG5000 show tight and loose mushroom conformations, respectively. Small amount of LYZ could displace the interfacial water surrounding the tight mushroomed PEG2000 chains by hydrogen bond attraction, leading to protein adsorption. The loose mushroomed PEG5000 chains exhibit a more flexible conformation and high elastic repulsion energy that could prevent protein adsorption of all BSA and most of LYZ. From the analysis of QCM, PEG2000 and PEG5000 show tight and extended brush conformations. The LYZ adsorbed mass has critical regions of PEG2000 (0.19 chain/nm(2)) and PEG5000 (0.16 chain/nm(2)) graft density. When graft density of PEG is higher than the critical region (brush conformations), the attraction of hydrogen bonds between PEG and LYZ is the dominant factor. When graft density of PEG is lower than the critical region (mushroom conformations), elastic repulsion between PEG and proteins is driven by the high conformation entropy of PEG chains, which is the dominant force of steric repulsion in PEG-protein systems. Therefore, the adsorption of BSA is suppressed by the high elastic repulsion energy of PEG chains, whereas the adsorption of LYZ is balanced by the interactions between the repulsion of entropy elasticity and the attraction of hydrogen bonds.

  4. 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.

  5. 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.

  6. 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.

  7. 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. PMID:27327124

  8. Bovine serum albumin (BSA) can replace patient serum as a protein source in an in vitro fertilization (IVF) program.

    PubMed

    Benadiva, C A; Kuczynski-Brown, B; Maguire, T G; Mastoianni, L; Flickinger, G L

    1989-06-01

    Alternate protein sources have been suggested to replace the commonly used cord or patient serum for in vitro fertilization (IVF) procedures. During an 11-month period 127 patients treated for in vitro fertilization had either their serum (N = 71) or bovine serum albumin (BSA; N = 56) used as the protein source in the insemination and growth media. Ham's F-10 + 0.5% BSA was used for sperm swim-up and insemination media and 1% BSA was used for the growth media. Patient's serum was added to Ham's F-10 culture media at concentrations of 7.5 and 15% for insemination and growth, respectively. Embryo transfer was performed with Ham's F-10 containing 90% maternal serum in both groups. Fertilization rate of 259 oocytes inseminated in medium containing patient's serum did not differ when compared with 200 oocytes inseminated in medium containing BSA. Likewise, rates of abnormal fertilization, cleavage, and pregnancy were similar in both groups. In a second experiment, 148 normally fertilized oocytes were transferred after 24 hr in culture to growth media containing two different concentrations of BSA (0.5 or 1%). Cleavage rates for the two groups were similar and the percentage of embryos developed to greater than or equal to 4 cells did not differ significantly. We conclude that a single concentration of BSA can safely be used to supplement culture media in human IVF with several practical and economical benefits.

  9. Larger red-shift in optical emissions obtained from the thin films of globular proteins (BSA, lysozyme) - polyelectrolyte (PAA) complexes

    NASA Astrophysics Data System (ADS)

    Talukdar, Hrishikesh; Kundu, Sarathi; Basu, Saibal

    2016-09-01

    Globular proteins (lysozyme and BSA) and polyelectrolyte (sodium polyacrylic acid) are used to form protein-polyelectrolyte complexes (PPC). Out-of-plane structures of ≈30-60 nm thick PPC films and their surface morphologies have been studied by using X-ray reflectivity and atomic force microscopy, whereas optical behaviors of PPC and protein conformations have been studied by using UV-vis, photoluminescence and FTIR spectroscopy respectively. Our study reveals that thin films of PPC show a larger red-shift of 23 and 16 nm in the optical emissions in comparison to that of pure protein whereas bulk PPC show a small blue-shift of ≈3 nm. A small amount of peak-shift is found to occur due to the heat treatment or concentration variation of the polyelectrolyte/protein in bulk solution but cannot produce such film thickness independent larger red-shift. Position of the emission peak remains nearly unchanged with the film thickness. Mechanism for such larger red-shift has been proposed.

  10. Binding properties of drospirenone with human serum albumin and lysozyme in vitro

    NASA Astrophysics Data System (ADS)

    Wang, Qing; Ma, Xiangling; He, Jiawei; Sun, Qiaomei; Li, Yuanzhi; Li, Hui

    2016-01-01

    The interaction of drospirenone (DP) with human serum albumin (HSA)/lysozyme (LYZ) was investigated using different optical techniques and molecular models. Results from the emission and time resolved fluorescence studies revealed that HSA/LYZ emission quenching with DP was initiated by static quenching mechanism. The LYZ-DP system was more easily influenced by temperature than the HSA-DP system. Displacement experiments demonstrated that the DP binding site was mainly located in site 1 of HSA. Based on the docking methods, DP was mainly bound in the active site hinge region where Trp-62 and Trp-63 are located. Conformation study showed that DP had different effects on the local conformation of HSA and LYZ molecules.

  11. Binding of estrogen receptor with estrogen conjugated to bovine serum albumin (BSA).

    PubMed

    Taguchi, Yasuto; Koslowski, Mirek; Bodenner, Donald L

    2004-08-19

    BACKGROUND: The classic model of estrogen action requires that the estrogen receptor (ER) activates gene expression by binding directly or indirectly to DNA. Recent studies, however, strongly suggest that ER can act through nongenomic signal transduction pathways and may be mediated by a membrane bound form of the ER. Estradiol covalently linked to membrane impermeable BSA (E2-BSA) has been widely used as an agent to study these novel membrane-associated ER events. However, a recent report suggests that E2-BSA does not compete for E2 binding to purified ER in vitro. To resolve this apparent discrepancy, we performed competition studies examining the binding of E2 and E2-BSA to both purified ER preparations and ER within intact cells. To eliminate potential artifacts due to contamination of commercially available E2-BSA preparations with unconjugated E2 (usually between 3-5%), the latter was carefully removed by ultrafiltration. RESULTS: As previously reported, a 10-to 1000-fold molar excess of E2-BSA was unable to compete with 3H-E2 binding to ER when added simultaneously. However, when ER was pre-incubated with the same concentrations of E2-BSA, the binding of 3H-E2 was significantly reduced. E2-BSA binding to a putative membrane-associated ER was directly visualized using fluorescein labeled E2-BSA (E2-BSA-FITC). Staining was restricted to the cell membrane when E2-BSA-FITC was incubated with stable transfectants of the murine ERalpha within ER-negative HeLa cells and with MC7 cells that endogenously produce ERalpha. This staining appeared highly specific since it was competed by pre-incubation with E2 in a dose dependent manner and with the competitor ICI-182,780. CONCLUSIONS: These results demonstrate that E2-BSA does bind to purified ER in vitro and to ER in intact cells. It seems likely that the size and structure of E2-BSA requires more energy for it to bind to the ER and consequently binds more slowly than E2. More importantly, these findings demonstrate

  12. Binding of estrogen receptor with estrogen conjugated to bovine serum albumin (BSA)

    PubMed Central

    Taguchi, Yasuto; Koslowski, Mirek; Bodenner, Donald L

    2004-01-01

    Background The classic model of estrogen action requires that the estrogen receptor (ER) activates gene expression by binding directly or indirectly to DNA. Recent studies, however, strongly suggest that ER can act through nongenomic signal transduction pathways and may be mediated by a membrane bound form of the ER. Estradiol covalently linked to membrane impermeable BSA (E2-BSA) has been widely used as an agent to study these novel membrane-associated ER events. However, a recent report suggests that E2-BSA does not compete for E2 binding to purified ER in vitro. To resolve this apparent discrepancy, we performed competition studies examining the binding of E2 and E2-BSA to both purified ER preparations and ER within intact cells. To eliminate potential artifacts due to contamination of commercially available E2-BSA preparations with unconjugated E2 (usually between 3–5%), the latter was carefully removed by ultrafiltration. Results As previously reported, a 10-to 1000-fold molar excess of E2-BSA was unable to compete with 3H-E2 binding to ER when added simultaneously. However, when ER was pre-incubated with the same concentrations of E2-BSA, the binding of 3H-E2 was significantly reduced. E2-BSA binding to a putative membrane-associated ER was directly visualized using fluorescein labeled E2-BSA (E2-BSA-FITC). Staining was restricted to the cell membrane when E2-BSA-FITC was incubated with stable transfectants of the murine ERα within ER-negative HeLa cells and with MC7 cells that endogenously produce ERα. This staining appeared highly specific since it was competed by pre-incubation with E2 in a dose dependent manner and with the competitor ICI-182,780. Conclusions These results demonstrate that E2-BSA does bind to purified ER in vitro and to ER in intact cells. It seems likely that the size and structure of E2-BSA requires more energy for it to bind to the ER and consequently binds more slowly than E2. More importantly, these findings demonstrate that in

  13. 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.

  14. 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. PMID:26608224

  15. Interaction of bovine serum albumin and lysozyme with stainless steel studied by time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy.

    PubMed

    Hedberg, Yolanda S; Killian, Manuela S; Blomberg, Eva; Virtanen, Sannakaisa; Schmuki, Patrik; Odnevall Wallinder, Inger

    2012-11-27

    An in-depth mechanistic understanding of the interaction between stainless steel surfaces and proteins is essential from a corrosion and protein-induced metal release perspective when stainless steel is used in surgical implants and in food applications. The interaction between lysozyme (LSZ) from chicken egg white and bovine serum albumin (BSA) and AISI 316L stainless steel surfaces was studied ex situ by means of X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) after different adsorption time periods (0.5, 24, and 168 h). The effect of XPS measurements, storage (aging), sodium dodecyl sulfate (SDS), and elevated temperature (up to 200 °C) on the protein layers, as well as changes in surface oxide composition, were investigated. Both BSA and LSZ adsorption induced an enrichment of chromium in the oxide layer. BSA induced significant changes to the entire oxide, while LSZ only induced a depletion of iron at the utmost layer. SDS was not able to remove preadsorbed proteins completely, despite its high concentration and relatively long treatment time (up to 36.5 h), but induced partial denaturation of the protein coatings. High-temperature treatment (200 °C) and XPS exposure (X-ray irradiation and/or photoelectron emission) induced significant denaturation of both proteins. The heating treatment up to 200 °C removed some proteins, far from all. Amino acid fragment intensities determined from ToF-SIMS are discussed in terms of significant differences with adsorption time, between the proteins, and between freshly adsorbed and aged samples. Stainless steel-protein interactions were shown to be strong and protein-dependent. The findings assist in the understanding of previous studies of metal release and surface changes upon exposure to similar protein solutions.

  16. Mixed macromolecular crowding inhibits amyloid formation of hen egg white lysozyme.

    PubMed

    Zhou, Bing-Rui; Zhou, Zheng; Hu, Qing-Lian; Chen, Jie; Liang, Yi

    2008-03-01

    The effects of two single macromolecular crowding agents, Ficoll 70 and bovine serum albumin (BSA), and one mixed macromolecular crowding agent containing both BSA and Ficoll 70, on amyloid formation of hen egg white lysozyme have been examined by thioflavin T binding, Congo red binding, transmission electron microscopy, and activity assay, as a function of crowder concentration and composition. Both the mixed crowding agent and the protein crowding agent BSA at 100 g/l almost completely inhibit amyloid formation of lysozyme and stabilize lysozyme activity on the investigated time scale, but Ficoll 70 at the same concentration neither impedes amyloid formation of lysozyme effectively nor stabilizes lysozyme activity. Further kinetic and isothermal titration calorimetry analyses indicate that a mixture of 5 g/l BSA and 95 g/l Ficoll 70 inhibits amyloid formation of lysozyme and maintains lysozyme activity via mixed macromolecular crowding as well as weak, nonspecific interactions between BSA and nonnative lysozyme. Our data demonstrate that BSA and Ficoll 70 cooperatively contribute to both the inhibitory effect and the stabilization effect of the mixed crowding agent, suggesting that mixed macromolecular crowding inside the cell may play a role in posttranslational quality control mechanism.

  17. 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.

  18. Binding interactions between lysozyme and injectable hydrogels derived from albumin-pH/thermo responsive poly(amino urethane) conjugates in aqueous solution.

    PubMed

    Rapeekan, Jirathititiporn; Songtipya, Ponusa; Lee, Doo Sung; Manokruang, Kiattikhun

    2016-10-01

    Injectable hydrogels are alternative materials for drug and protein delivery in biomedical applications, which can potentially eliminate the need of surgical implantation in the treatment procedures. Prior to administration, such hydrogels, in a liquid state, must demonstrate good interactions with the incorporated molecules to maintain the sustain release of active agents and to avoid unappreciative burst release. The injectable hydrogels derived from BSA-pH/temperature responsive poly(amino urethane) conjugates have been reported to demonstrated good sustainability for delivery of lysozyme, both in vitro and in vivo. However, the interactions between such conjugates and the loading lysozyme were not fully understood. In this present work, we reported the binding interactions between the studied complex systems, BSA-pH/temperature responsive poly(amino urethane) conjugates (CONJ1 and CONJ2) and lysozyme. Fluorescence spectroscopy in a combination with thermodynamic analysis exhibited that the binding between the conjugates and lysozyme occurred through static quenching and the binding interactions in the complexes were mainly van der Waals forces and hydrogen bonds. The binding constants (KA) determined at 300, 308 and 318K of CONJ1 to lysozyme were 7.96×10(4), 6.45×10(4) and 3.20×10(4)M(-1), respectively and those of CONJ2 to lysozyme were 2.63×10(4), 2.53×10(4) and 1.19×10(4)M(-1), respectively. FTIR analysis showed that the complexes between the conjugates and lysozyme demonstrated sufficiently small deviation in the conformational structures from the native lysozyme. In addition, the morphology revealed by TEM and AFM imaging portrayed the behavior of complex formation in such a way that the conjugates, before complex formation, displayed the core-shell structures. After the complex formation, a number of lysozyme particles were noticeably entrapped as if they penetrated into the preformed core-shell conjugates. PMID:27423103

  19. 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.

  20. 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.

  1. 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.

  2. Interaction of different polyphenols with bovine serum albumin (BSA) and human salivary alpha-amylase (HSA) by fluorescence quenching.

    PubMed

    Soares, Susana; Mateus, Nuno; Freitas, Victor de

    2007-08-01

    Phenolic compounds are responsible for major organoleptic characteristics of plant-derived food and beverages; these substances have received much attention, given that the major function of these compounds is their antioxidant ability. In the context of this study, our major aim was study the binding of several phenolic compounds such as (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, malvidin-3-glucoside, tannic acid, procyanidin B4, procyanidin B2 gallate, and procyanidin oligomers to different proteins (bovine serum albumin and human alpha-amylase) by fluorescence quenching of protein intrinsic fluorescence. From the spectra obtained, the Stern-Volmer, the apparent static, and the bimolecular quenching constants were calculated. The structure of polyphenols revealed to significantly affect the binding/quenching process; in general, the binding affinity increased with the molecular weight of polyphenol compounds and in the presence of galloyl groups. For catechin monomer and procyanidin dimer B4, the K(SV) was 14,100 and 13,800 M(-1), respectively, and for galloyl derivatives, the K(SV) was 19,500 and 21,900 M(-1), respectively. Tannic acid was shown to be the major quenching molecule for both proteins. However, comparing different proteins, the same polyphenol showed different quenching effects, which are suggested to be related to the three-dimensional structure of the proteins studied. For (+)-catechin and BSA, the K(SV) was 8700 M(-1), and with alpha-amylase, it was 14,100 M(-1); for tannic acid, the K(SV) was 10,0548 and 11,0674 M(-1), respectively. From the results obtained, besides the main binding analysis performed, we conclude that this technique is more sensitive than thought because we can detect several interactions that have not been proven by other methods, namely, nephelometry. Overall, fluorescence quenching has proven to be a very sensitive technique with many potentialities to analyze the interaction between polyphenols and proteins.

  3. 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). PMID:26462444

  4. 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.

  5. Probing deep into the interaction of a fluorescent chalcone derivative and bovine serum albumin (BSA): an experimental and computational study.

    PubMed

    Alvim, Haline G O; Fagg, Emma L; de Oliveira, Aline L; de Oliveira, Heibbe C B; Freitas, Sonia M; Xavier, Mary-Ann E; Soares, Thereza A; Gomes, Alexandre F; Gozzo, Fabio C; Silva, Wender A; Neto, Brenno A D

    2013-08-01

    In the present manuscript, a novel fluorescent chalcone derivative is synthesized and its photophysical properties are fully characterized. The designed fluorophore is applied as a probe to study protein-dye interactions with bovine serum albumin. Circular dichroism gave interesting results on the thermodynamics of the interaction. NMR spectroscopy, especially relaxation measurements, revealed the atoms in the chalcone derivative that interacts with the protein upon binding. Molecular docking calculations indicate that the most favourable binding sites are near the two tryptophan residues. Furthermore, ab initio and DFT calculations offer insights into the reactivity and physicochemical properties of this novel fluorophore. PMID:23680860

  6. 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.

  7. 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

  8. 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.

  9. Development of a sandwich enzyme-linked immunosorbent assay (ELISA) for determining of bovine serum albumin (BSA) in trivalent measles-mump-rubella (MMR) vaccines.

    PubMed

    Khamehchian, Sedigheh; Madani, Rasool; Golchinfar, Fariba; Taghavian, Mohammad

    2008-01-01

    A sandwich enzyme-linked immunosorbent assay (ELISA), using polyclonal antibody, was developed and compared with the commercial kit for detecting and estimating of BSA content in Measles-Mump-Rubella (MMR) vaccine samples in detection limit of nanogram level. The test depends on the capturing and detecting of BSA antigen by the polyclonal antibody. Initially, a detection range of 0-64 ng/ml was established, could be used for estimation of BSA content according to WHO requirement (50 ng/ml) in MMR vaccines. Comparative analysis of the test results for 85 MMR vaccine samples obtained with the commercial kit gave a sensitivity of 58.8% and a specificity of 97%. A high correlation (r = 0.94) was observed between BSA sandwich ELISA and commercial kit for BSA content in MMR samples. However, variations in values also were observed for the two assays. These variations may have been due to difference of upper limit of detection range of BSA content in commercial kit (32 ng/ml) and new sandwich ELISA (64 ng/ml) as well as the use of a different polyclonal antibody. In concerning the cutoff value for the WHO requirement and employment of standard solution of 64 ng/ml in developing assay, it would be adequate to use this test for assessing BSA content in viral vaccines same as MMR vaccines.

  10. Human serum albumin-coated gold nanoparticles for selective extraction of lysozyme from real-world samples prior to capillary electrophoresis.

    PubMed

    Yeh, Pei-Rong; Tseng, Wei-Lung

    2012-12-14

    This study describes the use of human serum albumin (HSA)-modified gold nanoparticles (HSA-AuNPs) for the selective extraction and enrichment of high-pI protein, lysozyme (Lyz) prior to analysis by capillary electrophoresis (CE) with UV detection. HSA-AuNPs are capable of extracting Lyz from a complex matrix because a HSA capping layer not only stabilizes gold nanoparticles in a high-salt environment but also exhibits strong electrostatic attraction with Lyz under neutral pH condition. Efficient separation of Lyz and other high-pI proteins has been successfully achieved by the filling of cationic polyelectrolyte, poly(diallydimethylammonium chloride) (PDDAC), to the background electrolyte. After capturing Lyz with HSA-AuNPs, PDDAC-filled CE can be directly used for the analysis of the extracted Lyz without the addition of the releasing agent into the extractor. The extraction efficiency relied on the pH of the solution and the concentration of HSA-AuNPs. Under optimal extraction conditions, the limit of detection at a signal-to-noise ratio of 3 for Lyz was down to 8 nM. The combination of HSA-AuNP extraction and PDDAC-filled CE has been applied the analyses of Lyz in hen egg white, human milk, and human tear. Also, this NP-based extraction can be coupled to matrix-assisted desorption/ionization time-of-flight mass spectrometry and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

  11. 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

  12. 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.

  13. Polyethyleneimine assisted-two-step polymerization to develop surface imprinted cryogels for lysozyme purification.

    PubMed

    Erol, Kadir; Köse, Kazım; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

    2016-10-01

    Surface imprinting strategy is one of the promising approaches to synthesize plastic antibodies while overcoming the problems in the protein imprinting research. In this study, we focused our attentions on developing two-step polymerization to imprint on the bare surface employing polyethyleneimine (PEI) assisted-coordination of template molecules, lysozyme. For this aim, we firstly synthesized poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA) cryogels as a bare structure. Then, we immobilized PEI onto the cryogels through the addition reaction between GMA and PEI molecules. After that, we determined the amount of free amine (NH2) groups of PEI molecules, subsequently immobilized methacrylate functionalities onto the half of them and another half was used to chelate Cu(II) ions as a mediator between template, lysozyme and PEI groups. After the characterization of the materials developed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and the micro-computed tomography (μCT), we optimized the lysozyme adsorption conditions from aqueous solution. Before performing lysozyme purification from chicken egg white, we evaluated the effects of pH, interaction time, the initial lysozyme concentration, temperature and ionic strength on the lysozyme adsorption. Moreover, the selectivity of surface imprinted cryogels was examined against cytochrome c and bovine serum albumin (BSA) as the competitors. Finally, the mathematical modeling, which was applied to describe the adsorption process, showed that the experimental data is very well-fitted to the Langmuir adsorption isotherm. PMID:27424087

  14. Effect of environmental contaminants on nasal lysozyme secretions.

    PubMed

    Noble, Rudolf E

    2002-02-01

    Human nasal secretions are comprised of lysozyme and albumin as their main protein components. Lysozyme, an anti-microbial substance, is produced by nasal serous cells while albumin is obtained, primarily, from increased nasal vasculature permeability. We measured lysozyme levels in nasal secretions following challenge by a variety of non-infectious environmental contaminants. The methodology given presents a simple and rapid method of collecting nasal secretions and determining their lysozyme content, a technique which can be used for a host of environmental irritants.

  15. BSA-boronic acid conjugate as lectin mimetics.

    PubMed

    Narla, Satya Nandana; Pinnamaneni, Poornima; Nie, Huan; Li, Yu; Sun, Xue-Long

    2014-01-10

    We report bovine serum albumin (BSA)-boronic acid (BA) conjugates as lectin mimetics and their glyco-capturing capacity. The BSA-BA conjugates were synthesized by amidation of carboxylic acid groups in BSA with aminophenyl boronic acid in the presence of EDC, and were characterized by Alizarin Red S (ARS) assay and SDS-PAGE gel. The BSA-BA conjugates were immobilized onto maleimide-functionalized silica beads and their sugar capturing capacity and specificity were confirmed by ARS displacement assay. Further, surface plasmon resonance (SPR) analysis of the glyco-capturing activity of the BSA-BA conjugates was conducted by immobilizing BSA-BA onto SPR gold chip. Overall, we demonstrated a BSA-BA-based lectin mimetics for glyco-capturing applications. These lectin mimetics are expected to provide an important tool for glycomics and biosensor research and applications.

  16. Electrochemical deposition of mineralized BSA/collagen coating.

    PubMed

    Zhuang, Junjun; Lin, Jun; Li, Juan; Wang, Huiming; Cheng, Kui; Weng, Wenjian

    2016-09-01

    In this work, mineralized collagen coatings with different loading quantity of bovine serum albumin (BSA) were prepared via in situ electrochemical deposition on titanium substrate. The microstructure and BSA loading quantity of the coatings could be controlled by the electrochemical deposition parameters, such as deposition potential, BSA concentration and its adding sequence in the electrolyte. The BSA loading quantity in the coatings was obtained in the range of 0.0170-0.173mg/cm(2), enhancing the cell adhesion and proliferation of the coatings with the simultaneous release. The distinct release behaviors of BSA were attributed to their gradient distribution with different mineralization degrees, which could be adjusted by the deposition process. These results suggest that in situ electrochemical deposition is a promising way to incorporate functional molecules into the mineralized collagen coatings and the mineralized BSA/collagen coatings are highly promising for improving the rhBMP-2 loading capability (1.8-fold).

  17. Purification of Lysozyme by Intrinsically Shielded Hydrogel Beads

    NASA Astrophysics Data System (ADS)

    Li, Cong; Zhang, R.; Wang, L.; Bowyer, A.; Eisenthal, R.; Shen, Yehua; Hubble, J.

    2013-07-01

    Macro-sized intrinsically shielded hydrogel beads have been prepared from BSA and CM-dextran grafted with CB using a technique based on freeze-thawing gelation method. The size of the beads lies in around 500 μm. Isothemal titration calorimetry (ITC) showed that the relative binding affinities of the lysozyme for CB, compared with BSA, at pH 3.0 was stronger than that at pH 7.4. They were employed for the affinity separation of lysozyme using chromatography column. Their adsorption capacity for lysozyme at pH 3.0 is higher than that at pH 9. In a binary mixture of lysozyme and ovalbumin, the beads showed very high selectivity toward lysozyme. Lysozyme of very high purity (> 93%) was obtained from a mixture of lysozyme and ovalbumin, and 85% from egg white solution. The results indicate that the macro-sized bead can be used for the separation, purification, and recovery of lysozyme in a chromatograph column.

  18. Lysozyme Crystal

    NASA Technical Reports Server (NTRS)

    2004-01-01

    To the crystallographer, this may not be a diamond but it is just as priceless. A Lysozyme crystal grown in orbit looks great under a microscope, but the real test is X-ray crystallography. The colors are caused by polarizing filters. Proteins can form crystals generated by rows and columns of molecules that form up like soldiers on a parade ground. Shining X-rays through a crystal will produce a pattern of dots that can be decoded to reveal the arrangement of the atoms in the molecules making up the crystal. Like the troops in formation, uniformity and order are everything in X-ray crystallography. X-rays have much shorter wavelengths than visible light, so the best looking crystals under the microscope won't necessarily pass muster under the X-rays. In order to have crystals to use for X-ray diffraction studies, crystals need to be fairly large and well ordered. Scientists also need lots of crystals since exposure to air, the process of X-raying them, and other factors destroy them. Growing protein crystals in space has yielded striking results. Lysozyme's structure is well known and it has become a standard in many crystallization studies on Earth and in space.

  19. 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

  20. Adsorption of bovine serum albumin on silver surfaces enhances the release of silver at pH neutral conditions.

    PubMed

    Wang, X; Herting, G; Wallinder, I Odnevall; Blomberg, E

    2015-07-28

    Metallic biomaterials are widely used to replace and/or restore the function of damaged bodily parts. The use of silver as antibacterial coatings onto implants has recently gained large interest in medical applications. The extent of silver that can be released into different biological fluids from such coatings is, except for the surface characteristics of the coating, governed by parameters such as protein characteristics, adsorbed layer properties, formation of silver-protein complexes as well as concentrations of proteins in the solution. This study aims to relate the structure of adsorbed net negatively charged bovine serum albumin (BSA), which is the most abundant protein in serum, to the release of silver from metallic silver surfaces in order to elucidate if the net charge of the protein has any effect of the silver release. Simultaneous adsorption measurements were performed in real time on the very same surface using combined ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D) measurements to provide a more comprehensive understanding on adsorption kinetics and layer structures. The amount of released silver into solution was measured by means of graphite furnace atomic absorption spectroscopy (GF-AAS). The structure of the adsorbed BSA layer largely influenced the amount of released silver, an enhancement that increased with BSA concentration. These observations are in complete contrast to the effect of net positively charged lysozyme (LSZ) adsorbed on silver, previously studied by the authors, for which a complete surface coverage suppressed the possibility for silver release. The underlying mechanisms behind the enhanced release of silver in the presence of BSA were mainly attributed to surface complexation between BSA and silver followed by an enhanced exchange rate of these surface complexes with BSA molecules in the solution, which in turn increase the amount of released silver in solution. PMID:26111372

  1. 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.

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

    PubMed

    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.

  3. 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

  4. Emergent membrane-affecting properties of BSA-gold nanoparticleconstructs

    NASA Astrophysics Data System (ADS)

    Lystvet, Sina M.; Volden, Sondre; Yasuda, Masahiro; Halskau, Øyvind, Jr.; Glomm, Wilhelm R.

    2011-04-01

    By adsorbing bovine serum albumin (BSA) on gold nanoparticles (Aunps) with diameters 30 nm and 80 nm, different degrees of protein unfolding were obtained. Adsorption and adlayer conformation were characterized by UV-vis spectroscopy, ζ-potential measurements, steady-state and time-resolved fluorescence. The unfolding was also studied using 1-anilino-8-naphthalene sulfonate (ANS) as an extrinsic probe, showing that BSA unfolds more on 80 nm Aunp than on 30 nm Aunp. Langmuir monolayer studies using two distinct methods of introducing the BSA and BSA-Aunp constructs accompanied with Brewster Angle Microscopy (BAM) and Digital Video Microscope (DVM) imaging demonstrated that BSA-Aunp constructs induce film miscibility with l-α-phosphatidylethanolamine not seen for BSA or Aunp alone. The changes induced by partial unfolding clearly give better film-penetration ability, as well as disruption of liquid crystalline domains in the film, thereby inducing film miscibility. Gold or protein only does not possess the nanoscale film-affecting properties of the protein-goldconstructs, and as such the surface-active and miscibility-affecting characteristics of the BSA-Aunp represent emergent qualities.

  5. Effects of PEG size on structure, function and stability of PEGylated BSA.

    PubMed

    Plesner, Bitten; Fee, Conan J; Westh, Peter; Nielsen, Anders D

    2011-10-01

    The effects of PEGylation on the structural, thermal and functional stability of bovine serum albumin (BSA) were investigated using BSA and 6 linear mono-PEGylated BSA compounds. The secondary and tertiary structure of BSA measured by circular dichroism (CD) was independent of PEGylation. In contrast, the thermal stability of BSA was affected by PEGylation. The apparent unfolding temperature T(max) measured by differential scanning calorimetry (DSC) decreased with PEGylation, whereas the temperature of aggregation, T(agg), measured by dynamic light scattering (DLS) increased with PEGylation. The unfolding temperature and the temperature of aggregation were both independent of the molecular weight of the PEG chain. Possible functional changes of BSA after PEGylation were measured by Isothermal Titration Calorimetry (ITC), where the binding of sodium dodecyl sulphate (SDS) to BSA and PEGylated BSA was analysed. At 25°C, two distinct classes of binding sites (high affinity and low affinity) for BSA and one class of binding site (low affinity) for PEGylated BSA were identified. The binding isotherm was modelled assuming independence and thermodynamic equivalence of the sites within each class. From the present biophysical characterisation, it is concluded that after PEGylation BSA appears to be unaffected structurally (secondary and tertiary structure), slightly destabilised thermally (unfolding temperature), stabilised kinetically (temperature of aggregation) and has an altered functionality (binding profile). These biophysical characteristics are all independent of the molecular weight of the attached polymer chain.

  6. Effect of zeta potentials on bovine serum albumin adsorption to hydroxyapatite surfaces.

    PubMed

    Miyake, Nahoko; Sato, Toru; Maki, Yoshinobu

    2013-01-01

    The aim of the present study was to examine the adsorption of bovine serum albumin (BSA) to hydroxyapatite surfaces by means of zeta potential. The electrophoretic mobility of both hydroxyapatite and BSA were negative, with BSA itself less negative than hydroxyapatite. The zeta potential of the surface of BSA-adsorbed hydroxyapatite was significantly more negative than that of hydroxyapatite alone (p<0.0001). The BSA histogram indicated two negative peaks, and the zeta potential of BSA-adsorbed hydroxyapatite also showed two similar negative peaks. These results suggest that BSA adsorption to hydroxyapatite surfaces is related to electrostatic interaction. PMID:23903580

  7. Impact of surface modification in BSA nanoparticles for uptake in cancer cells.

    PubMed

    Choi, Jin-Seok; Meghani, Nilesh

    2016-09-01

    Recent studies have shown that cellular uptake of nanoparticles are strongly affected by the presence and physicochemical characteristics of protein on the surface of these nanoparticles. Hence, We developed surface-modified bovine serum albumin (BSA) nanoparticles (NPs) and evaluated the effect of surface modification on cellular uptake in two types of cancer cells, MCF-7 and A549. BSA NPs were prepared by desolvation method and their surface was modified with apo-transferrin, hyaluronic acid, and Poly(allylamine hydrochloride) (PAH). Morphology of surface-modified BSA NPs was characterized by field emission scanning electron microscopy and differential scanning calorimetry. In vitro-fluorescence release study was performed in phosphate buffered saline with trypsin (100μL/mL (v/v)) for 24h. Confocal microscopy was performed to evaluate cellular uptake followed by fluorescence analysis to evaluate the quantitative uptake of nanoparticles at 0.5, 1, and 2h. Different types of BSA NPs with a mean size of ∼100nm were successfully prepared. In vitro-fluorescent release showed sustained release pattern in surface-modified BSA NPs compared to unmodified BSA NPs. Surface-modified BSA NPs showed more cellular internalization than unmodified BSA NPs. The uptake of PAH-BSA NPs was about 2 times higher than that of unmodified BSA NPs in both cell types. In conclusion, surface-modified BSA NPs showed enhanced cellular uptake, and PAH-BSA NPs are more effective compared to ligand-specific surface-modified BSA NPs (HA-BSA NPs and Tf-BSA NPs).

  8. Highly sensitive bovine serum albumin biosensor based on liquid crystal

    NASA Astrophysics Data System (ADS)

    Sharma, Vikash; Kumar, Ajay; Ganguly, Prasun; Biradar, A. M.

    2014-01-01

    A highly sensitive liquid crystal (LC) based bovine serum albumin (BSA) protein biosensor is designed. A uniform homeotropic alignment of nematic LC was observed in BSA free substrate which changed into homogeneous in presence of BSA. The change in the LC orientation is found to depend strongly on BSA concentration. This change in the LC alignment is attributed to the modification in the surface conditions which is verified by contact angle measurements. We have detected an ultra low concentration (0.5 μg/ml) of BSA. The present study demonstrates the utilization of LC in the realization of high sensitivity biosensors.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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.

  10. 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.

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

    PubMed Central

    2011-01-01

    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. PMID:22053876

  12. [Binding mechanism of traditional Chinese medicine active component 5-hydroxymethyl-furfural and HSA or BSA].

    PubMed

    Guo, Ming; He, Ling; Lu, Xiao-Wang

    2012-03-01

    A combination of spectral experiment and molecular modeling techniques has been used to characterize the binding mechanism between an active component 5-hydroxymethyl-furfural (5-HMF) of traditional Chinese medicine and human serum albumin (HSA) or bovine serum albumin (BSA). The interaction mechanism of 5-HMF binding with HSA/BSA is analyzed. Although the drug can bind with HSA/BSA to form stable complexes, there are some differences in the bond strength. The values of binding distances (r) are different and low, which indicated the occurrence of energy transfer. The drug had conformational effect on HSA/BSA, which resulted in different changes of hydrophobic environment of the binding domain in HSA/BSA. The 'phase diagram' of fluorescence revealed that the changes on the conformational pattern of proteins have been affected by drug conformed to the "all-or-none" pattern. The interactions between drug and protein influenced by Co(II) were also discussed. Its effects acting on 5-HMF-HSA/BSA interactions are different. The computational modeling method was used to study the interaction between 5-HMF and HSA/BSA. The results of molecular model studies revealed that the binding modes for drug-serum albumin systems are mainly hydrophobic interactions and hydrogen bonding. These results are in accordance with spectral results. The research results have given a better theoretical reference for the study of pharmacological mechanism of 5-hydroxymethyl-furfural.

  13. 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.

  14. Preparation of bovine serum albumin nanospheres as drug targeting carriers.

    PubMed

    Nakagawa, Y; Takayama, K; Ueda, H; Machida, Y; Nagai, T

    1987-12-01

    Bovine serum albumin nanospheres (BSA-NS) of mean diameter about 170 nm were prepared by means of the tanning method with glutaraldehyde, and their efficacy as drug targeting carriers was evaluated. To gain insight of biodegradability, BSA microspheres (BSA-MS) were first administered to rats and their distributions in the lungs and liver were observed by a scanning electron microscope. A large amount of BSA-MS was found in the lungs and their surface was slightly degraded at 1 week after the administration. For investigating biocompatibility, the weight increase of the spleen and liver was measured after the administration of the BSA-NS to mice. The spleen weight of the group receiving BSA-NS was equivalent to that of the control group, though the liver weight was significantly increased. It was observed that conjugates of BSA-NS with antibody selectively concentrated on the surface of Sepharose beads which were coated with antigen.

  15. 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.

  16. 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

  17. 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

    2016-01-01

    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

  18. 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.

  19. Choline-induced selective fluorescence quenching of acetylcholinesterase conjugated Au@BSA clusters.

    PubMed

    Mathew, Meegle S; Baksi, Ananya; Pradeep, T; Joseph, Kuruvilla

    2016-07-15

    We have developed a highly selective sensitive fluorescent detection of acetylcholine (ACh) using bovine serum albumin (BSA) protected atomically precise clusters of gold. The gold quantum clusters (AuQC@BSA) synthesized using bovine serum albumin and conjugated with acetylcholinesterase (AChE), an enzyme specific for acetylcholine, resulting in AuQC@BSA-AChE. The enzyme, AChE hydrolyzes acetylcholine (ACh) to choline (Ch) which in turn interacts with AuQC@BSA-AChE and quenches its fluorescence, enabling sensing. We have carried out the real time monitoring of the hydrolysis of ACh using electrospray ionization mass spectrometry (ESI MS) to find out the mechanism of fluorescent quenching. The validity of present method for determination of concentration of acetylcholine in real system such as blood was demonstrated. Further, the sensor, AuQC@BSA-AChE can be easily coated on paper and an efficient and cheap sensor can be developed and detection limit for ACh is found to be 10nM. The fluorescent intensity of AuQC@BSA-AChE is sensitive towards acetylcholine in range of 10nM to 6.4µM. This suggests that AuQC@BSA-AChE has an excellent potential to be used for diagnosis of various neuropsychological and neuropsychiatric disorders.

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

    PubMed

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

    2014-01-01

    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.

  1. 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

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

    PubMed

    Zhang, Qiulan; Ni, Yongnian; Kokot, Serge

    2016-04-01

    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.

  3. Metal chelate affinity precipitation: purification of BSA using poly(N-vinylcaprolactam-co-methacrylic acid) copolymers.

    PubMed

    Ling, Yuan-Qing; Nie, Hua-Li; Brandford-White, Christopher; Williams, Gareth R; Zhu, Li-Min

    2012-06-01

    This investigation involves the metal chelate affinity precipitation of bovine serum albumin (BSA) using a copper ion loaded thermo-sensitive copolymer. The copolymer of N-vinylcaprolactam with methacrylic acid PNVCL-co-MAA was synthesized by free radical polymerization in aqueous solution, and Cu(II) ions were attached to provide affinity properties for BSA. A maximum loading of 48.1mg Cu(2+) per gram of polymer was attained. The influence of pH, temperature, BSA and NaCl concentrations on BSA precipitation and of pH, ethylenediaminetetraacetic acid (EDTA) and NaCl concentrations on elution were systematically probed. The optimum conditions for BSA precipitation occurred when pH, temperature and BSA concentration were 6.0, 10°C and 1.0 mg/ml, respectively and the most favorable elution conditions were at pH 4.0, with 0.2M NaCl and 0.06 M EDTA. The maximum amounts of BSA precipitation and elution were 37.5 and 33.7 mg BSA/g polymer, respectively. It proved possible to perform multiple precipitation/elution cycles with a minimal loss of polymer efficacy. The results show that PNVCL-co-MAA is a suitable matrix for the purification of target proteins from unfractionated materials.

  4. 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.

  5. On the study of BSA-loaded calcium-deficient hydroxyapatite nano-carriers for controlled drug delivery.

    PubMed

    Liu, Tse-Ying; Chen, San-Yuan; Liu, Dean-Mo; Liou, Sz-Chian

    2005-09-20

    Calcium-deficient hydroxyapatite (CDHA) nano-crystals incorporated with bovine serum albumin (BSA) to form BSA-loaded nano-carriers were synthesized via both in-situ and ex-situ processes. Amount of BSA uptake by the CDHA nano-crystals and subsequent release behaviors of the BSA-loaded nano-carriers were investigated. The amount of BSA uptake by CDHA decreases with increasing pH but a larger amount was observed in the ex-situ compared to in-situ process above pH=8.0. The release profile showed a bursting behavior for the nano-carrier prepared via the ex-situ process, which is probably due to the desorption of BSA molecules. In contrast, for the sample synthesized via the in-situ process at a higher pH level, a slower release profile without bursting behavior due to the dissolution of the BSA-incorporated CDHA crystal is seen from high solution TEM that indicates different extent of interaction between BSA and CDHA. On the other hand, for the nano-carriers prepared via the same process at lower pH level, a two-stage release profile was detected. An initial bursting release is due to the desorption of BSA from the CDHA surface, followed by a slow release as a result of the dissolution of the BSA-incorporated nano-crystals along its c-axis direction.

  6. 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...

  7. 5alpha-Reduced androgens block estradiol-BSA-stimulated release of oxytocin.

    PubMed

    Caldwell, Jack D; Song, Yan; Englöf, Ila; Höfle, Simone; Key, Mary; Morris, Mariana

    2003-06-27

    In this study we test the postulate that estradiol conjugated to bovine serum albumin (E-BSA) acts via receptors for the steroid-binding protein sex hormone binding globulin (SHBG) by attempting to block E-BSA-stimulated release of oxytocin with two antagonists of SHBG receptor actions: the 5alpha-reduced androgens dihydrotestosterone (DHT) and 3alpha-diol. Simultaneous superfusion with either DHT or 3alpha-diol significantly blocked E-BSA-stimulated release of oxytocin. We also found that a wide range of free 17beta-estradiol was unable to stimulate oxytocin release, suggesting that E-BSA stimulates receptors other than those for free estradiol to release oxytocin, perhaps SHBG receptors.

  8. Impairment of human keratinocyte mobility and proliferation by advanced glycation end products-modified BSA.

    PubMed

    Zhu, Ping; Yang, Chuan; Chen, Li-Hong; Ren, Meng; Lao, Guo-Juan; Yan, Li

    2011-07-01

    The migration and proliferation of keratinocytes is critical to wound re-epithelialization and defects in this function are associated with the clinical phenomenon of chronic non-healing wounds. Advanced glycation end products (AGEs) occur through non-enzymatic glycation of long-lived proteins in diabetes and play important roles in diabetic complications. However, specific roles for AGEs in keratinocyte migration and proliferation, and the underlying molecular mechanisms, have not been fully established. The aim of the current study was to elucidate the interaction between AGE-modified bovine serum albumin (AGE-BSA) and keratinocytes. As a result, we found that AGE-BSA had no effect on the viability of keratinocytes for up to 48 h of incubation with 50 μg/ml of AGE-BSA. AGE-BSA (but not non-glycated BSA) exerted a concentration-dependent suppression of keratinocyte migration at a range of concentrations. The expression of matrix metalloproteinase-9 (MMP-9) was significantly up-regulated in keratinocytes incubated with increasing AGE-BSA, but tissue inhibitor of metalloproteinases-1 (TIMP-1) expression was down-regulated. AGE-BSA also profoundly depressed phospho-focal adhesion kinase-Tyr397 (p-FAK) and α2β1 integrin expression, while total-FAK expression levels remained constant, in keratinocytes. The proliferative capacity of keratinocytes was diminished after 72 h AGE-BSA incubation. Taken together, these findings suggested that in the presence of AGE-BSA, keratinocytes lose their migratory and proliferation abilities. These data also indicated that, in the context of the chronic hyperglycemia in diabetes, the effects of AGE-BSA on keratinocyte migration might be mediated through MMP-9/TIMP-1, p-FAK and α2β1 integrin.

  9. Conjugates of folic acids with BSA-coated quantum dots for cancer cell targeting and imaging by single-photon and two-photon excitation.

    PubMed

    Meng, He; Chen, Ji-Yao; Mi, Lan; Wang, Pei-Nan; Ge, Mei-Ying; Yue, Yang; Dai, Ning

    2011-01-01

    Bovine serum albumin (BSA)-coated CdTe/ZnS quantum dots (BSA-QDs) were selected to conjugate with folic acid (FA), forming FA-BSA-QDs. This study aims to develop these small FA-BSA-QDs (less than 10 nm) for the diagnosis of cancers in which the FA receptor (FR) is overexpressed. The enhancement of cellular uptake in FR-positive human nasopharyngeal carcinoma cells (KB cells) for FA-BSA-QDs was found by means of confocal fluorescence microscopy under single-photon and two-photon excitation. The uptake enhancement for FA-BSA-QDs was further evaluated by flow-cytometric analysis in 10(4) KB cells, and was about 3 times higher than for BSA-QDs on average. The uptake enhancement was suppressed when KB cells had been pretreated with excess FA, reflecting that the enhancement was mediated by the association of FR at cell membranes with FA-BSA-QDs. When human embryonic kidney cells (293T) (FR-negative cells) and KB cells, respectively, were incubated with FA-BSA-QDs (1 μM) for 40 min, the FA-BSA-QD uptake by 293T cells was much weaker than that by KB cells, demonstrating that FA-BSA-QDs could undergo preferential binding on FR-positive cancer cells. These characteristics suggest that FA-BSA-QDs are potential candidates for cancer diagnosis.

  10. Interactions of two food colourants with BSA: Analysis by Debye-Hückel theory.

    PubMed

    Li, Tian; Cheng, Zhengjun; Cao, Lijun; Jiang, Xiaohui; Fan, Lei

    2016-11-15

    We have focused on exploring pH- and ionic strength-modulated binding of acid red 1 (AR1) and acid green 50 (AG50) with bovine serum albumin (BSA) by fluorescence, UV-vis absorption and FTIR spectra. The results implied that the quenching mechanism of BSA-AR1/AG50 system was a static quenching, electrostatic force dominated the formation of BSA-AR1/AG50 complex, and the binding affinity of AR1 was greater than that of AG50 on the subdomain IIA of BSA. Moreover, their true thermodynamic binding constant (Keq), true free energy change (ΔG(0)I→0), and effective charge (ZP) in the anion receptor pocket of BSA were calculated using Debye-Hückel limiting law. The local charge bound by AR1/AG50 rather than the overall or surface charge of BSA played a key role in determining their interaction strength. Besides, the thermal and structural stabilization of BSA was discussed by analyzing the changes of Tm and Hurea without/with the addition of AR1/AG50, respectively.

  11. BSA-templated MnO2 nanoparticles as both peroxidase and oxidase mimics.

    PubMed

    Liu, Xing; Wang, Qi; Zhao, Huihui; Zhang, Lichun; Su, Yingying; Lv, Yi

    2012-10-01

    Inorganic nanomaterials that mimic enzymes are fascinating as they potentially have improved properties relative to native enzymes, such as greater resistance to extremes of pH and temperature and lower sensitivity to proteases. Although many artificial enzymes have been investigated, searching for highly-efficient and stable catalysts is still of great interest. In this paper, we first demonstrated that bovine serum albumin (BSA)-stabilized MnO(2) nanoparticles (NPs) exhibited highly peroxidase-, oxidase-, and catalase-like activities. The activities of the BSA-MnO(2) NPs were evaluated using the typical horseradish peroxidase (HRP) substrates o-phenylenediamine (OPD) and 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of either hydrogen peroxide or dissolved oxygen. These small-sized BSA-MnO(2) NPs with good dispersion, solubility and biocompatibility exhibited typical Michaelis-Menten kinetics and high affinity for H(2)O(2), OPD and TMB, indicating that BSA-MnO(2) NPs can be used as satisfactory enzyme mimics. Based on these findings, BSA-MnO(2) NPs were used as colorimetric immunoassay tags for the detection of goat anti-human IgG in place of HRP. The colorimetric immunoassay using BSA-MnO(2) NPs has the advantages of being fast, robust, inexpensive, easily prepared and with no HRP and H(2)O(2) being needed. These water-soluble BSA-MnO(2) NPs may have promising potential applications in biotechnology, bioassays, and biomedicine.

  12. Ascorbic acid and BSA protein in solution and films: interaction and surface morphological structure.

    PubMed

    Maciel, Rafael R G; de Almeida, Adriele A; Godinho, Odin G C; Gorza, Filipe D S; Pedro, Graciela C; Trescher, Tarquin F; Silva, Josmary R; de Souza, Nara C

    2013-01-01

    This paper reports on the study of the interactions between ascorbic acid (AA) and bovine serum albumin (BSA) in aqueous solution as well as in films (BSA/AA films) prepared by the layer-by-layer technique. Regarding to solution studies, a hyperchromism (in the range of ultraviolet) was found as a function of AA concentration, which suggested the formation of aggregates from AA and BSA. Binding constant, K, determined for aggregates from BSA and AA was found to be about 10(2) M(-1), which indicated low affinity of AA with BSA. For the BSA/AA films, it was also noted that the AA adsorption process and surface morphological structures depended on AA concentration. By changing the contact time between the AA and BSA, a hypochromism was revealed, which was associated to decrease of accessibility of solvent to tryptophan due to formation of aggregates. Furthermore, different morphological structures of aggregates were observed, which were attributed to the diffusion-limited aggregation. Since most of studies of interactions of drugs and proteins are performed in solution, the analysis of these processes by using films can be very valuable because this kind of system is able to employ several techniques of investigation in solid state.

  13. Ascorbic Acid and BSA Protein in Solution and Films: Interaction and Surface Morphological Structure

    PubMed Central

    Maciel, Rafael R. G.; de Almeida, Adriele A.; Godinho, Odin G. C.; Gorza, Filipe D. S.; Pedro, Graciela C.; Trescher, Tarquin F.; Silva, Josmary R.; de Souza, Nara C.

    2013-01-01

    This paper reports on the study of the interactions between ascorbic acid (AA) and bovine serum albumin (BSA) in aqueous solution as well as in films (BSA/AA films) prepared by the layer-by-layer technique. Regarding to solution studies, a hyperchromism (in the range of ultraviolet) was found as a function of AA concentration, which suggested the formation of aggregates from AA and BSA. Binding constant, K, determined for aggregates from BSA and AA was found to be about 102 M−1, which indicated low affinity of AA with BSA. For the BSA/AA films, it was also noted that the AA adsorption process and surface morphological structures depended on AA concentration. By changing the contact time between the AA and BSA, a hypochromism was revealed, which was associated to decrease of accessibility of solvent to tryptophan due to formation of aggregates. Furthermore, different morphological structures of aggregates were observed, which were attributed to the diffusion-limited aggregation. Since most of studies of interactions of drugs and proteins are performed in solution, the analysis of these processes by using films can be very valuable because this kind of system is able to employ several techniques of investigation in solid state. PMID:23984366

  14. Ascorbic acid and BSA protein in solution and films: interaction and surface morphological structure.

    PubMed

    Maciel, Rafael R G; de Almeida, Adriele A; Godinho, Odin G C; Gorza, Filipe D S; Pedro, Graciela C; Trescher, Tarquin F; Silva, Josmary R; de Souza, Nara C

    2013-01-01

    This paper reports on the study of the interactions between ascorbic acid (AA) and bovine serum albumin (BSA) in aqueous solution as well as in films (BSA/AA films) prepared by the layer-by-layer technique. Regarding to solution studies, a hyperchromism (in the range of ultraviolet) was found as a function of AA concentration, which suggested the formation of aggregates from AA and BSA. Binding constant, K, determined for aggregates from BSA and AA was found to be about 10(2) M(-1), which indicated low affinity of AA with BSA. For the BSA/AA films, it was also noted that the AA adsorption process and surface morphological structures depended on AA concentration. By changing the contact time between the AA and BSA, a hypochromism was revealed, which was associated to decrease of accessibility of solvent to tryptophan due to formation of aggregates. Furthermore, different morphological structures of aggregates were observed, which were attributed to the diffusion-limited aggregation. Since most of studies of interactions of drugs and proteins are performed in solution, the analysis of these processes by using films can be very valuable because this kind of system is able to employ several techniques of investigation in solid state. PMID:23984366

  15. Interactions of two food colourants with BSA: Analysis by Debye-Hückel theory.

    PubMed

    Li, Tian; Cheng, Zhengjun; Cao, Lijun; Jiang, Xiaohui; Fan, Lei

    2016-11-15

    We have focused on exploring pH- and ionic strength-modulated binding of acid red 1 (AR1) and acid green 50 (AG50) with bovine serum albumin (BSA) by fluorescence, UV-vis absorption and FTIR spectra. The results implied that the quenching mechanism of BSA-AR1/AG50 system was a static quenching, electrostatic force dominated the formation of BSA-AR1/AG50 complex, and the binding affinity of AR1 was greater than that of AG50 on the subdomain IIA of BSA. Moreover, their true thermodynamic binding constant (Keq), true free energy change (ΔG(0)I→0), and effective charge (ZP) in the anion receptor pocket of BSA were calculated using Debye-Hückel limiting law. The local charge bound by AR1/AG50 rather than the overall or surface charge of BSA played a key role in determining their interaction strength. Besides, the thermal and structural stabilization of BSA was discussed by analyzing the changes of Tm and Hurea without/with the addition of AR1/AG50, respectively. PMID:27283623

  16. 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.

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

    PubMed

    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.

  18. 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...

  19. Metformin-loaded BSA nanoparticles in cancer therapy: a new perspective for an old antidiabetic drug.

    PubMed

    Jose, Pinkybel; Sundar, K; Anjali, C H; Ravindran, Aswathy

    2015-03-01

    Clinical and experimental data suggest that there is a strong association between type II diabetic mellitus and pancreatic cancer. The present study focuses on exploring the anticancer and antidiabetic properties of metformin-loaded bovine serum albumin nanoparticles (BSA NPs) on (MiaPaCa-2) pancreatic carcinoma cell lines. Albumin nanoparticles were synthesized using coacervation method and the average size of the particles was found to be 97 nm. The particles were stable and showed a spherical morphology with narrow size distribution. We investigated the impact of two stages characterized in type II diabetes mellitus (hyperglycemia and hyperinsulinemia) on the proliferation of MiaPaCa-2 cells and compared the inhibitory effects of bare metformin to that of MET-BSA NPs. Further, different concentrations of insulin and glucose were added along with bare metformin, bare BSA, and metformin encapsulated BSA carrier on MiaPaCa-2 cells to check the strong association between type II diabetes and pancreatic cancer. The results revealed that MET-BSA NPs showed more toxicity when compared with drug and carrier individually.

  20. 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

  1. Stereoselective interaction of cinchona alkaloid isomers with bovine serum albumin.

    PubMed

    Liu, Yan; Chen, Mingmao; Jiang, Longguang; Song, Ling

    2015-08-15

    The dependence of the interaction between bovine serum albumin (BSA) and two cinchona alkaloids, quinine (QN) and quinidine (QD), on the absolute configuration of these stereoisomers has been comprehensively studied. The FTIR spectra showed that QN and QD interacted with both CO and C-N groups of BSA, resulting in changes to the secondary structure of the protein. Fluorescence quenching of BSA by the stereoisomers revealed lower efficiency for QD in quenching the Trp emission of BSA when compared to QN. Further analysis accurately described the different binding behaviors and recognition discrepancies of QN and QD towards BSA, which was reflected through binding affinities, driving forces, energy changes and conformational changes during the ligand-protein interactions. Synchronous fluorescence further proved that QD was farther from Trp and Tyr than that of QN. This work could provide basic data for clarifying the binding interaction, metabolism and distribution of cinchona alkaloid stereoisomers in vivo.

  2. Spectroscopic investigation of interaction between mangiferin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Lin, Hui; Lan, Jingfeng; Guan, Min; Sheng, Fenling; Zhang, Haixia

    2009-09-01

    The mechanism of interaction between mangiferin (MA) and bovine serum albumin (BSA) in aqueous solution was investigated by fluorescence spectra, synchronous fluorescence spectra, absorbance spectra and Fourier transform infrared (FT-IR) spectroscopy. The binding constants and binding sites of MA to BSA at different reaction times were calculated. And the distance between MA and BSA was estimated to be 5.20 nm based on Föster's theory. In addition, synchronous fluorescence and FT-IR measurements revealed that the secondary structures of the protein changed after the interaction of MA with BSA. As a conclusion, the interaction between the anti-diabetes Chinese medicine MA and BSA may provide some significant information for the mechanism of the traditional chinese medicine MA on the protein level to cure diabetes or other diseases.

  3. 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.

  4. Albumin Test

    MedlinePlus

    ... to a variety of conditions in addition to malnutrition , a decrease in albumin needs to be evaluated ... can also be seen in inflammation , shock, and malnutrition . They may be seen with conditions in which ...

  5. Preparation and Characterization of 125I Labeled Bovine Serum Albumin

    PubMed Central

    Ashwitha Rai, K. S.; Jyothi; Rasmi, R. R.; Sarnaik, Jayula; Kadwad, V. B.; Shenoy, K. B.; Somashekarappa, H. M.

    2015-01-01

    Bovine serum albumin is a model protein, which has been conventionally used as protein standard and in many areas of biochemistry, pharmacology and medicine. Radioiodination procedure for bovine serum albumin employing chloramine-T as an oxidant with slight modification was evaluated critically to establish the optimal conditions for the preparation of radiolabeled tracer (125I-BSA) with required specific activity without impairing the immune reactivity and biological activity. Optimized radioiodination procedure involving 10 µg of chloramine-T along with 20 µg of sodium metabisulphite with 60 seconds incubation at 2° yielded 125I-BSA with high integrity. PMID:25767326

  6. Systematic study on the preparation of BSA nanoparticles.

    PubMed

    Galisteo-González, F; Molina-Bolívar, J A

    2014-11-01

    Albumins, in the form of nanoparticles, are increasingly used as drug carriers in the medical field, and the size effect of these nanomaterials is of major importance since it may affect their bioavailability and the in vivo behaviour after intravenous injection. This research provides a comprehensive study on the preparation of BSA nanoparticles, based on a simple coacervation method, with suitable size, size distribution, and surface charge for drug-delivery applications. Numerous experimental variables were examined in order to characterize their impact on nanoparticle size, distribution, electrophoretic mobility, and yield. Particle size was controlled by adjusting self-assembly phenomena of the protein molecules, which was affected by preparation conditions including BSA content, pH, and ionic strength (a parameter that strongly influences nanoparticle formation but surprisingly has not been previously studied in detail). Small particles with a narrow size distribution were obtained under experimental conditions where the repulsion between BSA molecules was high, i.e. at pH values far from the isoelectric point of the protein and low salt concentration. Changes in temperature, volume, and rate of addition of the dehydrating agent (ethanol) also affect nanoparticle characteristics, as they influence the nucleation rate and particle growth. The effect of these experimental conditions on the quantity of protein still dissolved in the aqueous phase after desolvation (i.e. the yield of BSA nanoparticles) was also studied. Nanoparticles surface charge was modulated with the extension of cross-linking. Finally, long-term colloidal stability of samples was evaluated after 2 months of storage.

  7. Gastric acid output and circulating anti-bovine serum albumin in adults

    PubMed Central

    Kraft, S. C.; Rothberg, R. M.; Knauer, C. M.; Svoboda, A. C.; Monroe, L. S.; Farr, R. S.

    1967-01-01

    Gastric acid output and circulating antibodies to a dietary protein, bovine serum albumin (BSA), were studied in 241 adult human subjects. Among individuals 41 years of age and older there was a higher than expected incidence of circulating anti-BSA which correlated with a high stimulated gastric acid output. When other possible contributing factors such as the site of gastroduodenal disease or a history of allergy were considered, the relationship between high gastric acid and an increased incidence of anti-BSA again was demonstrated. The quantity and immunoglobulin classes of anti-BSA were not correlated with differences in gastric acid output or dietary histories, except that none of the sixteen patients who denied recent BSA intake had demonstrable anti-BSA activity. These data suggest that for a given individual the capacity to maintain or reinitiate anti-BSA production is a multifaceted phenomenon subject to many variables, one of which is gastric acidity. PMID:6035195

  8. Spectroscopic investigation of the interaction between riboflavin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Guo, Xing-Jia; Sun, Xiu-Dan; Xu, Shu-Kun

    2009-08-01

    The mutual interaction of riboflavin (RF) with bovine serum albumin (BSA) was investigated using fluorescence spectroscopy under simulative physiological conditions. The fluorescence quenching mechanism of BSA by RF should belong to dynamic quenching according to the Stern-Volmer equation, but also the effect of ground complex formation and energy transfer could not be completely precluded in BSA-RF system. The binding constants and the corresponding thermodynamic parameters at different temperatures were calculated, which indicated the presence of hydrophobic forces between RF and BSA. The averaged binding distance between riboflavin and BSA was also obtained based on the theory of FÖrster's non-radiation energy transfer. Moreover, the effect of riboflavin on the conformation of BSA was analyzed using synchronous fluorescence. The effects of some common ions Cu 2+, Zn 2+, Ca 2+, and Mg 2+ on the binding constant between riboflavin and BSA were also examined.

  9. Molecular spectroscopic studies on the interaction of morin with bovine serum albumin.

    PubMed

    Hu, Yan-Jun; Yue, Hua-Li; Li, Xiao-Ling; Zhang, Si-Si; Tang, E; Zhang, Li-Ping

    2012-07-01

    The interaction between morin and bovine serum albumin (BSA) was studied using molecular spectroscopic approach at different temperatures under imitated physiological conditions. Quenching of intrinsic tryptophanyl fluorescence of BSA with increasing morin concentration is the actuating tool in the analysis. The obtained quenching mechanisms, binding constants, binding sites and corresponding thermodynamic parameters at different temperatures indicate that the hydrophobic interaction play a major role in the morin-BSA association. Binding affinity between morin and BSA was determined using Scatchard equation and the modified Stern-Volmer equation, and the corresponding Structure-affinity relationships of flavonoids were discussed. Site marker competitive displacement experiments demonstrated that morin binds with high affinity to site II (subdomain IIIA) of BSA. Furthermore, the circular dichroism spectral results indicated that the conformation of BSA changed in the presence of morin. In addition, the effect of some common metal ions on the binding constant between morin and BSA was examined.

  10. Solution combustion synthesis of calcium phosphate particles for controlled release of bovine serum albumin.

    PubMed

    Zhao, Junfeng; Zhao, Junjie; Qian, Yu; Zhang, Xiali; Zhou, Feifei; Zhang, Hong; Lu, Hongbin; Chen, JianHua; Wang, XuHong; Yu, Wencong

    2015-05-01

    Four different phase compositions of calcium phosphate (CaP) particles were prepared via a solution combustion method. X-ray diffraction (XRD) and Rietveld analysis results revealed that the variations in the nominal Ca/P (molar) ratios were found to provide a favorable control in the different proportions of CaP materials. Bovine serum albumin (BSA) was used as a model protein to study the loading and release behavior. The release profile indicated that the BSA release rates depended on the phase compositions of the CaP particles, and showed an order of TCP-BSA>BCP-1-BSA>BCP-2-BSA>HA-BSA. The results suggested that the BSA protein release rate can be controlled by varying the phase compositions of CaP carriers. Moreover, the release process involved two stages: firstly surface diffusion via ion exchange and secondly intraparticle diffusion.

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

    PubMed

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

    2013-05-01

    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 and 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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).

  16. 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

  17. Interaction of Di-2-pyridylketone 2-pyridine Carboxylic Acid Hydrazone and Its Copper Complex with BSA: Effect on Antitumor Activity as Revealed by Spectroscopic Studies.

    PubMed

    Li, Cuiping; Huang, Tengfei; Fu, Yun; Liu, Youxun; Zhou, Sufeng; Qi, Zhangyang; Li, Changzheng

    2016-04-28

    The drug, di-2-pyridylketone-2-pyridine carboxylic acid hydrazone (DPPCAH) and its copper complex (DPPCAH-Cu) exhibit significant antitumor activity. However, the mechanism of their pharmacological interaction with the biological molecule bovine serum albumin (BSA) remains poorly understood. The present study elucidates the interactions between the drug and BSA through MTT assays, spectroscopic methods and molecular docking analysis. Our results indicate that BSA could attenuate effect on the cytotoxicity of DPPCAH, but not DPPCAH-Cu. Data from fluorescence quenching measurements demonstrated that both DPPCAH and DPPCAH-Cu could bind to BSA, with a reversed effect on the environment of tryptophan residues in polarity. CD spectra revealed that the DPPCAH-Cu exerted a slightly stronger effect on the secondary structure of BSA than DPPCAH. The association constant of DPPCAH with BSA was greater than that of DPPCAH-Cu. Docking studies indicated that the binding of DPPCAH to BSA involved a greater number of hydrogen bonds compared to DPPCAH-Cu. The calculated distances between bound ligands and tryptophans in BSA were in agreement with fluorescence resonance energy transfer results. Thus, the binding affinity of the drug (DPPCAH or DPPCAH-Cu) with BSA partially contributes to its antitumor activity; the greater the drug affinity is to BSA, the less is its antitumor activity.

  18. Study on interaction between a new fluorescent probe 2-methylbenzo[b][1,10]phenanthrolin-7(12H)-one and BSA.

    PubMed

    Qiu, Bin; Guo, Longhua; Chen, Mingluan; Lin, Zhenyu; Chen, Guonan

    2011-03-01

    A new fluorescence reagent, 2-methylbenzo[b][1,10]phenanthrolin-7(12H)-one (mBPO), synthesized in our laboratory was used as the probe for protein and its interaction with Bovine Serum Albumin (BSA) was investigated in detail in this paper. It was found that BSA had the ability to quench the fluorescence of mBPO at 411 nm (λ(ex) = 286 nm), and the quenched intensity of fluorescence was proportional to the concentration of BSA. Based on this fact, mBPO has been used as a fluorescence probe for the detection of BSA. Under the optimal conditions, the calibration graph is linear up to 0.5 mg L(-1) for BSA and the limit of detection (LOD) was 0.06 mg L(-1). The regression equation is y = 1048.8x + 7.2093 with R(2) = 0.9913. The mechanism for the interaction of mBPO with BSA was also studied, while the binding constant and the number of binding sites were calculated. According to the thermodynamics parameter, the binding mode between mBPO and BSA was deduced. The results suggested the interaction between mBPO and BSA to be hydrophobic force in nature. It also proved that the fluorescence quenching reaction was affected by the tryptophan residue of BSA. For there are two tryptophan (Trp) residues, in site 134 and site 212 of BSA, and mBPO maybe has interaction with them respectively.

  19. Interaction of Di-2-pyridylketone 2-pyridine Carboxylic Acid Hydrazone and Its Copper Complex with BSA: Effect on Antitumor Activity as Revealed by Spectroscopic Studies.

    PubMed

    Li, Cuiping; Huang, Tengfei; Fu, Yun; Liu, Youxun; Zhou, Sufeng; Qi, Zhangyang; Li, Changzheng

    2016-01-01

    The drug, di-2-pyridylketone-2-pyridine carboxylic acid hydrazone (DPPCAH) and its copper complex (DPPCAH-Cu) exhibit significant antitumor activity. However, the mechanism of their pharmacological interaction with the biological molecule bovine serum albumin (BSA) remains poorly understood. The present study elucidates the interactions between the drug and BSA through MTT assays, spectroscopic methods and molecular docking analysis. Our results indicate that BSA could attenuate effect on the cytotoxicity of DPPCAH, but not DPPCAH-Cu. Data from fluorescence quenching measurements demonstrated that both DPPCAH and DPPCAH-Cu could bind to BSA, with a reversed effect on the environment of tryptophan residues in polarity. CD spectra revealed that the DPPCAH-Cu exerted a slightly stronger effect on the secondary structure of BSA than DPPCAH. The association constant of DPPCAH with BSA was greater than that of DPPCAH-Cu. Docking studies indicated that the binding of DPPCAH to BSA involved a greater number of hydrogen bonds compared to DPPCAH-Cu. The calculated distances between bound ligands and tryptophans in BSA were in agreement with fluorescence resonance energy transfer results. Thus, the binding affinity of the drug (DPPCAH or DPPCAH-Cu) with BSA partially contributes to its antitumor activity; the greater the drug affinity is to BSA, the less is its antitumor activity. PMID:27136517

  20. 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.

  1. Studies of interaction between colchicine and bovine serum albumin by fluorescence quenching method

    NASA Astrophysics Data System (ADS)

    Hu, Yan-Jun; Liu, Yi; Zhang, Li-Xia; Zhao, Ru-Ming; Qu, Song-Sheng

    2005-08-01

    We investigated the interaction between colchicine and bovine serum albumin (BSA) by fluorescence and UV-Vis absorption spectroscopy. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by colchicine is a result of the formation of colchicine-BSA complex; van der Waals interactions and hydrogen bonds play a major role in stabilizing the complex. The modified Stern-Volmer quenching constant Ka and corresponding thermodynamic parameters ΔH, ΔG, ΔS at different temperatures were calculated. The distance r between donor (BSA) and acceptor (colchicine) was obtained according to fluorescence resonance energy transfer (FRET).

  2. 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.

  3. 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.

  4. Characterization of the binding of chrysoidine, an illegal food additive to bovine serum albumin.

    PubMed

    Yang, Bingjun; Hao, Fang; Li, Jiarong; Wei, Kai; Wang, Wenyu; Liu, Rutao

    2014-03-01

    Chrysoidine is an industrial azo dye and the presence of chrysoidine in water and food has become an environmental concern due to its negative effects on human beings. Binding of dyes to serum albumins significantly influence their absorption, distribution, metabolism, and excretion properties. In this work, the interactions of chrysoidine with bovine serum albumin (BSA) were explored. Isothermal titration calorimetry results reveal the binding stoichiometry of chrysoidine to BSA is 1:15.5, and van der Waals and hydrogen bonding interactions are the major driving force in the binding of chrysoidine to BSA. Molecular docking simulations show that chrysoidine binds to BSA at a cavity close to Sudlow site I in domain IIA. However, no detectable conformational change of BSA occurs in the presence of chrysoidine as revealed by UV-vis absorption, circular dichroism and fluorescence spectroscopy studies.

  5. 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)

  6. Interaction of cationic surfactant cethyltrimethylammonium bromide with bovine serum albumin in dependence on pH: A study of tryptophan fluorescence

    NASA Astrophysics Data System (ADS)

    Vlasova, Irina M.; Zhuravleva, Valeria V.; Vlasov, Alexander A.; Saletsky, Alexander M.

    2013-02-01

    The interaction of cationic surfactant cethyltrimethylammonium bromide (CTAB) with bovine serum albumin (BSA) at various values of pH has been studied using steady-state non-polarized tryptophan fluorescence of BSA and polarized tryptophan fluorescence of BSA. By analysis of intensity of tryptophan fluorescence of BSA, by analysis of position of maximum of spectrum of BSA tryptophan fluorescence, by analysis of polarization of BSA tryptophan fluorescence the qualitative rearrangements of BSA globules at denaturation under action of CTAB are registered. The estimation of parameters of rotational diffusion of BSA molecules helps one to determine the quantitative changes of size of BSA at CTAB-induced denaturation. It is shown that denaturation of BSA, taking place at interaction of cationic surfactant CTAB with BSA, has one-stage mono-phase character. At interaction of CTAB with BSA the deepest denaturation of BSA is reached at 4 mM CTAB (at pH 3.5-8.0). More intensive denaturation of BSA under action of CTAB takes place at values of pH, higher than the isoelectric point of BSA.

  7. In vitro evaluation of doxorubicin-incorporated magnetic albumin nanospheres.

    PubMed

    Zeybek, Ayça; Şanlı-Mohamed, Gülşah; Ak, Güliz; Yılmaz, Habibe; Şanlıer, Şenay H

    2014-07-01

    Magnetic albumin nanospheres that incorporate doxorubicin (M-DOX-BSA-NPs) were prepared previously by our research group to develop magnetically responsive drug carrier system. This nanocarrier was synthesized as a drug delivery system for targeted chemotherapy. In this work, cytotoxic effects of doxorubicin (DOX)-loaded/unloaded or magnetic/non-magnetic nanoparticles and free DOX against PC-3 cells and A549 cells were determined with the MTT test and the results were compared with each other. DOX-loaded magnetic albumin nanospheres (M-DOX-BSA-NPs) were found more cytotoxic than other formulations. The quantitative data obtained from flow cytometry analysis further verified the higher targeting and killing ability of M-DOX-BSA-NPs than free DOX on both of the cancer cell lines. Additionally, the results of cell cycle analysis have showed that M-DOX-BSA-NPs affected G1 and G2 phases. Finally, cell images were obtained using spin-disk confocal microscopy, and cellular uptake of M-DOX-BSA-NPs was visualized. The findings of this study suggest that M-DOX-BSA-NPs represent a potential doxorubicin delivery system for targeted drug transport into prostate and lung cancer cells.

  8. Study on the structural changes of bovine serum albumin with effects on polydatin binding by a multitechnique approach

    NASA Astrophysics Data System (ADS)

    Peng, Xialian; Yao, Di; Pan, Yingming; Yu, Qing; Ni, Shouhai; Bian, Hedong; Huang, Fuping; Liang, Hong

    2011-10-01

    Polydatin is a traditional Chinese medicine which shows effective biological activity as antimicrobial and antiviral agent. The secondary structure changes of bovine serum albumin (BSA) were investigated by the methods of Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD) and Raman spectroscopy. The experimental results indicated that polydatin changed the secondary structure of BSA. The presence of polydatin decreased α-helix content of BSA. The conformations of disulfide bridges and the microenvironment of Tyr, Trp residues were also changed.

  9. Detection of Hg2+ based on the selective inhibition of peroxidase mimetic activity of BSA-Au clusters.

    PubMed

    Zhu, Rui; Zhou, Yan; Wang, Xi-Liang; Liang, Li-Ping; Long, Yi-Juan; Wang, Qin-Long; Zhang, Hai-Jie; Huang, Xiao-Xiao; Zheng, Hu-Zhi

    2013-12-15

    It was found that Hg(2+) can inhibit the peroxidase mimetic activity of bovine serum albumin (BSA) protected Au clusters (BSA-Au) due to the specific interaction between Hg(2+) and Au(+) existed onto the surface of BSA-Au clusters. By coupling with 3, 3', 5, 5'-tetramethylbenzidine (TMB)-H2O2 chromogenic reaction, a novel method for Hg(2+) detection was developed based on the inhibiting effect of Hg(2+) on BSA-Au clusters peroxidase-like activity. This method exhibited high selectivity and sensitivity. As low as 3 nM (0.6 ppb, 3σ) Hg(2+) could be detected with a linear range from 10 nM (2 ppb) to 10 µM (2 ppm) and this method was successfully applied for the determination of total mercury content in skin lightening products.

  10. Receptor-mediated hepatic uptake of M6P-BSA-conjugated triplex-forming oligonucleotides in rats.

    PubMed

    Ye, Zhaoyang; Cheng, Kun; Guntaka, Ramareddy V; Mahato, Ram I

    2006-01-01

    Excessive production of extracellular matrix, predominantly type I collagen, results in liver fibrosis. Earlier we synthesized mannose 6-phosphate-bovine serum albumin (M6P-BSA) and conjugated to the type I collagen specific triplex-forming oligonucleotide (TFO) for its enhanced delivery to hepatic stellate cells (HSCs), which is the principal liver fibrogenic cell. In this report, we demonstrate a time-dependent cellular uptake of M6P-BSA-33P-TFO by HSC-T6 cells. Both cellular uptake and nuclear deposition of M6P-BSA-33P-TFO were significantly higher than those of 33P-TFO, leading to enhanced inhibition of type I collagen transcription. Following systemic administration into rats, hepatic accumulation of M6P-BSA-33P-TFO increased from 55% to 68% with the number of M6P per BSA from 14 to 27. Unlike 33P-TFO, there was no significant decrease in the hepatic uptake of (M6P)20-BSA-33P-TFO in fibrotic rats. Prior administration of excess M6P-BSA decreased the hepatic uptake of (M6P)20-BSA-33P-TFO from 66% to 40% in normal rats, and from 60% to 15% in fibrotic rats, suggesting M6P/insulin-like growth factor II (M6P/IGF II) receptor-mediated endocytosis of M6P-BSA-33P-TFO by HSCs. Almost 82% of the total liver uptake in fibrotic rats was contributed by HSCs. In conclusion, by conjugation with M6P-BSA, the TFO could be potentially used for the treatment of liver fibrosis.

  11. 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)…

  12. Competitive binding of phenylbutazone and colchicine to serum albumin in multidrug therapy: A spectroscopic study

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Maciążek-Jurczyk, M.; Bojko, B.; Równicka, J.; Zubik-Skupień, I.; Temba, E.; Pentak, D.; Sułkowski, W. W.

    2008-06-01

    The binding sites for phenylbutazone and colchicine were identified in tertiary structure of bovine and human serum albumin with the use of spectrofluorescence analysis. It was found that phenylbutazone has two binding sites in both sera albumins (HSA and BSA), while colchicine has one binding site in BSA as well as in HSA. The comparison of the quenching effect of BSA and HSA fluorescence by phenylbutazone and colchicine allows us to identify subdomain IIA in protein as the binding site for these two drugs. In this subdomain tryptophan 214 is located. The participation of tyrosyl and tryptophanyl residues of protein was also estimated in the drug-albumin complex. The comparison of quenching of fluorescence of HSA and BSA excited at 280 nm with that at 295 nm allowed us to state that the participation of tyrosyl residues of albumin in the phenylbutazone-serum albumin interaction is significant. The analysis of quenching of fluorescence of BSA in the binary and ternary systems showed that phenylbutazone does not affect the complex formed between colchicine and BSA. Similarly, colchicine has no effect on the Phe-BSA complex. However marked differences were observed for the complex with HSA. On the basis of Ka and KQ values it was concluded that colchicine may probably cause displacement of phenylbutazone from its complex with serum albumin (SA). Static and dynamic quenching for the binary and ternary systems is also discussed. The competition of phenylbutazone and colchicine in binding to serum albumin should be taken into account in the multi-drug therapy.

  13. Preparation and properties of BSA-loaded microspheres based on multi-(amino acid) copolymer for protein delivery.

    PubMed

    Chen, Xingtao; Lv, Guoyu; Zhang, Jue; Tang, Songchao; Yan, Yonggang; Wu, Zhaoying; Su, Jiacan; Wei, Jie

    2014-01-01

    A multi-(amino acid) copolymer (MAC) based on ω-aminocaproic acid, γ-aminobutyric acid, L-alanine, L-lysine, L-glutamate, and hydroxyproline was synthetized, and MAC microspheres encapsulating bovine serum albumin (BSA) were prepared by a double-emulsion solvent extraction method. The experimental results show that various preparation parameters including surfactant ratio of Tween 80 to Span 80, surfactant concentration, benzyl alcohol in the external water phase, and polymer concentration had obvious effects on the particle size, morphology, and encapsulation efficiency of the BSA-loaded microspheres. The sizes of BSA-loaded microspheres ranged from 60.2 μm to 79.7 μm, showing different degrees of porous structure. The encapsulation efficiency of BSA-loaded microspheres also ranged from 38.8% to 50.8%. BSA release from microspheres showed the classic biphasic profile, which was governed by diffusion and polymer erosion. The initial burst release of BSA from microspheres at the first week followed by constant slow release for the next 7 weeks were observed. BSA-loaded microspheres could degrade gradually in phosphate buffered saline buffer with pH value maintained at around 7.1 during 8 weeks incubation, suggesting that microsphere degradation did not cause a dramatic pH drop in phosphate buffered saline buffer because no acidic degradation products were released from the microspheres. Therefore, the MAC microspheres might have great potential as carriers for protein delivery.

  14. Systematic investigation of the toxicity interaction of ZnSe@ZnS QDs on BSA by spectroscopic and microcalorimetry techniques.

    PubMed

    Ding, Ling; Zhou, Peijiang; Zhan, Hongju; Zhao, Xiaohu; Chen, Chi; He, Zhenyu

    2013-08-01

    The interaction of ZnSe@ZnS quantum dots (QDs) and bovine serum albumin (BSA) was investigated by means of fluorescence (FL) spectrometry, circular dichroism (CD) spectra, and isothermal titration calorimetry (ITC). The fluorescence intensity of BSA decreased regularly with the increasing of QDs concentration. The decrease of BSA fluorescence intensity was proved to be a kind of static quenching. CD results show the helicity of BSA decreased from 38.04% to 26.51% with the addition of QDs, which suggests a stronger structural change that is related to a low degree of surface coverage. And also, both ion strength and pH value could affect the interaction between BSA and QDs, suggesting that both the static electronic attraction and H-bond contribute to the interaction between BSA and QDs. The thermodynamics of interaction between BSA and QDs were calculated from ITC data. Both enthalpy and entropy changes were favorable for the interaction in Tris-buffer, while only enthalpy change was favorable for the interaction in NaCl or HCl solution.

  15. Noninvasive real-time fluorescence imaging of the lymphatic uptake of BSA-IRDye 680 conjugate administered subcutaneously in mice.

    PubMed

    Wu, Fang; Bhansali, Suraj G; Tamhane, Mitalee; Kumar, Rajiv; Vathy, Lisa A; Ding, Hong; Yong, Ken-Tye; Bergey, Earl J; Prasad, Paras N; Morris, Marilyn E

    2012-05-01

    The goal of our studies was to determine lymphatic uptake of bovine serum albumin (BSA) using real-time noninvasive fluorescence imaging. BSA labeled with near-infrared dye (IRDye) 680 was used as a model protein-dye conjugate. The conjugation of BSA with IRDye 680 was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Size-exclusion high-performance liquid chromatography and SDS-PAGE demonstrated that the IRDye 680-labeled BSA conjugate in the lymph node (LN) homogenate samples was stable at physiological temperature (37°C) for at least 5 days. Whole-body noninvasive optical imaging of hairless SKH-1 mice was performed after subcutaneous (s.c.) injection (dose = 0.1 mg/kg) into the front footpad. Noninvasive fluorescence imaging demonstrated that BSA-IRDye 680 conjugates were dynamically taken up by the lymphatic system, accumulated in the axillary LNs and then cleared, indicating that lymphatic transport plays a role in the absorption of BSA. Ex vivo tissue imaging of LN homogenates provided confirmatory data with respect to the uptake of fluorescent-labeled BSA determined by in vivo imaging. Noninvasive real-time imaging of LNs provides a novel tool for evaluating uptake and accumulation of fluorescent-labeled proteins by the lymphatic system after s.c. injection in a mouse model.

  16. Cytotoxicity of BSA-Stabilized Gold Nanoclusters: In Vitro and In Vivo Study.

    PubMed

    Dong, Liyun; Li, Mulin; Zhang, Song; Li, Jun; Shen, Guanxin; Tu, Yating; Zhu, Jintao; Tao, Juan

    2015-06-01

    Gold nanoclusters (Au NCs) are one of the most promising fluorescent nanomaterials for bioimaging, targeting, and cancer therapy due to their tunable optical properties, yet their biocompatibility still remains unclear. Herein, the cytotoxicity of bovine serum albumin (BSA)-stabilized Au NCs is studied by using three tumor cell lines and two normal cell lines. The results indicate that Au NCs induce the decline of cell viabilities of different cell lines to varying degrees in a dose- and time-dependent manner, and umbilical vein endothelial cells which had a higher intake of Au NCs than melanoma cells show more toxicity. Addition of free BSA to BSA-Au NCs solutions can relieve the cytotoxicity, implying that BSA can prevent cell damage. Moreover, Au NCs increase intracellular reactive oxygen species (ROS) production, further causing cell apoptosis. Furthermore, N-acetylcysteine, a ROS scavenger, partially reverses Au NCs-induced cell apoptosis and cytotoxicity, indicating that ROS might be one of the primary reasons for the toxicity of BSA-Au NCs. Surprisingly, Au NCs with concentrations of 5 and 20 nM significantly inhibit tumor growth in the xenograft mice model of human liver cancer, which might provide a new avenue for the design of anti-cancer drug delivery vehicles.

  17. The impact of skin viability on drug metabolism and permeation -- BSA toxicity on primary keratinocytes.

    PubMed

    Haberland, A; Schreiber, S; Maia, C Santos; Rübbelke, M K; Schaller, M; Korting, H C; Kleuser, B; Schimke, I; Schäfer-Korting, M

    2006-04-01

    For testing cutaneous absorption of drugs, ingredients of cosmetics and also for risk assessment of industrial compounds predictable in vitro test protocols are under investigation using excised skin or reconstructed human epidermis. Since the metabolizing enzymes expressed by viable skin can influence the absorption behaviour of substances by changing their structure and thereby their physicochemical characteristics, the metabolic capacity should be considered in the design of the test protocols of compounds susceptible to metabolism. Then data, generated using viable reconstructed epidermis may reflect the in vivo situation. Interestingly, bovine serum albumin (BSA) commonly used in receptor media in permeation studies to facilitate solubility of highly lipophilic substances strongly inhibited the metabolism of topically applied prednicarbate in reconstructed epidermis. Here, we show that 5% BSA is toxic to reconstructed epidermis and keratinocytes which was consistent with the earlier findings. While media toxicity (deficiency media) was at least partly the cause of both apoptotic and necrotic processes in keratinocytes, BSA only slightly increased the rate of necrotic cells. Moreover, caspase inhibitors did not reduce BSA toxicity. Yet, the results show that BSA toxicity on keratinocytes has to be carefully considered if this protein is used in permeation studies with reconstructed epidermis.

  18. Silver nanoclusters emitting weak NIR fluorescence biomineralized by BSA

    NASA Astrophysics Data System (ADS)

    Li, Baoshun; Li, Jianjun; Zhao, Junwu

    2015-01-01

    Noble metal (e.g., gold and silver) nanomaterials possess unique physical and chemical properties. In present work, silver nanoclusters (also known as silver quantum clusters or silver quantum dots) were synthesized by bovine serum albumin (BSA) biomineralization. The synthesized silver nanoclusters were characterized by UV-VIS absorption spectroscopy, fluorescence spectroscopy, upconversion emission spectroscopy, TEM, HRTEM and FTIR spectroscopy. TEM results showed that the average size of the silver nanoclusters was 2.23 nm. Fluorescence results showed that these silver nanoclusters could emit weak near-infrared (NIR) fluorescence (the central emission wavelength being about 765 nm). And the central excitation wavelength was about 395 nm, in the UV spectral region. These silver nanoclusters showed an extraordinarily large gap (about 370 nm) between the central excitation wavelength and central emission wavelength. In addition, it was found that these silver nanoclusters possess upconversion emission property. Upconversion emission results showed that the upconversion emission spectrum of the silver nanoclusters agreed well with their normal fluorescence emission spectrum. The synthesized silver nanoclusters showed high stability in aqueous solution and it was considered that they might be confined in BSA molecules. It was found that silver nanoclusters might enhance and broaden the absorption of proteins, and the protein absorption peak showed an obvious red shift (being 7 nm) after the formation of silver nanoclusters.

  19. 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.

  20. Spectroscopic studies on the interaction between troxerutin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Wang, Tianhu; Zhao, Zhimin; Zhang, Lin; Ji, Lei

    2009-11-01

    The interaction between troxerutin and bovine serum albumin (BSA) was investigated by fluorescence and absorption spectroscopy under simulative physiological conditions. Results show that troxerutin causes the fluorescence quenching of BSA through a static quenching procedure. The binding constant KA and number of binding sites n of troxerutin with BSA were obtained. Positive values of thermodynamic parameters enthalpy change (Δ H) and entropy change (Δ S) indicate that the interaction between troxerutin and BSA is driven mainly by hydrophobic forces. It seems that the binding is spontaneous at standard state for the change in standard Gibbs free energy (Δ G) value is negative. The binding distance between the donor (BSA) and the acceptor (troxerutin) was calculated to be about 4.21 nm based on the Förster theory. The effect of troxerutin on the conformation of BSA was also analyzed by using synchronous fluorescence spectroscopy.

  1. 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.

  2. Study on the interaction of sodium morin-5-sulfonate with bovine serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Shahabadi, Nahid; Mohammadpour, Mahnaz

    2012-02-01

    In the present investigation, an attempt has been made to study the interaction of sodium morin-5-sulfonate (NaMSA) with the transport proteins, bovine serum albumin (BSA) employing UV-vis, fluorometric and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the compound was a static procedure. Various binding parameters were evaluated. The negative value of Δ H, positive value of Δ S and the negative value of Δ G indicated that electrostatic interactions and hydrogen bonding play major roles in the binding of the NaMSA and BSA. Based on the Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (NaMSA) was evaluated. The results of CD and UV-vis spectroscopy showed that the binding of this complex to BSA induces some conformational changes in BSA.

  3. Study on the interaction between NCP-(4-hydroxycoumarins) and bovine serum albumin by spectroscopic techniques.

    PubMed

    Yu, Xianyong; Lu, Shiyu; Yang, Ying; Li, Xiaofang; Yi, Pinggui

    2012-06-01

    The interaction between N-confused porphyrins-(4-hydroxycoumarins) diad (NCP-(4-hydroxycoumarins)) and bovine serum albumin (BSA) was studied using fluorescence and ultraviolet spectroscopy at different temperatures under imitated physiological conditions. The experimental results showed that the fluorescence of BSA was quenched by NCP-(4-hydroxycoumarins) through a combined quenching procedure. The binding constants, binding sites and corresponding thermodynamic parameters between NCP-(4-hydroxycoumarins) and BSA at different temperatures were obtained. According to Förster non-radiation energy transfer theory, the binding distance between BSA and NCP-(4-hydroxycoumarins) was calculated to be about 2.1 nm. The effect of NCP-(4-hydroxycoumarins) on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. In addition, the effect of some metal ions Cu(2+), Ca(2+), Mg(2+), and Ni(2+) on the binding constant between NCP-(4-hydroxycoumarins) and BSA was examined.

  4. Study on the interaction of food colourant quinoline yellow with bovine serum albumin by spectroscopic techniques.

    PubMed

    Shahabadi, Nahid; Maghsudi, Maryam; Rouhani, Shohre

    2012-12-01

    The interaction of a food colourant, quinoline yellow (Qy), and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorometry, FT-IR and circular dichroism (CD) techniques. The experimental results indicated that the quenching mechanism of BSA by the dye 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 Qy and BSA. Based on Forster's theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (Qy) was evaluated. The results of CD and UV-vis spectroscopy showed that this dye could bind to BSA and the conformation of BSA changed.

  5. Structural influence of graft and block polycations on the adsorption of BSA.

    PubMed

    Zhang, Li; Jin, Fengmin; Zhang, Tingbin; Zhang, Ling; Xing, Jinfeng

    2016-04-01

    Protein adsorption is considered as an important factor for the low transfection efficiency of polycations in vivo. In this study, two typical polycations of equal molecular weight with different structures were chosen to investigate their adsorption on bovine serum albumin (BSA), including the block copolymer named poly (N-vinylpyrrolidone)-b-poly (2-dimethylaminoethyl methacrylate) (PVP-b-PDMAEMA, i.e. PbP) and graft copolymer named PVP-g-PDMAEMA (PgP), respectively. Fluorescence spectroscopy was used to confirm the binding constants and binding sites between polycations and BSA in static state. The binding constants were 4.1×10(4)M(-1) vs 8.3×10(4)M(-1) and binding sites were 0.3 vs 1.1 for PbP and PgP, respectively, indicating PgP had stronger binding affinity with BSA. Surface plasmon resonance (SPR) was used to study the dynamical non-specific interaction between BSA and polycations as well as the polyplexes. The numbers of both PbP and PgP adsorbed on BSA increased with concentration of polycations increasing, and the number of PgP adsorbed on BSA is higher compared with PbP when their concentration is low. When their concentration is high, the number of PbP adsorbed on BSA is more than that of PgP. However, PgP/DNA polyplexes showed higher adsorption amount compared with PbP/DNA polyplexes at different N/P ratios.

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

    PubMed

    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 Cu(2+) 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. 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.

  8. 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.

  9. Study of adsorption of bovine serum albumin to Langmuir Blodgett film coated surfaces using work of adhesion as a tool

    NASA Astrophysics Data System (ADS)

    Sandhya, S.; Lakshmanan, Muthuselvi; Dhathathreyan, A.

    2008-08-01

    This work reports on the use of rate of change of work of adhesion (Δ W) as a tool to study adsorption of bovine serum albumin (BSA) to glass and Langmuir-Blodgett film of dihexadecyl phosphate (DHP) and dioctadecyl dimethyl ammonium bromide (DOMA) coated surfaces. Pure BSA and BSA with additives - sorbitol and urea - have been adsorbed to bare glass surfaces and DHP and DOMA coated surfaces. The results suggest that an increase in Δ W with time indicates promotion of adsorption while a decrease indicates hindered adsorption. Further adsorption of BSA was most effective on DHP coated surface compared with bare glass and DOMA coated glass. In case of mixtures of BSA with urea and sorbitol, BSA + urea showed hindered adsorption while adsorption of BSA + sorbitol was efficient for all substrates.

  10. Albumin-fatty acid interactions at monolayer interface

    NASA Astrophysics Data System (ADS)

    Gew, Lai Ti; Misran, Misni

    2014-05-01

    The fluid mosaic model of Singer and Nicolson in 1972 shows how proteins are embedded in membranes. To elucidate the interactions between proteins and the surrounding lipids, stearic acid (SA) and bovine serum albumin (BSA) were used as lipid-protein components to mimic the normal membrane bilayer environment using the Langmuir-Blodgett technique. Surface pressure ( π)-molecular area ( A) isotherms were recorded for the SA monolayer in the presence of BSA on water. The mixed monolayer was successfully transferred onto an oxidized silicon wafer and imaged by tapping mode atomic force microscopy (AFM). Miscibility, compressibility and thermodynamic stability of the mixed system were examined. A large negative deviation of A ex, together with the minimum value of Δ G ex, was observed when the mole fraction of BSA ( X BSA) was 0.8, indicating this to be the most stable mixture. In a compressibility analysis, X BSA was observed at below 50 mN m-1, denoting a liquid-expanded phase and showing the occurrence of a strong interaction of SA with BSA molecules in this phase. AFM observations supported the quantitative data indicating that BSA was strongly attracted onto the membrane surface as predicted.

  11. A novel affinity disks for bovine serum albumin purification.

    PubMed

    Tuzmen, Nalan; Kalburcu, Tülden; Uygun, Deniz Aktaş; Akgol, Sinan; Denizli, Adil

    2015-01-01

    The adsorption characteristics of bovine serum albumin (BSA) onto the supermacroporous poly(hydroxyethylmethacrylate)-Reactive Green 19 [p(HEMA)-RG] cryogel disks have been investigated in this paper. p(HEMA) cryogel disks were prepared by radical polymerization initiated by N,N,N',N'-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. Reactive Green (RG) 19 was covalently attached to the p(HEMA) cryogel disks. These disks were used in BSA adsorption studies to interrogate the effects of pH, initial protein concentration, ionic strength, and temperature. BSA adsorption capacity of the p(HEMA)-RG cryogel disk was significantly improved after the incorporation of RG. Adsorption capacity reached a plateau value at about 0.8 mg/mL at pH 4.0. The amount of adsorbed BSA decreased from 37.7 to 13.9 mg/g with increasing NaCl concentration. The enthalpy of BSA adsorption onto the p(HEMA)-RG cryogel disk was calculated as -58.4 kJ/mol. The adsorption equilibrium isotherm was fitted well by the Freundlich model. BSA was desorbed from cryogel disks (over 90 %) using 0.5 M NaSCN, and the purity of desorbed BSA was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The experimental results showed that the p(HEMA)-RG cryogel disks have potential for the quick protein separation and purification process. PMID:25308615

  12. 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.

  13. 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.

  14. 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.

  15. Culture of ovine embryos in the absence of bovine serum albumin.

    PubMed

    Russler-Long, J A; Dickey, J F; Richardson, M E; Ivey, K W

    1991-02-01

    Bovine serum albumin (BSA), a relatively impure protein, is routinely used as a component of embryo culture media. Since media containing BSA are chemically undefined, it would be desirable to replace BSA with substitutes of similar activity which are either chemically better defined and/or better standardized than BSA. Two commercial products, Ultroser((R)) G (USG) and Solcoseryl((R)) (SOL), were evaluated as replacements for BSA in culture with respect to the development of ovine embryos in vitro. A total of 126 late 8-cell and early 16-cell embryos were distributed among modified Brinster's medium for ovum culture (BMOC-2) containing either 1.5% BSA, 2.0% USG or 2.0% SOL. All three culture media supported development of ovine embryos. Results indicate that 8- and 16-cell embryos will develop into blastocysts in a BSA-free medium containing either USG or SOL. A higher number of embryos developed into blastocysts in media containing BSA than in media containing USG or SOL, and more blastocysts hatched in media containing BSA. Although the overall degree of embryonic development was more advanced in BSA-supplemented media, the concentrations of USG and SOL that were used in this study may not have been optimal for ovine embryo culture. PMID:16726908

  16. 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.

  17. 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.

  18. Stability of the complex BSA-6-propyl-2-thiouracil in the presence of Gu·HCl and urea

    NASA Astrophysics Data System (ADS)

    Równicka, Joanna; Sułkowska, Anna; Pożycka, Jadwiga; Bojko, Barbara; Sułkowski, Wiesław W.

    2006-07-01

    Pathologic structure of albumin is present in blood of uremic or diabetic patients. The defective binding of albumin can cause, among others, inhibition of the metabolism of amphipathic hormones and the enhancement of the toxicity of drugs. We aim to show the alteration of the binding site of 6-propyl-2-thiouracil (PTU) in bovine serum albumin (BSA) in the presence of urea and guanidine hydrochloride. This study shows that PTU has the tendency to interact within the hydrophobic domain IIA or IB of serum albumin and to quench the fluorescence of tryptophanyl side chains by the static and collisional quenching mechanism. For the binding to the native protein, two classes of binding sites are seen. In the first one, the binding constant is equal to K bI-9.6×10 4 M -1, and in the second class, the binding constant is K bII-7.1×10 3 M -1. For the binding to the denaturated serum albumin, only one class of the binding sites can be observed. The binding constants for BSA denatured with urea and Gu·HCl are lower and are equal to 2.2×10 4 M -1 and 3.5×10 4 M -1, respectively. Evaluation of the binding ability of serum albumin is also important in case of older people because weaker drug-protein interaction can result in the increase of drug concentration in the blood serum.

  19. 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.

  20. 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

  1. Paeoniflorin protects HUVECs from AGE-BSA-induced injury via an autophagic pathway by acting on the RAGE.

    PubMed

    Chen, Yufang; Du, Xing; Zhou, Yande; Zhang, Yanlin; Yang, Yaping; Liu, Zhihua; Liu, Chunfeng; Xie, Ying

    2015-01-01

    The aim of our study was to investigate the protective effects of Paeoniflorin (PF) against injury induced by AGE-modified bovine serum albumin (AGE-BSA) in human umbilical vein endothelial cells (HUVECs), and to examine the underlying mechanisms of these effects. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine cell viability. Protein expression levels were determined by western blotting. For function-blocking experiments, we used small interfering RNA molecules (siRNA) for function-blocking experiments. At 6 h, we found that 100 μg/mL AGE-BSA reduced the viability of HUVECs. However, pretreatment with PF restored cell viability in a dose-dependent manner. AGE-BSA increased the levels of microtubule-associated protein light chain 3-II (LC3-II) and the receptor for advanced glycation end products (RAGE). Expression of p62 protein was also increased, but not at a statistically significant level. Pretreatment with PF further increased levels of LC3-II and RAGE, but reduced the expression of p62. In cells transfected with Atg5 and RAGE siRNA, cell viability and expression of LC3-II decreased in both the AGE-BSA and PF + AGE-BSA treatments. PF can protect HUVECs from AGE-BSA-induced injury by upregulating autophagy and promoting the completion of autophagy flux. RAGE plays an important role in this autophagic protection effect.

  2. 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

    2015-08-01

    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.

  3. Isolation and characterization of serum albumin from Camelus dromedarius

    PubMed Central

    MALIK, AJAMALUDDIN; AL-SENAIDY, ABDULRAHMAN; SKRZYPCZAK-JANKUN, EWA; JANKUN, JERZY

    2013-01-01

    Serum albumin constitutes 35–50 mg/ml of plasma proteins and performs various physiological activities including the regulation of osmotic pressure on blood, maintaining buffering of the blood pH, carrying different fatty acids and other small molecules, such as bilirubin, hormones, drugs and metal ions, as well as participating in immunological responses. Serum albumin is an extensively used protein in biotechnological and pharmaceutical industries. The camel (Camelus dromedarius) is well tailored to successfully survive in extremely hot and dry climates. Plasma osmolality in the camel increases during water-deprived conditions. In such circumstances serum albumin is crucial in the regulation of blood pressure. The study of biochemical, biophysical and immunological aspects of camel serum albumin (CSA) are likely to provide molecular insights into camel physiology and may render it an alternative to human serum albumin (HSA) and bovine serum albumin (BSA) in all cases. However, these proteins are currently not available or cannot be utilized due to a variety of considerations. In this study, 12 mg of highly pure CSA was obtained from 1 ml plasma. Coomassie Brilliant Blue staining of SDS-PAGE yielded one band and RP-HPLC results revealed a single sharp peak, indicating homogenous preparation of the CSA. The charge/mass ratio and surface hydrophobicity of the CSA was similar to that of BSA. Mass spectrometry analysis of the purified protein confirmed the identity of CSA. PMID:24137219

  4. Spectroscopy and Fluorescence Lifetime Imaging Microscopy To Probe the Interaction of Bovine Serum Albumin with Graphene Oxide.

    PubMed

    Kuchlyan, Jagannath; Kundu, Niloy; Banik, Debasis; Roy, Arpita; Sarkar, Nilmoni

    2015-12-29

    The interaction of graphene oxide (GO) with bovine serum albumin (BSA) in aqueous buffer solution has been investigated with various spectroscopic and imaging techniques. At single molecular resolution this interaction has been performed using fluorescence correlation spectroscopy (FCS) and fluorescence lifetime imaging microscopy (FLIM) techniques. The conformational dynamics of BSA on GO's influence have been explored by FCS and circular dichroism (CD) spectroscopy. For the FCS studies BSA was labeled covalently by a fluorophore, Alexa Fluor 488. On the addition of GO in phosphate buffer of 10 mM at pH 7.4 the diffusion time (τD) and the hydrodynamic radius (Rh) of BSA increase due to adsorption of BSA. Conformational relaxation time components of native BSA drastically vary with the addition of GO, signifying the change of conformational dynamics of BSA after addition of GO. The adsorption isotherm also indicates significant adsorption of BSA on the GO surface. Adsorption of BSA on the GO surface has shown in direct images of atomic force microscopy (AFM) and FLIM. Fluorescence quenching study of BSA with addition of GO also indicates that there is strong interaction between BSA and GO. PMID:26646418

  5. Spectroscopy and Fluorescence Lifetime Imaging Microscopy To Probe the Interaction of Bovine Serum Albumin with Graphene Oxide.

    PubMed

    Kuchlyan, Jagannath; Kundu, Niloy; Banik, Debasis; Roy, Arpita; Sarkar, Nilmoni

    2015-12-29

    The interaction of graphene oxide (GO) with bovine serum albumin (BSA) in aqueous buffer solution has been investigated with various spectroscopic and imaging techniques. At single molecular resolution this interaction has been performed using fluorescence correlation spectroscopy (FCS) and fluorescence lifetime imaging microscopy (FLIM) techniques. The conformational dynamics of BSA on GO's influence have been explored by FCS and circular dichroism (CD) spectroscopy. For the FCS studies BSA was labeled covalently by a fluorophore, Alexa Fluor 488. On the addition of GO in phosphate buffer of 10 mM at pH 7.4 the diffusion time (τD) and the hydrodynamic radius (Rh) of BSA increase due to adsorption of BSA. Conformational relaxation time components of native BSA drastically vary with the addition of GO, signifying the change of conformational dynamics of BSA after addition of GO. The adsorption isotherm also indicates significant adsorption of BSA on the GO surface. Adsorption of BSA on the GO surface has shown in direct images of atomic force microscopy (AFM) and FLIM. Fluorescence quenching study of BSA with addition of GO also indicates that there is strong interaction between BSA and GO.

  6. One-step electrochemically co-assembled redox-active [Ru(bpy)2(tatp)]2+-BSA-SWCNTs hybrid film for non-redox protein biosensors.

    PubMed

    Ji, Shi-Bo; Yan, Zhi-Hong; Wu, Jun-Wen; Chen, Lin-Lin; Li, Hong

    2013-01-15

    A redox-active [Ru(bpy)(2)(tatp)](2+)-BSA-SWCNTs (bpy=2,2'-bipyridine, tatp=1,4,8,9-tetra-aza-triphenylene, BSA=bovine serum albumin, SWCNTs=single-walled carbon nanotubes) hybrid film is fabricated on an indium-tin oxide (ITO) electrode via one-step electrochemical co-assembly approach. BSA is inherently dispersive and therefore served as the linking mediator of SWCNTs, which facilitate the redox reactions of [Ru(bpy)(2)(tatp)](2+) employed as a reporter of BSA. The evidences from differential pulse voltammetry, cyclic voltammetry, scanning electron microscope, emission spectroscopy and fluorescence microscope reveal that the [Ru(bpy)(2)(tatp)](2+)-BSA-SWCNTs hybrid can be electrochemically co-assembled on the ITO electrode, showing two pairs of well-defined Ru(II)-based redox waves. Furthermore, the electrochemical co-assembly of the [Ru(bpy)(2)(tatp)](2+)-BSA-SWCNTs hybrid is found to be strongly dependent on the simultaneous presence of BSA and SWCNTs, indicating a good linear response to BSA in the range from 6 to 50mgL(-1). The results from this study provide an electrochemical co-assembly method for the development of non-redox protein biosensors.

  7. Kinetic investigation on the oxidation of tris(1,10-phenanthroline)iron(II) by oxone: the effect of BSA-SDS interaction.

    PubMed

    Mandal, Harasit Kumar; Kundu, Arjama; Balti, Subrata; Mahapatra, Ambikesh

    2012-07-15

    The kinetic investigations of oxidation of tris(1,10-phenanthroline)iron(II) by oxone have been studied spectrophotometrically in phosphate buffer medium of pH 6.8, temperature 308 K, and ionic strength 0.25 mol L(-1). The reactions were also carried out in presence of globular transport protein, bovine serum albumin (BSA) having isoelectric point 4.9, anionic surfactant sodium dodecyl sulfate (SDS), and their mixtures. The critical aggregation concentration (CAC) and critical micelle concentration (CMC) of SDS in presence of BSA have been determined using conductivity and kinetic measurement techniques. The secondary structure of BSA was examined by Circular Dichroism (CD) measurement at 308 K. The helix nature of BSA decreases with increase of SDS concentration. The effect of pH on rate in presence of BSA is opposite to its absence, and the effect of urea on rate in presence of BSA indicates the denaturation of BSA. The results depict that amphiphile SDS interacts with BSA and different molecular events, for example, specific binding, cooperative binding, protein unfolding, and micelle formation act. Activation parameters of the reaction in different environments have been determined.

  8. One-step electrochemically co-assembled redox-active [Ru(bpy)2(tatp)]2+-BSA-SWCNTs hybrid film for non-redox protein biosensors.

    PubMed

    Ji, Shi-Bo; Yan, Zhi-Hong; Wu, Jun-Wen; Chen, Lin-Lin; Li, Hong

    2013-01-15

    A redox-active [Ru(bpy)(2)(tatp)](2+)-BSA-SWCNTs (bpy=2,2'-bipyridine, tatp=1,4,8,9-tetra-aza-triphenylene, BSA=bovine serum albumin, SWCNTs=single-walled carbon nanotubes) hybrid film is fabricated on an indium-tin oxide (ITO) electrode via one-step electrochemical co-assembly approach. BSA is inherently dispersive and therefore served as the linking mediator of SWCNTs, which facilitate the redox reactions of [Ru(bpy)(2)(tatp)](2+) employed as a reporter of BSA. The evidences from differential pulse voltammetry, cyclic voltammetry, scanning electron microscope, emission spectroscopy and fluorescence microscope reveal that the [Ru(bpy)(2)(tatp)](2+)-BSA-SWCNTs hybrid can be electrochemically co-assembled on the ITO electrode, showing two pairs of well-defined Ru(II)-based redox waves. Furthermore, the electrochemical co-assembly of the [Ru(bpy)(2)(tatp)](2+)-BSA-SWCNTs hybrid is found to be strongly dependent on the simultaneous presence of BSA and SWCNTs, indicating a good linear response to BSA in the range from 6 to 50mgL(-1). The results from this study provide an electrochemical co-assembly method for the development of non-redox protein biosensors. PMID:22824544

  9. Albumin-based nanoparticle trehalose lyophilisation stress-down to preserve structure/function and enhanced binding.

    PubMed

    Siri, Macarena; Grasselli, Mariano; Alonso, Silvia Del V

    2016-07-15

    The aim of this study was to preserve albumin nanoparticle structure/function during the lyophilisation process. Bovine serum albumin nanoparticles were obtained by γ-irradiation. Nanoparticles were lyophilised in buffer, miliQ water or in trehalose/miliQ solution. The size and charge of the nanoparticles were tested after lyophilisation by light scattering and Z potential. The most relevant results in size of BSA nanoparticle were those lyophilised in PBS between 20 and 350nm, assembled in different aggregates, and negative Z potential obtained was 37±8mV in all, and those nanoparticles lyophilised with trehalose had a size range of 70±2nm and a negative Z potential of 20±5mV. Structure determination of surface aminoacids SH groups in the BSA NP lyophilised in PBS showed an increase in the free SH groups. Different aggregates had different amount of SH groups exposure from 55 to 938 (from smaller to bigger aggregates), whereas BSA NP lyophilised with trehalose showed no significant difference if compared with BSA NP. The binding properties of the BSA nanoparticle with a theragnostic probe (merocyanine 540) were studied after lyophilisation. Results showed more affinity between the BSA NP lyophilised with trehalose than that observed with non lyophilised BSA NP. As a result, the lyophilisation condition in trehalose 100μM solution is the best one to preserve the BSA NP structure/function and the one with the enhance binding affinity of the BSA NP.

  10. Albumin-based nanoparticle trehalose lyophilisation stress-down to preserve structure/function and enhanced binding.

    PubMed

    Siri, Macarena; Grasselli, Mariano; Alonso, Silvia Del V

    2016-07-15

    The aim of this study was to preserve albumin nanoparticle structure/function during the lyophilisation process. Bovine serum albumin nanoparticles were obtained by γ-irradiation. Nanoparticles were lyophilised in buffer, miliQ water or in trehalose/miliQ solution. The size and charge of the nanoparticles were tested after lyophilisation by light scattering and Z potential. The most relevant results in size of BSA nanoparticle were those lyophilised in PBS between 20 and 350nm, assembled in different aggregates, and negative Z potential obtained was 37±8mV in all, and those nanoparticles lyophilised with trehalose had a size range of 70±2nm and a negative Z potential of 20±5mV. Structure determination of surface aminoacids SH groups in the BSA NP lyophilised in PBS showed an increase in the free SH groups. Different aggregates had different amount of SH groups exposure from 55 to 938 (from smaller to bigger aggregates), whereas BSA NP lyophilised with trehalose showed no significant difference if compared with BSA NP. The binding properties of the BSA nanoparticle with a theragnostic probe (merocyanine 540) were studied after lyophilisation. Results showed more affinity between the BSA NP lyophilised with trehalose than that observed with non lyophilised BSA NP. As a result, the lyophilisation condition in trehalose 100μM solution is the best one to preserve the BSA NP structure/function and the one with the enhance binding affinity of the BSA NP. PMID:27174378

  11. Inactivation of Gram-Negative Bacteria by Lysozyme, Denatured Lysozyme, and Lysozyme-Derived Peptides under High Hydrostatic Pressure

    PubMed Central

    Masschalck, Barbara; Van Houdt, Rob; Van Haver, Ellen G. R.; Michiels, Chris W.

    2001-01-01

    We have studied the inactivation of six gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens, Salmonella enterica serovar Typhimurium, Salmonella enteritidis, Shigella sonnei, and Shigella flexneri) by high hydrostatic pressure treatment in the presence of hen egg-white lysozyme, partially or completely denatured lysozyme, or a synthetic cationic peptide derived from either hen egg white or coliphage T4 lysozyme. None of these compounds had a bactericidal or bacteriostatic effect on any of the tested bacteria at atmospheric pressure. Under high pressure, all bacteria except both Salmonella species showed higher inactivation in the presence of 100 μg of lysozyme/ml than without this additive, indicating that pressure sensitized the bacteria to lysozyme. This extra inactivation by lysozyme was accompanied by the formation of spheroplasts. Complete knockout of the muramidase enzymatic activity of lysozyme by heat treatment fully eliminated its bactericidal effect under pressure, but partially denatured lysozyme was still active against some bacteria. Contrary to some recent reports, these results indicate that enzymatic activity is indispensable for the antimicrobial activity of lysozyme. However, partial heat denaturation extended the activity spectrum of lysozyme under pressure to serovar Typhimurium, suggesting enhanced uptake of partially denatured lysozyme through the serovar Typhimurium outer membrane. All test bacteria were sensitized by high pressure to a peptide corresponding to amino acid residues 96 to 116 of hen egg white, and all except E. coli and P. fluorescens were sensitized by high pressure to a peptide corresponding to amino acid residues 143 to 155 of T4 lysozyme. Since they are not enzymatically active, these peptides probably have a different mechanism of action than all lysozyme polypeptides. PMID:11133464

  12. 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.

  13. 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.

  14. Nucleolin is a receptor for maleylated-bovine serum albumin on macrophages.

    PubMed

    Miki, Yuichi; Koyama, Keisuke; Kurusu, Haruna; Hirano, Kazuya; Beppu, Masatoshi; Fujiwara, Yasuyuki

    2015-01-01

    Scavenger receptors have a broad range of functions that include pathogen clearance, and identification of the scavenger receptor family has been of great benefit to the field of physiology. The shuttling-protein nucleolin has recently been shown to possess scavenger receptor-like activity. We therefore investigated whether or not nucleolin is a receptor for maleylated-bovine serum albumin (maleylated-BSA), which is a common ligand for scavenger receptors. Binding and phagocytosis of native control-BSA by thioglycollate-elicited mouse peritoneal macrophages was weak, but that of maleylated-BSA was strong. Surface plasmon-resonance analysis revealed that nucleolin strongly associated with maleylated-BSA but not control-BSA or maleic anhydride. Further, co-treatment of macrophages with anti-nucleolin antibody, but not control-immunoglobulin G, inhibited binding of maleylated-BSA. In addition, antineoplastic guanine rich oligonucleotide (AGRO), a nucleolin-specific oligonucleotide aptamer, inhibited binding of maleylated-BSA. Further, binding of maleylated-BSA to nucleolin-transfected HEK293 cells was higher than that by control HEK cells. These results indicate that nucleolin is a receptor that enables macrophages to recognize maleylated-BSA.

  15. Zinc oxide nanoparticle and bovine serum albumin interaction and nanoparticles influence on cytotoxicity in vitro.

    PubMed

    Žūkienė, Rasa; Snitka, Valentinas

    2015-11-01

    Bovine serum albumin (BSA) and zinc oxide nanoparticles (ZnO NPs) are chosen as a model system to investigate NPs-protein corona complex formation. ZnO NPs with average size of ∼ 20 nm are coated with BSA using covalent and non-covalent conjugation at temperatures of 4 °C and 20 °C. The interaction mechanism between ZnO NPs and BSA is studied by using UV-vis absorption, fluorescence, synchronous fluorescence and Raman spectroscopy. Raman spectra of BSA in the presence of ZnO NPs are registered for the first time and confirm decreased α-helix content, increased unstructured folding and β-sheet content in BSA structure. The synchronous fluorescence spectra revealed that the hydrophobicity of the tyrosine residue is decreased and that of the tryptophan is increased. The relation of elucidated changes in BSA structure of BSA-coated ZnO NPs cytotoxicity is tested for CHO cell viability and reactive oxygen species (ROS) generation in vitro. Covalent and non-covalent binding of BSA to ZnO NPs reduces ZnO NPs cytotoxicity and ROS generation, however changes in BSA conformation makes corona less protective against ZnO NPs.

  16. 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. PMID:26920314

  17. 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.

  18. 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.

  19. Spectroscopic analyses on interaction of Naphazoline hydrochloride with bovine serum albumin.

    PubMed

    Zhu, Shizhong; Liu, Yang

    2012-12-01

    The fluorescence and ultraviolet spectroscopy were explored to study the interaction between Naphazoline hydrochloride (Naphcon) and bovine serum albumin (BSA) at three different temperatures (292, 301, and 310 K) under imitated physiological conditions. The quenching mechanism of BSA by Naphacon was interpreted using the Stern-Volmer mechanism, and a combined quenching (dynamic and static quenching). The binding constants, binding sites and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between BSA and Naphcon was found to be 4.71 nm. Synchronous fluorescence spectroscopy showed the conformation of BSA changed in the presence of Naphacon. In addition, the effect of some common metal ions (Mg(2+), Ca(2+), Ni(2+), Cu(2+), and Fe(2+)) on the binding constant between Naphcon and BSA was examined.

  20. Spectroscopic analyses on interaction of Naphazoline hydrochloride with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Zhu, Shizhong; Liu, Yang

    2012-12-01

    The fluorescence and ultraviolet spectroscopy were explored to study the interaction between Naphazoline hydrochloride (Naphcon) and bovine serum albumin (BSA) at three different temperatures (292, 301, and 310 K) under imitated physiological conditions. The quenching mechanism of BSA by Naphacon was interpreted using the Stern-Volmer mechanism, and a combined quenching (dynamic and static quenching). The binding constants, binding sites and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between BSA and Naphcon was found to be 4.71 nm. Synchronous fluorescence spectroscopy showed the conformation of BSA changed in the presence of Naphacon. In addition, the effect of some common metal ions (Mg2+, Ca2+, Ni2+, Cu2+, and Fe2+) on the binding constant between Naphcon and BSA was examined.

  1. 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.

  2. Phase behavior of mixtures of rods (tobacco mosaic virus) and spheres (polyethylene oxide, bovine serum albumin).

    PubMed Central

    Adams, M; Fraden, S

    1998-01-01

    Aqueous suspensions of mixtures of the rodlike virus tobacco mosaic virus (TMV) with globular macromolecules such as polyethylene oxide (PEO) or bovine serum albumin (BSA) phase separate and exhibit rich and strikingly similar phase behavior. Isotropic, nematic, lamellar, and crystalline phases are observed as a function of the concentration of the constituents and ionic strength. The observed phase behavior is considered to arise from attractions between the two particles induced by the presence of BSA or PEO. For the TMV/BSA mixtures, the BSA adsorbs to the TMV and bridging of the BSA between TMV produces the attractions. For TMV/PEO mixtures, attractions are entropically driven via excluded volume effects known alternatively as the "depletion interaction" or "macromolecular crowding." PMID:9449368

  3. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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.

  6. 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.

  7. 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.

  8. Immunization of AGE-modified albumin inhibits diabetic nephropathy progression in diabetic mice

    PubMed Central

    Mashitah, Musthika Wida; Azizah, Nurona; Samsu, Nur; Indra, Muhammad Rasjad; Bilal, Muhammad; Yunisa, Meti Verdian; Arisanti, Amildya Dwi

    2015-01-01

    Background Diabetic nephropathy (DN) is a serious vascular complication of diabetes and an important cause of end-stage renal disease. One mechanism by which hyperglycemia causes nephropathy is through the formation of advanced glycation end products (AGE). Development of vaccination would be a promising therapy for the future, while to date, anti-AGE therapy is based on medicines that are needed to be consumed lifelong. This study aimed to find out the effect of immunization of AGE-modified albumin against DN pathogenesis in streptozotocin-induced diabetic in mice. Methods We used 24 BALB/c male mice as experimental animals, which were divided into six groups, two nondiabetic groups (negative control and AGE-modified bovine serum albumin [BSA] preimmunized groups) and four streptozotocin-induced diabetic groups (diabetic control group and diabetic preimmunized groups for AGE-BSA, Keyhole limpet hemocyanin (KLH), and AGE-BSA-KLH, respectively). Results Diabetic preimmunized groups for AGE-BSA, KLH, and AGE-BSA-KLH showed amelioration in renal function and histopathology compared with the diabetic control group. Preimmunization also maintained nephrin intensity and decreased serum AGE level, kidney AGE deposition, and kidney cells apoptosis. Conclusion AGE-BSA and AGE-BSA-KLH immunizations inhibit the progression of DN. Our results strengthen the evidence that the anti-AGE antibodies have a protective role against diabetic vascular complication, especially DN. This study provides a basis for the development of DN-based immunotherapy with AGE immunization as a potential candidate. PMID:26346342

  9. 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).

  10. 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.

  11. Scientist prepare Lysozyme Protein Crystal

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Dan Carter and Charles Sisk center a Lysozyme Protein crystal grown aboard the USML-2 shuttle mission. Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein crystallography. It is used as an excellent model system for better understanding parameters involved in microgravity crystal growth experiments. The goal is to compare kinetic data from microgravity experiments with data from laboratory experiments to study the equilibrium.

  12. Studies of quality control of 99mTc-labelled macroaggregated albumin--Part 1. Aggregation of non-mercaptalbumin and its conformation.

    PubMed

    Fukuoka, M; Kobayashi, T; Satoh, T; Tanaka, A; Kubodera, A

    1993-07-01

    The aggregative condition of albumin was investigated using bovine serum albumin (BSA) as a model for quality control of 99mTc-macroaggregated albumin (99mTc-MAA). Uniformalized aggregates were obtained from the oxidized non-mercapt-type of BSA by heating. The size of the aggregates was affected by the pH and the types of buffer solutions used as well as the concentrations of albumin and buffers. The beta form structure of the albumin was more stable on heating and this may contribute to its aggregation. Aggregation of oxidized non-mercaptalbumin afforded a portion of smaller sized particles in MAA, this being an inappropriate factor for scintiscanning of lungs. Our results suggest that it is necessary to remove oxidized type albumin from human serum albumin as the starting material, in order to prepare MAA with a uniform and larger particle size.

  13. 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.

  14. 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.

  15. Albumin and multiple sclerosis.

    PubMed

    LeVine, Steven M

    2016-01-01

    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. PMID:27067000

  16. Acceleration of suspending single-walled carbon nanotubes in BSA aqueous solution induced by amino acid molecules.

    PubMed

    Kato, Haruhisa; Nakamura, Ayako; Horie, Masanori

    2015-01-01

    Single-walled carbon nanotube (SWCNT) suspensions in aqueous media were prepared using bovine serum albumin (BSA) and amino acid molecules. It was found that the amino acid molecules clearly decreased the time required for suspending the SWCNTs in BSA aqueous solutions. Dynamic light scattering measurements revealed that the particle sizes of the SWCNTs suspended in aqueous media with and without amino acid molecules were approximately the same and stable for more than one week. The zeta potential values of the BSA molecules in pure water and amino acid aqueous solutions were different, and these values were also reflected in the surface potential of colloidal SWCNT particles in the corresponding aqueous media, thus inducing different dispersibility of SWCNTs in aqueous media. Pulsed field gradient nuclear magnetic resonance measurements showed that the interactions between the SWCNTs and the amino acid molecules are weak and comprise chemical exchange interactions and not bonding interactions. Amino acid molecules play a fascinating role in the preparation of SWCNT suspensions in BSA aqueous media by increasing electrostatic repulsive interactions between SWCNT colloidal particles and consequently enhancing the dispersion ability of the BSA molecules.

  17. Spectroscopic investigations on the binding of dibazol to bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Wang, Tianhu; Zhao, Zhimin; Wei, Benzheng; Zhang, Lin; Ji, Lei

    2010-04-01

    The characteristics of the binding reaction of dibazol to bovine serum albumin (BSA) were investigated by fluorescence, UV-vis, resonance light scattering (RLS) and Fourier transform infrared (FT-IR) spectroscopy. Results show that dibazol causes the fluorescence quenching of BSA through a static quenching procedure. The binding constants for the formation of a complex between dibazol and BSA are 0.83, 1.23 and 1.62 × 10 5 mol -1 L at 295, 302 and 309 K, respectively. Positive values of thermodynamic parameters namely enthalpy change (Δ H) and entropy change (Δ S) indicate that the interaction between dibazol and BSA is driven mainly by hydrophobic forces. It seems that the binding is spontaneous at standard state for the change in standard Gibbs free energy (Δ G) value is negative. The binding distance between BSA and dibazol was calculated to be about 4.28 nm according to the Förster theory. The site marker competitive experiments confirmed that the binding of dibazol to BSA primarily occurred in site I of BSA. In addition, the effect of dibazol on the conformation of BSA was also analyzed by using synchronous fluorescence and FT-IR spectroscopy.

  18. Fluorescence Studies of Lysozyme Nucleation

    NASA Technical Reports Server (NTRS)

    Pusey, Marc L.; Smith, Lori

    1998-01-01

    Fluorescence is one of the most powerful tools available for the study of macromolecules. For example, fluorescence can be used to study self association through methods such as anisotropy (the rotational rate of the molecule in solution), quenching (the accessibility of a bound probe to the bulk solution), and resonance energy transfer (measurement of the distance between two species). Fluorescence can also be used to study the local environment of the probe molecules, and the changes in that environment which accompany crystal nucleation and growth. However fluorescent techniques have been very much underutilized in macromolecular growth studies. One major advantage is that the fluorescent species generally must be at low concentration, typically ca 10-5 to 10-6 M. Thus one can study a very wide range of solution conditions, ranging from very high to very low protein concentration, he latter of which are not readily accessible to scattering techniques. We have prepared a number of fluorescent derivatives of chicken egg white lysozyme (CEWL). Fluorescent probes have been attached to two different sites, ASP 101 and the N-terrninal amine, with a sought for use in different lines of study. Preliminary resonance energy transfer studies have been -carried out using pyrene acetic acid (Ex 340 mn, Em 376 nm) lysozyme as a donor and cascade blue (Ex 377 run, Em 423 nm) labeled lysozyme as an acceptor. The emission of both the pyrene and cascade blue probes was followed as a function of the salt protein concentrations. The data show an increase in cascade blue and a concomitant decrease in the pyrene fluorescence as either the salt or protein concentrations are increased, suggesting that the two species are approaching each other close enough for resonance energy transfer to occur. This data can be analyzed to measure the distance between the probe molecules and, knowing their locations on the protein molecule their distances from and orientations with respect to each

  19. 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

  20. Spectroscopic investigation of the interaction between chrysin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Zhang, Guowen; Chen, Xiuxia; Guo, Jinbao; Wang, Junjie

    2009-03-01

    The interaction of chrysin with bovine serum albumin (BSA) in physiological buffer solution (pH 7.4) was studied by fluorescence, UV/vis absorption and resonance light scattering (RLS) spectroscopy. The experimental results showed that there was a strong fluorescence quenching of BSA by chrysin. The probable quenching mechanism of fluorescence of BSA by chrysin was a static quenching by forming the BSA-chrysin complex. The addition of increasing chrysin to BSA solution led to the gradual enhancement in RLS intensity, implying the formation of an aggregate in solution. The binding constants K and number of binding sites n of chrysin with BSA were obtained by fluorescence quenching method. The thermodynamic parameters of the interaction of chrysin with BSA were measured according to the van's Hoff equation. The enthalpy change (Δ H θ) and the entropy change (Δ S θ) were calculated to be 39.19 kJ mol -1, 211.91 J mol -1 K -1 respectively, which indicated that the interaction between chrysin and BSA was driven mainly by hydrophobic interaction. The binding was shown to be spontaneous at the standard state because the changes in standard Gibbs free energy (Δ G θ) values were negative. The binding distance of chrysin from the tryptophan residue in BSA was calculated to be 2.44 nm based on the Förster theory of non-radiation energy transfer. The results of synchronous fluorescence spectra demonstrated that chrysin induced a conformational change of BSA. In addition, the effect of some inorganic ions on the binding constants of chrysin with BSA was also investigated.

  1. 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.

  2. Spectroscopic study of TPPS4 nanostructures in the presence of bovine serum albumin.

    PubMed

    Valanciunaite, Jurga; Bagdonas, Saulius; Streckyte, Giedre; Rotomskis, Ricardas

    2006-04-01

    The influence of bovine serum albumin (BSA) on the formation of J-aggregates of meso-tetra(4-sulfonatophenyl)porphine (TPPS4) in aqueous acid solution (pH 1.3) has been investigated by means of absorption and fluorescence spectroscopy. TPPS4 concentration was kept constant at 2 microM while BSA concentration was varied to get TPPS4 : BSA molar ratios from 1 : 0.005 to 1 : 20. In the presence of protein at all used concentrations the intensity of J-aggregates absorption band was higher than that in the pure solution. Spectral changes indicated that the dynamic equilibrium of the aggregated TPPS4 species was highly dependent on the molar ratio between TPPS4 and BSA. Small relative concentrations of BSA (TPPS4 : BSA, 1 : 0.005-1 : 0.1) had a stimulating effect on formation of J-aggregates. Several fractions of J-aggregates located in protein and aqueous moieties were detected in mixed solutions at intermediate BSA concentrations (TPPS4 : BSA, 1 : 0.5-1 : 8), when the absorbance intensity of the J-aggregates was the highest. At the highest used BSA concentrations (TPPS4 : BSA, 1 : 10-1 : 20) the spectral properties of the remaining J-aggregates were similar to those typical for pure porphyrin solution. Additionally, the split of the Soret band into two with peaks at 440 nm and 423 nm was followed by the simultaneous appearance of Q bands and reflected the formation of TPPS4-BSA complexes including both protonated and deprotonated TPPS4 forms.

  3. 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.

  4. [Study on the interaction between fangchinoline and bovine serum albumin].

    PubMed

    Wu, Qiu-hua; Wang, Chun; Wang, Zhi; Ma, Jing-jun; Zang, Xiao-huan; Qin, Na-xin

    2007-12-01

    The binding reaction of fangchinoline with bovine serum albumin was studied at different temperatures by fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. It was shown that fangchinoline has a strong ability of quenching the fluorescence of BSA. The Stern-Volmer curve of the fluorescence quenching of BSA by fangchinoline indicated that the quenching mechanism of fangchinoline to BSA was a static quenching. According to the Förster theory of non-radiation energy transfer, the binding distances (r) at different temperature were 2.51 nm (27 degrees C), 2.72 nm (37 degrees C) and 2.89 nm (47 degrees C), respectively, while the binding constants (KA) were 1.05 x 10(5) L x mol(-1) (27 degrees C), 3.31x 10(5) L x mol(-1) (37 degrees C), and 7.24 x 10(5) L x mol(-1) (47 degrees C), respectively. The thermodynamic parameters showed that the interaction of fangchinoline and BSA was mainly driven by hydrophobic force. Synchronous spectrum was used to investigate the conformational changes of BSA. PMID:18330294

  5. 76 FR 28226 - Southwest Health Alliances, Inc., Doing Business as BSA Provider Network; Analysis of Agreement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... Southwest Health Alliances, Inc., Doing Business as BSA Provider Network; Analysis of Agreement Containing... agreement containing a proposed Consent Order with Southwest Health Alliances, Inc., dba BSA Provider Network (``BSA Provider Network'' or ``Respondent''). The agreement settles charges that BSA...

  6. 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.

  7. Development of etoposide-loaded bovine serum albumin nanosuspensions for parenteral delivery.

    PubMed

    Wang, Zhonglan; Li, Zhongwen; Zhang, Dong; Miao, Lei; Huang, Guihua

    2015-01-01

    Nanosuspensions emerge as a promising strategy for delivery of poorly water-soluble drugs. Albumin is a versatile protein carrier for drug delivery and targeting. The purpose of this study was to develop a formulation of etoposide-loaded bovine serum albumin (BSA) nanosuspensions, to study in vitro characterization, and to estimate the in vivo safety and tissue distribution of etoposide-loaded BSA nanosuspensions for parenteral delivery. Etoposide-loaded BSA nanosuspensions were prepared by high-pressure homogenization-solvent precipitation method. The particle size, zeta potential, drug entrapment efficiency, and drug loading of the lyophilized formulation were 182.3 nm, -22.18 mV, 86.44%, and 8.49% respectively. In vitro release files of the formulation presented sustained release properties. Preliminary safety study was conducted to evaluate the delivery system, and results indicated that myelosuppression effect of the etoposide-loaded BSA nanosuspensions group was significantly lower than the Injection® group. Furthermore, results of tissue distribution studies showed that the concentration and AUC of etoposide were increased significantly in lung, liver, spleen while reduced in heart, kidney compared with the etoposide injection® group after i.v. administration of etoposide-loaded BSA nanosuspensions. The formulation played a role in targeting delivery to lung, reduce toxicity, and side effects of etoposide. In conclusion, etoposide-loaded BSA nanosuspensions were promising for parenteral delivery of etoposide.

  8. 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.

  9. 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.

  10. BSA activated CdTe quantum dot nanosensor for antimony ion detection.

    PubMed

    Ge, Shenguang; Zhang, Congcong; Zhu, Yuanna; Yu, Jinghua; Zhang, Shuangshuang

    2010-01-01

    A novel fluorescent nanosensor for Sb(3+) determination was reported based on thioglycolic acid (TGA)-capped CdTe quantum dot (QD) nanoparticles. It was the first antimony ion sensor using QD nanoparticles in a receptor-fluorophore system. The water-soluable TGA-capped CdTe QDs were prepared through a hydrothermal route, NaHTe was used as the Te precursor for CdTe QDs synthesis. Bovine serum albumin (BSA) conjugated to TGA-capped CdTe via an amide link interacting with carboxyl of the TGA-capped CdTe. When antimony ion enters the BSA, the lone pair electrons of the nitrogen and oxygen atom become involved in the coordination, switching off the QD emission and a dramatic quenching of the fluorescence intensity results, allowing the detection of low concentrations of antimony ions. Using the operating principle, the antimony ion sensor based on QD nanoparticles showed a very good linearity in the range 0.10-22.0 microg L(-1), with the detection limit lower than 2.94 x 10(-8) g L(-1) and the relative standard deviation (RSD) 2.54% (n = 6). In a study of interferences, the antimony-sensitive TGA-QD-BSA sensor showed good selectivity. Therefore, a simple, fast, sensitive, and highly selective assay for antimony has been built. The presented method has been applied successfully to the determination of antimony in real water samples (n = 6) with satisfactory results.

  11. 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.

  12. 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.

  13. 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

    2011-04-01

    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.

  14. Characterization and analytical application of Morin - Bovine serum albumin system by spectroscopic approaches

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Huang, Wei; Miao, Xiaowen; Tang, Bo

    2012-12-01

    It is found that the fluorescence intensity of Morin can be strongly quenched by proteins. Based on this, a new fluorimetric method for the determination of protein was developed. Under optimum conditions, the quenchment of Morin fluorescence was in proportion to the concentration of proteins in the range 0.0001-0.1000 g · L-1 for bovine serum albumin (BSA) and 0.0005-0.1000 g · L-1 for human serum albumin (HSA). The reaction mechanism indicates that proteins can bind with Morin at the 3-hydroxyl and the 4-carbonyl and form a non-fluorescence complex 4:1 molar ratio of Morin/BSA, which results in the fluorescence of Morin and BSA are all quenched.

  15. 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.

  16. Lysozyme

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein crystallography. It is used as an excellent model system for better understanding parameters involved in microgravity experiments with data from laboratory experiments to study the equilibrium rate of hanging drop experiments in microgravity.

  17. 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.

  18. Study on the interaction between carbonyl-fused N-confused porphyrin and bovine serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Yu, Xianyong; Liao, Zhixi; Jiang, Bingfei; Zheng, Lingyi; Li, Xiaofang

    2014-12-01

    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 4.37 nm. What is more, the conformation of BSA was observed from synchronous fluorescence spectroscopy.

  19. Surface molecularly imprinted magnetic microspheres for the recognition of albumin.

    PubMed

    Kartal, Fatma; Denizli, Adil

    2014-08-01

    A new approach, combining metal coordination with the molecular imprinting technique, was developed to prepare affinity materials. Magnetic poly(glycidyl methacrylate) microspheres in monosize form were used for specific recognition toward the target protein. The magnetic poly(glycidyl methacrylate) microspheres were prepared by dispersion polymerization in the presence of magnetite nanopowder. Surface imprinted magnetic poly(glycidyl methacrylate) microspheres based on metal coordination were prepared and used for the selective recognition of human serum albumin. Iminodiacetic acid was used as the metal coordinating agent and human serum albumin was anchored by Cu(2+) ions on the surface of magnetic poly(glycidyl methacrylate) microspheres by metal coordination. The magnetic poly(glycidyl methacrylate) microspheres were coated with a polymer formed by condensation of tetraethyl orthosilicate and 3-aminopropyltrimethoxysilane. The human serum albumin imprinted magnetic poly(glycidyl methacrylate) microspheres were characterized by scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy and particle size analysis. The maximum adsorption capacity of human serum albumin imprinted magnetic poly(glycidyl methacrylate) microspheres was 37.7 mg/g polymer at pH 6.0. The selectivity experiments of human serum albumin imprinted magnetic poly(glycidyl methacrylate) microspheres prepared with different concentrations in the presence of lysozyme, bovine serum albumin and cytochrome C were performed in order to determine the relative selectivity coefficients.

  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. 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.

  2. Synthesis of three rimantadine schiff bases and their biological effects on serum albumin.

    PubMed

    Liu, Bing-Mi; Ma, Ping; Wang, Xin; Kong, Yu-Mei; Zhang, Li-Ping; Liu, Bin

    2014-01-01

    Three new rimantadine Schiff bases (RSBs) were prepared, and then the interaction of RSBs with bovine serum albumin (BSA) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption spectroscopy under physiological conditions. The results showed that the three RSBs effectively quenched the intrinsic fluorescence of BSA via static quenching. Binding constant (K a), number of binding sites (n), and the binding distance (r) between three RSBs and BSA were calculated by Stern-Volmer equation and Förster's theory in this study. According to the results of displacement experiments of site probes, it was considered that the binding sites were located in hydrophobic cavities in sub-domains IIA of BSA. What is more, synchronous fluorescence studies indicated that the hydrophobicity around tryptophan residues was increased with the addition of rimantadine-o-vanillin (ROV) and rimantadine-4-methoxy-salicylaldehyde (RMS), while there was no apparent change with the addition of rimantadine-salicylaldehyde (RS). PMID:25587306

  3. 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.

  4. Synthesis of Three Rimantadine Schiff Bases and Their Biological Effects on Serum Albumin

    PubMed Central

    Liu, Bing-Mi; Ma, Ping; Wang, Xin; Kong, Yu-Mei; Zhang, Li-Ping; Liu, Bin

    2014-01-01

    Three new rimantadine Schiff bases (RSBs) were prepared, and then the interaction of RSBs with bovine serum albumin (BSA) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption spectroscopy under physiological conditions. The results showed that the three RSBs effectively quenched the intrinsic fluorescence of BSA via static quenching. Binding constant (Ka), number of binding sites (n), and the binding distance (r) between three RSBs and BSA were calculated by Stern-Volmer equation and Förster’s theory in this study. According to the results of displacement experiments of site probes, it was considered that the binding sites were located in hydrophobic cavities in sub-domains IIA of BSA. What is more, synchronous fluorescence studies indicated that the hydrophobicity around tryptophan residues was increased with the addition of rimantadine-o-vanillin (ROV) and rimantadine-4-methoxy-salicylaldehyde (RMS), while there was no apparent change with the addition of rimantadine-salicylaldehyde (RS). PMID:25587306

  5. Mechanistic insights into the interactions of magnetic nanoparticles with bovine serum albumin in presence of surfactants.

    PubMed

    Joseph, Delina; Sachar, Shilpee; Kishore, Nand; Chandra, Sudeshna

    2015-11-01

    This work reports the physicochemical parameters and the nature of association between magnetic nanoparticles and bovine serum albumin (BSA) in presence of cationic and anionic surfactants. Magnetic iron oxide nanoparticles (MNPs) are first synthesized using chemical co-precipitation method and subsequently characterized by FTIR, XRD, DLS, TEM and Zeta potential. The bare nanoparticles are then coated with BSA and their interactions studied using fluorescence spectroscopy, dynamic light scattering and circular dichroism techniques. The spectroscopic investigation sheds light into various aspects of binding and size variation during the molecular association of BSA with the MNPs in absence and presence of cationic and anionic surfactants. Isothermal titration calorimetry was used to probe the thermodynamic parameters of the systems. MNPs-BSA system was found to be more stable in presence of cationic surfactant. This study provides valuable mechanistic insights into the interactions taking place at the interface of the nanoparticles which further helps in designing a stable colloidal MNPs systems.

  6. The investigation of the interaction between NCP-EDA and bovine serum albumin by spectroscopic approaches.

    PubMed

    Yu, Xianyong; Lu, Shiyu; Yang, Ying; Li, Xiaofang; Yi, Pinggui

    2011-12-01

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between N-confused porphyrins-edaravone diad (NCP-EDA) and bovine serum albumin (BSA) under simulative physiological condition at different temperatures. The experimental results show that the fluorescence quenching mechanism between NCP-EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between NCP-EDA and BSA was calculated to be 3.63 nm. In addition, the effect of NCP-EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.

  7. Deciphering the binding patterns and conformation changes upon the bovine serum albumin-rosmarinic acid complex.

    PubMed

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

    2015-08-01

    Rosmarinic acid (RA) is an importantly and naturally occurring polyphenol from plants of the mint family with potent biological activities. Here, the in vitro interaction of RA with bovine serum albumin (BSA) has been investigated using various biophysical approaches as well as molecular modeling methods, to ascertain its binding mechanism and conformational changes. The fluorescence results demonstrated that the fluorescence quenching of BSA by RA was mainly the result of the formation of a ground state BSA-RA complex, and BSA had one high affinity RA binding site with a binding constant of 4.18 × 10(4) mol L(-1) at 298 K. Analysis of thermodynamic parameters revealed that hydrophobic and hydrogen bond interactions were the dominant intermolecular force in the complex formation. The primary binding site of RA in BSA (site I) had been identified by site marker competitive experiments. The distance between RA and the tryptophan residue of BSA was evaluated at 3.12 nm based on Förster's theory of non-radiation energy transfer. The UV-vis absorption, synchronous fluorescence, three-dimensional fluorescence, 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectra confirmed that the conformation and structure of BSA were altered in the presence of RA. Moreover, the nuclear magnetic spectroscopy showed that the aromatic groups of RA took part in the binding reaction during the BSA-RA complexation. In addition, the molecular picture of the interaction mechanism between BSA and RA at the atomic level was well examined by molecular docking and dynamics studies. In brief, RA can bind to BSA with noncovalent bonds in a relatively stable way, and these findings will be beneficial to the functional food research of RA.

  8. Deciphering the binding patterns and conformation changes upon the bovine serum albumin-rosmarinic acid complex.

    PubMed

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

    2015-08-01

    Rosmarinic acid (RA) is an importantly and naturally occurring polyphenol from plants of the mint family with potent biological activities. Here, the in vitro interaction of RA with bovine serum albumin (BSA) has been investigated using various biophysical approaches as well as molecular modeling methods, to ascertain its binding mechanism and conformational changes. The fluorescence results demonstrated that the fluorescence quenching of BSA by RA was mainly the result of the formation of a ground state BSA-RA complex, and BSA had one high affinity RA binding site with a binding constant of 4.18 × 10(4) mol L(-1) at 298 K. Analysis of thermodynamic parameters revealed that hydrophobic and hydrogen bond interactions were the dominant intermolecular force in the complex formation. The primary binding site of RA in BSA (site I) had been identified by site marker competitive experiments. The distance between RA and the tryptophan residue of BSA was evaluated at 3.12 nm based on Förster's theory of non-radiation energy transfer. The UV-vis absorption, synchronous fluorescence, three-dimensional fluorescence, 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectra confirmed that the conformation and structure of BSA were altered in the presence of RA. Moreover, the nuclear magnetic spectroscopy showed that the aromatic groups of RA took part in the binding reaction during the BSA-RA complexation. In addition, the molecular picture of the interaction mechanism between BSA and RA at the atomic level was well examined by molecular docking and dynamics studies. In brief, RA can bind to BSA with noncovalent bonds in a relatively stable way, and these findings will be beneficial to the functional food research of RA. PMID:26146359

  9. 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.

  10. 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

  11. Ion-Mobility-Based Quantification of Surface-Coating-Dependent Binding of Serum Albumin to Superparamagnetic Iron Oxide Nanoparticles.

    PubMed

    Jeon, Seongho; Oberreit, Derek R; Van Schooneveld, Gary; Gao, Zhe; Bischof, John C; Haynes, Christy L; Hogan, Christopher J

    2016-09-21

    Protein binding and protein-induced nanoparticle aggregation are known to occur for a variety of nanomaterials, with the extent of binding and aggregation highly dependent on nanoparticle surface properties. However, often lacking are techniques that enable quantification of the extent of protein binding and aggregation, particularly for nanoparticles with polydisperse size distributions. In this study, we adapt ion mobility spectrometry (IMS) to examine the binding of bovine serum albumin to commercially available anionic-surfactant-coated superparamagnetic iron oxide nanoparticles (SPIONs), which are initially ∼21 nm in mean mobility diameter and have a polydisperse size distribution function (geometric standard deviation near 1.4). IMS, carried out with a hydrosol-to-aerosol converting nebulizer, a differential mobility analyzer, and a condensation particle counter, enables measurements of SPION size distribution functions for varying BSA/SPION number concentration ratios. IMS measurements suggest that initially (at BSA concentrations below 50 nM) BSA binds reversibly to SPION surfaces with a binding site density in the 0.05-0.08 nm(-2) range. However, at higher BSA concentrations, BSA induces SPION-SPION aggregation, evidenced by larger shifts in SPION size distribution functions (mean diameters beyond 40 nm for BSA concentrations near 100 nM) and geometric standard deviations (near 1.3) consistent with self-preserving aggregation theories. The onset of BSA aggregation is correlated with a modest but statistically significant decrease in the specific absorption rate (SAR) of SPIONs placed within an alternating magnetic field. The coating of SPIONs with mesoporous silica (MS-SPIONs) as well as PEGylation (MS-SPIONs-PEG) is found to completely mitigate BSA binding and BSA-induced aggregation; IMS-inferred size distribution functions are insensitive to BSA concentration for MS-SPIONs and MS-SPIONs-PEG. The SARs of MS-SPIONs are additionally insensitive to BSA

  12. 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. PMID:24852109

  13. Trehalose limits BSA aggregation in spray-dried formulations at high temperatures: implications in preparing polymer implants for long-term protein delivery.

    PubMed

    Rajagopal, Karthikan; Wood, Joseph; Tran, Benjamin; Patapoff, Thomas W; Nivaggioli, Thierry

    2013-08-01

    Polymer implants are promising systems for sustained release applications but their utility for protein delivery has been hindered because of concerns over drug stability at elevated temperatures required for processing. Using bovine serum albumin (BSA) as a model, we have assessed whether proteins can be formulated for processing at elevated temperatures. Specifically, the effect of trehalose and histidine-HCl buffer on BSA stability in a spray-dried formulation has been investigated at temperatures ranging from 80°C to 110°C. When both the sugar and buffer are present, aggregation is suppressed even when exposed to 100°C, the extrusion temperature of poly(lactide-co-glycolide) (PLGA), a bioresorbable polymer. Estimation of aggregation rate constants (k) indicate that though both trehalose and histidine-HCl buffer contribute to BSA stability, the effect because of trehalose alone is more pronounced. BSA-loaded PLGA implants were prepared using hot-melt extrusion process and in vitro release was conducted in phosphate buffered saline at 37°C. Comparison of drug released from implants prepared using four different formulations confirmed that maximal release was achieved from the formulation in which BSA was least aggregated. These studies demonstrate that when trehalose and histidine-HCl buffer are included in spray-dried formulations, BSA stability is maintained both during processing at 100°C and long-term residence within implants.

  14. Spectroscopic studies on the interaction of BSA and 5-spiro-3'-piperidine-2″-spiro-3″-indole-4',2″-diones

    NASA Astrophysics Data System (ADS)

    Yu, Xianyong; Yao, Qing; Tao, Hongwen; Yang, Ying; Li, Lei; Li, Xiaofang; Zhu, Shizhong

    2013-03-01

    The interaction of 5-spiro-3'-piperidine-2″-spiro-3″-indole-4',2″-diones (SPSDs), an anti-tumor drug, to bovine serum albumin (BSA) in aqueous solution has been investigated by fluorescence spectra and ultraviolet-visible (UV-vis) spectra at pH 7.40. We have studied the effect of four substituents on the SPSD for the first time. The results of fluorescence titration indicated that SPSD can quench the intrinsic fluorescence of BSA and the quenching mechanism has been analyzed. The binding sites number (n), the binding constant (KA) and the spatial-distance (r) of SPSD with BSA without or with substituents on the benzene ring at 302 and 310 K have been calculated. The results show that the presence of the substituents increased the binding constant and changed the binding distance between the acceptor and the donor, which possibly results from the formation of SPSD-BSA complex. We have investigated the possible sub-domain on BSA where bind SPSD by displacement experiments. The effect of SPSD on the conformation of BSA has also been analyzed using synchronous fluorescence under experimental conditions.

  15. Endocytosis of albumin and thyroglobulin at the basolateral membrane of thyrocytes organized in follicles.

    PubMed

    Gire, V; Kostrouch, Z; Bernier-Valentin, F; Rabilloud, R; Munari-Silem, Y; Rousset, B

    1996-02-01

    Serum proteins such as albumin are present inside thyroid follicles in both normal and pathological situations. To analyze the mechanism of entry of these proteins, we investigated the ability of polarized thyrocytes to internalize soluble molecules at their basolateral pole. Experiments were conducted on in vitro reconstituted thyroid follicles using BSA and pig thyroglobulin (Tg) coupled to gold particles for electron microscopy, conjugated to fluorescein for conventional and confocal fluorescence microscopy, or radioiodinated for biochemical measurements. Incubations were carried out at 37 C. BSA and Tg coupled to gold particles were rapidly internalized from the culture medium and sequentially found in small vesicles and early endosomes and in late endosomes and lysosomes. Fluorescence microscope analyses revealed that the majority of cells forming reconstituted thyroid follicles are capable of internalizing BSA and Tg, but that Tg was more efficiently endocytosed than BSA. Using radioiodinated ligands, it was observed that the endocytosis of Tg was 10 times higher than that of BSA. The internalization of [125I]Tg was inhibited by increasing concentrations of unlabeled Tg. In contrast, endocytosis of 125I-labeled BSA was independent of the unlabeled BSA concentration. Experiments performed at 4 C indicated the presence of a basolateral membrane binding activity for [125I]Tg; the Tg concentration that reduced the binding of labeled Tg by 50% ranged from 4-6 microM. These data are evidence of a process of internalization of soluble molecules at the basolateral pole of thyrocytes, with BSA being internalized by fluid phase endocytosis and Tg by selective endocytosis. Our findings explain how serum albumin can enter thyroid follicles and disclose a new cellular handling and transport pathway of Tg. We propose that selective uptake of Tg operating on molecules secreted at the basolateral surface of thyrocytes could control the amount of Tg released in the

  16. 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.

  17. Intermolecular interaction of prednisolone with bovine serum albumin: spectroscopic and molecular docking methods.

    PubMed

    Shi, Jie-hua; Zhu, Ying-Yao; Wang, Jing; Chen, Jun; Shen, Ya-Jing

    2013-02-15

    The intermolecular interaction of prednisolone with bovine serum albumin (BSA) was studied using fluorescence, circular dichroism (CD) and molecular docking methods. The experimental results showed that the fluorescence quenching of the BSA at 338 nm by prednisolone resulted from the formation of prednisolone-BSA complex. The number of binding sites (n) for prednisolone binding on BSA was approximately equal to 1. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH(0)=-149.6 kJ mol(-1) and ΔS(0)=-370.7 J mol(-1)K(-1)) and the results of molecular docking, it could be suggested that the interaction forces were mainly Van der Waals and hydrogen bonding interactions. Moreover, in the binding process of BSA with prednisolone, prednisolone molecule can be inserted into the hydrophobic cavity of subdomain IIIA (site II) of BSA. The distance between prednisolone and Trp residue of BSA was calculated as 2.264 nm according to Forster's non-radiative energy transfer theory.

  18. Binding of manganese and iron tetraphenylporphine sulfonates to albumin is relevant to their contrast properties.

    PubMed

    Yushmanov, V E; Tominaga, T T; Borissevitch, I E; Imasato, H; Tabak, M

    1996-01-01

    The interaction of Fe(III) and Mn(III) complexes of TPPS4 with bovine serum albumin (BSA) was studied by T1 relaxation measurements of water protons and high resolution 1H NMR of the porphyrin moieties. At excess of BSA, both metalloporphyrins bind to BSA as the high spin monomers. The relaxivity of bound MnTPPS4 is significantly higher as compared to the free form in solution. When metalloporphyrins are in excess, they aggregate at the BSA surface, up to two MnTPPS4, and up to 10-15 FeTPPS4 units per BSA globule. Bound aggregates are unable to enhance magnetic relaxation of water protons due to the antiferromagnetic coupling between metal ions in the aggregates. Therefore, the dose-effect dependences for metalloporphyrins in the range of metalloporphyrin/BSA ratio of 0 to 25 at the constant BSA concentration at pH 7.4 are characterized by a local maximum at about 2 for MnTPPS4, and a global maximum at about 3 for FeTPPS4, MnTPPS4 complex is more effective than FeTPPS4 in the whole concentration range. It is suggested that the difference in binding and aggregation properties of metalloporphyrins may be relevant to their relaxation efficiency in vivo, blood transport, and biodistribution. PMID:8725191

  19. 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.

  20. Interaction of the irisflorentin with bovine serum albumin: A fluorescence quenching study

    NASA Astrophysics Data System (ADS)

    Zhang, Guowen; Wang, Anping; Jiang, Ting; Guo, Jinbao

    2008-11-01

    The interaction between irisflorentin (IFR) and bovine serum albumin (BSA) in physiological buffer (pH = 7.4) was investigated by fluorescence quenching technique and UV/vis absorption spectroscopy. The results of fluorescence titration revealed that IFR could strongly quench the intrinsic fluorescence of BSA through a dynamic quenching procedure. The apparent binding constants KA and number of binding sites n of IFR with BSA were obtained by fluorescence quenching method. The thermodynamic parameters, enthalpy change (Δ H θ) and entropy change (Δ S θ), were calculated to be 18.45 kJ mol -1 >0 and 149.72 J mol -1 K -1 >0, respectively, which indicated that the interaction of IFR with BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative. The distance r between donor (BSA) and acceptor (IFR) was calculated to be 3.88 nm based on Förster's non-radiative energy transfer theory. The results of synchronous fluorescence spectra showed that binding of IFR with BSA can induce conformational changes in BSA.

  1. Mechanism of denaturation of bovine serum albumin by dodecyl trimethylammonium bromide.

    PubMed

    Moosavi-Movahedi, A A; Bordbar, A K; Taleshi, A A; Naderimanesh, H M; Ghadam, P

    1996-09-01

    Bovine serum albumin (BSA) denaturation has been extensively studied by different anionic and cationic surfactant. Dodecyl trimethylammonium bromide (DTAB) is a cationic surfactant, and it is suggested that it binds to the C-terminal section of BSA. In the present study, the thermodynamical denaturation of BSA by dodecyl trimethylammonium bromide (DTAB) has been studied with various experimental techniques. Equilibrium dialysis, thermal denaturation, gel electrophoresis, titration microcalorimetry at pH 7, I = 0.005, and different temperatures were all performed. The enthalpy obtained from the van't Hoff relation and calorimetry method as well as electrophoresis results were utilized to explain the BSA tranistion state. Major findings included: the binding isotherm shifts at a low free concentrations of DTAB and at a higher temperature suggest endothermicity for enthalpy of interaction; the calorimetry enthalpy (delta Hcal) of interaction was smaller than the van't Hoff enthalpy (delta HvH) for BSA-DTAB interaction; and the aggregation of BSA increased with increasing DTAB concentration. This study suggests that BSA unfolding induced by DTAB follows a multistate transition model and does not follow the two-state mechanism assumed for most single subunit proteins.

  2. Human islet purification: a prospective comparison of Euro-Ficoll and bovine serum albumin density gradients.

    PubMed

    Chadwick, D R; Robertson, G S; Contractor, H; Swift, S; Rose, S; Thirdborough, S T; Chamberlain, R; James, R F; Bell, P R; London, N J

    1993-01-01

    Euro-Ficoll (EF) and bovine serum albumin (BSA) are the two most commonly used media for the density gradient purification of human pancreatic islets. The aim of this study was to compare these two media with respect to the efficiency of human islet isolation. Ten human pancreata were collagenase-digested, and samples of digest were separated on either a continuous linear density gradient of BSA or a discontinuous gradient of EF (1.108/1.096/1.037/Euro-Collins). Efficiency of islet purification was assessed by insulin and amylase assay of aliquots aspirated from the BSA gradients, and from the interfaces of the EF gradients. Islets were obtained from two interfaces in the EF gradients. Islet yield from the upper interface was generally poor (median 28% of total insulin; range 2-71%), but purity was better than for an equivalent yield using BSA [1% (0-3%) amylase contamination for EF versus 6% (0-37%) for BSA; P = 0.013]. Pooling both EF interfaces increased yield to 66% (17-81%) but markedly reduced purity [46% (0-50%) amylase for EF versus 31% (0-52%) for BSA]. In conclusion, the efficiency of human islet purification is similar, though disappointingly low, with BSA and with EF. Considerable scope exists, therefore, for improvement in the density gradient purification of human islets. PMID:8329732

  3. 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

    2016-03-01

    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 × 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. PMID:26688207

  4. Screening and identification of BSA bound ligands from Puerariae lobata flower by BSA functionalized Fe₃O₄ magnetic nanoparticles coupled with HPLC-MS/MS.

    PubMed

    Liu, Liangliang; Ma, Yongjian; Chen, Xiaoqing; Xiong, Xiang; Shi, Shuyun

    2012-03-01

    Puerariae lobata flower (Willdenow) has a long history used to treat alcoholic intoxication in China, which contains a series of isoflavones as its chief pharmacologically active constituents. In this study, bovine serum albumin (BSA) functionalized iron oxide magnetic nanoparticles (Fe₃O₄ MNPs) coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) were used to screen and identify active compounds from ethanolic extract of P. lobata flower. Thirteen active isoflavones were screened and identified as glycitin (1), tectoridin (2), daidzin (3), 3'-methoxy daidzin (4), ononin (5), 3'-hydroxyl daidzein (6), tectorigenin (7), biochanin A (8), prunetin (9), genistein (10), 3'-methoxy daidzein (11), irisolidone (12) and 5,7-dihydroxy-3',4'-methylenedioxyisoflavone (13), while compounds 4, 6, 9, 11 and 13 were identified from this plant for the first time. Furthermore, the activity of each bound ligand was evaluated on-line. The results indicated that the binding affinities of compounds with BSA were highly dependent on chemical structures and the methoxylation and hydroxylation on B-ring could improve the activity. The effective method could be widely applied for rapid screening and identification of active compounds from complex mixtures. PMID:22305973

  5. Severe anaphylactic reaction to bovine serum albumin at the first attempt of artificial insemination.

    PubMed

    Wüthrich, B; Stern, A; Johansson, S G

    1995-02-01

    A 33-year-old woman without history of previous atopic diseases or drug allergies developed a severe anaphylactic reaction with asthma, vomiting, itching, generalized urticaria, and angioedema during artificial insemination with her husband's sperm. The sperm-processing medium contained bovine serum albumin (BSA). Skin prick test and RAST demonstrated an IgE-mediated hypersensitivity to BSA as well as a polyvalent atopic sensitization to pollens, animal danders, cow's milk, beef, pork, and mutton. SDS-PAGE studies indicated serum albumin to be the appropriate allergen with a high degree of cross-reactivity between serum albumin from different animal species. Artificial insemination with fluid containing potential allergens can, therefore, represent an unnecessary risk for atopic females, even in the absence of prior clinical symptoms of allergic diseases. Preoperative testing with the medium is recommended. PMID:7604943

  6. Spectroscopic investigation on sonodynamic and sonocatalytic damage of BSA molecules by Thymol Blue (TB) derivants under ultrasonic irradiation.

    PubMed

    Wang, Qi; Wu, Qiong; Wang, Jun; Chen, Dandan; Li, Ying; Gao, Jingqun; Wang, Baoxin

    2014-07-15

    In this paper, the Thymol Blue derivants including Thymol Blue (thymolsulfonphthalein), Thymol Blue-DA (3,3'-Bis [N,N-bis (carboxymethyl) aminomethyl] thymolsulfonphthalein) and Thymol Blue-DA-Fe(III) (3,3'-Bis [N,N-bis (carboxymethyl) aminomethyl] thymolsulfonphthalein-Ferrous(III)) were adopted as sonosensitizers to study the sonodynamic and sonocatalytic activities under ultrasonic irradiation. At first, the interaction of Thymol Blue derivants with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. On that basis, the sonodynamic and sonocatalytic damages of Thymol Blue derivants to BSA under ultrasonic irradiation were investigated by the combination of UV-vis, circular dichroism (CD) and fluorescence spectroscopy. Meanwhile, some influenced factors (ultrasonic irradiation time, Thymol Blue derivants concentration and ionic strength) on the damaging degree of BSA molecules were also reviewed. In addition, synchronous fluorescence spectra were used to estimate the binding and damage sites of Thymol Blue derivants to BSA. Finally, the generation of ROS during sonodynamic and sonocatalytic processes was confirmed by the method of Oxidation-Extraction Spectrometry (OEP). Perhaps, this paper may offer some important subjects for the study of Thymol Blue derivants in sonodynamic therapy (SDT) and sonocatalytic therapy (SCT) technologies for tumor treatment and the effect of the amino acid and central metal.

  7. Magnetic hydrogel beads based on PVA/sodium alginate/laponite RD and studying their BSA adsorption.

    PubMed

    Mahdavinia, Gholam Reza; Mousanezhad, Sedigheh; Hosseinzadeh, Hamed; Darvishi, Farshad; Sabzi, Mohammad

    2016-08-20

    In this study double physically crosslinked magnetic hydrogel beads were developed by a simple method including solution mixing of sodium alginate and poly(vinyl alcohol) (PVA) containing magnetic laponite RD (Rapid Dispersion). Sodium alginate and PVA were physically crosslinked by Ca(2+) and freezing-thawing cycles, respectively. Magnetic laponite RD nanoparticles were incorporated into the system to create magnetic response and strengthen the hydrogels. All hybrids double physically crosslinked hydrogel beads were stable under different pH values without any disintegration. Furthermore, adsorption of bovine serum albumin (BSA) on the hydrogel beads was investigated on the subject of pH, ion strength, initial BSA concentration, and temperature. Nanocomposite beads exhibited maximum adsorption capacity for BSA at pH=4.5. The experimental adsorption isotherm data were well followed Langmuir model and based on this model the maximum adsorption capacity was obtained 127.3mgg(-1) at 308K. Thermodynamic parameters revealed spontaneous and monolayer adsorption of BSA on magnetic nanocomposites beads.

  8. Spectroscopic investigation on sonodynamic and sonocatalytic damage of BSA molecules by Thymol Blue (TB) derivants under ultrasonic irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Wu, Qiong; Wang, Jun; Chen, Dandan; Li, Ying; Gao, Jingqun; Wang, Baoxin

    2014-07-01

    In this paper, the Thymol Blue derivants including Thymol Blue (thymolsulfonphthalein), Thymol Blue-DA (3,3‧-Bis [N,N-bis (carboxymethyl) aminomethyl] thymolsulfonphthalein) and Thymol Blue-DA-Fe(III) (3,3‧-Bis [N,N-bis (carboxymethyl) aminomethyl] thymolsulfonphthalein-Ferrous(III)) were adopted as sonosensitizers to study the sonodynamic and sonocatalytic activities under ultrasonic irradiation. At first, the interaction of Thymol Blue derivants with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. On that basis, the sonodynamic and sonocatalytic damages of Thymol Blue derivants to BSA under ultrasonic irradiation were investigated by the combination of UV-vis, circular dichroism (CD) and fluorescence spectroscopy. Meanwhile, some influenced factors (ultrasonic irradiation time, Thymol Blue derivants concentration and ionic strength) on the damaging degree of BSA molecules were also reviewed. In addition, synchronous fluorescence spectra were used to estimate the binding and damage sites of Thymol Blue derivants to BSA. Finally, the generation of ROS during sonodynamic and sonocatalytic processes was confirmed by the method of Oxidation-Extraction Spectrometry (OEP). Perhaps, this paper may offer some important subjects for the study of Thymol Blue derivants in sonodynamic therapy (SDT) and sonocatalytic therapy (SCT) technologies for tumor treatment and the effect of the amino acid and central metal.

  9. Interaction of drugs with bovine and human serum albumin

    NASA Astrophysics Data System (ADS)

    Sułkowska, Anna

    2002-09-01

    The study on the interaction of antithyroid drugs: 2-mercapto-1-methylimidazole (Methimazole, MMI) and 6 n-propyl-2-thiouracil (PTU) with two kinds of serum albumin: bovine (BSA) and human (HSA) has been undertaken. Fluorescence emission spectra of serum albumin in the presence of MMI or PTU, recorded at the excitation wavelengths 280 and 295 nm, clearly show that the studied drugs act as quenchers. A decrease in fluorescence intensity at 340 or 350 nm, when excited at 280 or 295 nm, respectively, is attributed to changes in the environment of the protein fluorophores caused to the presence of the ligand. The 295 nm lights excites tryptophan residues, while the 280 nm lights excites both tryptophan and tyrosine residues. A comparison of quenching effects, when protein is excited at 295 and 280 nm, reveals that the tryptophanyl group interacts with the ligand. The differences in interactions of pyrimidine derivatives with HSA and BSA were observed using spectrofluorimetry technique. As the HSA structure contains only one tryptophanyl residue (Trp 214), while BSA has two ones (Trp 135 and Trp 214), the similar decrease of fluorescence points at the subdomain IIA, where Trp 214 was located, as a binding site of the studied drugs.

  10. Cationic spin probe reporting on thermal denaturation and complexation-decomplexation of BSA with SDS. Potential applications in protein purification processes.

    PubMed

    Matei, Iulia; Ariciu, Ana Maria; Neacsu, Maria Victoria; Collauto, Alberto; Salifoglou, Athanasios; Ionita, Gabriela

    2014-09-25

    In this work, we present evidence on the suitability of spin probes to report on the thermal treatment of bovine serum albumin (BSA), in the temperature range 293-343 K, and indirectly monitor the release of sodium dodecyl sulfate (SDS) from its complex with BSA using a covalent gel with β-cyclodextrin (β-CD) in the network. The spin probes used, 5- and 7-doxyl-stearic acids (5-DSA, 7-DSA) or 4-(N,N'-dimethyl-N-hexadecyl)ammonium-2,2',6,6'-tetramethylpiperidine-1-oxyl iodide (CAT16), present similar, fatty acid-like structural features. Their continuous wave electron paramagnetic resonance (CW-EPR) spectra, however, reflect different dynamics when complexed with BSA: a restricted motion for 5-DSA, almost nonsensitive to the heating/cooling cycle, and a faster temperature-dependent dynamic motion for CAT16. Molecular docking allows us to rationalize these results by revealing the different binding modes of 5-DSA and CAT16. The EPR data on the temperature effect on BSA are supported by circular dichroism results projecting recovery, upon cooling, of the initial binding ability of BSA for samples heated to 323 K. The interactions occurring in BSA/SDS/β-CD systems are investigated by CW-EPR and FT-ESEEM spectroscopies. It is found that the covalent gel containing β-CD can efficiently remove SDS from the BSA/SDS complex. The gel is not permeable to BSA but it can encapsulate SDS, thus yielding the free protein in solution and allowing recovery of the native protein conformation. Collectively, the accrued knowledge supports potential applications in protein purification biotechnological processes.

  11. 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. PMID:26882128

  12. 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.

  13. Electrochemistry of the interaction of furazolidone and bovine serum albumin.

    PubMed

    Fotouhi, Lida; Banafsheh, Sara; Heravi, Majid M

    2009-11-01

    The electrochemical behavior of the interaction of furazolidone (Fu) with bovine serum albumin (BSA) was investigated by cyclic voltammetry and differential pulse voltammetry at a glassy carbon electrode. Fu shows an irreversible reduction at -0.34 V in pH 4.0 Britton-Robinson buffer (B-R) buffer-10% DMF solution. After the addition of BSA into the Fu solution, the reductive peak currents decreased without any significant shift of the peak potential and the appearance of new peaks. The electrochemical parameters of the interaction system were calculated in the absence and presence of BSA. This electrochemical method was further applied to the determination of BSA samples and the results were in good agreement with the traditional cellulose acetate electrophoresis. The linear dynamic range was between 10.0 and 80.0 mg l(-1). The detection limit was 7.6 mg l(-1) and the recoveries were obtained from 97.0% to 104.0%.

  14. 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

  15. EPR studies of intermolecular interactions and competitive binding of drugs in a drug-BSA binding model.

    PubMed

    Akdogan, Y; Emrullahoglu, M; Tatlidil, D; Ucuncu, M; Cakan-Akdogan, G

    2016-08-10

    Understanding intermolecular interactions between drugs and proteins is very important in drug delivery studies. Here, we studied different binding interactions between salicylic acid and bovine serum albumin (BSA) using electron paramagnetic resonance (EPR) spectroscopy. Salicylic acid was labeled with a stable radical (spin label) in order to monitor its mobilized (free) or immobilized (bound to BSA) states. In addition to spin labeled salicylic acid (SL-salicylic acid), its derivatives including SL-benzoic acid, SL-phenol, SL-benzene, SL-cyclohexane and SL-hexane were synthesized to reveal the effects of various drug binding interactions. EPR results of these SL-molecules showed that hydrophobic interaction is the main driving force. Whereas each of the two functional groups (-COOH and -OH) on the benzene ring has a minute but detectable effect on the drug-protein complex formation. In order to investigate the effect of electrostatic interaction on drug binding, cationic BSA (cBSA) was synthesized, altering the negative net charge of BSA to positive. The salicylic acid loading capacity of cBSA is significantly higher compared to that of BSA, indicating the importance of electrostatic interaction in drug binding. Moreover, the competitive binding properties of salicylic acid, ibuprofen and aspirin to BSA were studied. The combined EPR results of SL-salicylic acid/ibuprofen and SL-ibuprofen/salicylic acid showed that ibuprofen is able to replace up to ∼83% of bound SL-salicylic acid, and salicylic acid can replace only ∼14% of the bound SL-ibuprofen. This indicates that ∼97% of all salicylic acid and ibuprofen binding sites are shared. On the other hand, aspirin replaces only ∼23% of bound SL-salicylic acid, and salicylic acid replaces ∼50% of bound SL-aspirin, indicating that ∼73% of all salicylic acid and aspirin binding sites are shared. These results show that EPR spectroscopy in combination with the spin labeling technique is a very powerful

  16. EPR studies of intermolecular interactions and competitive binding of drugs in a drug-BSA binding model.

    PubMed

    Akdogan, Y; Emrullahoglu, M; Tatlidil, D; Ucuncu, M; Cakan-Akdogan, G

    2016-08-10

    Understanding intermolecular interactions between drugs and proteins is very important in drug delivery studies. Here, we studied different binding interactions between salicylic acid and bovine serum albumin (BSA) using electron paramagnetic resonance (EPR) spectroscopy. Salicylic acid was labeled with a stable radical (spin label) in order to monitor its mobilized (free) or immobilized (bound to BSA) states. In addition to spin labeled salicylic acid (SL-salicylic acid), its derivatives including SL-benzoic acid, SL-phenol, SL-benzene, SL-cyclohexane and SL-hexane were synthesized to reveal the effects of various drug binding interactions. EPR results of these SL-molecules showed that hydrophobic interaction is the main driving force. Whereas each of the two functional groups (-COOH and -OH) on the benzene ring has a minute but detectable effect on the drug-protein complex formation. In order to investigate the effect of electrostatic interaction on drug binding, cationic BSA (cBSA) was synthesized, altering the negative net charge of BSA to positive. The salicylic acid loading capacity of cBSA is significantly higher compared to that of BSA, indicating the importance of electrostatic interaction in drug binding. Moreover, the competitive binding properties of salicylic acid, ibuprofen and aspirin to BSA were studied. The combined EPR results of SL-salicylic acid/ibuprofen and SL-ibuprofen/salicylic acid showed that ibuprofen is able to replace up to ∼83% of bound SL-salicylic acid, and salicylic acid can replace only ∼14% of the bound SL-ibuprofen. This indicates that ∼97% of all salicylic acid and ibuprofen binding sites are shared. On the other hand, aspirin replaces only ∼23% of bound SL-salicylic acid, and salicylic acid replaces ∼50% of bound SL-aspirin, indicating that ∼73% of all salicylic acid and aspirin binding sites are shared. These results show that EPR spectroscopy in combination with the spin labeling technique is a very powerful

  17. Polyvinyl alcohol and amino acids as substitutes for bovine serum albumin in culture media for mouse preimplantation embryos.

    PubMed

    Biggers, J D; Summers, M C; McGinnis, L K

    1997-01-01

    The effect of replacing bovine serum albumin (BSA) in a simple defined medium (KSOM) with polyvinyl alcohol (PVA) and/or amino acids on the percentages of mouse zygotes that develop to at least the blastocyst stage and that hatch at least partially or completely is reported. Blastocysts could form when BSA was replaced with only PVA, but at a moderately reduced rate; however, partial hatching, and hence complete hatching, were severely impaired when BSA was replaced with only PVA. The substitution of BSA with amino acids alone resulted in a high rate of blastocyst formation and moderate impairment of hatching. The addition of PVA to BSA-free KSOM supplemented with amino acids had no extra effect. BSA had significant effects when added to BSA-free KSOM supplemented with amino acids. The BSA caused a significant increase in the rate of partial hatching, and may even have had a small effect on the rate of blastocyst formation. The results also showed that glucose, at a high concentration of 5.56 mM, does not inhibit the development of mouse zygotes to hatched blastocysts when cultured in KSOM supplemented with amino acids. PMID:9286737

  18. Binding of [3H]palmitate to BSA.

    PubMed

    Elmadhoun, B M; Wang, G Q; Templeton, J F; Burczynski, F J

    1998-10-01

    Determination of the BSA-palmitate high-affinity binding constant (Ka) traditionally relied on the heptane-water partitioning technique. We used this technique to calculate Ka for the BSA-[3H]palmitate complex, to determine if Ka was independent of protein concentration, and to determine if the unbound [3H]palmitate concentration is constant at different BSA concentrations using constant BSA-to-palmitate molar ratios (range 1:1 to 1:4). After extensive extraction of non-[3H]palmitate radiolabeled substances, the heptane-to-buffer partition ratio, in the absence of BSA, was 702 +/- 19 (mean +/- SD, n = 6). This value was much lower than the predicted value of 1,376 and was highly dependent on which phase (organic or aqueous) initially contained the [3H]palmitic acid. The data were consistent with the notion of self-association of [3H]palmitate in the aqueous phase. Ka for the BSA-[3H]palmitate complex was determined to be similar (2.2 +/- 0.1) x 10(8) M-1 (mean +/- SD, P > 0.05) at all BSA concentrations studied. At each BSA-to-palmitate molar ratio, the equilibrium unbound ligand concentration was constant only at low BSA concentrations (<10 microM) and at low BSA-to-palmitate molar ratios (i.e., 1:1 and 1:2). At higher BSA concentrations and molar ratios, the unbound ligand concentration increased with an increase in protein concentration. Hepatocyte uptake using the manufacturer-supplied radiolabeled product was significantly higher than with the purified product, suggesting that a non-[3H]palmitate radiolabel is also a substrate for the uptake process.

  19. 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

  20. Kinetic studies of bovine serum albumin interaction with PG and TBHQ using surface plasmon resonance.

    PubMed

    Fathi, Farzaneh; Ezzati Nazhad Dolatanbadi, Jafar; Rashidi, Mohammad-Reza; Omidi, Yadollah

    2016-10-01

    Propyl gallate (PG) and tert-butylhydroquinone (TBHQ) are examples of phenolic antioxidant agents, which have widespread uses in food industry. In this study, for the first time, we report on the interaction of PG and TBHQ with bovine serum albumin (BSA) using surface plasmon resonance (SPR). In order to modify Au slide with carboxyl functional group, 11-mercaptoundecanoic acid (MUA) was used. After activation of carboxylic groups, BSA was immobilized onto the MUA through both covalent amide bond and electrostatic binding formation. The SPR analysis showed dose-response sensograms of BSA upon increasing concentration of PG and TBHQ. At pH 4.5, the equilibrium dissociation constant or affinity unit (KD) for PG and TBHQ were 1.89e(-10) and 1.49e(-10) and at pH 7.5 were 4.74e(-10) and 1.83e(-9), respectively. The smaller amount of KD demonstrated high food additive molecules affinity to BSA. Based on these findings, it can be concluded that PG and TBHQ molecules can interact with BSA and effectively distributed within the body. Besides, SPR can be considered as useful automatic tool for quantification of PG and TBHQ interaction with serum albumin and it can deliver precise real-time kinetic data.

  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. 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. PMID:25907012

  3. Kinetic studies of bovine serum albumin interaction with PG and TBHQ using surface plasmon resonance.

    PubMed

    Fathi, Farzaneh; Ezzati Nazhad Dolatanbadi, Jafar; Rashidi, Mohammad-Reza; Omidi, Yadollah

    2016-10-01

    Propyl gallate (PG) and tert-butylhydroquinone (TBHQ) are examples of phenolic antioxidant agents, which have widespread uses in food industry. In this study, for the first time, we report on the interaction of PG and TBHQ with bovine serum albumin (BSA) using surface plasmon resonance (SPR). In order to modify Au slide with carboxyl functional group, 11-mercaptoundecanoic acid (MUA) was used. After activation of carboxylic groups, BSA was immobilized onto the MUA through both covalent amide bond and electrostatic binding formation. The SPR analysis showed dose-response sensograms of BSA upon increasing concentration of PG and TBHQ. At pH 4.5, the equilibrium dissociation constant or affinity unit (KD) for PG and TBHQ were 1.89e(-10) and 1.49e(-10) and at pH 7.5 were 4.74e(-10) and 1.83e(-9), respectively. The smaller amount of KD demonstrated high food additive molecules affinity to BSA. Based on these findings, it can be concluded that PG and TBHQ molecules can interact with BSA and effectively distributed within the body. Besides, SPR can be considered as useful automatic tool for quantification of PG and TBHQ interaction with serum albumin and it can deliver precise real-time kinetic data. PMID:27327906

  4. 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.

  5. 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

  6. Optimization and evaluation of a thermoresponsive ophthalmic in situ gel containing curcumin-loaded albumin nanoparticles.

    PubMed

    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.

  7. Acetylated Lysozyme as Impurity in Lysozyme Crystals: Constant Distribution Coefficient

    NASA Technical Reports Server (NTRS)

    Thomas, B. R.; Chernov, A. A.

    2000-01-01

    Hen egg white lysozyme (HEWL) was acetylated to modify molecular charge keeping the molecular size and weight nearly constant. Two derivatives, A and B, more and less acetylated, respectively, were obtained, separated, purified and added to the solution from which crystals of tetragonal HEWL crystals were grown. Amounts of the A or B impurities added were 0.76, 0.38 and 0.1 milligram per millimeter while HEWL concentration were 20, 30 and 40 milligram per milliliter. The crystals grown in 18 experiments for each impurity were dissolved and quantities of A or B additives in these crystals were analyzed by cation exchange high performance liquid chromatography. All the data for each set of 18 samples with the different impurity and regular HEWL concentrations is well described by one distribution coefficient K = 2.15 plus or minus 0.13 for A and K = 3.42 plus or minus 0.25 for B. The observed independence of the distribution coefficient on both the impurity concentration and supersaturation is explained by the dilution model described in this paper. It shows that impurity adsorption and incorporation rate is proportional to the impurity concentration and that the growth rate is proportional to the crystallizing protein in solution. With the kinetic coefficient for crystallization, beta = 5.10(exp -7) centimeters per second, the frequency at which an impurity molecule near the growing interface irreversibly joins a molecular site on the crystal was found to be 3 1 per second, much higher than the average frequency for crystal molecules. For best quality protein crystals it is better to have low microheterogeneous protein impurity concentration and high supers aturation.

  8. 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

  9. 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

  10. 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.

  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. [Detection of autoantibodies to polymerized human serum albumin].

    PubMed

    Manns, M; Müller, M; Meyer zum Büschenfelde, K H

    1984-11-01

    Binding activity of antibodies against polymerized human serum albumin (pHSA) was measured in the serum of 348 patients with various hepatic and non-hepatic diseases and in the serum of 108 control persons. The methods used were passive hemagglutination (PH) with antigen loaded human erythrocytes and radial immunodiffusion (ID). In the PH-method only HBsAg-positive sera reacted. Blocking experiments with pHSA, polymerized bovine serum albumin (pBSA) and monomeric human serum albumin (mHSA) showed, that the PH-method measures HBsAG associated receptors for pHSA. In HBeAG-positive cases titers were significantly higher than in anti-HBe-positive sera. Using the ID-method it could be shown, that 40% of sera of patients with liver diseases (n = 272), 37% of patients with LED (n = 27), 72% of patients with rheumatoid arthritis (n = 32), 6% of patients with glomerulonephritis (n = 17) and 2% of normal persons (n = 108) reacted. These sera reacted in the immunodiffusion assay with pHSA and pBSA but not with mHSA. Autoantibodies against non species specific determinants of pHSA which are not specific for liver diseases and possibly due to disturbed immunoregulation can be demonstrated by immunodiffusion. They may possibly be modulators of the pHSA mediated binding of hepatitis B-virus to hepatocytes.

  13. 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

  14. 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.

  15. Bull serum albumin coated Au@Agnanorods as SERS probes for ultrasensitive osteosarcoma cell detection.

    PubMed

    Yue, Ji; Liu, Zhen; Cai, Xingyu; Ding, Xianting; Chen, Shouhui; Tao, Ke; Zhao, Tingbao

    2016-04-01

    Surface-Enhanced Raman scattering (SERS) has been widely used for imaging and sensing. However, limited reports are currently available on SERS-based cancer cell targeting strategy due to the challenge of synthesizing highly sensitive, reproducible and biocompatible SERS probe. Herein, we developed novel SERS probes, based on BSA (Bull Serum Albumin) coated gold-silver core-shell nanorods modified with Raman reporter 5,5-dithiobis 2-nitrobenzoic acid (DTNB) (Au@AgNRs@BSA@Anti-MICA), for in vitro cancer cell detection. Our results demonstrate that the SERS probe is very robust for cancer cell ultrasensitive detection with good biocompatibility and strong SERS signal. PMID:26838436

  16. 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.

  17. Influence of galloyl moiety in interaction of epicatechin with bovine serum albumin: a spectroscopic and thermodynamic characterization.

    PubMed

    Pal, Sandip; Saha, Chabita; Hossain, Maidul; Dey, Subrata Kumar; Kumar, Gopinatha Suresh

    2012-01-01

    The health benefits stemming from green tea are well known, but the exact mechanism of its biological activity is not elucidated. Epicatechin (EC) and epicatechin gallate (ECG) are two dietary catechins ubiquitously present in green tea. Serum albumins functionally carry these catechins through the circulatory system and eliminate reactive oxygen species (ROS) induced injury. In the present study ECG is observed to have higher antioxidant activity; which is attributed to the presence of galloyl moiety. The binding affinity of these catechins to bovine serum albumin (BSA) will govern the efficacy of their biological activity. EC and ECG bind with BSA with binding constants 1.0 × 10(6) M(-1) and 6.6 × 10(7) M(-1), respectively. Changes in secondary structure of BSA on interaction with EC and ECG have been identified by circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. Thermodynamic characterization reveals the binding process to be exothermic, spontaneous and entropy driven. Mixed binding forces (hydrophobic, electrostatic and hydrogen bonding) exist between ECG and BSA. Binding site for EC is primarily site-II in sub-domain IIIA of BSA and for ECG; it is site-I in sub-domain IIA. ECG with its high antioxidant activity accompanied by high affinity for BSA could be a model in drug designing.

  18. Spectroscopic study of the interaction of styrylcyanine dyes Sbo, Sil and their derivatives with bovine serum albumin.

    PubMed

    Kurtaliev, Eldar N

    2011-07-01

    The spectral-luminescent characteristics of newly synthesized styrylcyanine dyes on the base of dyes Sbo ((E)-2-(4-(dimethylamino)styryl)-3-methylbenzo[d]oxazol-3-ium iodide) and Sil ((E)-2-(4-(dimethylamino)styryl)-1,3,3-trimethyl-3H-indolium perchlorate) in aqueous solutions without and in the presence of bovine serum albumin (BSA) were studied. It was established that the absorption spectra of dyes Tol-6, Dbo-10 and Dil-10 with increasing amount of BSA appear new bands with λ(max)=505 nm, λ(max)=512 nm and λ(max)=566 nm, respectively, whose intensity increases in proportion to the amount of albumin. The intensity of the glow of the main band of fluorescence in the presence of BSA sharply increases. The binding constant (K) and the number of binding sites (N) of studied dyes with BSA were determined. The dependence of binding constants with BSA on the dipole moment of dye molecules was determined, which indicates that besides electrostatic forces of attraction between molecules styrylcyanine dyes with BSA, hydrophobic interactions are essential.

  19. Physicochemical studies on the interaction of serum albumin with pulmonary surfactant extract in films and bulk bilayer phase.

    PubMed

    Nag, Kaushik; Vidyashankar, Sangeetha; Devraj, Ravi; Fritzen Garcia, Mauricia; Panda, Amiya K

    2010-12-15

    Functionality, structure and composition of the adsorbed films of bovine lipid extract surfactant (BLES), in the absence and presence of bovine serum albumin (BSA), at the air-buffer interface was characterized through surface tension, atomic force microscopy and time of flight secondary ion mass spectrometric methods. Gel and fluid domains of BLES films were found to be altered significantly in the presence of BSA. Differential scanning calorimetric studies on BLES dispersions in presence of BSA revealed that the perturbations of the lipid bilayer structures were significant only at higher amount of BSA. FTIR studies on the BLES dispersions in buffer solution revealed that BSA could affect the lipid head-group hydrations in bilayer as well as the methylene and methyl vibration modes of fatty acyl chains of the phospholipids present in BLES. Serum albumin could perturb the film structure at pathophysiological concentration while higher amount of BSA was required in perturbing the bilayer structures. The studies suggest a connected perturbed bilayer to monolayer transition model for surfactant inactivation at the alveolar-air interface in dysfunctional surfactants.

  20. Fluorescence spectroscopic study of serum albumin-bromadiolone interaction: fluorimetric determination of bromadiolone.

    PubMed

    Deepa, Subbiah; Mishra, Ashok K

    2005-07-01

    Bromadiolone (BRD), a substituted 4-hydroxycoumarin derivative, is known to possess anti-coagulant activity with acute toxicity. In this paper, we report a study on the interaction of bromadiolone with the plasma proteins bovine serum albumin (BSA) and human serum albumin (HSA), using the intrinsic fluorescence emission properties of bromadiolone. Bromadiolone is weakly fluorescent in aqueous buffer medium, with an emission at 397 nm. Binding of bromadiolone with serum albumins (SA) leads to a marked enhancement in the fluorescence emission intensity and steady state fluorescence anisotropy (r(ss)), accompanied by a blueshift of 10 nm. In the serum albumin-bromadiolone complex, selective excitation of tryptophan (Trp) residue results in emission from bromadiolone, thereby indicating a Förster type energy transfer from Trp to BRD. This quenching of Trp fluorescence by BRD was used to estimate the binding constant of the SA-BRD complex. The binding constants for BRD with BSA and HSA were 7.5 x 10(4) and 3.7 x 10(5)L mol(-1), respectively. Based on this, a new method involving SA as fluorescence-enhancing reagent for estimation of BRD in aqueous samples has been suggested. The detection limits of bromadiolone under the optimum conditions were 0.77 and 0.19 microg mL(-1) in presence of BSA and HSA, respectively. PMID:15925260

  1. 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).

  2. 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.

  3. 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. PMID:27664607

  4. New insight into the stereoselective interactions of quinine and quinidine, with bovine serum albumin.

    PubMed

    Liu, Yan; Chen, Mingmao; Wang, Shuaihua; Lin, Jingjing; Cai, Lizhen; Song, Ling

    2014-05-01

    Quinine (QN) and quinidine (QD), the chief quinoline alkaloids of various species of cinchona bark, are stereoisomers to each other. In this study, a series of appropriate and efficient methods have been applied to compare the binding modes of QN and QD with bovine serum albumin (BSA). The isothermal titration calorimetry and room temperature phosphorescence results show that both QN and QD can interact with BSA at one binding site to form drug-protein complexes, mainly through enthalpic driving force with the binding affinity order: QN > QD. The fluorescence resonance energy transfer and time-resolved fluorescence spectroscopy exhibits that QN has a larger energy transfer and more intensified binding capacity for BSA than QD. Data of dynamic light scattering reveal that the aggregate state of BSA is changed during this binding process, and the particle size distribution of QN-BSA bioconjugate is larger than that of QD. Nuclear magnetic resonance analysis indicates that aromatic protons make more contribution during ligand-protein complexation than that of aliphatic protons. The circular dichroism spectra exhibit different degrees of changes in BSA secondary structures in the presence of QN and QD, respectively.

  5. Studies on the interaction between triphenyltin and bovine serum albumin by fluorescence and CD spectroscopy.

    PubMed

    Cao, Xiangyu; Dong, Dianbo; Liu, Jianli; Jia, Chunyun; Liu, Wan; Yang, Wei

    2013-01-26

    The interaction between triphenyltin (TPT) and bovine serum albumin (BSA) in physiological buffer (pH=7.4) was investigated by the fluorescence quenching technique. The results of fluorescence titration revealed that TPT could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The apparent binding constants K and number of binding sites n of TPT with BSA were (7.04±0.0057)×10(2) and (0.77±0.016) which were obtained by the fluorescence quenching method. The thermodynamic parameters enthalpy change (ΔH), entropy change (ΔS) were positive, which indicated that the interaction of TPT with BSA was driven mainly by hydrophobic forces. The process of binding was a spontaneous process in which Gibbs free energy change was negative. The distance r between donor (BSA) and acceptor (TPT) was calculated to be 3.05nm based on Forster's non-radiative energy transfer theory. The results of synchronous fluorescence, three-dimensional fluorescence and Circular Dichroism (CD) spectra showed that the triphenyltin induced conformational changes of BSA. PMID:23360747

  6. 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.

  7. Heat-induced cross-linking and degradation of wheat gluten, serum albumin, and mixtures thereof.

    PubMed

    Rombouts, Ine; Lagrain, Bert; Delcour, Jan A

    2012-10-10

    Some wheat-based food systems, such as cakes, cookies, and egg noodles, contain mixtures of animal and plant (gluten) proteins and are processed under (mildly) alkaline conditions. Although changes in these proteins during processing can affect end product quality, they have seldom been studied. This study investigated protein cross-linking and degradation during heating (0-120 min, pH 8.0, 50-130 °C) of (mixtures of) wheat gluten and bovine serum albumin (BSA). The decrease in protein extractabilities in sodium dodecyl sulfate containing buffer under (non)reducing conditions and the levels of (cross-linked) amino acids were measured. No indications for polymerization at 50 °C were found. Below 100 °C, BSA polymerized more readily than wheat gluten. Above 100 °C, the opposite was observed. The kinetics of heat-induced polymerization of a 1:1 gluten-BSA mixture were similar to that of isolated gluten, implying that gluten decelerated BSA denaturation. Severe heating (130 °C, >15 min) induced degradation reactions in gluten but not in BSA. At all conditions used in this study, disulfide (SS) bonds contributed to the extractability loss. In addition, above 110 °C, β-elimination of cystine led to non-SS cross-links. Intramolecular SS bonds more often transformed in intermolecular non-SS bonds in BSA than in gluten. PMID:22950662

  8. 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. PMID:19788065

  9. 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.

  10. Maleylated-BSA suppresses lipopolysaccharide-induced IL-6 production by activating the ERK-signaling pathway in murine RAW264.7 cells.

    PubMed

    Tada, Rui; Koide, Yusuke; Yamamuro, Mitsuaki; Tanaka, Riki; Hidaka, Akira; Nagao, Koichiro; Aramaki, Yukihiko

    2014-03-01

    Macrophages are well known for their ability to induce diverse beneficial immune responses, especially in the defense against pathogens. However, an excessive activation of macrophages may cause harmful inflammation. In this context, the suppression of excessive macrophage activation would be a promising therapeutic strategy for treating inflammatory diseases. We have previously found that maleylated-bovine serum albumin (maleylated-BSA) suppresses the production of inflammatory mediators in murine macrophages. However, the immunosuppressive effects and underlying mechanism(s) of maleylated-BSA remain unclear. Here, we report that pretreatment with maleylated-BSA strongly inhibited the production of interleukin 6 (IL-6) induced by bacterial lipopolysaccharide (LPS) in murine RAW264.7 cells. This inhibitory effect of maleylated-BSA on LPS-induced IL-6 production was eliminated by treatment with an extracellular signal-regulated kinase (ERK) inhibitor, U0126, indicating the involvement of ERK pathways. Taken together, we have shown that maleylated-BSA suppresses LPS-induced production of IL-6 via the activation of an ERK signaling pathway in murine macrophages. The findings of this study imply the possibility of a novel therapeutic strategy for inflammatory diseases.

  11. Intestinal transmission of macromolecules (BSA and FITC-dextran) in the neonatal pig: enhancing effect of colostrum, proteins and proteinase inhibitors.

    PubMed

    Weström, B R; Ohlsson, B G; Svendsen, J; Tagesson, C; Karlsson, B W

    1985-01-01

    The effects of colostrum and constituents/factors in colostrum which may influence intestinal macromolecular transmission in the newborn preclosure pig were investigated. Unsuckled piglets were given, by use of a stomach tube, bovine serum albumin (BSA) and fluorescein-isothiocyanate (FITC)-labelled dextran 70,000 (FITC-D) as markers together with colostrum or the factors under study. The serum levels of BSA and FITC-D 4 h after feeding were then determined as a measure of the transfer. It was found that the two colostrums tested, bovine and especially porcine, markedly enhanced the transmission of both BSA and FITC-D. Furthermore, increasing amounts of the model proteins, BSA and bovine IgG (50-200 mg/ml), significantly increased the transfer of FITC-D, whereas unlabelled dextran 70,000 given in similar amounts did not. Proteinase inhibitors obtained from sow colostrum or soy bean also enhanced the transmission of both BSA and FITC-D while the inactive inhibitors, given as trypsin-inhibitor complexes, had no effect. On the other hand, addition of a proteinase, porcine trypsin, significantly decreased the transmission of FITC-D. These findings indicate that the intestinal transmission of macromolecules in the preclosure piglet is governed by the amount of protein available in the intestine. Therefore, feeding colostrum with a high protein content and proteinase inhibitors is likely to favour efficient intestinal transmission, although other colostrum factors may also be of importance.

  12. Synthesis of tumor-targeted folate conjugated fluorescent magnetic albumin nanoparticles for enhanced intracellular dual-modal imaging into human brain tumor cells.

    PubMed

    Wang, Xueqin; Tu, Miaomiao; Tian, Baoming; Yi, Yanjie; Wei, ZhenZhen; Wei, Fang

    2016-11-01

    Superparamagnetic iron oxide nanoparticles (SPIO NPs), utilized as carriers are attractive materials widely applied in biomedical fields, but target-specific SPIO NPs with lower toxicity and excellent biocompatibility are still lacking for intracellular visualization in human brain tumor diagnosis and therapy. Herein, bovine serum albumin (BSA) coated superparamagnetic iron oxide, i.e. γ-Fe2O3 nanoparticles (BSA-SPIO NPs), are synthesized. Tumor-specific ligand folic acid (FA) is then conjugated onto BSA-SPIO NPs to fabricate tumor-targeted NPs, FA-BSA-SPIO NPs as a contrast agent for MRI imaging. The FA-BSA-SPIO NPs are also labeled with fluorescein isothiocyanate (FITC) for intracellular visualization after cellular uptake and internalization by glioma U251 cells. The biological effects of the FA-BSA-SPIO NPs are investigated in human brain tumor U251 cells in detail. These results show that the prepared FA-BSA-SPIO NPs display undetectable cytotoxicity, excellent biocompatibility, and potent cellular uptake. Moreover, the study shows that the made FA-BSA-SPIO NPs are effectively internalized for MRI imaging and intracellular visualization after FITC labeling in the targeted U251 cells. Therefore, the present study demonstrates that the fabricated FITC-FA-BSA-SPIO NPs hold promising perspectives by providing a dual-modal imaging as non-toxic and target-specific vehicles in human brain tumor treatment in future.

  13. Synthesis of tumor-targeted folate conjugated fluorescent magnetic albumin nanoparticles for enhanced intracellular dual-modal imaging into human brain tumor cells.

    PubMed

    Wang, Xueqin; Tu, Miaomiao; Tian, Baoming; Yi, Yanjie; Wei, ZhenZhen; Wei, Fang

    2016-11-01

    Superparamagnetic iron oxide nanoparticles (SPIO NPs), utilized as carriers are attractive materials widely applied in biomedical fields, but target-specific SPIO NPs with lower toxicity and excellent biocompatibility are still lacking for intracellular visualization in human brain tumor diagnosis and therapy. Herein, bovine serum albumin (BSA) coated superparamagnetic iron oxide, i.e. γ-Fe2O3 nanoparticles (BSA-SPIO NPs), are synthesized. Tumor-specific ligand folic acid (FA) is then conjugated onto BSA-SPIO NPs to fabricate tumor-targeted NPs, FA-BSA-SPIO NPs as a contrast agent for MRI imaging. The FA-BSA-SPIO NPs are also labeled with fluorescein isothiocyanate (FITC) for intracellular visualization after cellular uptake and internalization by glioma U251 cells. The biological effects of the FA-BSA-SPIO NPs are investigated in human brain tumor U251 cells in detail. These results show that the prepared FA-BSA-SPIO NPs display undetectable cytotoxicity, excellent biocompatibility, and potent cellular uptake. Moreover, the study shows that the made FA-BSA-SPIO NPs are effectively internalized for MRI imaging and intracellular visualization after FITC labeling in the targeted U251 cells. Therefore, the present study demonstrates that the fabricated FITC-FA-BSA-SPIO NPs hold promising perspectives by providing a dual-modal imaging as non-toxic and target-specific vehicles in human brain tumor treatment in future. PMID:27523645

  14. Role of single-walled carbon nanotubes on ester hydrolysis and topography of electrospun bovine serum albumin/poly(vinyl alcohol) membranes.

    PubMed

    Ford, Ericka N J; Suthiwangcharoen, Nisaraporn; D'Angelo, Paola A; Nagarajan, Ramanathan

    2014-07-23

    Electrospun membranes were studied for the chemical deactivation of threat agents by means of enzymatic proteins. Protein loading and the surface chemistry of hybrid nanofibers influenced the efficacy by which embedded enzymes could digest the substrate of interest. Bovine serum albumin (BSA), selected as a model protein, was electrospun into biologically active fibers of poly(vinyl alcohol), PVA. Single-walled carbon nanotubes (SWNTs) were blended within these mixtures to promote protein assembly during the process of electrospinning and subsequently the ester hydrolysis of the substrates. The SWNT incorporation was shown to influence the topography of PVA/BSA nanofibers and enzymatic activity against paraoxon, a simulant for organophosphate agents and a phosphorus analogue of p-nitrophenyl acetate (PNA). The esterase activity of BSA against PNA was uncompromised upon its inclusion within nanofibrous membranes because similar amounts of PNA were hydrolyzed by BSA in solution and the electrospun BSA. However, the availability of BSA along the fiber surface was shown to affect the ester hydrolysis of paraoxon. Atomic force microscopy images of nanofibers implicated the surface migration of BSA during the electrospinning of SWNT filled dispersions, especially as greater weight fractions of protein were added to the spinning mixtures. In turn, the PVA/SWNT/BSA nanofibers outperformed the nanotube free PVA/BSA membranes in terms of paraoxon digestion. The results support the development of electrospun polymer nanofiber platforms, modulated by SWNTs for enzyme catalytic applications relevant to soldier protective ensembles. PMID:25007411

  15. BSA modification to reduce CTAB induced nonspecificity and cytotoxicity of aptamer-conjugated gold nanorods

    NASA Astrophysics Data System (ADS)

    Yasun, Emir; Li, Chunmei; Barut, Inci; Janvier, Denisse; Qiu, Liping; Cui, Cheng; Tan, Weihong

    2015-05-01

    Aptamer-conjugated gold nanorods (AuNRs) are excellent candidates for targeted hyperthermia therapy of cancer cells. However, in high concentrations of AuNRs, aptamer conjugation alone fails to result in highly cell-specific AuNRs due to the presence of positively charged cetyltrimethylammonium bromide (CTAB) as a templating surfactant. Besides causing nonspecific electrostatic interactions with the cell surfaces, CTAB can also be cytotoxic, leading to uncontrolled cell death. To avoid the nonspecific interactions and cytotoxicity triggered by CTAB, we report the further biologically inspired modification of aptamer-conjugated AuNRs with bovine serum albumin (BSA) protein. Following this modification, interaction between CTAB and the cell surface was efficiently blocked, thereby dramatically reducing the side effects of CTAB. This approach may provide a general and simple method to avoid one of the most serious issues in biomedical applications of nanomaterials: nonspecific binding of the nanomaterials with biological cells.Aptamer-conjugated gold nanorods (AuNRs) are excellent candidates for targeted hyperthermia therapy of cancer cells. However, in high concentrations of AuNRs, aptamer conjugation alone fails to result in highly cell-specific AuNRs due to the presence of positively charged cetyltrimethylammonium bromide (CTAB) as a templating surfactant. Besides causing nonspecific electrostatic interactions with the cell surfaces, CTAB can also be cytotoxic, leading to uncontrolled cell death. To avoid the nonspecific interactions and cytotoxicity triggered by CTAB, we report the further biologically inspired modification of aptamer-conjugated AuNRs with bovine serum albumin (BSA) protein. Following this modification, interaction between CTAB and the cell surface was efficiently blocked, thereby dramatically reducing the side effects of CTAB. This approach may provide a general and simple method to avoid one of the most serious issues in biomedical applications

  16. Growth kinetics of tetragonal lysozyme crystals

    NASA Technical Reports Server (NTRS)

    Pusey, M.; Naumann, R.

    1986-01-01

    A method for immobilizing protein crystals in small volumes to determine growth rates on various faces is applied to study the growth kinetics of the (100) face of tetragonal hen-egg white lysozyme crystals at different degrees of bulk saturation. In normal gravity, transport is found to be dominated by convection for crystal sizes larger than a few microns, while in a microgravity environment, transport is diffusion-limited for sizes up to a few mm. It is found that convection can be significant even in microgravity for crystals approaching cm sizes, and that lysozyme growth is limited by surface kinetics in normal gravity.

  17. Thermophysical properties of lysozyme (protein) solutions

    NASA Technical Reports Server (NTRS)

    Liu, Jiaching; Yang, Wen-Jei

    1992-01-01

    Thermophysical properties of protein solutions composed of the lysozyme crystals with a 0.1 M sodium acetate and 5 percent NaCl solution as the buffer (pH = 4.0) are determined. The properties being measured include specific heat, thermal conductivity, dynamic viscosity, and surface tension. The protein concentrations are varied. Thermal diffusivity is calculated using the measured results. The purpose of the research is to measure thermophysical properties of lysozyme solutions which would serve as the data bank for controlling and modeling the crystal growth process on earth as well as in space.

  18. 17 beta-estradiol-BSA conjugates and 17 beta-estradiol regulate growth plate chondrocytes by common membrane associated mechanisms involving PKC dependent and independent signal transduction.

    PubMed

    Sylvia, V L; Walton, J; Lopez, D; Dean, D D; Boyan, B D; Schwartz, Z

    2001-01-01

    Nuclear receptors for 17 beta-estradiol (E(2)) are present in growth plate chondrocytes from both male and female rats and regulation of chondrocytes through these receptors has been studied for many years; however, recent studies indicate that an alternative pathway involving a membrane receptor may also be involved in the cell response. E(2) was found to directly affect the fluidity of chondrocyte membranes derived from female, but not male, rats. In addition, E(2) activates protein kinase C (PKC) in a nongenomic manner in female cells, and chelerythrine, a specific inhibitor of PKC, inhibits E(2)-dependent alkaline phosphatase activity and proteoglycan sulfation in these cells, indicating PKC is involved in the signal transduction mechanism. The aims of the present study were: (1) to examine the effect of a cell membrane-impermeable 17 beta-estradiol-bovine serum albumin conjugate (E(2)-BSA) on chondrocyte proliferation, differentiation, and matrix synthesis; (2) to determine the pathway that mediates the membrane effect of E(2)-BSA on PKC; and (3) to compare the action of E(2)-BSA to that of E(2). Confluent, fourth passage resting zone (RC) and growth zone (GC) chondrocytes from female rat costochondral cartilage were treated with 10(-9) to 10(-7) M E(2) or E(2)-BSA and changes in alkaline phosphatase specific activity, proteoglycan sulfation, and [(3)H]-thymidine incorporation measured. To examine the pathway of PKC activation, chondrocyte cultures were treated with E(2)-BSA in the presence or absence of GDP beta S (inhibitor of G-proteins), GTP gamma S (activator of G-proteins), U73122 or D609 (inhibitors of phospholipase C [PLC]), wortmannin (inhibitor of phospholipase D [PLD]) or LY294002 (inhibitor of phosphatidylinositol 3-kinase). E(2)-BSA mimicked the effects of E(2) on alkaline phosphatase specific activity and proteoglycan sulfation, causing dose-dependent increases in both RC and GC cell cultures. Both forms of estradiol inhibited [(3)H

  19. 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+.

  20. 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.

  1. 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. PMID:26471614

  2. Albumin - blood (serum) test

    MedlinePlus

    ... conditions for which the test may be performed: Burns (widespread) Wilson disease If you are receiving large amounts of intravenous fluids, the result of this test may be inaccurate. Albumin will be decreased during pregnancy.

  3. 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. PMID:27574421

  4. 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

  5. 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

    2016-01-01

    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.

  6. 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.

  7. 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.

  8. Recombinant goose-type lysozyme in channel catfish: Lysozyme activity and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were: 1) to investigate whether recombinant channel catfish lysozyme g (CC-Lys-g) produced in E. coli expression system possesses any lysozyme activity; and 2) to evaluate whether channel catfish lysozyme g plasmid DNA could be used as an immunostimulant to protect chann...

  9. Recombinant goose-type lysozyme in channel catfish: lysozyme activity and efficacy as plasmid DNA immunostimulant against Aeromonas hydrophila infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were: 1) to investigate whether recombinant channel catfish lysozyme g (CC-Lys-g) produced in E. coli expression system possesses any lysozyme activity; and 2) to evaluate whether channel catfish lysozyme g plasmid DNA could be used as an immunostimulant to protect chann...

  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. 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.

  12. Pathophysiology of rhinitis. Lactoferrin and lysozyme in nasal secretions.

    PubMed Central

    Raphael, G D; Jeney, E V; Baraniuk, J N; Kim, I; Meredith, S D; Kaliner, M A

    1989-01-01

    The antimicrobial proteins lactoferrin (Lf) and lysozyme (Ly) are invariably found in nasal secretions. To investigate the cellular sources and the secretory control of these nasal proteins in vivo, 34 adult subjects underwent nasal provocation tests with methacholine (MC), histamine (H), and gustatory stimuli. Nasal lavages were collected and analyzed for total protein (TP), albumin (Alb), Lf, and Ly. MC (25 mg), H (1 mg), and gustatory stimuli (spicy foods) all increased the concentrations of TP, Alb, Lf, and Ly. However, when each protein was assessed as a percentage of TP (i.e., Alb% = Alb/TP; Lf% = Lf/TP; Ly% = Ly/TP), MC and gustatory stimuli, which both induce glandular secretion, selectively augmented Lf% and Ly% without changing Alb%, while H, which primarily increases vascular permeability, increased Alb% without significantly affecting Lf% or Ly%. Gel electrophoresis and immunoblotting analysis of nasal secretions demonstrated both Lf and Ly in cholinergically induced secretions. Furthermore, histochemical analyses of nasal turbinate tissue revealed Lf and Ly colocalization within the serous cells of submucosal glands, providing evidence that both proteins are strictly glandular products within the nasal mucosa. Therefore, both Lf and Ly are produced and secreted from the glands, and their secretion may be pharmacologically regulated in attempts to improve host defenses. Images PMID:2681268

  13. Glutaraldehyde mediated conjugation of amino-coated magnetic nanoparticles with albumin protein for nanothermotherapy.

    PubMed

    Zhao, Lingyun; Yang, Bing; Dai, Xiaochen; Wang, Xiaowen; Gao, Fuping; Zhang, Xiaodong; Tang, Jintian

    2010-11-01

    A novel bioconjugation of amino saline capped Fe3O4 magnetic nanoparticles (MNPs) with bovine serum albumin (BSA) was developed by applying glutaraldehyde as activator. Briefly, Fe3O4 MNs were synthesized by the chemical co-precipitation method. Surface modification of the prepared MNPs was performed by employing amino saline as the coating agent. Glutaraldehyde was further applied as an activation agent through which BSA was conjugated to the amino-coated MNPs. The structure of the BSA-MNs was confirmed by FTIR analysis. Physico-chemical characterizations of the BSA-MNPs, such as surface morphology, surface charge and magnetic properties were investigated by Transmission Electron Microscopy (TEM), zeta-Potential and Vibrating Sample Magnetometer (VSM), etc. Magnetic inductive heating characteristics of the BSA-MNPs were analyzed by exposing the MNPs suspension (magnetic fluid) under alternative magnetic field (AMF). The results demonstrate that BSA was successfully conjugated with amino-coated MNs mediated through glutaraldehyde activation. The nanoparticles were spherical shaped with approximately 10 nm diameter. Possessing ideal magnetic inductive heating characteristics, which can generate very rapid and efficient heating while upon AMF exposure, BSA-MNPs can be applied as a novel candidature for magnetic nanothermotherapy for cancer treatment. In vitro cytotoxicity study on the human hepatocellular liver carcinoma cells (HepG-2) indicates that BSA-MNP is an efficient agent for cancer nanothermotherapy with satisfied biocompatibility, as rare cytotoxicity was observed in the absence of AMF. Moreover, our investigation provides a methodology for fabrication protein conjugated MNPs, for instance monoclonal antibody conjugated MNPs for targeting cancer nanothermotherapy. PMID:21137877

  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. 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

    2016-02-01

    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 (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). PMID:26519916

  16. Roles of bovine serum albumin and copper in the assay and stability of ammonia monooxygenase activity in vitro.

    PubMed Central

    Juliette, L Y; Hyman, M R; Arp, D J

    1995-01-01

    We investigated the effects of bovine serum albumin (BSA) on both the assay and the stability of ammonia-oxidizing activity in cell extracts of Nitrosomonas europaea. Ammonia-dependent O2 uptake activity of freshly prepared extracts did not require BSA. However, a dependence on BSA developed in extracts within a short time. The role of BSA in the assay of ammonia-oxidizing activity apparently is to absorb endogenous free fatty acids which are present in the extracts, because (i) only proteins which bind fatty acids, e.g., BSA or beta-lactoglobulin, supported ammonia-oxidizing activity; (ii) exogenous palmitoleic acid completely inhibited ammonia-dependent O2 uptake activity; (iii) the inhibition caused by palmitoleic acid was reversed only by proteins which bind fatty acids; and (iv) the concentration of endogenous free palmitoleic acid increased during aging of cell extracts. Additionally, the presence of BSA (10 mg/ml) or CuCl2 (500 microM) stabilized ammonia-dependent O2 uptake activity for 2 to 3 days at 4 degrees C. The stabilizing effect of BSA or CuCl2 was apparently due to an inhibition of lipolysis, because both additives inhibited the increase in concentrations of free palmitoleic acid in aging extracts. Other additives which are known to modify lipase activity were also found to stabilize ammonia-oxidizing activity. These additives included HgCl2, lecithin, and phenylmethylsulfonyl fluoride. PMID:7665467

  17. Systematic investigation of the toxic mechanism of PFOA and PFOS on bovine serum albumin by spectroscopic and molecular modeling.

    PubMed

    Chen, Huilun; He, Pengzhen; Rao, Honghao; Wang, Fei; Liu, Haijun; Yao, Jun

    2015-06-01

    Perfluorinated compounds (PFCs), an emerging class of globally environmental contaminations, pose a great threat to humans with wide exposure from food and other potential sources. The effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on bovine serum albumin (BSA) under normal physiological conditions were characterized by fluorescence, UV-Vis absorption, Fourier transform infrared (FT-IR) spectroscopy and molecular docking methods. The fluorescence study suggested that the fluorescence quenching of BSA by PFCs was a static procedure forming a PFCs-BSA complex. The negative values of enthalpy change (ΔH) and entropy change (ΔS) indicated that van der Waals forces and hydrogen bonds were the dominant intermolecular forces in the binding of PFCs to BSA. The displacement experiments of site markers and molecular docking revealed that the binding of PFOA to BSA took place in sub-domain IIA (Sudlow site I) whereas PFOS was mainly located in the sub-domain IIIA (Sudlow site II) and partially bound into site I. Furthermore, the results of UV-Vis and FT-IR spectra demonstrated that the microenvironment and the secondary structure of BSA were changed in the presence of PFCs. These results indicated that PFCs indeed impact the conformation of BSA and PFOS was more toxic than PFOA, which were supported by theoretical molecular modeling methods.

  18. [Intermolecular Interactions between Cytisine and Bovine Serum Albumin A Synchronous Fluorescence Spectroscopic Analysis and Molecular Docking Research].

    PubMed

    Wu, Yu-hang; Han, Zhong-bao; Ma, Jia-ze; He, Yan; Liu, Li-yan; Xin, Shi-gang; Yu, Zhan

    2016-03-01

    Cytisine (Cy) is one of the alkaloids that exist naturally in the plant genera Laburnum of the family Fabaceae. With strong bioactivities, Cy is commercialized for smoking cessation for years. In this work, the study of intermolecular interactions between Cy and bovine serum albumin (BSA) was performed by applying fluorescence spectroscopic methods under simulated physiological conditions. The mechanism of fluorescence quenching of BSA by Cy was also studied. Parameters such as bathing temperature, time and solution pH were investigated to optimize the fluorescence quenching. The binding type, binding ratio and binding constant between BSA and Cy were calculated by using the Stem-Volmer equation. Experimental results indicated that Cy can quench the fluorescent emission of BSA statically by forming a 1 : 1 type non-covalent complex and the binding constant is 5.6 x 10(3) L x mol(-1). Synchronous fluorescence spectral research shows Cy may affect the fluorescence emission of Trp residues of BSA. Furthermore, molecular docking is utilized to model the complex and probe the plausible quenching mechanism. It can be noted that the hydrogen bindings and hydrophobic interactions between Cy and BSA change the micro-environment of Trp213, which leads to the fluorescence quenching of BSA. PMID:27400521

  19. Systematic investigation of the toxic mechanism of PFOA and PFOS on bovine serum albumin by spectroscopic and molecular modeling.

    PubMed

    Chen, Huilun; He, Pengzhen; Rao, Honghao; Wang, Fei; Liu, Haijun; Yao, Jun

    2015-06-01

    Perfluorinated compounds (PFCs), an emerging class of globally environmental contaminations, pose a great threat to humans with wide exposure from food and other potential sources. The effects of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on bovine serum albumin (BSA) under normal physiological conditions were characterized by fluorescence, UV-Vis absorption, Fourier transform infrared (FT-IR) spectroscopy and molecular docking methods. The fluorescence study suggested that the fluorescence quenching of BSA by PFCs was a static procedure forming a PFCs-BSA complex. The negative values of enthalpy change (ΔH) and entropy change (ΔS) indicated that van der Waals forces and hydrogen bonds were the dominant intermolecular forces in the binding of PFCs to BSA. The displacement experiments of site markers and molecular docking revealed that the binding of PFOA to BSA took place in sub-domain IIA (Sudlow site I) whereas PFOS was mainly located in the sub-domain IIIA (Sudlow site II) and partially bound into site I. Furthermore, the results of UV-Vis and FT-IR spectra demonstrated that the microenvironment and the secondary structure of BSA were changed in the presence of PFCs. These results indicated that PFCs indeed impact the conformation of BSA and PFOS was more toxic than PFOA, which were supported by theoretical molecular modeling methods. PMID:25497588

  20. 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. PMID:27262260

  1. 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.

  2. Site specificity of glycation and carboxymethylation of bovine serum albumin by fructose.

    PubMed

    Hinton, D J S; Ames, J M

    2006-06-01

    We report an investigation of the site specificity, extent and nature of modification of bovine serum albumin (BSA) incubated with fructose or glucose at physiological temperature and pH. Sites of early glycation (Heyns rearrangement products (HRP) from fructose; fructoselysine (FL) from glucose) as well as advanced glycation (N(epsilon)-(carboxymethyl)lysine; CML) were analyzed by liquid chromatography-mass spectrometry. The major site of modification by fructose, like glucose, is Lysine-524 and this results in, respectively, 31 and 76% loss of the corresponding unmodified tryptic peptide, Gln525-Lys533. In addition, total lysine, HRP, FL, CML and N(epsilon)-(carboxyethyl)lysine in the incubations, was quantified. Almost all of the loss of lysine in the fructose-modified BSA was attributed to the formation of CML, with the yield of CML being up to 17-fold higher than glucose-modified BSA. A mechanism for the formation of CML from the HRP is proposed. PMID:16583308

  3. 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.

  4. Synthesis, crystal structure, interaction with BSA and antibacterial activity of La(III) and Sm(III) complexes with enrofloxacin.

    PubMed

    Wang, Yan-Jun; Hu, Rui-Ding; Jiang, Dong-Hua; Zhang, Ping-Hua; Lin, Qiu-Yue; Wang, Yun-Yun

    2011-03-01

    Two new La(III) and Sm(III) complexes with enrofloxacin (HER, 1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid, C(19)H(21)FN(3)O(3)), [La(2)(ER)(6)(H(2)O)(2)]·14H(2)O(1) and [Sm(2)(ER)(6)(H(2)O)(2)]·14H(2)O(2) have been synthesized and characterized by elemental analysis, FT-IR, TG-DTG and X-ray single crystal diffraction. Both of the complexes are triclinic system with space group Pī. The structure of the complexes show that each rare earth atom in both complexes was nine-coordinated. Two of the enrofloxacin ions acted as tridentate chelate and bridging ligands, while the others as bidentate chelate ligands. The binding reaction between the complexes and bovine serum albumin (BSA) was studied by UV-vis absorption spectra and fluorescence spectroscopy. The results indicated that the two complexes had a quite strong ability to quench the fluorescence from BSA and the binding reaction was mainly a static quenching process. The binding constants K ( A )/(L·mol(-1)) were 1.46 × 10(5)(1) and 8.59 × 10(6)(2) and one binding site was formed. The synchronous spectroscopy suggested that tryptophan residues were placed in BSA. It was also found that the two complexes exhibited greater antimicrobial activity than enrofloxacin at given concentrations.

  5. Synthesis, purification and mass spectrometric characterisation of a fluorescent Au9@BSA nanocluster and its enzymatic digestion by trypsin.

    PubMed

    Fernández-Iglesias, Nerea; Bettmer, Jörg

    2014-01-21

    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.

  6. Triazolopyridyl ketones as a novel class of antileishmanial agents. DNA binding and BSA interaction.

    PubMed

    Adam, Rosa; Bilbao-Ramos, Pablo; López-Molina, Sonia; Abarca, Belén; Ballesteros, Rafael; González-Rosende, M Eugenia; Dea-Ayuela, M Auxiliadora; Alzuet-Piña, Gloria

    2014-08-01

    A new series of triazolopyridyl pyridyl ketones has been synthetized by regioselective lithiation of the corresponding [1,2,3]triazolo[1,5-a]pyridine at 7 position followed by reaction with different electrophiles. The in vitro antileishmanial activity of these compounds was evaluated against Leishmaniainfantum, Leishmaniabraziliensis, Leishmaniaguyanensis and Leishmaniaamazonensis. Compounds 6 and 7 were found to be the most active leishmanicidal agents. Both of them showed activities at micromolar concentration against cultured promastigotes of Leishmania spp. (IC₅₀=99.8-26.8 μM), without cytotoxicity on J774 macrophage cells. These two compounds were also tested in vivo in a murine model of acute infection by L. infantum. The triazolopyridine derivative 6 was effective against both spleen and liver parasites forms, while 7 was inactive against liver parasites. Mechanistic aspects of the antileishmanial activity were investigated by means of DNA binding studies (UV-titration and viscosimetry). Results have revealed that these active ligands are able to interact strongly with DNA [Kb=1.14 × 10(5)M(-1) (6) and 3.26 × 10(5)M(-1) (7)]. Moreover, a DNA groove binding has been proposed for both 6 and 7. To provide more insight on the mode of action of compounds 6 and 7 under biological conditions, their interaction with bovine serum albumin (BSA) was monitored by fluorescence titrations and UV-visible spectroscopy. The quenching constants and binding parameters were determined. Triazolopyridine ketones 6 and 7 have exhibited significant affinity towards BSA [Kb=2.5 × 10(4)M(-1) (6) and 1.9 × 10(4)M(-1) (7)]. Finally, to identify the binding location of compounds 6 and 7 on the BSA, competitive binding experiments were carried out, using warfarin, a characteristic marker for site I, and ibuprofen as one for site II. Results derived from these studies have indicated that both compounds interact at BSA site I and, to a lesser extent, at site II.

  7. 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 (BSA) were investigated by circular dichroism, fluorescence and absorption spectroscopy under physiological conditions. Berbamine caused a static quenching of the intrinsic fluorescence of BSA, and the quenching data were analyzed by application of the Stern-Volmer equation. There was a single primary berbamine-binding site on BSA with a binding constant of 2.577 × 10 4 L mol -1 at 298 K. The thermodynamic parameters, enthalpy change (Δ H0) and entropy change (Δ S0) for the reaction were -76.5 kJ mol -1 and -173.4 J mol -1 K -1 according to the van't Hoff equation. The results showed that the hydrogen bond and van der Waals interaction were the predominant forces in the binding process. Competitive experiments revealed a displacement of warfarin by berbamine, indicating that the binding site was located at Drug sites I. The distance r between the donor (BSA) and the acceptor (berbamine) was obtained according to the Förster non-radiation energy transfer theory. The results of three-dimensional fluorescence spectra, UV-vis absorption difference spectra and circular dichroism of BSA in the presence of berbamine showed that the conformation of BSA was changed. The results provide a quantitative understanding of the effect of berbamine on the structure of bovine serum albumin, providing a useful guideline for further drug design.

  8. Synthesis and characterization of bovine serum albumin-copper nanocomposites for antibacterial applications.

    PubMed

    Rastogi, Lori; Arunachalam, J

    2013-08-01

    A method for the synthesis of bovine serum albumin (BSA) and copper (Cu(0)) nanocomposites is described. The synthesis is achieved by adding [100mM] hydrazine hydrate ((N2H4·H2O) to [10mM] copper sulfate (CuSO4·5H2O) solution in the presence of 0.02% bovine serum albumin at pH-10.0 and then heating the reaction mixture at 50°C for 3h. The process resulted into the formation of well-dispersed hexagonal Cu-BSA composite particles (size 5±2.5) μm consisting of embedded copper nanoparticles (Cu NPs). The nanoparticles embedded in composite were of average diameters of 28±12nm. Phase analysis, purity and morphology of the product have been studied by various physical techniques. Effect of various reaction parameters have been investigated on the morphology of synthesized nanocomposite. Efforts have been made to investigate the possible mechanism of Cu-BSA composite synthesis which gave it unique hexagonal morphology. The important characteristic of the reported method is that the highly stable Cu NPs present in composite were synthesized without any inert atmosphere which could be dried under vacuum and stored for long term use. The synthesized Cu NPs containing BSA composite material exhibited good antibacterial potential against both Gram positive and Gram negative bacterial strains. The minimum inhibitory concentration (MIC) of Cu NPs in the form Cu-BSA composite on Escherichia coli was calculated to be 50μgmL(-1). Transmission electron microscopic and cytoplasmic leakage analysis revealed that Cu-BSA composite attached to the bacteria causing irreversible membrane damage leading to leakage of intracellular metabolites and eventually death of the organism. PMID:23531744

  9. A Fluorescence Quenching Study of the Interaction of Nebivolol Hydrochloride with Bovine and Human Serum Albumin

    NASA Astrophysics Data System (ADS)

    Abdel-Aziz, L.; Abdel-Fattah, L.; El-Kosasy, A.; Gaied, M.

    2015-09-01

    The interaction of nebivolol hydrochloride (NH), a β1-blocker, with bovine serum albumin (BSA) has been investigated at different pH values using the fluorescence quenching technique. The effect of different temperatures was studied at physiological pH 7.4. The binding constants of NH with BSA at 288, 298, and 309 K were found to be 2.691 × 1011, 1.38 × 1010, and 6.27 × 108 M-1, respectively. From the Arrhenius plot, the thermodynamic parameters, ΔH0 and ΔS0, were estimated to be -204.48 kJ/mol and -491.42 J/mol × K, respectively. This indicates that Van der Waals interactions and hydrogen bonds play a major role in the reaction. The effect of some inorganic divalent cations (Cu2+, Ni2+, and Zn2+) on binding of NH to BSA was also studied at physiological pH 7.4. Conformational investigation of BSA was done using synchronous fluorescence, showing the change in the microenvironment of the tryptophan residues. Fluorescence quenching reactions of NH to human serum albumin (HSA) and to γ-globulins were investigated and the binding parameters were obtained.

  10. 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. PMID:27614847

  11. 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.

  12. Investigations of acetaminophen binding to bovine serum albumin in the presence of fatty acid: Fluorescence and 1H NMR studies

    NASA Astrophysics Data System (ADS)

    Bojko, B.; Sułkowska, A.; Maciążek-Jurczyk, M.; Równicka, J.; Sułkowski, W. W.

    2009-04-01

    The binding of acetaminophen to bovine serum albumin (BSA) was studied by the quenching fluorescence method and the proton nuclear magnetic resonance technique ( 1H NMR). For fluorescence measurements 1-anilino-9-naphthalene sulfonate (ANS) hydrophobic probe was used to verify subdomain IIIA as acetaminophen's likely binding site. Three binding sites of acetaminophen in subdomain IIA of bovine serum albumin were found. Quenching constants calculated by the Stern-Volmer modified method were used to estimate the influence of myristic acid (MYR) on the drug binding to the albumin. The influence of [fatty acid]/[albumin] molar ratios on the affinity of the protein towards acetaminophen was described. Changes of chemical shifts and relaxation times of the drug indicated that the presence of MYR inhibits interaction in the AA-albumin complex. It is suggested that the elevated level of fatty acids does not significantly influence the pharmacokinetics of acetaminophen.

  13. Investigation of the Interaction of Naringin Palmitate with Bovine Serum Albumin: Spectroscopic Analysis and Molecular Docking

    PubMed Central

    Zhang, Xia; Li, Lin; Xu, Zhenbo; Liang, Zhili; Su, Jianyu; Huang, Jianrong; Li, Bing

    2013-01-01

    Background Bovine serum albumin (BSA) contains high affinity binding sites for several endogenous and exogenous compounds and has been used to replace human serum albumin (HSA), as these two compounds share a similar structure. Naringin palmitate is a modified product of naringin that is produced by an acylation reaction with palmitic acid, which is considered to be an effective substance for enhancing naringin lipophilicity. In this study, the interaction of naringin palmitate with BSA was characterised by spectroscopic and molecular docking techniques. Methodology/Principal Findings The goal of this study was to investigate the interactions between naringin palmitate and BSA under physiological conditions, and differences in naringin and naringin palmitate affinities for BSA were further compared and analysed. The formation of naringin palmitate-BSA was revealed by fluorescence quenching, and the Stern-Volmer quenching constant (KSV) was found to decrease with increasing temperature, suggesting that a static quenching mechanism was involved. The changes in enthalpy (ΔH) and entropy (ΔS) for the interaction were detected at −4.11±0.18 kJ·mol−1 and −76.59±0.32 J·mol−1·K−1, respectively, which indicated that the naringin palmitate-BSA interaction occurred mainly through van der Waals forces and hydrogen bond formation. The negative free energy change (ΔG) values of naringin palmitate at different temperatures suggested a spontaneous interaction. Circular dichroism studies revealed that the α-helical content of BSA decreased after interacting with naringin palmitate. Displacement studies suggested that naringin palmitate was partially bound to site I (subdomain IIA) of the BSA, which was also substantiated by the molecular docking studies. Conclusions/Significance In conclusion, naringin palmitate was transported by BSA and was easily removed afterwards. As a consequence, an extension of naringin applications for use in food, cosmetic and medicinal

  14. Quercetin Influence on Thermal Denaturation of Bovine Serum Albumin.

    PubMed

    Precupas, Aurica; Sandu, Romica; Popa, Vlad T

    2016-09-01

    The effect of quercetin (QUER) binding on bovine serum albumin (BSA) thermal denaturation was systematically investigated by means of differential scanning calorimetry (DSC). Additional information concerning thermodynamic and structural binding parameters was provided by isothermal titration calorimetry (ITC) and molecular docking. The most relevant effect of QUER is manifested in the modification of the two-step thermal fingerprint of protein denaturation. Higher QUER concentrations result in a single-step denaturation thermogram, ascribed to the interplay between specific and nonspecific binding and enhancement of the solvent unfolding action. Analysis of ITC data indicate sequential binding of two molecules of QUER occurring spontaneously at different binding sites of BSA involving hydrophobic, electrostatic and hydrogen binding forces. Identification of QUER binding sites was possible through corroboration of DSC runs in the presence of site markers and molecular docking. Modeling of ligand-protein interaction confirmed the experimental data. On one hand, a neutral form of QUER binds in a nonplanar conformation to Sudlow's site I, a large hydrophobic cavity of subdomain IIA of BSA and decreases its thermal stability. On the other hand, a second molecule of QUER, the anionic form, is bound in planar conformation to Sudlow's site II, situated in the subdomain IIIA of the folded protein, and increases the thermal stability of the corresponding structural domain of the protein. PMID:27505141

  15. Lysozyme Photochemistry as a Function of Temperature. The Protective Effect of Nanoparticles on Lysozyme Photostability.

    PubMed

    Oliveira Silva, Catarina; Petersen, Steffen B; Pinto Reis, Catarina; Rijo, Patrícia; Molpeceres, Jesús; Vorum, Henrik; Neves-Petersen, Maria Teresa

    2015-01-01

    The presence of aromatic residues and their close spatial proximity to disulphide bridges makes hen egg white lysozyme labile to UV excitation. UVB induced photo-oxidation of tryptophan and tyrosine residues leads to photochemical products, such as, kynurenine, N-formylkynurenine and dityrosine and to the disruption of disulphide bridges in proteins. We here report that lysozyme UV induced photochemistry is modulated by temperature, excitation power, illumination time, excitation wavelength and by the presence of plasmonic quencher surfaces, such as gold, and by the presence of natural fluorescence quenchers, such as hyaluronic acid and oleic acid. We show evidence that the photo-oxidation effects triggered by 295 nm at 20°C are reversible and non-reversible at 10°C, 25°C and 30°C. This paper provides evidence that the 295 nm damage threshold of lysozyme lies between 0.1 μW and 0.3 μW. Protein conformational changes induced by temperature and UV light have been detected upon monitoring changes in the fluorescence emission spectra of lysozyme tryptophan residues and SYPRO® Orange. Lysozyme has been conjugated onto gold nanoparticles, coated with hyaluronic acid and oleic acid (HAOA). Steady state and time resolved fluorescence studies of free and conjugated lysozyme onto HAOA gold nanoparticles reveals that the presence of the polymer decreased the rate of the observed photochemical reactions and induced a preference for short fluorescence decay lifetimes. Size and surface charge of the HAOA gold nanoparticles have been determined by dynamic light scattering and zeta potential measurements. TEM analysis of the particles confirms the presence of a gold core surrounded by a HAOA matrix. We conclude that HAOA gold nanoparticles may efficiently protect lysozyme from the photochemical effects of UVB light and this nanocarrier could be potentially applied to other proteins with clinical relevance. In addition, this study confirms that the temperature plays a

  16. Lysozymes and lysozyme-like proteins from the fall armyworm, Spodoptera frugiperda.

    PubMed

    Chapelle, Michael; Girard, Pierre-Alain; Cousserans, François; Volkoff, Nathalie-Anne; Duvic, Bernard

    2009-12-01

    Lysozyme is an important component of the insect non-specific immune response against bacteria that is characterized by its ability to break down bacterial cell-walls. By searching an EST database from the fall armyworm, Spodoptera frugiperda (Negre et al., 2006), we identified five sequences encoding proteins of the lysozyme family. The deduced protein sequences corresponded to three classical c-type lysozymes Sf-Lys1, Sf-Lys2 and Sf-Lys3, and two lysozyme-like proteins, Sf-LLP1 and Sf-LLP2. Sf-Lys1 was purified from the hemolymph of Escherichia coli-challenged S. frugiperda larvae. The mature protein had a molecular mass of 13.975 Da with an isoelectric point of 8.77 and showed 98.3% and 96.7% identity with lysozymes from Spodoptera litura and Spodoptera exigua, respectively. As the other insect lysozymes, Sf-Lys1 was active against gram positive bacteria such as Micrococcus luteus but also induced a slight permeabilization of the inner membrane of E. coli. Genes encoding these five Sf-Lys or Sf-LLPs were differentially up-regulated in three immune-competent tissues (hemocytes, fat body and gut) after challenges with non-pathogenic bacteria, E. coli and M. luteus, or entomopathogenic bacterium, Photorhabdus luminescens. Sf-Lys1 and Sf-Lys2 were mainly induced in fat body in the presence of E. coli or P. luminescens. Sf-Lys3, which had an acidic isoelectric point, was found to be the most up-regulated of all five Sf-Lys or Sf-LLPs in hemocytes and gut after challenge with P. luminescens. More molecular data are now available to investigate differences in physiological functions of these different members of the lysozyme superfamily. PMID:19828200

  17. [Albumin in sepsis].

    PubMed

    Tamion, F

    2010-09-01

    Human serum albumin is a small (66kD) globular protein representing over 60 % of the total plasma protein content. It is made up of 585 amino 6 acids and contains 35 cysteine residues forming disulfide bridges that contribute to its overall tertiary structure. It has a free cysteine-derived thiol group at Cys-34, which accounts for 80 % of its redox activity. Physiologically, serum albumin exists in a reduced form with a free thiol contributing to its antioxidant properties. It is synthesized primarily in the liver and is an acute-phase protein. It is a multifunctional plasma protein ascribed ligand-binding and transport properties as well as antioxidants and enzymatic functions. It maintains colloid osmotic pressure, modulates inflammatory response and may influence oxidative damage. Hypoalbuminemia is common in the intensive care unit and may be due to decreased synthesis by the liver and/or to increased losses or increased proteolysis and clearance. Although albumin was long used to control vascular collapse in critically ill patients, the evidence suggests that it does not offer a benefit over crystalloid solutions in vascular collapse. However, human serum albumin is an important circulating antioxidant and it may be beneficial in critically ill patients to limit oxidative damage. A number of studies suggest that in specific groups of hypoalbuminemic critically ill patients, albumin administration may have beneficial effects on organ function, although the exact mechanisms remain undefined. Further trials are needed to confirm theses observations and to clearly demonstrate whether albumin should be administered in critically ill patients with hypoalbuminemia. PMID:20675098

  18. Transendothelial albumin flux: evidence against active transport of albumin

    SciTech Connect

    Siflinger-Birnboim, A.; Del Vecchio, P.J.; Cooper, J.A.; Malik, A.B.

    1986-03-01

    The authors studied whether albumin is actively transported across cultured pulmonary endothelium by comparing the transendothelial flux of /sup 125/I-albumin from the luminal-to-abluminal side to the flux from the abluminal-to-luminal side. Bovine pulmonary artery endothelial cells were grown to confluence on gelatinized polycarbonated filters separating abluminal from luminal compartments. Each compartment had an albumin concentration of 1 g/100 ml to equalize oncotic pressure gradients. The effect of hydrostatic pressure was eliminated by maintaining an equal level of fluid in both compartments. The transendothelial flux of albumin across the monolayer was measured by placing /sup 125/I-albumin tracer either on the luminal or the abluminal side. Equal fluxes of /sup 125/I-albumin from luminal-to-abluminal side and from abluminal-to-luminal side were observed. The results indicate that the pulmonary endothelium behaves symmetrically for albumin, indicating the absence of active transport of albumin.

  19. The role of colloid particles in the albumin-lanthanides interaction: The study of aggregation mechanisms.

    PubMed

    Tikhonova, Tatiana N; Shirshin, Evgeny A; Romanchuk, Anna Yu; Fadeev, Victor V

    2016-10-01

    We studied the interaction between bovine serum albumin (BSA) and lanthanide ions in aqueous solution in the 4.0÷9.5pH range. A strong increase of the solution turbidity was observed at pH values exceeding 6, which corresponds to the formation of Ln(OH)3 nanoparticles, while no changes were observed near the isoelectric point of BSA (pH 4.7). The results of the dynamic light scattering and protein adsorption measurements clearly demonstrated that the observed turbidity enhancement was caused by albumin sorption on the surface of Ln(OH)3 and colloid particles bridging via adsorbed protein molecules. Upon pH increase from 4.5 to 6.5, albumin adsorption on lanthanide colloids was observed, while the following increase of pH from 6.5 to 9.5 led to protein desorption. The predominant role of the electrostatic interactions in the adsorption and desorption processes were revealed in the zeta-potential measurements. No reversibility was observed upon decreasing pH from 9.5 to 4.5 that was suggested to be due to the other interaction mechanisms present in the system. It was shown that while for all lanthanide ions the interaction mechanism with BSA was similar, its manifestation in the optical properties of the system was significantly different. This was interpreted as a consequence of the differences in lanthanides hydrolysis constants. PMID:27419645

  20. Genomic organization and evolution of ruminant lysozyme c genes.

    PubMed

    Irwin, David M

    2015-01-18

    Ruminant stomach lysozyme is a long established model of adaptive gene evolution. Evolution of stomach lysozyme function required changes in the site of expression of the lysozyme c gene and changes in the enzymatic properties of the enzyme. In ruminant mammals, these changes were associated with a change in the size of the lysozyme c gene family. The recent release of near complete genome sequences from several ruminant species allows a more complete examination of the evolution and diversification of the lysozyme c gene family. Here we characterize the size of the lysozyme c gene family in extant ruminants and demonstrate that their pecoran ruminant ancestor had a family of at least 10 lysozyme c genes, which included at least two pseudogenes. Evolutionary analysis of the ruminant lysozyme c gene sequences demonstrate that each of the four exons of the lysozyme c gene has a unique evolutionary history, indicating that they participated independently in concerted evolution. These analyses also show that episodic changes in the evolutionary constraints on the protein sequences occurred, with lysozyme c genes expressed in the abomasum of the stomach of extant ruminant species showing the greatest levels of selective constraints.

  1. Interaction of copper(II) complex of compartmental Schiff base ligand N, N'-bis(3-hydroxysalicylidene)ethylenediamine with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Boghaei, Davar M.; Farvid, Shokouh S.; Gharagozlou, Mehrnaz

    2007-03-01

    Circular dichroism (CD) spectroscopy, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the interaction between copper(II) complex of compartmental Schiff base ligand (L), N, N'-bis(3-hydroxysalicylidene)ethylenediamine, and bovine serum albumin (BSA) in 0.1 mol dm -3 phosphate buffer solution adjusted to physiological pH 7.0 containing 20% (w/w) dimethylsulfoxide at room temperature. CD spectra show that the interaction of the copper(II) complex with BSA leads to changes in the α-helical content of BSA and therefore changes in secondary structure of the protein with the slight red shift (2 nm) in CD spectra. From the voltammetric data, i.e. changes in limiting current with addition of BSA, the binding constant ( K) of the interaction of copper(II) complex with BSA was found to be 1.96 × 10 4 dm 3 mol -1. From the shifts in potential with the addition of BSA, the equilibrium constant ratio ( K2/ K1) for the binding of the oxidized Cu IIL ( K1) and reduced Cu IL ( K2) species to BSA was found to be 3.77, which shows that the reduced form Cu IL is bound more strongly to BSA than the oxidized form Cu IIL.

  2. Combined computational and experimental studies of molecular interactions of albuterol sulfate with bovine serum albumin for pulmonary drug nanoparticles

    PubMed Central

    Lin, Shao-Hui; Cui, Wei; Wang, Gui-Ling; Meng, Shuai; Liu, Ying-Chun; Jin, Hong-Wei; Zhang, Liang-Ren; Xie, Ying

    2016-01-01

    Albumin-based nanoparticles (NPs) are a promising technology for developing drug-carrier systems, with improved deposition and retention profiles in lungs. Improved understanding of these drug–carrier interactions could lead to better drug-delivery systems. The present study combines computational and experimental methods to gain insights into the mechanism of binding of albuterol sulfate (AS) to bovine serum albumin (BSA) on the molecular level. Molecular dynamics simulation and surface plasmon resonance spectroscopy were used to determine that there are two binding sites on BSA for AS: the first of which is a high-affinity site corresponding to AS1 and the second of which appears to represent the integrated functions of several low-affinity sites corresponding to AS2, AS3, and AS8. AS1 was the strongest binding site, established via electrostatic interaction with Glu243 and Asp255 residues in a hydrophobic pocket. Hydrogen bonds and salt bridges played a main role in the critical binding of AS1 to BSA, and water bridges served a supporting role. Based upon the interaction mechanism, BSA NPs loaded with AS were prepared, and their drug-loading efficiency, morphology, and -release profiles were evaluated. Successful clinical development of AS-BSA-NPs may improve therapy and prevention of bronchospasm in patients with reversible obstructive airway disease, and thus provide a solid basis for expanding the role of NPs in the design of new drug-delivery systems.

  3. Combined computational and experimental studies of molecular interactions of albuterol sulfate with bovine serum albumin for pulmonary drug nanoparticles

    PubMed Central

    Lin, Shao-Hui; Cui, Wei; Wang, Gui-Ling; Meng, Shuai; Liu, Ying-Chun; Jin, Hong-Wei; Zhang, Liang-Ren; Xie, Ying

    2016-01-01

    Albumin-based nanoparticles (NPs) are a promising technology for developing drug-carrier systems, with improved deposition and retention profiles in lungs. Improved understanding of these drug–carrier interactions could lead to better drug-delivery systems. The present study combines computational and experimental methods to gain insights into the mechanism of binding of albuterol sulfate (AS) to bovine serum albumin (BSA) on the molecular level. Molecular dynamics simulation and surface plasmon resonance spectroscopy were used to determine that there are two binding sites on BSA for AS: the first of which is a high-affinity site corresponding to AS1 and the second of which appears to represent the integrated functions of several low-affinity sites corresponding to AS2, AS3, and AS8. AS1 was the strongest binding site, established via electrostatic interaction with Glu243 and Asp255 residues in a hydrophobic pocket. Hydrogen bonds and salt bridges played a main role in the critical binding of AS1 to BSA, and water bridges served a supporting role. Based upon the interaction mechanism, BSA NPs loaded with AS were prepared, and their drug-loading efficiency, morphology, and -release profiles were evaluated. Successful clinical development of AS-BSA-NPs may improve therapy and prevention of bronchospasm in patients with reversible obstructive airway disease, and thus provide a solid basis for expanding the role of NPs in the design of new drug-delivery systems. PMID:27695294

  4. Interaction of water-soluble amino acid Schiff base complexes with bovine serum albumin: Fluorescence and circular dichroism studies

    NASA Astrophysics Data System (ADS)

    Gharagozlou, Mehrnaz; Boghaei, Davar M.

    2008-12-01

    Fluorescence spectroscopy in combination with circular dichroism (CD) spectroscopy were used to investigate the interaction of water-soluble amino acid Schiff base complexes, [Zn(L 1,2)(phen)] where phen is 1,10-phenanthroline and H 2L 1,2 is amino acid Schiff base ligands, with bovine serum albumin (BSA) under the physiological conditions in phosphate buffer solution adjusted to pH 7.0. The quenching mechanism of fluorescence was suggested as static quenching according to the Stern-Volmer equation. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between amino acid Schiff base complexes and BSA. The thermodynamic parameters Δ G, Δ H and Δ S at different temperatures (298, 310 and 318 K) were calculated. The results indicate that the hydrophobic and hydrogen bonding interactions play a major role in [Zn(L 1)(phen)]-BSA association, whereas hydrophobic and electrostatic interactions participate a main role in [Zn(L 2)(phen)]-BSA binding process. Binding studies concerning the number of binding sites and apparent binding constant Kb were performed by fluorescence quenching method. The distance R between the donor (BSA) and acceptor (amino acid Schiff base complexes) has been obtained utilizing fluorescence resonant energy transfer (FRET). Furthermore, CD spectra were used to investigate the structural changes of the BSA molecule with the addition of amino acid Schiff base complexes. The results indicate that the interaction of amino acid Schiff base complexes with BSA leads to changes in the secondary structure of the protein. Fractional contents of the secondary structure of BSA ( fα, fβ, fturn and frandom) were calculated with and without amino acid Schiff base complexes utilizing circular dichroism spectroscopy. Our results clarified that amino acid Schiff base complexes could bind to BSA and be effectively transported and eliminated in the body, which could be a useful guideline for further drug

  5. Release and pharmacokinetics of near-infrared labeled albumin from monodisperse poly(d,l-lactic-co-hydroxymethyl glycolic acid) microspheres after subcapsular renal injection.

    PubMed

    Kazazi-Hyseni, F; van Vuuren, S H; van der Giezen, D M; Pieters, E H; Ramazani, F; Rodriguez, S; Veldhuis, G J; Goldschmeding, R; van Nostrum, C F; Hennink, W E; Kok, R J

    2015-08-01

    Subcapsular renal injection is a novel administration method for local delivery of therapeutics for the treatment of kidney related diseases. The aim of this study was to investigate the feasibility of polymeric microspheres for sustained release of protein therapeutics in the kidney and study the subsequent redistribution of the released protein. For this purpose, monodisperse poly(d,l-lactic-co-hydroxymethyl glycolic acid) (PLHMGA) microspheres (40 μm in diameter) loaded with near-infrared dye-labeled bovine serum albumin (NIR-BSA) were prepared by a membrane emulsification method. Rats were injected with either free NIR-BSA or with NIR-BSA loaded microspheres (NIR-BSA-ms) and the pharmacokinetics of the released NIR-BSA was studied for 3 weeks by ex vivo imaging of organs and blood. Quantitative release data were obtained from kidney homogenates and possible metabolism of the protein was investigated by SDS-PAGE analysis of the samples. The ex vivo images showed a rapid decrease of the NIR signal within 24h in kidneys injected with free NIR-BSA, while, importantly, the signal of the labeled protein was still visible at day 21 in kidneys injected with NIR-BSA-ms. SDS-PAGE analysis of the kidney homogenates showed that intact NIR-BSA was released from the microspheres. The locally released NIR-BSA drained to the systemic circulation and subsequently accumulated in the liver, where it was degraded and excreted renally. The in vivo release of NIR-BSA was calculated after extracting the protein from the remaining microspheres in kidney homogenates. The in vivo release rate was faster (89 ± 4% of the loading in 2 weeks) compared to the in vitro release of NIR-BSA (38 ± 1% in 2 weeks). In conclusion, PLHMGA microspheres injected under the kidney capsule provide a local depot from which a formulated protein is released over a prolonged time-period.

  6. Dynamics of Lysozyme in Trehalose solutions

    NASA Astrophysics Data System (ADS)

    Ghatty, Pavan; Uberbacher, Edward C.

    2008-03-01

    Anhydrobiosis in Tardigrades and Nematodes has been a topic of constant interest and intrigue in the scientific community. An increase in the concentration of Trehalose has been attributed to the ability of some organisms to survive extreme conditions of temperature, pressure and pH. Although there exist many experimental studies attributing this effect to Trehalose, the molecular details governing the interaction between Trehalose and proteins remains unclear. We have conducted a 20ns study of Lysozyme in varying concentrations of Trehalose in water. Strong and weak hydrogen bonds and hydrophobic interactions between water, Trehalose and protein seem to dictate the interactions in the system. We have observed a hydrogen bonded network of Trehalose around the protein entrapping a layer of water between itself and protein. Lysozyme remains in a near-native conformation throughout the simulation giving hints on the ability of Trehalose in preserving the structure of protiens.

  7. Adhesion of Staphylococcus epidermidis to biomaterials is inhibited by fibronectin and albumin.

    PubMed

    Linnes, J C; Mikhova, K; Bryers, J D

    2012-08-01

    Decades of contradictory results have obscured the exact role of adsorbed fibronectin in the adhesion of the bacterium, Staphylococcus epidermidis, to biomaterials. Here, the ability of adsorbed fibronectin (FN) or bovine serum albumin (BSA) to modulate S. epidermidis adhesion to various biomaterials is reported. FN or BSA was adsorbed in increasing surface densities up to saturated monolayer coverage onto various common biomaterials, including poly(ethylene terephthalate), fluorinated ethylene propylene, poly(ether urethane), silicone, and borosilicate glass. Despite the wide range of surface characteristics represented, adsorption isotherms varied only subtly between materials for the two proteins considered. S. epidermidis adhesion to the various protein-coated biomaterials was quantified in a static-fluid batch adhesion assay. Although slight differences in overall adherent cell numbers were observed between the various protein-coated substrata, all materials exhibited significant dose-dependent decreases in S. epidermidis adhesion with increasing adsorption of either protein (FN, BSA) to all surfaces. Results here indicate that S. epidermidis adhesion to FN-coated surfaces is not a specific adhesion (i.e., receptor: ligand) mediated process, as no significant difference in adhesion was found between FN- and BSA-coated materials. Rather, results indicate that increasing surface density of either FN or BSA actually inhibited S. epidermidis adhesion to all biomaterials examined.

  8. The investigation of the interaction between piracetam and bovine serum albumin by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Guo, Xingjia; Han, Xiaowei; Tong, Jian; Guo, Chuang; Yang, Wenfeng; Zhu, Jifen; Fu, Bing

    2010-03-01

    The interaction between piracetam (OPA) with bovine serum albumin (BSA) has been thoroughly studied by fluorescence quenching technique in combination with UV-vis absorption, Fourier transform infrared (FT-IR), and circular dichroism (CD) spectroscopies under the simulative physiological conditions. The quenching of BSA fluorescence by OPA was found to be a static quenching process. The binding constants ( K a) are 3.014, 2.926, and 2.503 × 10 3 M -1 at 292, 298, and 309 K, respectively. According to the van't Hoff equation, the thermodynamic functions standard enthalpy (Δ H) and standard entropy (Δ S) for the reaction were calculated to be -74.560 kJ mol -1 and -159.380 J mol -1 K -1, which indicated that OPA binds to BSA mainly by hydrogen bonds and van der Waals interactions. The binding distance between BSA and OPA was calculated to be 4.10 nm according to the theory of FÖrster's non-radiation energy transfer. The displacement experiments confirmed that OPA could bind to the site I of BSA. Furthermore, the effects of pH and some common ions on the binding constant were also examined. And the alterations of protein secondary structure in the presence of OPA were observed by the CD and FT-IR spectra.

  9. Spectroscopic studies of interaction between CuO nanoparticles and bovine serum albumin.

    PubMed

    Esfandfar, Paniz; Falahati, Mojtaba; Saboury, AliAkbar

    2016-09-01

    Recently, the great interests in manufacturing and application of metal oxide nanoparticles in commercial and industrial products have led to focus on the potential impact of these particles on biomacromolecules. In the present study, the interaction of copper oxide (CuO) nanoparticles with bovine serum albumin (BSA) was studied by spectroscopic techniques. The zeta potential value for BSA and CuO nanoparticles with average diameter of around 50 nm at concentration of 10 μM in the deionized (DI) water were -5.8 and -22.5 mV, respectively. Circular dichroism studies did not show any changes in the content of secondary structure of the protein after CuO nanoparticles interaction. Fluorescence data revealed that the fluorescence quenching of BSA by CuO nanoparticles was the result of the formed complex of CuO nanoparticles - BSA. Binding constants and other thermodynamic parameters were determined at three different temperatures. The hydrogen bond interactions are the predominant intermolecular forces to stabilize the CuO nanoparticle - BSA complex. This study provides important insight into the interaction of CuO nanoparticles with proteins, which may be of importance for further application of these nanoparticles in biomedical applications. PMID:26555383

  10. Binding interaction of quinclorac with bovine serum albumin: A biophysical study

    NASA Astrophysics Data System (ADS)

    Han, Xiao-Le; Mei, Ping; Liu, Yi; Xiao, Qi; Jiang, Feng-Lei; Li, Ran

    2009-10-01

    Quinclorac (QUC) is a new class of highly selective auxin herbicides. The interaction between QUC and bovine serum albumin (BSA) was investigated by fluorescence spectroscopy, synchronous fluorescence, three-dimensional fluorescence, CD spectroscopy and UV-vis absorption spectroscopy under simulative physiological condition. It was proved that the probable quenching mechanism of BSA by quinclorac was dynamic quenching. The Stern-Volmer quenching model has been successfully applied and the activation energy of the interaction as much as 8.03 kJ mol -1, corresponding thermodynamic parameters Δ Hθ, Δ Sθ and Δ Gθ were calculated. The results indicated that the acting forces between QUC and BSA were mainly hydrogen bonding and van der Waals forces. According to the Förster non-radiation energy transfer theory, the average binding distance between donor (BSA) and acceptor (QUC) was obtained ( r = 3.12 nm). The alterations of protein secondary structure in the presence of QUC were confirmed by the evidences from three-dimensional fluorescence, synchronous fluorescence and CD spectroscopy. Furthermore, the site marker competitive experiments indicated that the binding of QUC to BSA primarily took place in Sudlow site I.

  11. Study on the chemiluminescence behavior of bovine serum albumin with luminol and its analytical application

    NASA Astrophysics Data System (ADS)

    Tan, Xijuan; Song, Zhenghua; Chen, Donghua; Wang, Zhuming

    2011-06-01

    In this paper, the luminescence behavior of bovine serum albumin (BSA) and luminol was first studied by flow injection chemiluminescence (CL). It was found that the hyperchromic effect of luminol in the presence of BSA led to the acceleration of the electrons transferring rate of excited 3-aminophthalate, which greatly enhanced the CL intensity of luminol/dissolved oxygen reaction. The increments of CL intensity were proportional to the concentrations of BSA with a linear range from 0.01 to 7 nmol L -1. It was also found that azithromycin could inhibit the CL intensity of luminol/BSA reaction. The decrements of CL intensity were logarithm over the concentrations of azithromycin ranging from 0.1 to 700 ng mL -1. At a flow rate of 2.0 mL min -1, a complete analytical process, which included sampling and washing, could be performed within 30 s with relative standard deviations of less than 3.1%. This proposed method was successfully applied in assaying azithromycin in pharmaceutical and human serum samples with recoveries from 91.0 to 104.3%. The possible luminescence mechanism of luminol/BSA/azithromycin reaction was discussed in detail by CL, UV and fluorescence methods.

  12. Study of the interaction between N-confused porphyrin and bovine serum albumin by fluorescence spectroscopy.

    PubMed

    Yu, Xianyong; Liu, Ronghua; Yi, Rongqiong; Yang, Fengxian; Huang, Haowen; Chen, Jian; Ji, Danhong; Yang, Ying; Li, Xiaofang; Yi, Pinggui

    2011-04-01

    The fluorescence and ultraviolet spectroscopy were explored to study the interaction between N-confused porphyrins (NCP) and bovine serum albumin (BSA) under imitated physiological condition. The experimental results indicated that the fluorescence quenching mechanism between BSA and NCP was static quenching procedure at low NCP concentration at 293 and 305 K or a combined quenching (static and dynamic) procedure at higher NCP concentration at 305 K. The binding constants, binding sites and the corresponding thermodynamic parameters ΔH, ΔS, and ΔG were calculated at different temperatures. The comparison of binding potency of the three NCP to BSA showed that the substituting groups in benzene ring could enhance the binding affinity. From the thermodynamic parameters, we concluded that the action force was mainly hydrophobic interaction. The binding distances between NCP and BSA were calculated using Förster non-radiation energy transfer theory. In addition, the effect of NCP on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.

  13. Locating the Binding Sites of Pb(II) Ion with Human and Bovine Serum Albumins

    PubMed Central

    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 KPb-HSA = 8.2 (±0.8)×104 M−1 and KPb-BSA = 7.5 (±0.7)×104 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. PMID:22574219

  14. Spectroscopic study on binding of gentisic acid to bovine serum albumin.

    PubMed

    Garzón, Andrés; Bravo, Iván; Carrión-Jiménez, M Rosario; Rubio-Moraga, Ángela; Albaladejo, José

    2015-01-01

    The interaction of (gentisic acid) GA with (bovine serum albumin) BSA has been studied by different spectroscopic techniques. GA is a monoanionic specie at the working pH of 7.4, it was determined by combining UV-Vis absorption spectroscopy and theoretical calculations. A set of fluorescence quenching experiments at different temperatures was carried out employing the native fluorescence of BSA. A Stern-Volmer constant (KSV) of (2.07±0.12)×10(4) mol(-1) L and a binding constant (Ka) of (8.47±4.39)×10(3) were determined at 310 K. The static quenching caused by the BSA-GA complex formation seems to play a significant role in the overall quenching process. A single binding site on BSA for GA was observed. ΔH=-55.6±0.2 kJ mol(-1) and ΔS=-104.3±0.6 J mol(-1) K(-1) were determined in a set of experiments on the dependence of Ka with the temperature. The binding process is, therefore, spontaneous and enthalpy-driven. Van der Waals forces and hydrogen bonds could also play the major role in the binding mode. The secondary structure changes of BSA in the absence and presence of GA were studied by FTIR and UV-Vis absorption spectroscopy.

  15. Growth and dissolution kinetics of tetragonal lysozyme

    NASA Technical Reports Server (NTRS)

    Monaco, L. A.; Rosenberger, F.

    1993-01-01

    The growth and dissolution kinetics of lysozyme in a 25 ml solution bridge inside a closed growth cell was investigated. It was found that, under all growth conditions, the growth habit forming (110) and (101) faces grew through layer spreading with different growth rate dependence on supersaturation/temperature. On the other hand, (100) faces which formed only at low temperatures underwent a thermal roughening transition around 12 C.

  16. Urinary albumin in space missions.

    PubMed

    Cirillo, Massimo; De Santo, Natale G; Heer, Martina; Norsk, Peter; Elmann-Larsen, Benny; Bellini, Luigi; Stellato, Davide; Drummer, Christian

    2002-07-01

    Proteinuria was hypothesized for space mission but research data are missing. Urinary albumin, as index of proteinuria, was analyzed in frozen urine samples collected by astronauts during space missions onboard MIR station and on ground (control). Urinary albumin was measured by a double antibody radioimmunoassay. On average, 24h urinary albumin was 27.4% lower in space than on ground; the difference was statistically significant. Low urinary albumin excretion could be another effect of exposure to weightlessness (microgravity).

  17. Binding to Bovine Serum Albumin Protects β-Carotene against Oxidative Degradation.

    PubMed

    Chang, Hui-Ting; Cheng, Hong; Han, Rui-Min; Zhang, Jian-Ping; Skibsted, Leif H

    2016-07-27

    Binding to bovine serum albumin (BSA) was found to protect β-carotene (β-Car) dissolved in air-saturated phosphate buffer solution/tetrahydrofuran (9:1, v/v) efficiently against photobleaching resulting from laser flash excitation at 532 nm. From dependence of the relative photobleaching yield upon the BSA concentration, an association constant of Ka = 4.67 × 10(5) L mol(-1) for β-Car binding to BSA was determined at 25 °C. Transient absorption spectroscopy confirmed less bleaching of β-Car on the microsecond time scale in the presence of BSA, while kinetics of triplet-state β-Car was unaffected by the presence of oxygen. The protection of β-Car against this type of reaction seems accordingly to depend upon dissipation of excitation energy from an excited state into the protein matrix. Static quenching of BSA fluorescence by β-Car had a Stern-Volmer constant of Ksv = 2.67 × 10(4) L mol(-1), with ΔH = 17 kJ mol(-1) and ΔS = 142 J mol(-1) K(-1) at 25 °C. Quenching of tryptophan (Trp) fluorescence by β-Car suggests involvement of Trp in binding of β-Car to BSA through hydrophobic interaction, while the lower value for the Stern-Volmer constant Ksv compared to the binding constant, Ka, may indicate involvement of β-Car aggregates. Bound β-Car increased the random coil fraction of BSA at the expense of α-helix, as shown by circular dichroism, affecting the β-Car configuration, as shown by Raman spectroscopy. PMID:27399620

  18. Pancreatic islet purification using bovine serum albumin: the importance of density gradient temperature and osmolality.

    PubMed

    Chadwick, D R; Robertson, G S; Toomey, P; Contractor, H; Rose, S; James, R F; Bell, P R; London, N J

    1993-01-01

    Euro-Ficoll and bovine serum albumin (BSA) are two of the most commonly used density gradient media for the purification of pancreatic islets. Euro-Ficoll is based upon Euro-Collins, a cold storage medium, and must, therefore, be used at 4 degrees C. The ionic composition of BSA, however, is likely to contribute to hypothermic cellular swelling, and this may influence the efficiency of islet purification using this medium at 4 degrees C. Experience in this laboratory also suggested that batch-to-batch variation in islet purity using BSA was related to differences in BSA osmolality. The aim of this study was to assess the effect of gradient medium temperature and osmolality on the purification of human and porcine islets using BSA. Pancreata were collagenase-digested, and islets were purified on continuous linear density gradients of BSA. The distribution of insulin and amylase in each gradient was assayed, and used to calculate the median density of islets and exocrine tissue, and the efficiency of islet purification (% amylase contamination at a fixed insulin yield), using: 1) gradient osmolalities of 300, 400, and 500 mOsm/kg H2O (seven porcine pancreata), and 2) gradients at 4 degrees C and at 22 degrees C (eight human and seven porcine pancreata). Increase in density gradient osmolality produced increases in porcine exocrine tissue density which exceeded changes in islet density, resulting in improved islet purity, maximal at a BSA osmolality of 400 mOsm/kg H2O. For human pancreata there was no significant change in pancreatic tissue densities nor islet purity with temperature.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7512874

  19. Biomolecular interaction study of hydralazine with bovine serum albumin and effect of β-cyclodextrin on binding by fluorescence, 3D, synchronous, CD, and Raman spectroscopic methods.

    PubMed

    Bolattin, Mallavva B; Nandibewoor, Sharanappa T; Chimatadar, Shivamurti A

    2016-07-01

    Spectrofluoremetric technique was employed to study the binding behavior of hydralazine with bovine serum albumin (BSA) at different temperatures. Binding study of bovine serum albumin with hydralazine has been studied by ultraviolet-visible spectroscopy, fluorescence spectroscopy and confirmed by three-dimensional, synchronous, circular dichroism, and Raman spectroscopic methods. Effect of β-cyclodextrin on binding was studied. The experimental results showed a static quenching mechanism in the interaction of hydralazine with bovine serum albumin. The binding constant and the number of binding sites are calculated according to Stern-Volmer equation. The thermodynamic parameters ∆H(o) , ∆G(o) , ∆S(o) at different temperatures were calculated. These indicated that the hydrogen bonding and weak van der Waals forces played an important role in the interaction. Based on the Förster's theory of non-radiation energy transfer, the binding average distance, r, between the donor (BSA) and acceptor (hydralazine) was evaluated and found to be 3.95 nm. Spectral results showed that the binding of hydralazine to BSA induced conformational changes in BSA. The effect of common ions on the binding of hydralazine to BSA was also examined. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Colorimetric and fluorometric dual-readout sensor for lysozyme.

    PubMed

    Zheng, Hanye; Qiu, Suyan; Xu, Kefeng; Luo, Linguang; Song, Yibiao; Lin, Zhenyu; Guo, Longhua; Qiu, Bin; Chen, Guonan

    2013-11-01

    A novel, highly sensitive and selective dual-readout sensor (colorimetric and fluorometric) for the detection of lysozyme was proposed. The fluorescence of triazolylcoumarin molecules was quenched by Au nanoparticles (AuNPs) initially through the fluorescence resonance energy transfer (FRET), after the addition of lysozyme, the stronger binding of lysozyme onto the surfaces of AuNPs made triazolylcoumarin molecules remove from the AuNPs surface and led to the recovery of the fluorescence of triazolylcoumarin molecules, and accompanied by the discernable color change of the solution from red to purple. The lowest detectable concentration for lysozyme was 50 ng mL(-1) by the naked eye, and the limit of detection (LOD) was 23 ng mL(-1) by fluorescence measurements. In addition, satisfactory results for lysozyme detection in hen egg white were confirmed in the study. Moreover, the presented sensor provides a reliable option to determine lysozyme with high sensitivity and selectivity. PMID:23978821

  1. Experimental, computational and chemometrics studies of BSA-vitamin B6 interaction by UV-Vis, FT-IR, fluorescence spectroscopy, molecular dynamics simulation and hard-soft modeling methods.

    PubMed

    Manouchehri, Firouzeh; Izadmanesh, Yahya; Aghaee, Elham; Ghasemi, Jahan B

    2016-10-01

    The interaction of pyridoxine (Vitamin B6) with bovine serum albumin (BSA) is investigated under pseudo-physiological conditions by UV-Vis, fluorescence and FTIR spectroscopy. The intrinsic fluorescence of BSA was quenched by VB6, which was rationalized in terms of the static quenching mechanism. According to fluorescence quenching calculations, the bimolecular quenching constant (kq), dynamic quenching (KSV) and static quenching (KLB) at 310K were obtained. The efficiency of energy transfer and the distance between the donor (BSA) and the acceptor (VB6) were calculated by Foster's non-radiative energy transfer theory and were equal to 41.1% and 2.11nm. The collected UV-Vis and fluorescence spectra were combined into a row-and column-wise augmented matrix and resolved by multivariate curve resolution-alternating least squares (MCR-ALS). MCR-ALS helped to estimate the stoichiometry of interactions, concentration profiles and pure spectra for three species (BSA, VB6 and VB6-BSA complex) existed in the interaction procedure. Based on the MCR-ALS results, using mass balance equations, a model was developed and binding constant of complex was calculated using non-linear least squares curve fitting. FT-IR spectra showed that the conformation of proteins was altered in presence of VB6. Finally, the combined docking and molecular dynamics (MD) simulations were used to estimate the binding affinity of VB6 to BSA. Five-nanosecond MD simulations were performed on bovine serum albumin (BSA) to study the conformational features of its ligand binding site. From MD results, eleven BSA snapshots were extracted, at every 0.5ns, to explore the binding affinity (GOLD score) of VB6 using a docking procedure. MD simulations indicated that there is a considerable flexibility in the structure of protein that affected ligand recognition. Structural analyses and docking simulations indicated that VB6 binds to site I and GOLD score values depend on the conformations of both BSA and ligand

  2. Experimental, computational and chemometrics studies of BSA-vitamin B6 interaction by UV-Vis, FT-IR, fluorescence spectroscopy, molecular dynamics simulation and hard-soft modeling methods.

    PubMed

    Manouchehri, Firouzeh; Izadmanesh, Yahya; Aghaee, Elham; Ghasemi, Jahan B

    2016-10-01

    The interaction of pyridoxine (Vitamin B6) with bovine serum albumin (BSA) is investigated under pseudo-physiological conditions by UV-Vis, fluorescence and FTIR spectroscopy. The intrinsic fluorescence of BSA was quenched by VB6, which was rationalized in terms of the static quenching mechanism. According to fluorescence quenching calculations, the bimolecular quenching constant (kq), dynamic quenching (KSV) and static quenching (KLB) at 310K were obtained. The efficiency of energy transfer and the distance between the donor (BSA) and the acceptor (VB6) were calculated by Foster's non-radiative energy transfer theory and were equal to 41.1% and 2.11nm. The collected UV-Vis and fluorescence spectra were combined into a row-and column-wise augmented matrix and resolved by multivariate curve resolution-alternating least squares (MCR-ALS). MCR-ALS helped to estimate the stoichiometry of interactions, concentration profiles and pure spectra for three species (BSA, VB6 and VB6-BSA complex) existed in the interaction procedure. Based on the MCR-ALS results, using mass balance equations, a model was developed and binding constant of complex was calculated using non-linear least squares curve fitting. FT-IR spectra showed that the conformation of proteins was altered in presence of VB6. Finally, the combined docking and molecular dynamics (MD) simulations were used to estimate the binding affinity of VB6 to BSA. Five-nanosecond MD simulations were performed on bovine serum albumin (BSA) to study the conformational features of its ligand binding site. From MD results, eleven BSA snapshots were extracted, at every 0.5ns, to explore the binding affinity (GOLD score) of VB6 using a docking procedure. MD simulations indicated that there is a considerable flexibility in the structure of protein that affected ligand recognition. Structural analyses and docking simulations indicated that VB6 binds to site I and GOLD score values depend on the conformations of both BSA and ligand

  3. BSA-imprinted synthetic receptor for reversible template recognition.

    PubMed

    Wang, Huafang; He, Yunhua; He, Xiwen; Li, Wenyou; Chen, Langxing; Zhang, Yukui

    2009-06-01

    A novel approach to the manufacturing of protein-responsive imprints on a home-made chitosan substrate was established together with m-aminophenylboronic acid (APBA) as a functional monomer. The produced polymers were characterized using both (1) equilibrium adsorption assays and (2) high performance liquid chromatography analysis. Results confirmed that the synthesized BSA-MIP (molecularly imprinted polymer) has a high affinity towards its template compared to the determined control proteins. The produced BSA-MIP featured largely in its good adsorption reversibility, especially in competitive binding assays, which is of great biological significance in separations. Non-specific binding was reduced to almost zero in a BSA/BHb competitive binding event. An excellent HPLC profile of template recognition was found for BSA-MIP, even under harsh mobile phase conditions. In the present work, the adopted trapped-template-release method permits recovery of bound BSA [1]. The strategy of making an artificial protein-receptor with high adsorption affinity and reversibility is promising in on-line isolation of target protein from complicated biological environments.

  4. Polarization properties of fluorescent BSA protected Au25 nanoclusters.

    PubMed

    Raut, Sangram; Chib, Rahul; Rich, Ryan; Shumilov, Dmytro; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2013-04-21

    BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water. We demonstrated that the nanocluster absorption spectrum can be separated from the extinction spectrum by subtraction of Rayleigh scattering. The nanocluster absorption spectrum is well approximated by three Gaussian components. By a comparison of the emissions from BSA Au25 clusters and rhodamine B in water, we estimated the quantum yield of nanoclusters to be higher than 0.06. The fluorescence lifetime of BSA Au25 clusters is long and heterogeneous with an average value of 1.84 μs. In glycerol at -20 °C the anisotropy is high, reaching a value of 0.35. However, the excitation anisotropy strongly depends on the excitation wavelengths indicating a significant overlap of the different transition moments. The anisotropy decay in water reveals a correlation time below 0.2 μs. In propylene glycol the measured correlation time is longer and the initial anisotropy depends on the excitation wavelength. BSA Au25 clusters, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight.

  5. Electrochemistry of N-n-undecyl-N'-(sodium-p-aminobenzenesulfonate) thiourea and its interaction with bovine serum albumin.

    PubMed

    Luo, Hongxia; Du, Yang; Guo, Zhi-Xin

    2009-02-01

    In pH 5.5 phosphate buffer solution, N-n-undecyl-N'-(sodium-p-aminobenzenesulfonate) thiourea (UPT) produced a pair of redox peaks on the bare glassy carbon electrode. At the multi-walled carbon nanotube (MWNT) modified electrode, the electrochemical behavior of UPT enhanced greatly. In the presence of bovine serum albumin (BSA), the peak currents of UPT decreased linearly due to the formation of a super-molecular complex. This method was successfully applied to the determination of BSA in a bovine serum sample.

  6. Effect of bovine serum albumin on the structure and properties of Langmuir Blodgett films based phosphocholine and cholesterol

    NASA Astrophysics Data System (ADS)

    Dubatovka, K. I.; Zhavnerko, G. K.; Agabekov, V. E.

    2014-02-01

    Mono- and bilayer Langmuir-Blodgett films based on phosphocholine and cholesterol and prepared by horizontal and vertical deposition are investigated by atomic force microscopy. It was found that bovine serum albumin (BSA) included at the stage of film formation. At the same time, isolation has a considerable effect on their structure. It was shown that the globular formation of nanostructures with heights of 4-7 nm occurs as a result of transferring lipids to a hydrophobic surface from a subphase containing BSA, indicating the reorganization of monolayers during protein isolation and inclusion in its composition.

  7. Blood serum and BSA, but neither red blood cells nor hemoglobin can support vitellogenesis and egg production in the dengue vector Aedes aegypti

    PubMed Central

    Gonzales, Kristina K.; Tsujimoto, Hitoshi

    2015-01-01

    Aedes aegypti is the major vector of dengue, yellow fever and chikungunya viruses that put millions of people in endemic countries at risk. Mass rearing of this mosquito is crucial for strategies that use modified insects to reduce vector populations and transmission of pathogens, such as sterile insect technique or population replacement. A major problem for vector mosquito mass rearing is the requirement of vertebrate blood for egg production since it poses significant costs as well as potential health hazards. Also, regulations for human and animal use as blood source can pose a significant obstacle. A completely artificial diet that supports egg production in vector mosquitoes can solve this problem. In this study, we compared different blood fractions, serum and red blood cells, as dietary protein sources for mosquito egg production. We also tested artificial diets made from commercially available blood proteins (bovine serum albumin (BSA) and hemoglobin). We found that Ae. aegypti performed vitellogenesis and produced eggs when given whole bovine blood, serum, or an artificial diet containing BSA. Conversely, egg production was impaired after feeding of the red blood cell fraction or an artificial diet containing only hemoglobin. We also found that egg viability of serum-fed mosquitoes were comparable to that of whole blood and an iron supplemented BSA meal produced more viable eggs than a meal containing BSA alone. Our results indicate that serum proteins, not hemoglobin, may replace vertebrate blood in artificial diets for mass mosquito rearing. PMID:26020000

  8. Blood serum and BSA, but neither red blood cells nor hemoglobin can support vitellogenesis and egg production in the dengue vector Aedes aegypti.

    PubMed

    Gonzales, Kristina K; Tsujimoto, Hitoshi; Hansen, Immo A

    2015-01-01

    Aedes aegypti is the major vector of dengue, yellow fever and chikungunya viruses that put millions of people in endemic countries at risk. Mass rearing of this mosquito is crucial for strategies that use modified insects to reduce vector populations and transmission of pathogens, such as sterile insect technique or population replacement. A major problem for vector mosquito mass rearing is the requirement of vertebrate blood for egg production since it poses significant costs as well as potential health hazards. Also, regulations for human and animal use as blood source can pose a significant obstacle. A completely artificial diet that supports egg production in vector mosquitoes can solve this problem. In this study, we compared different blood fractions, serum and red blood cells, as dietary protein sources for mosquito egg production. We also tested artificial diets made from commercially available blood proteins (bovine serum albumin (BSA) and hemoglobin). We found that Ae. aegypti performed vitellogenesis and produced eggs when given whole bovine blood, serum, or an artificial diet containing BSA. Conversely, egg production was impaired after feeding of the red blood cell fraction or an artificial diet containing only hemoglobin. We also found that egg viability of serum-fed mosquitoes were comparable to that of whole blood and an iron supplemented BSA meal produced more viable eggs than a meal containing BSA alone. Our results indicate that serum proteins, not hemoglobin, may replace vertebrate blood in artificial diets for mass mosquito rearing.

  9. A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins.

    PubMed

    Nusrat, Saima; Siddiqi, Mohammad Khursheed; Zaman, Masihuz; Zaidi, Nida; Ajmal, Mohammad Rehan; Alam, Parvez; Qadeer, Atiyatul; Abdelhameed, Ali Saber; Khan, Rizwan Hasan

    2016-01-01

    Exogenous drugs that are used as antidote against chemotheray, inflammation or viral infection, gets absorbed and interacts reversibly to the major serum transport protein i.e. albumins, upon entering the circulatory system. To have a structural guideline in the rational drug designing and in the synthesis of drugs with greater efficacy, the binding mechanism of an antineoplastic and anti-inflammatory drug Nordihydroguaiaretic acid (NDGA) with human and bovine serum albumins (HSA & BSA) were examined by spectroscopic and computational methods. NDGA binds to site II of HSA with binding constant (Kb) ~105 M-1 and free energy (ΔG) ~ -7.5 kcal.mol-1. It also binds at site II of BSA but with lesser binding affinity (Kb) ~105 M-1 and ΔG ~ -6.5 kcal.mol-1. The negative value of ΔG, ΔH and ΔS for both the albumins at three different temperatures confirmed that the complex formation process between albumins and NDGA is spontaneous and exothermic. Furthermore, hydrogen bonds and hydrophobic interactions are the main forces involved in complex formation of NDGA with both the albumins as evaluated from fluorescence and molecular docking results. Binding of NDGA to both the albumins alter the conformation and causes minor change in the secondary structure of proteins as indicated by the CD spectra. PMID:27391941

  10. A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins

    PubMed Central

    Nusrat, Saima; Siddiqi, Mohammad Khursheed; Zaman, Masihuz; Zaidi, Nida; Ajmal, Mohammad Rehan; Alam, Parvez; Qadeer, Atiyatul; Abdelhameed, Ali Saber

    2016-01-01

    Exogenous drugs that are used as antidote against chemotheray, inflammation or viral infection, gets absorbed and interacts reversibly to the major serum transport protein i.e. albumins, upon entering the circulatory system. To have a structural guideline in the rational drug designing and in the synthesis of drugs with greater efficacy, the binding mechanism of an antineoplastic and anti-inflammatory drug Nordihydroguaiaretic acid (NDGA) with human and bovine serum albumins (HSA & BSA) were examined by spectroscopic and computational methods. NDGA binds to site II of HSA with binding constant (Kb) ~105 M-1 and free energy (ΔG) ~ -7.5 kcal.mol-1. It also binds at site II of BSA but with lesser binding affinity (Kb) ~105 M-1 and ΔG ~ -6.5 kcal.mol-1. The negative value of ΔG, ΔH and ΔS for both the albumins at three different temperatures confirmed that the complex formation process between albumins and NDGA is spontaneous and exothermic. Furthermore, hydrogen bonds and hydrophobic interactions are the main forces involved in complex formation of NDGA with both the albumins as evaluated from fluorescence and molecular docking results. Binding of NDGA to both the albumins alter the conformation and causes minor change in the secondary structure of proteins as indicated by the CD spectra. PMID:27391941

  11. 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).

  12. Lysozyme pattern formation in evaporating droplets

    NASA Astrophysics Data System (ADS)

    Gorr, Heather Meloy

    Liquid droplets containing suspended particles deposited on a solid, flat surface generally form ring-like structures due to the redistribution of solute during evaporation (the "coffee ring effect"). The forms of the deposited patterns depend on complex interactions between solute(s), solvent, and substrate in a rapidly changing, far from equilibrium system. Solute self-organization during evaporation of colloidal sessile droplets has attracted the attention of researchers over the past few decades due to a variety of technological applications. Recently, pattern formation during evaporation of various biofluids has been studied due to potential applications in medical screening and diagnosis. Due to the complexity of 'real' biological fluids and other multicomponent systems, a comprehensive understanding of pattern formation during droplet evaporation of these fluids is lacking. In this PhD dissertation, the morphology of the patterns remaining after evaporation of droplets of a simplified model biological fluid (aqueous lysozyme solutions + NaCl) are examined by atomic force microscopy (AFM) and optical microscopy. Lysozyme is a globular protein found in high concentration, for example, in human tears and saliva. The drop diameters, D, studied range from the micro- to the macro- scale (1 microm -- 2 mm). In this work, the effect of evaporation conditions, solution chemistry, and heat transfer within the droplet on pattern formation is examined. In micro-scale deposits of aqueous lysozyme solutions (1 microm < D < 50 microm), the protein motion and the resulting dried residue morphology are highly influenced by the decreased evaporation time of the drop. The effect of electrolytes on pattern formation is also investigated by adding varying concentrations NaCl to the lysozyme solutions. Finally, a novel pattern recognition program is described and implemented which classifies deposit images by their solution chemistries. The results presented in this Ph

  13. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment

    PubMed Central

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P.; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEONLA-BSA, which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEONLA-BSA particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEONLA-BSA changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment. PMID:26287178

  14. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

    PubMed

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-08-14

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment.

  15. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

    PubMed

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment. PMID:26287178

  16. Purification and properties of lysozyme produced by Staphylococcus aureus.

    PubMed

    Hawiger, J

    1968-02-01

    A method based on cold ethyl alcohol fractionation at different pH levels and ionic strengths and on gel filtration on a Sephadex G-200 column was used to concentrate and purify lysozyme from the culture supernatant fluid of Staphylococcus aureus strain 524. The final, nondialyzable product exhibited a 163-fold rise in specific activity over that of the starting material. Staphylococcal lysozyme is a glycosidase which splits N-acetylamino sugars from the susceptible substrate. Staphylococcal lysozyme was shown to be similar to egg white lysozyme in its optimal temperature for reaction, optimal pH, activation by NaCl and Ca(++) ions, inhibition by sodium citrate and ethylenediaminetetraacetate, and inactivation by Cu(++) ions and sodium dodecyl sulfate. It differs from the egg white lysozyme in its temperature susceptibility range (staphylococcal lysozyme is inactivated at 56 C). It acts on whole cells and cell walls of Micrococcus lysodeikticus, murein from S. aureus 524, and cell walls of S. epidermidis Zak. The last substrate was not susceptible to the action of egg white lysozyme in the test system used. The mechanism of action of staphylococcal lysozyme seems to be analogous to that of egg white lysozyme; however, the biological specificity of the two enzymes may be different.

  17. Purification and Properties of Lysozyme Produced by Staphylococcus aureus

    PubMed Central

    Hawiger, J.

    1968-01-01

    A method based on cold ethyl alcohol fractionation at different pH levels and ionic strengths and on gel filtration on a Sephadex G-200 column was used to concentrate and purify lysozyme from the culture supernatant fluid of Staphylococcus aureus strain 524. The final, nondialyzable product exhibited a 163-fold rise in specific activity over that of the starting material. Staphylococcal lysozyme is a glycosidase which splits N-acetylamino sugars from the susceptible substrate. Staphylococcal lysozyme was shown to be similar to egg white lysozyme in its optimal temperature for reaction, optimal pH, activation by NaCl and Ca++ ions, inhibition by sodium citrate and ethylenediaminetetraacetate, and inactivation by Cu++ ions and sodium dodecyl sulfate. It differs from the egg white lysozyme in its temperature susceptibility range (staphylococcal lysozyme is inactivated at 56 C). It acts on whole cells and cell walls of Micrococcus lysodeikticus, murein from S. aureus 524, and cell walls of S. epidermidis Zak. The last substrate was not susceptible to the action of egg white lysozyme in the test system used. The mechanism of action of staphylococcal lysozyme seems to be analogous to that of egg white lysozyme; however, the biological specificity of the two enzymes may be different. PMID:4966544

  18. Evaluation of oriented lysozyme immobilized with monoclonal antibody

    NASA Astrophysics Data System (ADS)

    Aoyagi, Satoka; Okada, Keigo; Shigyo, Ayako; Man, Naoki; Karen, Akiya

    2008-12-01

    The orientation of a lysozyme immobilized with a monoclonal antibody was evaluated based on determination of the uppermost surface structure using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Specific peaks of the oriented lysozyme immobilized with monoclonal anti-lysozyme antibody were obtained in comparison with reference samples, non-oriented immobilized lysozyme and immobilized anti-lysozyme antibody. All samples were freeze-dried before TOF-SIMS measurement, and then each sample was measured using TOF-SIMS with a bismuth cluster ion source. TOF-SIMS spectra were analyzed to select peaks specific to the oriented immobilized lysozyme as well as to identify their chemical formula and ensemble of amino acids. The possible chemical formulae of the lysozyme fragments were then investigated with an element matching program and a residue matching program. The results from TOF-SIMS spectra analysis were compared to the amino acid sequence of the lysozyme and its three-dimensional structure registered in the protein data bank. Finally, the fragment-ion-generating regions of the oriented immobilized lysozyme were determined based on the suggested residues and the three-dimensional structure.

  19. Purification and properties of lysozyme produced by Staphylococcus aureus.

    PubMed

    Hawiger, J

    1968-02-01

    A method based on cold ethyl alcohol fractionation at different pH levels and ionic strengths and on gel filtration on a Sephadex G-200 column was used to concentrate and purify lysozyme from the culture supernatant fluid of Staphylococcus aureus strain 524. The final, nondialyzable product exhibited a 163-fold rise in specific activity over that of the starting material. Staphylococcal lysozyme is a glycosidase which splits N-acetylamino sugars from the susceptible substrate. Staphylococcal lysozyme was shown to be similar to egg white lysozyme in its optimal temperature for reaction, optimal pH, activation by NaCl and Ca(++) ions, inhibition by sodium citrate and ethylenediaminetetraacetate, and inactivation by Cu(++) ions and sodium dodecyl sulfate. It differs from the egg white lysozyme in its temperature susceptibility range (staphylococcal lysozyme is inactivated at 56 C). It acts on whole cells and cell walls of Micrococcus lysodeikticus, murein from S. aureus 524, and cell walls of S. epidermidis Zak. The last substrate was not susceptible to the action of egg white lysozyme in the test system used. The mechanism of action of staphylococcal lysozyme seems to be analogous to that of egg white lysozyme; however, the biological specificity of the two enzymes may be different. PMID:4966544

  20. Probing the interaction of a new synthesized CdTe quantum dots with human serum albumin and bovine serum albumin by spectroscopic methods.

    PubMed

    Bardajee, Ghasem Rezanejade; Hooshyar, Zari

    2016-05-01

    A novel CdTe quantum dots (QDs) were prepared in aqueous phase via a facile method. At first, poly (acrylic amide) grafted onto sodium alginate (PAAm-g-SA) were successfully synthesized and then TGA capped CdTe QDs (CdTe-TGA QDs) were embed into it. The prepared CdTe-PAAm-g-SA QDs were optimized and characterized by transmission electron microscopy (TEM), thermo-gravimetric (TG) analysis, Fourier transform infrared (FT-IR), UV-vis and fluorescence spectroscopy. The characterization results indicated that CdTe-TGA QDs, with particles size of 2.90 nm, were uniformly dispersed on the chains of PAAm-g-SA biopolymer. CdTe-PAAm-g-SA QDs also exhibited excellent UV-vis absorption and high fluorescence intensity. To explore biological behavior of CdTe-PAAm-g-SA QDs, the interactions between CdTe-PAAm-g-SA QDs and human serum albumin (HSA) (or bovine serum albumin (BSA)) were investigated by cyclic voltammetry, FT-IR, UV-vis, and fluorescence spectroscopic. The results confirmed the formation of CdTe-PAAm-g-SA QDs-HSA (or BSA) complex with high binding affinities. The thermodynamic parameters (ΔG<0, ΔH<0 and ΔS<0) were indicated that binding reaction was spontaneous and van der Waals interactions and hydrogen-bond interactions played a major role in stabilizing the CdTe-PAAm-g-SA QDs-HSA (or BSA) complexes. The binding distance between CdTe-PAAm-g-SA QDs and HSA (or BSA)) was calculated about 1.37 nm and 1.27 nm, respectively, according to Forster non-radiative energy transfer theory (FRET). Analyzing FT-IR spectra showed that the formation of QDs-HSA and QDs-BSA complexes led to conformational changes of the HSA and BSA proteins. All these experimental results clarified the effective transportation and elimination of CdTe-PAAm-g-SA QDs in the body by binding to HSA and BSA, which could be a useful guideline for the estimation of QDs as a drug carrier.

  1. A Novel Conductive Poly(3,4-ethylenedioxythiophene)-BSA Film for the Construction of a Durable HRP Biosensor Modified with NanoAu Particles

    PubMed Central

    Xu, Fangcheng; Ren, Shuaibin; Gu, Yesong

    2016-01-01

    In this study, we have investigated the contribution of bovine serum albumin (BSA) to the durability of the electrochemically synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) film on a platinum (Pt) electrode. The electrode was capable to effectively adsorb the nano Au particles (AuNPs) to form a uniform layout, which was then able to immobilize the horseradish peroxidase (HRP) to construct a functional HRP/AuNPs/PEDOT(BSA)/Pt biosensor. Cyclic voltammetry was employed to evaluate the performance of the biosensor through the measurement of hydrogen peroxide. Our results revealed a satisfied linear correlation between the cathodic current and the concentration of H2O2. Furthermore, the addition of oxidized form of nicotinamide adenine dinucleotide, or NAD+, as the electron transfer mediator in the detection solution could dramatically enhance the sensitivity of detection by about 35.5%. The main advantages of the current biosensor are its durability, sensitivity, reliability, and biocompatibility. PMID:26999133

  2. Multiple specialised goose-type lysozymes potentially compensate for an exceptional lack of chicken-type lysozymes in Atlantic cod.

    PubMed

    Seppola, Marit; Bakkemo, Kathrine Ryvold; Mikkelsen, Helene; Myrnes, Bjørnar; Helland, Ronny; Irwin, David M; Nilsen, Inge W

    2016-01-01

    Previous analyses of the Atlantic cod genome showed unique combinations of lacking and expanded number of genes for the immune system. The present study examined lysozyme activity, lysozyme gene distribution and expression in cod. Enzymatic assays employing specific bacterial lysozyme inhibitors provided evidence for presence of g-type, but unexpectedly not for c-type lysozyme activity. Database homology searches failed to identify any c-type lysozyme gene in the cod genome or in expressed sequence tags from cod. In contrast, we identified four g-type lysozyme genes (LygF1a-d) constitutively expressed, although differentially, in all cod organs examined. The active site glutamate residue is replaced by alanine in LygF1a, thus making it enzymatic inactive, while LygF1d was found in two active site variants carrying alanine or glutamate, respectively. In vitro and in vivo infection by the intracellular bacterium Francisella noatunensis gave a significantly reduced LygF1a and b expression but increased expression of the LygF1c and d genes as did also the interferon gamma (IFNγ) cytokine. These results demonstrate a lack of c-type lysozyme that is unprecedented among vertebrates. Our results further indicate that serial gene duplications have produced multiple differentially regulated cod g-type lysozymes with specialised functions potentially compensating for the lack of c-type lysozymes. PMID:27324690

  3. Multiple specialised goose-type lysozymes potentially compensate for an exceptional lack of chicken-type lysozymes in Atlantic cod.

    PubMed

    Seppola, Marit; Bakkemo, Kathrine Ryvold; Mikkelsen, Helene; Myrnes, Bjørnar; Helland, Ronny; Irwin, David M; Nilsen, Inge W

    2016-01-01

    Previous analyses of the Atlantic cod genome showed unique combinations of lacking and expanded number of genes for the immune system. The present study examined lysozyme activity, lysozyme gene distribution and expression in cod. Enzymatic assays employing specific bacterial lysozyme inhibitors provided evidence for presence of g-type, but unexpectedly not for c-type lysozyme activity. Database homology searches failed to identify any c-type lysozyme gene in the cod genome or in expressed sequence tags from cod. In contrast, we identified four g-type lysozyme genes (LygF1a-d) constitutively expressed, although differentially, in all cod organs examined. The active site glutamate residue is replaced by alanine in LygF1a, thus making it enzymatic inactive, while LygF1d was found in two active site variants carrying alanine or glutamate, respectively. In vitro and in vivo infection by the intracellular bacterium Francisella noatunensis gave a significantly reduced LygF1a and b expression but increased expression of the LygF1c and d genes as did also the interferon gamma (IFNγ) cytokine. These results demonstrate a lack of c-type lysozyme that is unprecedented among vertebrates. Our results further indicate that serial gene duplications have produced multiple differentially regulated cod g-type lysozymes with specialised functions potentially compensating for the lack of c-type lysozymes.

  4. Amino acid sequences of lysozymes newly purified from invertebrates imply wide distribution of a novel class in the lysozyme family.

    PubMed

    Ito, Y; Yoshikawa, A; Hotani, T; Fukuda, S; Sugimura, K; Imoto, T

    1999-01-01

    Lysozymes were purified from three invertebrates: a marine bivalve, a marine conch, and an earthworm. The purified lysozymes all showed a similar molecular weight of 13 kDa on SDS/PAGE. Their N-terminal sequences up to the 33rd residue determined here were apparently homologous among them; in addition, they had a homology with a partial sequence of a starfish lysozyme which had been reported before. The complete sequence of the bivalve lysozyme was determined by peptide mapping and subsequent sequence analysis. This was composed of 123 amino acids including as many as 14 cysteine residues and did not show a clear homology with the known types of lysozymes. However, the homology search of this protein on the protein or nucleic acid database revealed two homologous proteins. One of them was a gene product, CELF22 A3.6 of C. elegans, which was a functionally unknown protein. The other was an isopeptidase of a medicinal leech, named destabilase. Thus, a new type of lysozyme found in at least four species across the three classes of the invertebrates demonstrates a novel class of protein/lysozyme family in invertebrates. The bivalve lysozyme, first characterized here, showed extremely high protein stability and hen lysozyme-like enzymatic features.

  5. Multiple specialised goose-type lysozymes potentially compensate for an exceptional lack of chicken-type lysozymes in Atlantic cod

    PubMed Central

    Seppola, Marit; Bakkemo, Kathrine Ryvold; Mikkelsen, Helene; Myrnes, Bjørnar; Helland, Ronny; Irwin, David M.; Nilsen, Inge W.

    2016-01-01

    Previous analyses of the Atlantic cod genome showed unique combinations of lacking and expanded number of genes for the immune system. The present study examined lysozyme activity, lysozyme gene distribution and expression in cod. Enzymatic assays employing specific bacterial lysozyme inhibitors provided evidence for presence of g-type, but unexpectedly not for c-type lysozyme activity. Database homology searches failed to identify any c-type lysozyme gene in the cod genome or in expressed sequence tags from cod. In contrast, we identified four g-type lysozyme genes (LygF1a-d) constitutively expressed, although differentially, in all cod organs examined. The active site glutamate residue is replaced by alanine in LygF1a, thus making it enzymatic inactive, while LygF1d was found in two active site variants carrying alanine or glutamate, respectively. In vitro and in vivo infection by the intracellular bacterium Francisella noatunensis gave a significantly reduced LygF1a and b expression but increased expression of the LygF1c and d genes as did also the interferon gamma (IFNγ) cytokine. These results demonstrate a lack of c-type lysozyme that is unprecedented among vertebrates. Our results further indicate that serial gene duplications have produced multiple differentially regulated cod g-type lysozymes with specialised functions potentially compensating for the lack of c-type lysozymes. PMID:27324690

  6. Resistance screening essay of wine lactic acid bacteria on lysozyme: efficacy of lysozyme in unclarified grape musts.

    PubMed

    Delfini, Claudio; Cersosimo, Manuela; Del Prete, Vincenzo; Strano, Morela; Gaetano, Giuseppe; Pagliara, Adolfo; Ambrò, Stefano

    2004-04-01

    In wine making, the bacteriolytic activity of lysozyme has primarily been used to control the malolactic fermentation in wines. The use of lysozyme in musts before settling and the beginning of the alcoholic fermentation to inhibit the growth of lactic acid bacteria could be very beneficial. In a resistance test carried out in MT/b broth, lysozyme had greater antimicrobial activity toward Oenococcus oeni than Lactobacillus species. Several strains of wine bacteria belonging to Oenococcus proved sensitive to the bacteriolytic activity of lysozyme at low concentrations in both synthetic medium (MT/b) (50 mg/L), white must, or red must made with or without the skins (100 mg/L). Lactobacillus and Pediococcus strains survived at lysozyme concentrations of 200-500 and 500 mg/L, respectively, in MT/b and musts. Suspended solids in unclarified musts may strongly bind to lysozyme thereby causing its removal by filtration or centrifugation. One hour after lysozyme was added to musts, it was quantified by HPLC and found after centrifugation to be 40-50% and only 10% in musts made with or without the skins, respectively. Although appreciable amounts of lysozyme were bound to wine components, this did not appear to be a serious hindrance to lysozyme activity.

  7. Amino acid sequences of lysozymes newly purified from invertebrates imply wide distribution of a novel class in the lysozyme family.

    PubMed

    Ito, Y; Yoshikawa, A; Hotani, T; Fukuda, S; Sugimura, K; Imoto, T

    1999-01-01

    Lysozymes were purified from three invertebrates: a marine bivalve, a marine conch, and an earthworm. The purified lysozymes all showed a similar molecular weight of 13 kDa on SDS/PAGE. Their N-terminal sequences up to the 33rd residue determined here were apparently homologous among them; in addition, they had a homology with a partial sequence of a starfish lysozyme which had been reported before. The complete sequence of the bivalve lysozyme was determined by peptide mapping and subsequent sequence analysis. This was composed of 123 amino acids including as many as 14 cysteine residues and did not show a clear homology with the known types of lysozymes. However, the homology search of this protein on the protein or nucleic acid database revealed two homologous proteins. One of them was a gene product, CELF22 A3.6 of C. elegans, which was a functionally unknown protein. The other was an isopeptidase of a medicinal leech, named destabilase. Thus, a new type of lysozyme found in at least four species across the three classes of the invertebrates demonstrates a novel class of protein/lysozyme family in invertebrates. The bivalve lysozyme, first characterized here, showed extremely high protein stability and hen lysozyme-like enzymatic features. PMID:9914527

  8. Apparently anomalous sedimentation behavior in mixed solvent systems with strong interactions between solution components: analysis of nonideal behavior by bovine serum albumin in 7 M urea at pH 3.3.

    PubMed

    Armstrong, J M; McKenzie, H A

    2001-04-01

    The use of the analytical ultracentrifuge to study nonideal behavior of macromolecules in multicomponent systems is discussed, noting the value of interference optics to extend the range of concentrations of macromolecule that may be studied. The choice of appropriate theory in the treatment of experimental data is examined, using a study of bovine serum albumin (BSA) in 7 M urea at pH 3.3 as an example. Under these conditions BSA undergoes extensive unfolding and exhibits marked nonideality, with the binding of approximately 200 molecules of urea per molecule of BSA.

  9. Bovine serum albumin adsorption onto colloidal Al2O3 particles: a new model based on zeta potential and UV-vis measurements.

    PubMed

    Rezwan, Kurosch; Meier, Lorenz P; Rezwan, Mandana; Vörös, Janos; Textor, Marcus; Gauckler, Ludwig J

    2004-11-01

    We investigated the adsorption of bovine serum albumin (BSA) on colloidal Al2O3 particles in an aqueous environment. Changes in the zeta potential of the Al2O3 particles upon the adsorption of BSA were measured using an electro-acoustic technique. The mass of protein adsorbed was determined by using UV-vis spectroscopy. The change of the isoelectric point of the Al2O3 powder-protein suspension was found to be a function of adsorbed protein mass. It was shown that approximately one monolayer of BSA was needed to fully mask the surface and to compromise the charge of Al2O3. From titration experiments it follows that about 30-36% of the negatively charged groups of the protein form bonds with the protonated and charged Al2O3 surface. On the basis of our observations we introduced a new adsorption model for BSA on Al2O3 particles.

  10. Dynamic surface properties of lysozyme solutions. Impact of urea and guanidine hydrochloride.

    PubMed

    Tihonov, M M; Milyaeva, O Yu; Noskov, B A

    2015-05-01

    Urea and guanidine hydrochloride (GuHCl) have different influence on surface properties of lysozyme solutions. The increase of GuHCl concentration leads to noticeable changes of kinetic dependencies of the dynamic surface elasticity and ellipsometric angles while the main effect of urea reduces to a strong drop of the static surface tension. The difference between the effects of these two denaturants on the surface properties of other investigated globular proteins is significantly weaker and is mainly a consequence of a different extent of the globule unfolding in the surface layer at equal concentrations of the denaturants. The obtained results for lysozyme solutions are connected with the strongly different denaturation mechanisms under the influence of urea and GuHCl. In the former case the protein preserves its globular structure in the adsorption layer at high urea concentrations (up to 9M) but without tightly packed interior of the globule and with a dynamic tertiary structure (molten globule state). On the contrary, the increase of GuHCl concentration leads to partial destruction of the protein tertiary structure in the surface layer, although this effect is not as strong as in the case of previously studied bovine serum albumin and β-lactoglobulin.

  11. Lysozyme Photochemistry as a Function of Temperature. The Protective Effect of Nanoparticles on Lysozyme Photostability

    PubMed Central

    Oliveira Silva, Catarina; Petersen, Steffen B.; Pinto Reis, Catarina; Rijo, Patrícia; Molpeceres, Jesús; Vorum, Henrik; Neves-Petersen, Maria Teresa

    2015-01-01

    The presence of aromatic residues and their close spatial proximity to disulphide bridges makes hen egg white lysozyme labile to UV excitation. UVB induced photo-oxidation of tryptophan and tyrosine residues leads to photochemical products, such as, kynurenine, N–formylkynurenine and dityrosine and to the disruption of disulphide bridges in proteins. We here report that lysozyme UV induced photochemistry is modulated by temperature, excitation power, illumination time, excitation wavelength and by the presence of plasmonic quencher surfaces, such as gold, and by the presence of natural fluorescence quenchers, such as hyaluronic acid and oleic acid. We show evidence that the photo-oxidation effects triggered by 295 nm at 20°C are reversible and non-reversible at 10°C, 25°C and 30°C. This paper provides evidence that the 295 nm damage threshold of lysozyme lies between 0.1 μW and 0.3 μW. Protein conformational changes induced by temperature and UV light have been detected upon monitoring changes in the fluorescence emission spectra of lysozyme tryptophan residues and SYPRO® Orange. Lysozyme has been conjugated onto gold nanoparticles, coated with hyaluronic acid and oleic acid (HAOA). Steady state and time resolved fluorescence studies of free and conjugated lysozyme onto HAOA gold nanoparticles reveals that the presence of the polymer decreased the rate of the observed photochemical reactions and induced a preference for short fluorescence decay lifetimes. Size and surface charge of the HAOA gold nanoparticles have been determined by dynamic light scattering and zeta potential measurements. TEM analysis of the particles confirms the presence of a gold core surrounded by a HAOA matrix. We conclude that HAOA gold nanoparticles may efficiently protect lysozyme from the photochemical effects of UVB light and this nanocarrier could be potentially applied to other proteins with clinical relevance. In addition, this study confirms that the temperature plays a

  12. Characterizing the Interaction between tartrazine and two serum albumins by a hybrid spectroscopic approach.

    PubMed

    Pan, Xingren; Qin, Pengfei; Liu, Rutao; Wang, Jing

    2011-06-22

    Tartrazine is an artificial azo dye commonly used in food products. The present study evaluated the interaction of tartrazine with two serum albumins (SAs), human serum albumin (HSA) and bovine serum albumin (BSA), under physiological conditions by means of fluorescence, three-dimensional fluorescence, UV-vis absorption, and circular dichroism (CD) techniques. The fluorescence data showed that tartrazine could bind to the two SAs to form a complex. The binding process was a spontaneous molecular interaction procedure, in which van der Waals and hydrogen bond interactions played a major role. Additionally, as shown by the UV-vis absorption, three-dimensional fluorescence, and CD results, tartrazine could lead to conformational and some microenvironmental changes of both SAs, which may affect the physiological functions of SAs. The work provides important insight into the mechanism of toxicity of tartrazine in vivo. PMID:21591756

  13. Tetragonal Lysozyme, From Monomer to Crystal

    NASA Technical Reports Server (NTRS)

    Pusey, Marc L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    The data now leads us to a comprehensive model for the process by which tetragonal lysozyme crystals are nucleated and subsequently grow. Lysozyme is typically desolubilized by addition of ionic salts. The salt anions bind to basic and other sites on the protein and promote protein-protein interactions, i.e., initiate the nucleation self assembly process. Formation of protein-protein interactions occurs at the expense of the protein-anion interactions, with the anions being released to the solution. The association follows a defined pattern, forming the "head to side" interactions of the crystal 4(3) helix. The presence of the high salt also promotes hydrophobic interactions between the protein molecules, further tightening their interaction. The solute assembly process persists after crystal nucleation, and the 4(3) helical structures form the subsequent growth units. AFM measurements show that the growth units follow the dimensions of these helices, and that those on the surface are more compact about the c-axis than in the bulk crystal, with adjacent helices riot being in contact. This further supports the role of hydrophobic interactions, as the surface is still in contact with the bulk solution. Once buried within the crystal the protein:salt ratio radically changes and the hydrophobic interactions relax to those measured crystallographically. Thus the crystal growth process recapitulates the initial stages of the nucleation process, and the two seamlessly merge. Experimental evidence, based upon face growth rate, AFM, and fluorescence energy transfer data, for a postulated model of the nucleation of tetragonal lysozyme crystals and how it transitions into crystal growth will be presented.

  14. Adaptive functional diversification of lysozyme in insectivorous bats.

    PubMed

    Liu, Yang; He, Guimei; Xu, Huihui; Han, Xiuqun; Jones, Gareth; Rossiter, Stephen J; Zhang, Shuyi

    2014-11-01

    The role of gene duplication in generating new genes and novel functions is well recognized and is exemplified by the digestion-related protein lysozyme. In ruminants, duplicated chicken-type lysozymes facilitate the degradation of symbiotic bacteria in the foregut. Chicken-type lysozyme has also been reported to show chitinase-like activity, yet no study has examined the molecular evolution of lysozymes in species that specialize on eating insects. Insectivorous bats number over 900 species, and lysozyme expression in the mouths of some of these species is associated with the ingestion of insect cuticle, suggesting a chitinase role. Here, we show that chicken-type lysozyme has undergone multiple duplication events in a major family of insect-eating bats (Vespertilionidae) and that new duplicates have undergone molecular adaptation. Examination of duplicates from two insectivorous bats-Pipistrellus abramus and Scotophilus kuhlii-indicated that the new copy was highly expressed in the tongue, whereas the other one was less tissue-specific. Functional assays applied to pipistrelle lysozymes confirmed that, of the two copies, the tongue duplicate was more efficient at breaking down glycol chitin, a chitin derivative. These results suggest that the evolution of lysozymes in vespertilionid bats has likely been driven in part by natural selection for insectivory.

  15. Regenerated cellulose fiber and film immobilized with lysozyme

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present work reports an initial engineering approach for fabricating lysozyme-bound regenerated cellulose fiber and film. Glycine-esterified cotton was dissolved in an ionic liquid solvent 1–Butyl–3–methylimidazolium Chloride (BMIMCl) in which lysozyme was activated and covalently attached to c...

  16. Immobilization of lysozyme on cotton fabrics; synthesis, characterication, and activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antimicrobial activity of lysozyme derives from the hydrolysis of the bacterial cell wall polysaccharide at the glycosidic bond that links N-acetyl-glucosamine and N-acetyl-muramic acid. Maintaining the activity of lysozyme while bound to a cellulose substrate is a goal toward developing enzyme...

  17. Effects of N-acetyl-L-cysteine-capped CdTe quantum dots on bovine serum albumin and bovine hemoglobin: isothermal titration calorimetry and spectroscopic investigations.

    PubMed

    Sun, Haoyu; Cui, Erqian; Tan, Zhigang; Liu, Rutao

    2014-12-01

    The interactions of N-acetyl-L-cysteine-capped CdTe quantum dots (QDs) with bovine serum albumin (BSA) and bovine hemoglobin (BHb) were investigated by isothermal titration calorimetry (ITC), fluorescence, synchronous fluorescence, fluorescence lifetime, ultraviolet-visible absorption, and circular dichroism techniques. Fluorescence data of BSA-QDs and BHb-QDs revealed that the quenching was static in every system. While CdTe QDs changed the microenvironment of tryptophan in BHb, the microenvironment of BSA kept unchanged. Adding CdTe QDs affected the skeleton and secondary structure of the protein (BSA and BHb). The ITC results indicated that the interaction between the protein (BSA and BHb) and QDs-612 was spontaneous and the predominant force was hydrophobic interaction. In addition, the binding constants were determined to be 1.19 × 10(5) L mol(-1) (BSA-QDs) and 2.19 × 10(5) L mol(-1) (BHb-QDs) at 298 K. From these results, we conclude that CdTe QDs have a larger impact on the structure of BHb than BSA.

  18. Antioxidative effects of magnetized extender containing bovine serum albumin on sperm oxidative stress during long-term liquid preservation of boar semen.

    PubMed

    Lee, Sang-Hee; Park, Choon-Keun

    2015-08-21

    Magnetized water is defined as water that has passed through a magnet and shows increased permeability into cells and electron-donating characteristics. These attributes can protect against membrane damage and remove reactive oxygen species (ROS) in mammalian cells. We explored the effects of improved magnetized semen extenders containing bovine serum albumin (BSA) as antioxidants on apoptosis in boar sperm. Ejaculated semen was diluted in magnetized extender (0G and 6000G) with or without BSA (0G + BSA and 6000G + BSA), and sperm were analyzed based on viability, acrosome reaction, and H2O2 level of live sperm using flow cytometry. Sperm were then preserved for 11 days at 18 °C. We found that viability was significantly higher in 6000G + BSA than under the other treatments (P < 0.05). The acrosome reaction was significantly lower in the 6000G + BSA group compared with the other treatments (P < 0.05). Live sperm with high intracellular H2O2 level were significantly lower in the 6000G + BSA group than under other treatments (P < 0.05). Based on our results, magnetized extenders have antioxidative effects on the liquid preservation of boar sperm. PMID:26143531

  19. Penetrable silica microspheres for immobilization of bovine serum albumin and their application to the study of the interaction between imatinib mesylate and protein by frontal affinity chromatography.

    PubMed

    Ma, Liyun; Li, Jing; Zhao, Juan; Liao, Han; Xu, Li; Shi, Zhi-guo

    2016-01-01

    In the current study, novel featured silica, named penetrable silica, simultaneously containing macropores and mesopores, was immobilized with bovine serum albumin (BSA) via Schiff base method. The obtained BSA-SiO2 was employed as the high-performance liquid chromatographic (HPLC) stationary phase. Firstly, D- and L-tryptophan were used as probes to investigate the chiral separation ability of the BSA-SiO2 stationary phase. An excellent enantioseparation factor was obtained up to 4.3 with acceptable stability within at least 1 month. Next, the BSA-SiO2 stationary phase was applied to study the interaction between imatinib mesylate (IM) and BSA by frontal affinity chromatography. A single type of binding site was found for IM with the immobilized BSA, and the hydrogen-bonding and van der Waals interactions were expected to be contributing interactions based on the thermodynamic studies, and this was a spontaneous process. Compared to the traditional silica for HPLC stationary phase, the proposed penetrable silica microsphere possessed a larger capacity to bond more BSA, minimizing column overloading effects and enhancing enantioseparation ability. In addition, the lower running column back pressure and fast mass transfer were meaningful for the column stability and lifetime. It was a good substrate to immobilize biomolecules for fast chiral resolution and screening drug-protein interactions.

  20. Influences of urea and pH on the interaction of cinchonidine with bovine serum albumin by steady state fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Tian; Li, Daojin

    2013-08-01

    The binding of cinchonidine to bovine serum albumin (BSA) in aqueous solution in the absence and presence of urea has been studied by fluorescence spectroscopic techniques at pH 7.40. Denaturation of BSA in the presence of urea is almost complete at [urea] ⩾ 8.0 M. Upon unfolding, two fluorescence peaks of BSA were observed. One peak was assigned to the fluorescence of Trp residue in a polar environment, and the other peak was assigned to the fluorescence of Tyr residues. In addition, the fluorescence quenching effects of cinchonidine were shown not only on the native but also on the unfolded form of BSA. The quenching rate constants and binding constants calculated in the absence and presence of the denaturant urea indicates that the binding capacity of cinchonidine to the denatured BSA deceases dramatically. In addition, influence of pH on the interaction between cinchonidine and BSA was investigated and the binding abilities of the drug to BSA deceased under lower pH conditions (pH 3.5 and 1.8) and higher pH conditions (pH 9.0).

  1. Influences of urea and pH on the interaction of cinchonidine with bovine serum albumin by steady state fluorescence spectroscopy.

    PubMed

    Zhang, Tian; Li, Daojin

    2013-08-01

    The binding of cinchonidine to bovine serum albumin (BSA) in aqueous solution in the absence and presence of urea has been studied by fluorescence spectroscopic techniques at pH 7.40. Denaturation of BSA in the presence of urea is almost complete at [urea] ≥8.0 M. Upon unfolding, two fluorescence peaks of BSA were observed. One peak was assigned to the fluorescence of Trp residue in a polar environment, and the other peak was assigned to the fluorescence of Tyr residues. In addition, the fluorescence quenching effects of cinchonidine were shown not only on the native but also on the unfolded form of BSA. The quenching rate constants and binding constants calculated in the absence and presence of the denaturant urea indicates that the binding capacity of cinchonidine to the denatured BSA deceases dramatically. In addition, influence of pH on the interaction between cinchonidine and BSA was investigated and the binding abilities of the drug to BSA deceased under lower pH conditions (pH 3.5 and 1.8) and higher pH conditions (pH 9.0).

  2. Antioxidative effects of magnetized extender containing bovine serum albumin on sperm oxidative stress during long-term liquid preservation of boar semen.

    PubMed

    Lee, Sang-Hee; Park, Choon-Keun

    2015-08-21

    Magnetized water is defined as water that has passed through a magnet and shows increased permeability into cells and electron-donating characteristics. These attributes can protect against membrane damage and remove reactive oxygen species (ROS) in mammalian cells. We explored the effects of improved magnetized semen extenders containing bovine serum albumin (BSA) as antioxidants on apoptosis in boar sperm. Ejaculated semen was diluted in magnetized extender (0G and 6000G) with or without BSA (0G + BSA and 6000G + BSA), and sperm were analyzed based on viability, acrosome reaction, and H2O2 level of live sperm using flow cytometry. Sperm were then preserved for 11 days at 18 °C. We found that viability was significantly higher in 6000G + BSA than under the other treatments (P < 0.05). The acrosome reaction was significantly lower in the 6000G + BSA group compared with the other treatments (P < 0.05). Live sperm with high intracellular H2O2 level were significantly lower in the 6000G + BSA group than under other treatments (P < 0.05). Based on our results, magnetized extenders have antioxidative effects on the liquid preservation of boar sperm.

  3. Penetrable silica microspheres for immobilization of bovine serum albumin and their application to the study of the interaction between imatinib mesylate and protein by frontal affinity chromatography.

    PubMed

    Ma, Liyun; Li, Jing; Zhao, Juan; Liao, Han; Xu, Li; Shi, Zhi-guo

    2016-01-01

    In the current study, novel featured silica, named penetrable silica, simultaneously containing macropores and mesopores, was immobilized with bovine serum albumin (BSA) via Schiff base method. The obtained BSA-SiO2 was employed as the high-performance liquid chromatographic (HPLC) stationary phase. Firstly, D- and L-tryptophan were used as probes to investigate the chiral separation ability of the BSA-SiO2 stationary phase. An excellent enantioseparation factor was obtained up to 4.3 with acceptable stability within at least 1 month. Next, the BSA-SiO2 stationary phase was applied to study the interaction between imatinib mesylate (IM) and BSA by frontal affinity chromatography. A single type of binding site was found for IM with the immobilized BSA, and the hydrogen-bonding and van der Waals interactions were expected to be contributing interactions based on the thermodynamic studies, and this was a spontaneous process. Compared to the traditional silica for HPLC stationary phase, the proposed penetrable silica microsphere possessed a larger capacity to bond more BSA, minimizing column overloading effects and enhancing enantioseparation ability. In addition, the lower running column back pressure and fast mass transfer were meaningful for the column stability and lifetime. It was a good substrate to immobilize biomolecules for fast chiral resolution and screening drug-protein interactions. PMID:26573171

  4. Polarization properties of fluorescent BSA protected Au25 nanoclusters

    NASA Astrophysics Data System (ADS)

    Raut, Sangram; Chib, Rahul; Rich, Ryan; Shumilov, Dmytro; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2013-03-01

    BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and studied their steady state and time resolved fluorescence properties including polarization behavior in different solvents: glycerol, propylene glycol and water. We demonstrated that the nanocluster absorption spectrum can be separated from the extinction spectrum by subtraction of Rayleigh scattering. The nanocluster absorption spectrum is well approximated by three Gaussian components. By a comparison of the emissions from BSA Au25 clusters and rhodamine B in water, we estimated the quantum yield of nanoclusters to be higher than 0.06. The fluorescence lifetime of BSA Au25 clusters is long and heterogeneous with an average value of 1.84 μs. In glycerol at -20 °C the anisotropy is high, reaching a value of 0.35. However, the excitation anisotropy strongly depends on the excitation wavelengths indicating a significant overlap of the different transition moments. The anisotropy decay in water reveals a correlation time below 0.2 μs. In propylene glycol the measured correlation time is longer and the initial anisotropy depends on the excitation wavelength. BSA Au25 clusters, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight.BSA protected gold nanoclusters (Au25) are attracting a great deal of attention due to their unique spectroscopic properties and possible use in biophysical applications. Although there are reports on synthetic strategies, spectroscopy and applications, little is known about their polarization behavior. In this study, we synthesized the BSA protected Au25 nanoclusters and

  5. Determination of monomer concentrations in crystallizing lysozyme solutions

    NASA Technical Reports Server (NTRS)

    Wilson, L. J.; Pusey, Marc L.

    1992-01-01

    We have developed a non-optical technique for the study of aggregation in lysozyme and other protein solutions. By monitoring the rate at which lysozyme traverses a semipermeable membrane it was possible to quantitate the degree of aggregation in supersaturated solutions. Using this technique, we have measured the concentration of monomers and larger aggregates in under- and oversaturated lysozyme solutions, and in the presence of crystals, at pH 4.0 and 3 percent NaCl (0.1M NaAc). Comparison of these concentration profiles with (110) face growth rate data supports the theory that tetragonal lysozyme crystals grow by addition of preformed aggregates and not by monomer addition. The data suggest that a considerable population of aggregates larger than dimers are present at lysozyme concentrations above 22 mg/ml. Determination of dimer concentrations, and equilibrium constants for subsequent aggregation levels, are currently underway.

  6. Effects of single-walled carbon nanotubes on lysozyme gelation.

    PubMed

    Tardani, Franco; La Mesa, Camillo

    2014-09-01

    The possibility to disperse carbon nanotubes in biocompatible matrices has got substantial interest from the scientific community. Along this research line, the inclusion of single walled carbon nanotubes in lysozyme-based hydrogels was investigated. Experiments were performed at different nanotube/lysozyme weight ratios. Carbon nanotubes were dispersed in protein solutions, in conditions suitable for thermal gelation. The state of the dispersions was determined before and after thermal treatment. Rheology, dynamic light scattering and different microscopies investigated the effect that carbon nanotubes exert on gelation. The gelation kinetics and changes in gelation temperature were determined. The effect of carbon and lysozyme content on the gel properties was, therefore, determined. At fixed lysozyme content, moderate amounts of carbon nanotubes do not disturb the properties of hydrogel composites. At moderately high volume fractions in carbon nanotubes, the gels become continuous in both lysozyme and nanotubes. This is because percolating networks are presumably formed. Support to the above statements comes by rheology.

  7. Albumin inhibits platelet-activating factor (PAF)-induced responses in platelets and macrophages: implications for the biologically active form of PAF.

    PubMed Central

    Grigoriadis, G.; Stewart, A. G.

    1992-01-01

    1. Platelet-activating factor (PAF) binds with high affinity to albumin leading Clay et al. (1990) to suggest that the active form of PAF is the albumin-PAF complex. 2. In the present study the proposal that albumin-bound, rather than monomeric PAF, is the active form of PAF at PAF receptors was critically evaluated by examining the effect of albumin on the potency of PAF in isolated platelets and macrophages. 3. Bovine serum albumin inhibited concentration-dependently PAF-induced responses in platelets and macrophages. The most probable explanation of this finding is that BSA reduced the concentration of free PAF. 4. Thus, we conclude that free PAF, rather than the albumin-PAF complex is the active form. Consequently, local concentrations of albumin will influence profoundly the potency of endogenously released PAF. Moreover, estimates of the affinity of PAF for PAF receptors made in buffers containing BSA, underestimate the true affinity of PAF for its receptors by approximately 3 orders of magnitude. PMID:1330167

  8. Small-angle neutron scattering studies of mineralization on BSA coated citrate capped gold nanoparticles used as a model surface for membrane scaling in RO wastewater desalination.

    PubMed

    Dahdal, Y N; Pipich, V; Rapaport, H; Oren, Y; Kasher, R; Schwahn, D

    2014-12-23

    Bovine serum albumin (BSA) coated on citrate capped gold nanoparticles (BSA-GNPs) was exposed to a simulated wastewater effluent (SSE) in order to study the mineralization and thereby mimic scaling at biofouled membranes of reverse osmosis (RO) wastewater desalination plants. RO is a leading technology of achieving freshwater quality as it has the capability of removing both dissolved inorganic salts and organic contaminants from tertiary wastewater effluents. The aim was to better understand one of the major problems facing this technology which is fouling of the membranes, mainly biofouling and scaling by calcium phosphate. The experiments were performed using the small-angle neutron scattering (SANS) technique. The nanoparticles, GNPs, stabilized by the citrate groups showed 30 Å large particles having a homogeneous distribution of gold and citrate with a gold volume fraction of the order of 1%. On the average two BSA monomers are grafted at 2.4 GNPs. The exposed BSA-GNPs to SSE solution led to immediate mineralization of stable composite particles of the order of 0.2 μm diameter and a mineral volume fraction between 50% and 80%. The volume fraction of the mineral was of the order of 10(-5), which is roughly 3 times larger but an order of magnitude smaller than the maximum possible contents of respectively calcium phosphate and calcium carbonate in the SSE solution. Considering the extreme low solubility product of calcium phosphate, we suggest total calcium phosphate and partially (5-10%) calcium carbonate formation in the presence of BSA-GNPs.

  9. Spectroscopic studies on interaction of BSA and Eu(III) complexes with H5ph-dtpa and H5dtpa ligands.

    PubMed

    Kong, Deyong; Qin, Cui; Fan, Ping; Li, Bing; Wang, Jun

    2015-04-01

    An novel aromatic aminopolycarboxylic acid ligand, N-(2-N,N-Dicarboxymethylaminophenyl) ethylenediamine-N,N',N'-triacetic acid (H5ph-dtpa), was synthesized by improving experimental method and its corresponding Eu(III) complex, Na2[EuIII(ph-dtpa)(H2O)]·6H2O, was successfully prepared through heat-refluxing method. As a comparison, the Eu(III) complex with diethylenetriamine-N,N,N',N',N″-pentaacetic acid (H5dtpa) ligand, Na2[Eu(III)(dtpa)(H2O)]·6H2O, was also prepared by the same method. And then, the interaction between prepared Eu(III) complexes ([EuIII(dtpa)(H2O)]2- and [EuIII(ph-dtpa)(H2O)]2-) and bovine serum albumin (BSA) in aqueous solution were studied by the combination of ultraviolet-visible (UV-vis), fluorescence and circular dichroism (CD) spectroscopies. In addition, the binding sites of Eu(III) complexes ([EuIII(dtpa)(H2O)]2- and [EuIII(ph-dtpa)(H2O)]2-) to BSA molecules were also estimated by synchronous fluorescence. Moreover, the theoretical and experimental results show that the Van der Waals, hydrogen bond and π-π stacking interactions are the mainly impulse to the reaction. The binding distances (r) between Eu(III) complexes ([EuIII(dtpa)(H2O)]2- and [EuIII(ph-dtpa)(H2O)]2-) and BSA were obtained according to Förster's non-radiative energy transfer theory. Also, the determined UV-vis absorption spectroscopy, synchronous fluorescence and circular dichroism (CD) spectra showed that the conformation of BSA could be changed in the presence of Eu(III) complexes. The obtained results can help understand the action mode between rare earth metal complexes of aminopolycarboxylic acid ligands with BSA and they are also expected to provide important information of designs of new inspired drugs.

  10. Small-angle neutron scattering studies of mineralization on BSA coated citrate capped gold nanoparticles used as a model surface for membrane scaling in RO wastewater desalination.

    PubMed

    Dahdal, Y N; Pipich, V; Rapaport, H; Oren, Y; Kasher, R; Schwahn, D

    2014-12-23

    Bovine serum albumin (BSA) coated on citrate capped gold nanoparticles (BSA-GNPs) was exposed to a simulated wastewater effluent (SSE) in order to study the mineralization and thereby mimic scaling at biofouled membranes of reverse osmosis (RO) wastewater desalination plants. RO is a leading technology of achieving freshwater quality as it has the capability of removing both dissolved inorganic salts and organic contaminants from tertiary wastewater effluents. The aim was to better understand one of the major problems facing this technology which is fouling of the membranes, mainly biofouling and scaling by calcium phosphate. The experiments were performed using the small-angle neutron scattering (SANS) technique. The nanoparticles, GNPs, stabilized by the citrate groups showed 30 Å large particles having a homogeneous distribution of gold and citrate with a gold volume fraction of the order of 1%. On the average two BSA monomers are grafted at 2.4 GNPs. The exposed BSA-GNPs to SSE solution led to immediate mineralization of stable composite particles of the order of 0.2 μm diameter and a mineral volume fraction between 50% and 80%. The volume fraction of the mineral was of the order of 10(-5), which is roughly 3 times larger but an order of magnitude smaller than the maximum possible contents of respectively calcium phosphate and calcium carbonate in the SSE solution. Considering the extreme low solubility product of calcium phosphate, we suggest total calcium phosphate and partially (5-10%) calcium carbonate formation in the presence of BSA-GNPs. PMID:25458085

  11. [Advantages of polyethylene glycol in comparison to bovine serum albumin in the indirect antiglobulin test in pregnant women].

    PubMed

    Trkuljić, M; Ostojić, G; Taseski, J

    2000-01-01

    Results of indirect antiglobulin test (IAT) adding polyethylene glycol (PEG) were compared with conventional IAT performed using bovine serume albumin (BSA) with the aim of prenatal protection of Rh(D) negative pregnant women. Investigation enrolled 986 samples of pregnant women sera and confirmed that the use of PEG-IAT increased the degree of detection of clinically significant antierythrocyte antibodies. Above all, form the Rhesus blood groups system (using exclusively PEG-IAT) was detected by one antibody of anti-D, anti-C, anti-e and two anti-E), while by using BSA, anti-e was not detected at all. Besides, the need for additional serologic techniques has been reduced (treating of erythrocytes by enzymes) and the work of laboratories for prenatal protection has been alleviated, and at the same time the quality of analyses was not diminished, which gave the preference to PEG-IAT compared to BSA-IAT in prenatal testing.

  12. Chitosan/bovine serum albumin co-micropatterns on functionalized titanium surfaces and their effects on osteoblasts.

    PubMed

    Li, Dan; Lu, Xiong; Lin, Hong; Ren, Fuzeng; Leng, Yang

    2013-02-01

    Chitosan (CS)/bovine serum albumin (BSA) micropatterns were prepared on functionalized Ti surfaces by micro-transfer molding (μ-TM). μ-TM realized the spatially controlled immobilization of cells and offered a new way of studying the interaction between micropatterns and cells. Two kinds of micropatterns were produced: (1) microgrooves representing a discontinuously grooved co-micropattern, with the rectangular CS region separated by BSA walls; (2) microcylinders representing a continuously interconnected co-micropattern, with the net-like CS region separated by BSA cylinders. A comparison of cell behaviors on the two types of micropatterns indicated that the shape rather than the size had a dominant effect on cell proliferation. The micropattern size in the same range of cell diameters favored cell proliferation. However, cell differentiation was more sensitive to the size rather than to the shape of the micropatterns. In conclusion, cell behavior can be regulated by micropatterns integrating different materials. PMID:23132401

  13. Application of MoS2 modified screen-printed electrodes for highly sensitive detection of bovine serum albumin.

    PubMed

    Kukkar, Manil; Sharma, Ashish; Kumar, Parveen; Kim, Ki-Hyun; Deep, Akash

    2016-10-01

    The present work reports the application of a new molybdenum disulphide (MoS2)-based electrochemical platform for highly sensitive quantitation of an iron-binding protein, bovine serum albumin (BSA). The gold screen-printed electrodes were modified with MoS2 nanoflakes, followed by bioconjugation with anti-BSA antibodies. Using the above bioelectrode, cyclic voltammetric analysis was carried out in the presence of a Fe(3+)/Fe(2+) redox probe which exhibited a linear response of peak current with varying concentrations of BSA up to 10 ng/mL (with a detection limit of 0.006 ng/mL). This study is novel in that it shows a considerable enhancement of signal during electrochemical sensing of a protein. PMID:27639148

  14. Giant unilamellar vesicles containing Rhodamine 6G as a marker for immunoassay of bovine serum albumin and lipocalin-2.

    PubMed

    Sakamoto, Misato; Shoji, Atsushi; Sugawara, Masao

    2016-07-15

    Functionalized giant unilamellar vesicles (GUVs) containing a fluorescence dye Rhodamine 6G is proposed as a marker in sandwich-type immunoassay for bovine serum albumin (BSA) and lipocalin-2 (LCN2). The GUVs were prepared by the electroformation method and functionalized with anti-BSA antibody and anti-LCN2 antibody, respectively. The purification of antibody-modified GUVs was achieved by conventional centrifugation and a washing step in a flow system. To antigen on an antibody slip, antibody-modified GUVs were added as a marker and incubated. After wash-out of excess reagents and lysis of the bound GUVs with Triton X-100, the fluorescence image was captured. The fluorometric immunoassays for BSA and LCN2 exhibited lower detection limits of 4 and 80 fg ml(-)(1), respectively. PMID:27117116

  15. Highly selective and sensitive detection of Cu2+ with lysine enhancing bovine serum albumin modified-carbon dots fluorescent probe.

    PubMed

    Liu, Jia-Ming; Lin, Li-ping; Wang, Xin-Xing; Lin, Shao-Qin; Cai, Wen-Lian; Zhang, Li-Hong; Zheng, Zhi-Yong

    2012-06-01

    Based on the ability of lysine (Lys) to enhance the fluorescence intensity of bovine serum albumin modified-carbon dots (CDs-BSA) to decrease surface defects and quench fluorescence of the CDs-BSA-Lys system in the presence of Cu(2+) under conditions of phosphate buffer (PBS, pH = 5.0) at 45 °C for 10 min, a sensitive Lys enhancing CDs-BSA fluorescent probe was designed. The environment-friendly, simple, rapid, selective and sensitive fluorescent probe has been utilized to detect Cu(2+) in hair and tap water samples and it achieved consistent results with those obtained by inductively coupled plasma mass spectroscopy (ICP-MS). The mechanism of the proposed assay for the detection of Cu(2+) is discussed. PMID:22531278

  16. Complexation of bovine serum albumin and sugar beet pectin: stabilising oil-in-water emulsions.

    PubMed

    Li, Xiangyang; Fang, Yapeng; Al-Assaf, Saphwan; Phillips, Glyn O; Jiang, Fatang

    2012-12-15

    In a previous study (Langmuir 28 (2012) 10164-10176.), we investigated the complexation of bovine serum albumin (BSA) with sugar beet pectin (SBP). A pH-composition phase diagram was established and structural transitions in relation to the phase diagram during complexation were identified. The present study examines the implications of these interactions on the emulsifying performance of BSA/SBP mixtures. Middle-chain triglycerides (MCTs) in water emulsions were prepared using conditions corresponding to different regions of the phase diagram. At high pHs and in the stable region of mixed individual soluble polymers where complexation is absent, there is no improved emulsifying performance, compared with the individual protein and polysaccharide. For these mixtures, the emulsion characteristics are controlled by the major component in the solutions, as determined by the competitive adsorption of the two components at the oil-water interface. At low pHs and low BSA/SBP ratios, and so mainly within the stable region of intramolecular soluble complexes, BSA/SBP mixtures greatly improve the stability of emulsions. Here, stabilisation is controlled by the cooperative adsorption of the two components at the oil-water interface. Through electrostatic complexation BSA promotes the adsorption of SBP on to interfaces to form a thick steric layer around emulsion droplets and thus providing better stability. At low pHs and high BSA/SBP ratios, that is, mainly within the unstable region of intermolecular insoluble complexes, emulsions prepared are extremely unstable due to bridging flocculation between emulsion droplets.

  17. Expanded and packed bed albumin adsorption on fluoride modified zirconia.

    PubMed

    Mullick, A; Griffith, C M; Flickinger, M C

    1998-11-01

    The expanded bed characteristics of 75-103microm fluoride-modified zirconia (FmZr) particles synthesized by a fed batch oil emulsion process were investigated. These particles are distinguished from commercially available expanded-bed adsorbents by virtue of their high density (2.8 g/cc) and the mixed mode protein retention mechanism which allows for the retention of both cationic and anionic proteins. The linear velocity versus bed porosity data agree with the Richardson-Zaki relationship with the terminal velocity in infinite medium of 2858.4 cm/h and a bed expansion index of 5.1. Residence time distribution (RTD) studies and bovine serum albumin (BSA) adsorption studies were performed as a function of the height of the settled bed to the column diameter (H:D) ratio and degree of bed expansion with superficial velocities of 440 to 870 cm/h. The settled bed, a 2x expanded bed, and a 3x expanded bed were studied for the H:D ratios of 1:1, 2:1, and 3:1. The dynamic binding capacity (DBC) at 5% breakthrough was low (2-8 mg BSA/mL settled bed) and was independent of the H:D ratio or the degree of bed expansion. The saturation DBC was 32.3 +/- 7.0 mg BSA/mL settled bed. The adsorption-desorption kinetics and intraparticle diffusion for protein adsorption on FmZr (38-75 micrometer) were investigated by studying the packed bed RTD and BSA adsorption as a function of temperature and flow rate. The data show that the adsorption-desorption kinetics along with intraparticle diffusion significantly influence protein adsorption on FmZr. Low residence times ( approximately 0.8 min) of BSA result in a DBC at 5% breakthrough which is 3.5-fold lower compared to that at 6-fold higher protein residence time. At low linear velocity (45 cm/h) the breakthrough curve is nearly symmetrical and becomes asymmetrical and more dispersed at higher linear velocity (270 cm/h) due to the influence of slow adsorption-desorption kinetics and intraparticle diffusion. Bioeng 60: 333-340, 1998. PMID

  18. Study on the interaction of Co (III) DiAmsar with serum albumins: Spectroscopic and molecular docking methods

    NASA Astrophysics Data System (ADS)

    Farahani, Bahman Vasheghani; Bardajee, Ghasem Rezanejade; Rajabi, Farzaneh Hosseinpour; Hooshyar, Zari

    2015-01-01

    This study was designed to examine the interaction of cobalt-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1,8-diamine (Co(III) DiAmsar) as a hexadentate ligand with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions in Tris-HCl buffer solution at pH 7.4. To this aim, at first, Co (III) DiAmsar was synthesized and characterized by nuclear magnetic resonance (NMR), and mass spectroscopy and then its interaction with HSA and BSA was investigated by means of various spectroscopic methods (Fourier transform infrared (FT-IR), UV-visible (UV-vis), fluorescence, and cyclic voltammetry (CV)) and molecular docking technique. The results of fluorescence titration revealed that the Co (III) DiAmsar strongly quench the intrinsic fluorescence of HSA and BSA through a static quenching procedure. Binding constants (Ka) and the number of binding sites (n ∼ 1) were calculated using Stern-Volmer equations. The ΔG parameters at different temperatures were calculated. Subsequently, the values of ΔH and ΔS were also calculated, which revealed that the van der Waals and hydrogen bonding interaction splay a major role in Co (III) DiAmsar-HSA and Co (III) DiAmsar-BSA associations. The distance r between donor (HSA and BSA) and acceptor (Co (III) DiAmsar) was obtained according to fluorescence resonance energy transfer. The data obtained by the molecular modeling study revealed the surrounding residues of HSA and BSA around Co (III) DiAmsar.

  19. Interaction of weakly bound antibiotics neomycin and lincomycin with bovine and human serum albumin: biophysical approach.

    PubMed

    Keswani, Neelam; Choudhary, Sinjan; Kishore, Nand

    2010-07-01

    The thermodynamics of interaction of neomycin and lincomycin with bovine serum albumin (BSA) and human serum albumin (HSA) has been studied using isothermal titration calorimetry (ITC), in combination with UV-visible, steady state and time resolved fluorescence spectroscopic measurements. Neomycin is observed to bind weakly to BSA and HSA whereas lincomycin did not show any evidence for binding with the native state of these proteins, rather it interacts in the presence of surfactants. The ITC results suggest 1 : 1 binding stoichiometry for neomycin in the studied temperature range. The values of the van't Hoff enthalpy do not agree with the calorimetric enthalpy in the case of neomycin, suggesting conformational changes in the protein upon ligand binding, as well as with the rise in the temperature. Experiments at different ionic strengths, and in the presence of tetrabutyl ammonium bromide and surfactants suggest the predominant involvement of electrostatic interactions in the complexation process of neomycin with BSA and HSA, and non-specific interaction behaviour of lincomycin with these proteins.

  20. Arginine and lysine reduce the high viscosity of serum albumin solutions for pharmaceutical injection.

    PubMed

    Inoue, Naoto; Takai, Eisuke; Arakawa, Tsutomu; Shiraki, Kentaro

    2014-05-01

    Therapeutic protein solutions for subcutaneous injection must be very highly concentrated, which increases their viscosity through protein-protein interactions. However, maintaining a solution viscosity below 50 cP is important for the preparation and injection of therapeutic protein solutions. In this study, we examined the effect of various amino acids on the solution viscosity of very highly concentrated bovine serum albumin (BSA) and human serum albumin (HSA) at a physiological pH. Among the amino acids tested, l-arginine hydrochloride (ArgHCl) and l-lysine hydrochloride (LysHCl) (50-200 mM) successfully reduced the viscosity of both BSA and HSA solutions; guanidine hydrochloride (GdnHCl), NaCl, and other sodium salts were equally as effective, indicating the electrostatic shielding effect of these additives. Fourier transform infrared spectroscopy showed that BSA is in its native state even in the presence of ArgHCl, LysHCl, and NaCl at high protein concentrations. These results indicate that weakened protein-protein interactions play a key role in reducing solution viscosity. ArgHCl and LysHCl, which are also non-toxic compounds, will be used as additives to reduce the solution viscosity of concentrated therapeutic proteins.

  1. Depolymerization of insulin amyloid fibrils by albumin-modified magnetic fluid

    NASA Astrophysics Data System (ADS)

    Siposova, Katarina; Kubovcikova, Martina; Bednarikova, Zuzana; Koneracka, Martina; Zavisova, Vlasta; Antosova, Andrea; Kopcansky, Peter; Daxnerova, Zuzana; Gazova, Zuzana

    2012-02-01

    Pathogenesis of amyloid-related diseases is associated with the presence of protein amyloid deposits. Insulin amyloids have been reported in a patient with diabetes undergoing treatment by injection of insulin and causes problems in the production and storage of this drug and in application of insulin pumps. We have studied the interference of insulin amyloid fibrils with a series of 18 albumin magnetic fluids (MFBSAs) consisting of magnetite nanoparticles modified by different amounts of bovine serum albumin (w/w BSA/Fe3O4 from 0.005 up to 15). We have found that MFBSAs are able to destroy amyloid fibrils in vitro. The extent of fibril depolymerization was affected by nanoparticle physical-chemical properties (hydrodynamic diameter, zeta potential and isoelectric point) determined by the BSA amount present in MFBSAs. The most effective were MFBSAs with lower BSA/Fe3O4 ratios (from 0.005 to 0.1) characteristic of about 90% depolymerizing activity. For the most active magnetic fluids (ratios 0.01 and 0.02) the DC50 values were determined in the range of low concentrations, indicating their ability to interfere with insulin fibrils at stoichiometric concentrations. We assume that the present findings represent a starting point for the application of the active MFBSAs as therapeutic agents targeting insulin amyloidosis.

  2. DNA binding, BSA interaction and SOD activity of two new nickel(II) complexes with glutamine Schiff base ligands.

    PubMed

    Wei, Qiang; Dong, Jianfang; Zhao, Peiran; Li, Manman; Cheng, Fengling; Kong, Jinming; Li, Lianzhi

    2016-08-01

    Two hexacoordinated octahedral nickel(II) complexes, [Ni(o-van-gln)(phen)(H2O)](1) and [Ni(sal-gln)(phen)(H2O)](2) [o-van-gln=a Schiff base derived from o-vanillin and glutamine, sal-gln=a Schiff base derived from salicylaldehyde and glutamine, phen=1,10-phenanthroline], have been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. X-ray studies showed that nickel atoms of both 1 and 2 exhibit distorted NiN3O3 octahedral geometry. In each crystal, intermolecular hydrogen bonds form a two-dimensional network structure. DNA-binding properties of these two nickel(II) complexes were investigated by using UV-Vis absorption, fluorescence, circular dichroism (CD) spectroscopies and viscosity measurements. Results indicated that the two complexes can bind to calf thymus DNA (CT-DNA) via an intercalative mode, and complex 1 exhibits higher interaction with CT-DNA than complex 2. Furthermore, the interactions between the nickel(II) complexes with bovine serum albumin (BSA) have been studied by spectroscopies. The results indicated that both complexes could quench the intrinsic fluorescence of BSA in a static quenching process. The binding constants (Kb) and the numbers of binding sites (n) obtained are 1.10×10(5)M(-1) and 1.05 for complex 1 and 5.05×10(4)M(-1) and 0.997 for complex 2, respectively. Site-selective competitive binding investigation indicated that the binding sites of both the complexes are located in site I of sub-domains IIA of BSA. Assay of superoxide dismutase (SOD) activity of the nickel(II) complexes revealed that they exhibit significant superoxide scavenging activity with IC50=3.4×10(-5)M for complex 1 and 4.3×10(-5)M for complex 2, respectively.

  3. DNA binding, BSA interaction and SOD activity of two new nickel(II) complexes with glutamine Schiff base ligands.

    PubMed

    Wei, Qiang; Dong, Jianfang; Zhao, Peiran; Li, Manman; Cheng, Fengling; Kong, Jinming; Li, Lianzhi

    2016-08-01

    Two hexacoordinated octahedral nickel(II) complexes, [Ni(o-van-gln)(phen)(H2O)](1) and [Ni(sal-gln)(phen)(H2O)](2) [o-van-gln=a Schiff base derived from o-vanillin and glutamine, sal-gln=a Schiff base derived from salicylaldehyde and glutamine, phen=1,10-phenanthroline], have been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. X-ray studies showed that nickel atoms of both 1 and 2 exhibit distorted NiN3O3 octahedral geometry. In each crystal, intermolecular hydrogen bonds form a two-dimensional network structure. DNA-binding properties of these two nickel(II) complexes were investigated by using UV-Vis absorption, fluorescence, circular dichroism (CD) spectroscopies and viscosity measurements. Results indicated that the two complexes can bind to calf thymus DNA (CT-DNA) via an intercalative mode, and complex 1 exhibits higher interaction with CT-DNA than complex 2. Furthermore, the interactions between the nickel(II) complexes with bovine serum albumin (BSA) have been studied by spectroscopies. The results indicated that both complexes could quench the intrinsic fluorescence of BSA in a static quenching process. The binding constants (Kb) and the numbers of binding sites (n) obtained are 1.10×10(5)M(-1) and 1.05 for complex 1 and 5.05×10(4)M(-1) and 0.997 for complex 2, respectively. Site-selective competitive binding investigation indicated that the binding sites of both the complexes are located in site I of sub-domains IIA of BSA. Assay of superoxide dismutase (SOD) activity of the nickel(II) complexes revealed that they exhibit significant superoxide scavenging activity with IC50=3.4×10(-5)M for complex 1 and 4.3×10(-5)M for complex 2, respectively. PMID:27295415

  4. The Importance of Protein-Protein Interactions on the pH-Induced Conformational Changes of Bovine Serum Albumin: A Small-Angle X-Ray Scattering Study

    PubMed Central

    Barbosa, Leandro R.S.; Ortore, Maria Grazia; Spinozzi, Francesco; Mariani, Paolo; Bernstorff, Sigrid; Itri, Rosangela

    2010-01-01

    Abstract The combined effects of concentration and pH on the conformational states of bovine serum albumin (BSA) are investigated by small-angle x-ray scattering. Serum albumins, at physiological conditions, are found at concentrations of ∼35–45 mg/mL (42 mg/mL in the case of humans). In this work, BSA at three different concentrations (10, 25, and 50 mg/mL) and pH values (2.0–9.0) have been studied. Data were analyzed by means of the Global Fitting procedure, with the protein form factor calculated from human serum albumin (HSA) crystallographic structure and the interference function described, considering repulsive and attractive interaction potentials within a random phase approximation. Small-angle x-ray scattering data show that BSA maintains its native state from pH 4.0 up to 9.0 at all investigated concentrations. A pH-dependence of the absolute net protein charge is shown and the charge number per BSA is quantified to 10(2), 8(1), 13(2), 20(2), and 26(2) for pH values 4.0, 5.4, 7.0, 8.0, and 9.0, respectively. The attractive potential diminishes as BSA concentration increases. The coexistence of monomers and dimers is observed at 50 mg/mL and pH 5.4, near the BSA isoelectric point. Samples at pH 2.0 show a different behavior, because BSA overall shape changes as a function of concentration. At 10 mg/mL, BSA is partially unfolded and a strong repulsive protein-protein interaction occurs due to the high amount of exposed charge. At 25 and 50 mg/mL, BSA undergoes some re-folding, which likely results in a molten-globule state. This work concludes by confirming that the protein concentration plays an important role on the pH-unfolded BSA state, due to a delicate compromise between interaction forces and crowding effects. PMID:20085727

  5. DLS microrheology at the onset of weak elasticity during thermal denaturation of BSA

    NASA Astrophysics Data System (ADS)

    Nobbmann, Ulf; Rega, Carlos A.; Jankevics, Hanna; Amin, Samiul

    2011-03-01

    The ability to precisely detect the onset of protein aggregation to draw insights into microstructural characteristics plays a critical role in a variety of biotechnological applications such as therapeutic protein stability. Rheological techniques are very sensitive to evolution of an aggregating network but have been limited in biotechnology, due to large sample volume and moderately high viscosity requirements in traditional mechanical rheometry. Dynamic Light Scattering (DLS) overcomes these limitations as experiments can be carried out on very dilute samples and small volumes. We present a method based on optical microrheology to study the onset of bovine serum albumin (BSA) aggregation to develop an understanding of the evolving network structure. The exponent of the tracer mean squared displacement power law fit and the elastic modulus G' emerge as two key parameters. The impact of probe chemistry and probe size on the extracted microrheological response is discussed. A Saluja et al., ``Ultrasonic rheology of a monoclonal antibody (IgG 2) solution: implication for physical stability of proteins in high concentration formulations'' J. of Pharm. Sci. (2007) 96, 3181-3195.

  6. Molecular dynamics simulation of free and forced BSA adsorption on a hydrophobic graphite surface.

    PubMed

    Mücksch, Christian; Urbassek, Herbert M

    2011-11-01

    The adsorption of bovine serum albumin (BSA) onto a hydrophobic graphite surface is studied using molecular-dynamics simulation. In addition to the free, that is, unsteered, adsorption, we also investigate forced adsorption, in which the action of an AFM tip pushing the protein with constant force to the surface is modeled. Using an implicit inviscid water model, the adsorption dynamics and energetics are monitored for two different initial protein orientations toward the surface. In all cases, we find that the protein partially unfolds and spreads on the surface. The spreading is in agreement with the well-known high biocompatibility of graphite-based implants. The denaturation is, however, greatly enhanced in the case of forced adsorption. We follow the position of the so-called lipid-binding pocket found in subdomain IIIA (Sudlow site II) during adsorption and find that it is tilted and moved toward the graphite surface in all cases, in agreement with its hydrophobic character. The relevance of our findings for the common measurement procedure of studying protein adhesion using AFM experiments is discussed.

  7. An Injectable PEG-BSA-Coumarin-GOx Hydrogel for Fluorescence Turn-on Glucose Detection.

    PubMed

    Srinivasan, Gayathri; Chen, Jun; Parisi, Joseph; Brückner, Christian; Yao, Xudong; Lei, Yu

    2015-11-01

    Diabetes mellitus is a chronic metabolic disorder, requiring vigilant monitoring of blood glucose levels. In this study, an injectable fluorescent enzymatic hydrogel was designed for rapid glucose detection. The leakage-free glucose-responsive hydrogel was constructed by the covalent linkage of a multi-arm poly-(ethylene glycol) (PEG), bovine serum albumin (BSA), glucose oxidase (GOx), and 4-(aminomethyl)-6,7-dimethoxycoumarin (Coumarin-NH2). The GOx serves as glucose-recognition element and the pH-sensitive Coumarin-NH2 as a fluorescence turn-on reporter. The material properties of the fluorescent hydrogel were systematically characterized which show high elasticity with good mechanical strength. Upon the addition of glucose, the as-developed fluorescent hydrogel shows a fast response time, good sensitivity, and good reproducibility at physiological pH and ambient temperature. The glucose-sensing mechanism is based on the oxidation of the glucose by GOx that generates protons to change the local pH. Consequently, protonation of the covalently immobilized and pH-sensitive Coumarin-NH2 turns on the fluorescence of the coumarin. The fluorescence hydrogel developed holds great promise as an injectable, implantable glucose-sensing biomaterials for in vivo continuous glucose monitoring.

  8. Selective determination of cysteine using BSA-stabilized gold nanoclusters with red emission.

    PubMed

    Cui, Ma-Lin; Liu, Jia-Ming; Wang, Xin-Xing; Lin, Li-Ping; Jiao, Li; Zhang, Li-Hong; Zheng, Zhi-Yong; Lin, Shao-Qin

    2012-11-21

    Gold nanoclusters (AuNCs) were synthesized by a macromolecules template using bovine serum albumin (BSA) as stabilizer which can emit red photoluminescence under illumination of ultraviolet light. The fluorescence intensity of AuNCs enhanced through decreasing the surface defects of AuNCs modified with cysteine, herein we present a novel fluorometry for determination of trace cysteine. This method with a wider linear range from 2.0 to 800 nmol mL(-1), higher sensitivity (detection limit was 1.2 nmol mL(-1)) and better selectivity has been utilized to determine cysteine content in real samples, and the results were in a good agreement with those determined by electrochemical biosensor. At the same time, the structures of AuNCs and AuNCs-cysteine were characterized by Fourier-transform infrared spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) and the mechanism of the proposed assay for the detection of cysteine has been discussed. PMID:23033064

  9. Controlling the taste receptor accessible structure of rebaudioside A via binding to bovine serum albumin.

    PubMed

    Mudgal, Samriddh; Keresztes, Ivan; Feigenson, Gerald W; Rizvi, S S H

    2016-04-15

    We illustrate a method that uses bovine serum albumin (BSA) to control the receptor-accessible part of rebaudioside A (Reb A). The critical micelle concentration (CMC) of Reb A was found to be 4.5 mM and 5 mM at pH 3 and 6.7 respectively. NMR studies show that below its CMC, Reb A binds weakly to BSA to generate a Reb A-protein complex ("RPC"), which is only modestly stable under varying conditions of pH (3.0-6.7) and temperature (4-40°C) with its binding affinities determined to be in the range of 5-280 mM. Furthermore, saturation transfer difference (STD) NMR experiments confirm that the RPC has fast exchange of the bitterness-instigating diterpene of Reb A into the binding sites of BSA. Our method can be used to alter the strength of Reb A-receptor interaction, as a result of binding of Reb A to BSA, which may ultimately lead to moderation of its taste.

  10. Controlling the taste receptor accessible structure of rebaudioside A via binding to bovine serum albumin.

    PubMed

    Mudgal, Samriddh; Keresztes, Ivan; Feigenson, Gerald W; Rizvi, S S H

    2016-04-15

    We illustrate a method that uses bovine serum albumin (BSA) to control the receptor-accessible part of rebaudioside A (Reb A). The critical micelle concentration (CMC) of Reb A was found to be 4.5 mM and 5 mM at pH 3 and 6.7 respectively. NMR studies show that below its CMC, Reb A binds weakly to BSA to generate a Reb A-protein complex ("RPC"), which is only modestly stable under varying conditions of pH (3.0-6.7) and temperature (4-40°C) with its binding affinities determined to be in the range of 5-280 mM. Furthermore, saturation transfer difference (STD) NMR experiments confirm that the RPC has fast exchange of the bitterness-instigating diterpene of Reb A into the binding sites of BSA. Our method can be used to alter the strength of Reb A-receptor interaction, as a result of binding of Reb A to BSA, which may ultimately lead to moderation of its taste. PMID:26616927

  11. Adsorption of serum albumin to thin films of poly(lactide-co-glycolide).

    PubMed

    Butler, S M; Tracy, M A; Tilton, R D

    1999-04-19

    Protein adsorption has been implicated in the variability of drug release from biodegradable microspheres. We used optical reflectometry to measure the extent and kinetics of bovine serum albumin (BSA) adsorption to smooth spin-cast films prepared from two poly(lactide-co-glycolide) (PLG) samples that have different end-groups, one being a hydrophilic carboxylic end group and the other a hydrophobic ester end group. One of us has previously shown that these end-groups influence microsphere degradation (Tracy et al. , 1998, Factors affecting the degradation rate of poly(lactide-co-glycolide) microspheres in vivo and in vitro. Biomaterials: submitted for publication.). Both films were moderately hydrophobic, and their wettability was independent of the type of end-group. BSA adsorbed readily to both native PLG films, attaining as much as 50% surface coverage by area and was insensitive to the type of end-group. Aging the films in water for 24 h prior to BSA exposure decreased the hydrophobicity of the films and this in turn correlated with a significant decrease in the initial BSA adsorption rate. This was consistent with the often-observed trend that surface hydrophobicity favors protein adsorption. In spite of the lower adsorption affinity revealed by this decreased initial adsorption rate, the final adsorbed amounts on the aged films exceeded those attained on native films, presumably due to the increase in total surface area produced by partial PLG erosion.

  12. Adsorption of bovine serum albumin on amorphous carbon surfaces studied with dip pen nanolithography

    NASA Astrophysics Data System (ADS)

    Yadav, Pradeep K.; McKavanagh, Fiona; Maguire, Paul D.; Lemoine, Patrick

    2011-10-01

    This article reports the use of dip pen nanolithography (DPN) for the study of adsorption of bovine serum albumin (BSA) proteins on amorphous carbon surfaces; tetrahedral amorphous carbon (t-aC) and silicon doped hydrogenated amorphous carbon (a-C:H:Si). Contact angle study shows that the BSA proteins reduce the contact angle on both carbon materials. We also noticed that the drop volume dependence is consistent with a negative line tension, i.e. due to an attractive protein/surface interaction. The DPN technique was used to write short-spaced (100 nm) BSA line patterns on both samples. We found a line merging effect, stronger in the case of the a-C:H:Si material. We discuss possible contributions from tip blunting, scratching, cross-talk between lever torsion and bending and nano-shaving of the patterns. We conclude that the observed effect is caused in large measure by the diffusion of BSA proteins on the amorphous carbon surfaces. This interpretation of the result is consistent with the contact angle data and AFM force curve analysis indicating larger tip/surface adhesion and spreading for the a-C:H:Si material. We conclude by discussing the advantages and limitations of DPN lithography to study biomolecular adsorption in nanoscale wetting environments.

  13. Conjugation of bovine serum albumin and glucose under combined high pressure and heat.

    PubMed

    Buckow, Roman; Wendorff, Johannes; Hemar, Yacine

    2011-04-27

    The effect of combined heat and pressure on the Maillard reaction between bovine serum albumin (BSA) and glucose was investigated. The effects in the range of 60-132 °C and at 0.1-600 MPa on the lysine availability of BSA were investigated at isothermal/isobaric conditions. The kinetic results showed that the protein-sugar conjugation rate increased with increasing temperature, whereas it decreased with increasing pressure. The reaction followed 1.4th order kinetics at most conditions investigated. A mathematical model describing BSA-glucose conjugation kinetics as a function of pressure and temperature is proposed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry were used to verify BSA-glucose conjugation and to identify the glucosylated sites. These indicated that the application of combined high pressure and high temperature resulted in significant differences in the progression of the Maillard reaction as compared to heat treatments at atmospheric pressure. PMID:21395313

  14. Bovine Serum Albumin Nanoparticles Containing Amphotericin B: Characterization, Cytotoxicity and In Vitro Antifungal Evaluation.

    PubMed

    Casa, Diani Meza; Karam, Thaysa Ksiaskiewcz; Alves, Aline de Cristo Soares; Zgoda, Aline Aparecida; Khalil, Najeh Maissar; Mainardes, Rubiana Mara

    2015-12-01

    In this study, nanoparticles based on bovine serum albumin (BSA) containing amphotericin B (AmB) were obtained by the desolvation method and characterized with respect to size, size distribution, AmB encapsulation efficiency, AmB state of aggregation, and AmB in vitro release profile. After, the effect of nanoparticles on the cytotoxicity of human erythrocytes in vitro and efficacy over strains of Candida spp. were evaluated. The mean particle size was 156 nm and the AmB encapsulation efficiency was over 82%. The in vitro release profile revealed a sustained release of approximately 48% of AmB over 5 days. AmB is present in BSA nanoparticles as monomer. AmB-loaded nanoparticles showed very low index of hemolysis (less than 8%) in 72 h of assay compared to free AmB, which presented 100% of hemolysis in 2 h of incubation. The AmB-loaded BSA nanoparticles were as effective as free AmB against Candida albicans and Candida tropicalis, considering their sustained release profile. Thus, BSA nanoparticles are potential carriers for AmB, reducing its molecular aggregation and prolonging its release, resulting in lower cytotoxicity while maintaining its antifungal activity.

  15. Elucidating the interaction of limonene with bovine serum albumin: a multi-technique approach.

    PubMed

    Chaturvedi, Sumit Kumar; Ahmad, Ejaz; Khan, Javed Masood; Alam, Parvez; Ishtikhar, Mohd; Khan, Rizwan Hasan

    2015-01-01

    The interaction of Bovine Serum Albumin (BSA) with limonene has been studied by UV-visible spectroscopy, fluorescence spectroscopy and molecular docking, and its effects on protein conformation, topology and stability were determined by Circular Dichroism (CD), Dynamic Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). A gradual decrease in Stern-Volmer quenching constants with the increase in temperature showed the static mode of fluorescence quenching. The obtained binding constant (Kb) was ∼10(4) M(-1). The temperature dependent Kb, Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes were calculated, which revealed that the reaction is spontaneous and exothermic. The UV-visible spectra showed a change in the peaks within the aromatic region indicating hydrophobic interactions with Trp, Tyr and Phe in the protein. Moreover, limonene induced an increase in α-helical contents probably on the cost of random coils or/and β-sheets of BSA, as observed from the far-UV CD spectra. The topology of BSA in the presence of limonene was slightly altered, as obtained from DLS results. The stability was also enhanced as revealed through thermal denaturation study by DSC and CD. Molecular docking study depicted that limonene fits into the hydrophobic pocket close to Sudlow site I in domain IIA of BSA. The present study will be helpful in understanding the binding mechanism of limonene and associated stability and conformational changes.

  16. Fabrication and characterization of SPR chips with the modified bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Chen, Xing; Zhang, Lu-lu; Cui, Da-fu

    2016-03-01

    A facile surface plasmon resonance (SPR) chip is developed for small molecule determination and analysis. The SPR chip was prepared based on a self assembling principle, in which the modified bovine serum albumin (BSA) was directly self-assembled onto the bare gold surface. The surface morphology of the chip with the modified BSA was investigated by atomic force microscopy (AFM) and its optical properties were characterized. The surface binding capacity of the bare facile SPR chip with a uniform morphology is 8 times of that of the bare control SPR chip. Based on the experiments of immune reaction between cortisol antibody and cortisol derivative, the sensitivity of the facile SPR chip with the modified BSA is much higher than that of the control SPR chip with the un-modified BSA. The facile SPR chip has been successfully used to detect small molecules. The lowest detection limit is 5 ng/mL with a linear range of 5—100 ng/mL for cortisol analysis. The novel facile SPR chip can also be applied to detect other small molecules.

  17. Lysozyme loading and release from Se doped hydroxyapatite nanoparticles.

    PubMed

    Wang, Yanhua; Hao, Hang; Zhang, Shengmin

    2016-04-01

    Element-substituted hydroxyapatite (HA) based nanocomposites have become a promising therapeutic material for improving bone defect repair. Selenium substituted HA nanoparticles can both induce apoptosis of bone tumor cells and enhance osteointegration. However, the effect of selenite ions on the proteins in combination with the HA nanoparticles remains to be elucidated. Here, we investigated the influence of selenium doping concentration on the loading and release of lysozyme (LSM) as a model protein drug. The selenium substituted HA-LSM composites with different doping concentrations were synthesized and characterized. The subsequent delivery of lysozyme was studied in a phosphate buffer solution (PBS). We found that selenium substituted HA-LSM composites with Se:P=10% showed the highest amount of lysozyme loading (41.7%), whereas the amount of lysozyme loaded in undoped HA nanoparticles was the lowest (34.1%). The doped selenium interacts with lysozyme molecules, which leads to the increase of β-sheet and unordered, and the decrease of self-association, α-helix and β-turns in protein structures. Moreover, selenium addition significantly slows the protein release from HA-LSM composites. The composites with Se:P=10% release lysozyme at the slightly slower rate among the samples with different Se doping concentrations. It also shows that the released lysozyme retains most of its enzymatic activity.

  18. Lysozyme loading and release from Se doped hydroxyapatite nanoparticles.

    PubMed

    Wang, Yanhua; Hao, Hang; Zhang, Shengmin

    2016-04-01

    Element-substituted hydroxyapatite (HA) based nanocomposites have become a promising therapeutic material for improving bone defect repair. Selenium substituted HA nanoparticles can both induce apoptosis of bone tumor cells and enhance osteointegration. However, the effect of selenite ions on the proteins in combination with the HA nanoparticles remains to be elucidated. Here, we investigated the influence of selenium doping concentration on the loading and release of lysozyme (LSM) as a model protein drug. The selenium substituted HA-LSM composites with different doping concentrations were synthesized and characterized. The subsequent delivery of lysozyme was studied in a phosphate buffer solution (PBS). We found that selenium substituted HA-LSM composites with Se:P=10% showed the highest amount of lysozyme loading (41.7%), whereas the amount of lysozyme loaded in undoped HA nanoparticles was the lowest (34.1%). The doped selenium interacts with lysozyme molecules, which leads to the increase of β-sheet and unordered, and the decrease of self-association, α-helix and β-turns in protein structures. Moreover, selenium addition significantly slows the protein release from HA-LSM composites. The composites with Se:P=10% release lysozyme at the slightly slower rate among the samples with different Se doping concentrations. It also shows that the released lysozyme retains most of its enzymatic activity. PMID:26838882

  19. The Effects of Acetate Buffer Concentration on Lysozyme Solubility

    NASA Technical Reports Server (NTRS)

    Forsythe, Elizabeth L.; Pusey, Marc L.

    1996-01-01

    The micro-solubility column technique was employed to systematically investigate the effects of buffer concentration on tetragonal lysozyme solubility. While keeping the NaCl concentrations constant at 2%, 3%, 4%, 5% and 7%, and the pH at 4.0, we have studied the solubility of tetragonal lysozyme over an acetate buffer concentration range of 0.01M to 0.5M as a function of temperature. The lysozyme solubility decreased with increasing acetate concentration from 0.01M to 0.1M. This decrease may simply be due to the net increase in solvent ionic strength. Increasing the acetate concentration beyond 0.1M resulted in an increase in the lysozyme solubility, which reached a peak at - 0.3M acetate concentration. This increase was believed to be due to the increased binding of acetate to the anionic binding sites of lysozyme, preventing their occupation by chloride. In keeping with the previously observed reversal of the Hoffmeister series for effectiveness of anions in crystallizing lysozyme, acetate would be a less effective precipitant than chloride. Further increasing the acetate concentration beyond 0.3M resulted in a subsequent gradual decrease in the lysozyme solubility at all NaCl concentrations.

  20. Modulation of Lysozyme Function and Degradation after Nitration with Peroxynitrite

    PubMed Central

    Curry-McCoy, Tiana V.; Osna, Natalia A.; Donohue, Terrence M.

    2009-01-01

    Background Peroxynitrite (PN) is formed from superoxide and nitric oxide, both of which are increased during hepatic ethanol metabolism. Peroxynitrite forms adducts with proteins, causing structural and functional alterations. Here, we investigated PN-induced alterations in lysozyme structure and function, and whether they altered the protein’s susceptibility to proteasome-catalyzed degradation. Methods Hen egg lysozyme was nitrated using varying amounts of either PN or the PN donor, 3-morpholinosynonimine (SIN-1). The activity, nitration status and the susceptibility of lysozyme to proteasome-catalyzed degradation were assessed. Results Lysozyme nitration by PN or SIN-1 caused dose-dependent formation of 3-nitrotyrosine-lysozyme adducts, causing decreased catalytic activity, and enhanced susceptibility to degradation by the 20S proteasome. Kinetic analyses revealed an increased affinity by the 20S proteasome toward nitrated lysozyme compared with the native protein. Conclusion Lysozyme nitration enhances the affinity of the modified enzyme for degradation by the proteasome, thereby increasing its susceptibility to proteolysis. General Significance Increased levels of peroxynitrite have been detected in tissues of ethanol-fed animals. The damaging effects from excessive peroxynitrite in the cell increase hepatotoxicity and cellular death by protein modification due to nitration. Cellular defenses against such changes include enhanced proteolysis by the proteasome in order to maintain protein quality control. PMID:19376194

  1. Nucleation and Growth According to Lysozyme

    NASA Technical Reports Server (NTRS)

    Pusey, Marc L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    How does one take a molecule, strongly asymmetric in both shape and charge distribution, and assemble it into a crystal? We propose a model for the nucleation and crystal growth process for tetragonal lysozyme that may be very germane to other monomeric proteins. The first species formed is postulated to be a dimer. Through repeating associations involving the same intermolecular interactions this becomes the 4(sub 3) helix, that in turn serves as the basic unit for nucleation and crystal growth. High salt attenuates surface charges while promoting hydrophobic interactions. Symmetry facilitates helix self-association. Assembly stability is enhanced when a four helix structure is obtained, with each bound to two neighbors. Only two unique interactions are required. The first are those for helix formation, where the dominant interaction is the intermolecular bridging anion. The second is the anti-parallel side-by-side helix-helix interaction, guided by alternating pairs of symmetry related salt bridges along each side. At this stage all eight unique positions of the P4(sub 3)2(sub 1)2(sub 1) unit cell are filled. From the above, the process is one of a) attenuating the most strongly interacting groups, such that b) the molecules begin to self-associate in defined patterns, so that c) symmetry is obtained, which d) propagates as a growing crystal. Simple and conceptually obvious in hindsight, this tells much about what we are empirically doing when we crystallize macromolecules. By adjusting the solution parameters we are empirically balancing the intermolecular interactions, preferentially attenuating the dominant strong (for lysozyme the charged groups) while strengthening the lesser strong (hydrophobic) interactions. Lysozyme is atypical in the breadth of its crystallization conditions; many proteins only crystallize under narrowly defined conditions, pointing to the criticality of the empirical balancing process. Lack of a singularly defined association pathway

  2. Spectral characterization of the binding and conformational changes of serum albumins upon interaction with an anticancer drug, anastrozole

    NASA Astrophysics Data System (ADS)

    Punith, Reeta; Seetharamappa, J.

    2012-06-01

    The present study employed different optical spectroscopic techniques viz., fluorescence, FTIR, circular dichroism (CD) and UV-vis absorption spectroscopy to investigate the mechanism of interaction of an anticancer drug, anastrozole (AZ) with transport proteins viz., bovine serum albumin (BSA) and human serum albumin (HSA). The drug, AZ quenched the intrinsic fluorescence of protein and the analysis of results revealed the presence of dynamic quenching mechanism. The binding characteristics of drug-protein were computed. The thermodynamic parameters, enthalpy change (ΔH°) and entropy change (ΔS°) were calculated to be +92.99 kJ/mol and +159.18 J/mol/K for AZ-BSA and, +99.43 kJ/mol and +159.19 J/mol/K for AZ-HSA, respectively. These results indicated that the hydrophobic forces stabilized the interaction between the drug and protein. CD, FTIR, absorption, synchronous and 3D fluorescence results indicated that the binding of AZ to protein induced structural perturbation in both serum albumins. The distance, r between the drug and protein was calculated based on the theory of Förster's resonance energy transfer and found to be 5.9 and 6.24 nm, respectively for AZ-BSA and AZ-HSA.

  3. Structural studies on serum albumins under green light irradiation.

    PubMed

    Comorosan, Sorin; Polosan, Silviu; Popescu, Irinel; Ionescu, Elena; Mitrica, Radu; Cristache, Ligia; State, Alina Elena

    2010-10-01

    This paper presents two new experimental results: the protective effect of green light (GL) on ultraviolet (UV) denaturation of proteins, and the effect of GL on protein macromolecular structures. The protective effect of GL was revealed on two serum albumins, bovine (BSA) and human (HSA), and recorded by electrophoresis, absorption, and circular dichroism spectra. The effect of GL irradiation on protein structure was recorded by using fluorescence spectroscopy and electrophoresis. These new effects were modeled by quantum-chemistry computation using Gaussian 03 W, leading to good fit between theoretical and experimental absorption and circular dichroism spectra. A mechanism for these phenomena is suggested, based on a double-photon absorption process. This nonlinear effect may lead to generation of long-lived Rydberg macromolecular systems, capable of long-range interactions. These newly suggested systems, with macroscopic quantum coherence behaviors, may block the UV denaturation processes. PMID:20473754

  4. The effects of radioiodination and fluorescent labelling on albumin

    SciTech Connect

    Crandall, R.E.; Janatova, J.; Andrade, J.D.

    1981-01-01

    The preparation and characterization of fluorescamine -, fluorescein isothiocyanate (FITC) -, and radioiodine-labelled bovine serum albumin is critically evaluated. Electrophoretic mobility and ion-exchange chromatography, together with measures of degree of conjugation and sulfhydryl content, are used to assess the changes due to conjugation. Fluorescamine labelling results in drastic changes in chromatographic behavior and electrophoretic mobility. FITC labelling also results in significant changes in chromatographic and electrophoretic properties. Radioiodination leads to minor changes in chromatographic properties and oxydation of sulfhydryl groups, with little or no change in electrophoretic properties. All three labels have some degree of lability and show increased levels of free label with time, even after extensive initial purification. It is concluded that the two fluorescent labels and possibly the radioiodine labelling method used here are unsuitable for certain studies of BSA, such as its adsorption at solid-liquid interfaces.

  5. Mesoscopic coarse-grained simulations of lysozyme adsorption.

    PubMed

    Yu, Gaobo; Liu, Jie; Zhou, Jian

    2014-05-01

    Coarse-grained simulations are adopted to study the adsorption behavior of lysozyme on different (hydrophobic, neutral hydrophilic, zwitterionic, negatively charged, and positively charged) surfaces at the mesoscopic microsecond time scale (1.2 μs). Simulation results indicate the following: (i) the conformation change of lysozyme on the hydrophobic surface is bigger than any other studied surfaces; (ii) the active sites of lysozyme are faced to the hydrophobic surface with a "top end-on" orientation, while they are exposed to the liquid phase on the hydrophilic surface with a "back-on" orientation; (iii) the neutral hydrophilic surface can induce the adsorption of lysozyme, while the nonspecific protein adsorption can be resisted by the zwitterionic surface; (iv) when the solution ionic strength is low, lysozyme can anchor on the negatively charged surface easily but cannot adsorb on the positively charged surface; (v) when the solution ionic strength is high, the positively charged lysozyme can also adsorb on the like-charged surface; (vi) the major positive potential center of lysozyme, especially the residue ARG128, plays a vital role in leading the adsorption of lysozyme on charged surfaces; (vii) when the ionic strength is high, a counterion layer is formed above the positively charged surface, which is the key factor why lysozyme can adsorb on a like-charged surface. The coarse-grained method based on the MARTINI force field for proteins and the BMW water model could provide an efficient way to understand protein interfacial adsorption behavior at a greater length scale and time scale. PMID:24785197

  6. Separation of lysozyme using superparamagnetic carboxymethyl chitosan nanoparticles.

    PubMed

    Sun, Jun; Su, Yujie; Rao, Shengqi; Yang, Yanjun

    2011-08-01

    Functionalized Fe(3)O(4) nanoparticles conjugated with polyethylene glycol (PEG) and carboxymethyl chitosan (CM-CTS) were developed and used as a novel magnetic absorbing carrier for the separation and purification of lysozyme from the aqueous solution and chicken egg white, respectively. The morphology of magnetic CM-CTS nanoparticles was observed by transmission electron microscope (TEM). It was found that the diameter of superparamagnetic carboxymethyl chitosan nanoparticles (Fe(3)O(4) (PEG+CM-CTS)) was about 15 nm, and could easily aggregate by a magnet when suspending in the aqueous solution. The adsorption capacity of lysozyme onto the superparamagnetic Fe(3)O(4) (PEG+CM-CTS) nanoparticles was determined by changing the medium pH, temperature, ionic strength and the concentration of lysozyme. The maximum adsorption loading reached 256.4 mg/g. Due to the small diameter, the adsorption equilibrium of lysozyme onto the nanoparticles reached very quickly within 20 min. The adsorption equilibrium of lysozyme onto the superparamagnetic nanoparticles fitted well with the Langmuir model. The nanoparticles were stable when subjected to six repeated adsorption-elution cycles. Separation and purification were monitored by determining the lysozyme activity using Micrococcus lysodeikticus as substrate. The lysozyme was purified from chicken egg white in a single step had higher purity, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Considering that the superparamagnetic nanoparticles possess the advantages of high efficiency, cost-effectiveness and excellent binding of a larger amount of lysozyme and easier separation from the reaction system, thus this type of superparamagnetic nanoparticles would bring advantages to the conventional separation techniques of lysozyme from chicken egg white.

  7. Kinetics of Thermal Denaturation and Aggregation of Bovine Serum Albumin

    PubMed Central

    Borzova, Vera A.; Markossian, Kira A.; Chebotareva, Natalia A.; Kleymenov, Sergey Yu.; Poliansky, Nikolay B.; Muranov, Konstantin O.; Stein-Margolina, Vita A.; Shubin, Vladimir V.; Markov, Denis I.; Kurganov, Boris I.

    2016-01-01

    Thermal aggregation of bovine serum albumin (BSA) has been studied using dynamic light scattering, asymmetric flow field-flow fractionation and analytical ultracentrifugation. The studies were carried out at fixed temperatures (60°C, 65°C, 70°C and 80°C) in 0.1 M phosphate buffer, pH 7.0, at BSA concentration of 1 mg/ml. Thermal denaturation of the protein was studied by differential scanning calorimetry. Analysis of the experimental data shows that at 65°C the stage of protein unfolding and individual stages of protein aggregation are markedly separated in time. This circumstance allowed us to propose the following mechanism of thermal aggregation of BSA. Protein unfolding results in the formation of two forms of the non-native protein with different propensity to aggregation. One of the forms (highly reactive unfolded form, Uhr) is characterized by a high rate of aggregation. Aggregation of Uhr leads to the formation of primary aggregates with the hydrodynamic radius (Rh,1) of 10.3 nm. The second form (low reactive unfolded form, Ulr) participates in the aggregation process by its attachment to the primary aggregates produced by the Uhr form and possesses ability for self-aggregation with formation of stable small-sized aggregates (Ast). At complete exhaustion of Ulr, secondary aggregates with the hydrodynamic radius (Rh,2) of 12.8 nm are formed. At 60°C the rates of unfolding and aggregation are commensurate, at 70°C the rates of formation of the primary and secondary aggregates are commensurate, at 80°C the registration of the initial stages of aggregation is complicated by formation of large-sized aggregates. PMID:27101281

  8. Solute effects on the irreversible aggregation of serum albumin.

    PubMed

    Bagger, Heidi L; Øgendal, Lars H; Westh, Peter

    2007-10-01

    Thermal stress on bovine serum albumin (BSA) promotes protein aggregation through the formation of intermolecular beta-sheets. We have used light scattering and chromatography to study effects of (<1 M) Na(2)SO(4), NaSCN, sucrose, sorbitol and urea on the rate of the thermal aggregation. Both salts were strong inhibitors of BSA aggregation and they reduced both the size and number (concentration) of aggregate particles compared to non-ionic solutes (or pure buffer). Hence, the salts appear to suppress both nucleation- and growth rate. The non-electrolyte additives reduced the initial aggregation rate (compared to pure buffer), but did not significantly limit the extent of aggregation in samples quenched after 27 min. heat exposure (40-50% aggregation in all samples). The non-electrolytes did, however, modify the aggregation process as they consistently brought about smaller but more concentrated aggregates than pure buffer. The results are discussed along the lines of linkage- and transition state theories. In this framework, the rate of the aggregation process is governed by the equilibrium between a thermally denatured state (D) and the transition state D( not equal). Thus, the effect of a solute relies on its preferential interactions with respectively D and D( not equal). The current results do not show any correlation between the solutes' preferential interactions with native BSA and their effect on the rate of aggregation. This suggests that non-specific, "Hofmeister-type" interactions, which scale with the solvent accessible surface area, are of minor importance. Rather, salt induced suppression of aggregation is suggested to depend on the modulation of specific electrostatic forces in the D( not equal) state.

  9. Reentrant condensation of lysozyme: Implications for studying dynamics of lysozyme in aqueous solutions of lithium chloride

    SciTech Connect

    Mamontov, Eugene; O'Neill, Hugh Michael

    2014-01-01

    Recent studies have outlined the use of eutectic solution of lithium chloride in water to study microscopic dynamics of lysozyme in an aqueous solvent that is remarkably similar to pure water in many respects, yet allows experiments over a wide temperature range without the solvent crystallization. The eutectic point in (H2O)R(LiCl) system corresponds to R 7.3, and it is of interest to investigate whether less concentrated aqueous solutions of LiCl could be employed in low-temperature studies of a solvated protein. We have investigated a range of concentrations of lysozyme and LiCl in aqueous solutions to identify systems that do not show phase separation and avoid solvent crystallization on cooling down. Compared to the lysozyme concentration in solution, the concentration of LiCl in the aqueous solvent plays the major role in determining systems suitable for low-temperature studies. We have observed interesting and rich phase behavior reminiscent of reentrant condensation of proteins.

  10. Reentrant condensation of lysozyme: Implications for studying dynamics of lysozyme in aqueous solutions of lithium chloride.

    PubMed

    Mamontov, Eugene; O'Neill, Hugh

    2014-06-01

    Recent studies have outlined the use of eutectic solutions of lithium chloride in water to study microscopic dynamics of lysozyme in an aqueous solvent that is remarkably similar to pure water in many respects, yet allows experiments over a wide temperature range without solvent crystallization. The eutectic point in a (H2O)R(LiCl) system corresponds to R ≈ 7.3, and it is of interest to investigate whether less-concentrated aqueous solutions of LiCl could be used in low-temperature studies of a solvated protein. We have investigated a range of concentrations of lysozyme and LiCl in aqueous solutions to identify systems that do not show phase separation and avoid solvent crystallization on cooling down. Compared to the lysozyme concentration in solution, the concentration of LiCl in the aqueous solvent plays the major role in determining systems suitable for low-temperature studies. We have observed interesting and rich phase behavior reminiscent of reentrant condensation of proteins. PMID:26819974

  11. Exploring the binding mechanism of 5-hydroxy-3‧,4‧,7-trimethoxyflavone with bovine serum albumin: Spectroscopic and computational approach

    NASA Astrophysics Data System (ADS)

    Sudha, A.; Srinivasan, P.; Thamilarasan, V.; Sengottuvelan, N.

    2016-03-01

    The current study was carried out to investigate the binding mechanism of a potential flavonoid compound 5-hydroxy-3‧,4‧,7-trimethoxyflavone (HTMF) with bovine serum albumin (BSA) using ultraviolet-visible, fluorescence, circular dichroism (CD) spectral measurements along with molecular docking and molecular dynamics (MD) simulation. It was confirmed from fluorescence spectra that the intrinsic fluorescence of BSA was robustly quenched by HTMF through a static quenching mechanism. The number of binding sites (n) for HTMF binding on BSA was found to be about one. The thermodynamic parameters estimated from the van't Hoff plot specified that hydrophobic force was the predominant force in the HTMF-BSA complex and there also exist hydrogen bonds and electrostatic interactions. The effect of HTMF on the BSA conformation examined using CD studies revealed that there is a decrease in the helical content of BSA upon HTMF interaction. The results of molecular docking study shed light on the binding mode which exposed that HTMF bind within the hydrophobic pocket of the subdomain IIIA of BSA. The stability of HTMF-BSA complex with respect to free protein was analyzed from the molecular dynamic studies. The electronic structure analysis of HTMF was achieved by using density functional theory (DFT) calculations at B3LYP/6-31G** level to support its antioxidant role. The results of computational analysis are in good consistence with the experimental data and the present findings suggested that HTMF exhibits a good binding propensity to BSA protein which will be helpful for the drug design.

  12. Ionic Liquid Surfactant Mediated Structural Transitions and Self-Assembly of Bovine Serum Albumin in Aqueous Media: Effect of Functionalization of Ionic Liquid Surfactants.

    PubMed

    Singh, Gurbir; Kang, Tejwant Singh

    2015-08-20

    The self-assembly of globular protein bovine serum albumin (BSA) has been investigated in aqueous solutions of ionic liquid surfactants (ILSs), 1-dodecyl-3-methyl imidazolium chloride, [C12mim][Cl], and its amide, [C12Amim][Cl], and ester, [C12Emim][Cl], functionalized counterparts. Dynamic light scattering (DLS) has provided insights into the alterations in hydrodynamic radii (D(h)) of BSA as a function of concentration of ILSs establishing the presence of different types of BSA-ILS complexes in different concentration regimes of ILSs. Isothermal titration calorimetry (ITC) has been exploited to quantify the ILSs interacting with BSA in dilute concentration regime of ILSs. The zeta-potential measurements shed light on changes in the charged state of BSA. The morphology of various self-assembled structures of BSA in different concentration regimes of ILSs have been explored using confocal laser scanning microscopy (CLSM) and scanning electron microscopy. The structural variations in ILSs have been found to produce remarkable effect on the nature and morphology of self-assembled structures of BSA. The presence of nonfunctionalized [C12mim][Cl] IL at all investigated concentrations has led to the formation of unordered large self-assembled structures of BSA. On the other hand, in specific concentration regimes, ordered self-assembled structures such as long rods and right-handedly twisted helical amyloid fibers have been observed in the presence of functionalized [C12Amim][Cl] and [C12Emim][Cl] ILSs, respectively. The nature of the formed helical fibers as amyloid ones has been confirmed using FTIR spectroscopy. Steady-state fluorescence and circular dichroism (CD) spectroscopy have provided insights into folding and unfolding of BSA as fashioned by interactions with ILSs in different concentration regimes supporting the observations made from other studies.

  13. Simultaneous determination of estrogens (ethinylestradiol and norgestimate) concentrations in human and bovine serum albumin by use of fluorescence spectroscopy and multivariate regression analysis.

    PubMed

    Hordge, LaQuana N; McDaniel, Kiara L; Jones, Derick D; Fakayode, Sayo O

    2016-05-15

    The endocrine disruption property of estrogens necessitates the immediate need for effective monitoring and development of analytical protocols for their analyses in biological and human specimens. This study explores the first combined utility of a steady-state fluorescence spectroscopy and multivariate partial-least-square (PLS) regression analysis for the simultaneous determination of two estrogens (17α-ethinylestradiol (EE) and norgestimate (NOR)) concentrations in bovine serum albumin (BSA) and human serum albumin (HSA) samples. The influence of EE and NOR concentrations and temperature on the emission spectra of EE-HSA EE-BSA, NOR-HSA, and NOR-BSA complexes was also investigated. The binding of EE with HSA and BSA resulted in increase in emission characteristics of HSA and BSA and a significant blue spectra shift. In contrast, the interaction of NOR with HSA and BSA quenched the emission characteristics of HSA and BSA. The observed emission spectral shifts preclude the effective use of traditional univariate regression analysis of fluorescent data for the determination of EE and NOR concentrations in HSA and BSA samples. Multivariate partial-least-squares (PLS) regression analysis was utilized to correlate the changes in emission spectra with EE and NOR concentrations in HSA and BSA samples. The figures-of-merit of the developed PLS regression models were excellent, with limits of detection as low as 1.6×10(-8) M for EE and 2.4×10(-7) M for NOR and good linearity (R(2)>0.994985). The PLS models correctly predicted EE and NOR concentrations in independent validation HSA and BSA samples with a root-mean-square-percent-relative-error (RMS%RE) of less than 6.0% at physiological condition. On the contrary, the use of univariate regression resulted in poor predictions of EE and NOR in HSA and BSA samples, with RMS%RE larger than 40% at physiological conditions. High accuracy, low sensitivity, simplicity, low-cost with no prior analyte extraction or separation

  14. Bovine Serum Albumin Nanoparticles Containing Quercetin: Characterization and Antioxidant Activity.

    PubMed

    Antônio, Emilli; Khalil, Najeh Maissar; Mainardes, Rubiana Mara

    2016-02-01

    Quercetin is a flavonoid reported as anti-allergic, anti-inflammatory, antiplatelet, anti-microbial, antioxidant, antineurodegenerative and antitumoral. However, due to its low water solubility, its efficacy is restricted. Nanotechnology can be an importante tool to improve the quercetin properties and increase its bioavailability. In this study, bovine serum albumin (BSA) nanoparticles containing quercetin were developed by desolvation technique, characterized the mean particle size, polydispersity, zeta potential, encapsulation efficiency, physical state of drug in nanoparticles and drug release profile as well as their antioxidant activity was evaluated. The influence of glutaraldehyde percentage in nanoparticles properties was evaluated and did not influence the nanoparticles parameters. Nanoparticles presented a mean size around 130 nm and encapsulation efficiency around 85%. Results from X-ray diffractometry showed that the crystal of the drug was converted to an amorphous state in polymeric matrix. Quercetin release profile demonstrated a biphasic pattern and after 96 h approximately 18% of drug was released. Kinetic models demonstrated that the quercetin release followed a second-order model and the release was governed by Fickian diffusion. After 96 h, quercetin-loaded nanoparticles were more effective than free quercetin for scanvenger of radical ABTS + and hypochlorous acid. BSA nanoparticles represents potential carriers for improve quercetin properties. PMID:27433585

  15. Bovine Serum Albumin Nanoparticles Containing Quercetin: Characterization and Antioxidant Activity.

    PubMed

    Antônio, Emilli; Khalil, Najeh Maissar; Mainardes, Rubiana Mara

    2016-02-01

    Quercetin is a flavonoid reported as anti-allergic, anti-inflammatory, antiplatelet, anti-microbial, antioxidant, antineurodegenerative and antitumoral. However, due to its low water solubility, its efficacy is restricted. Nanotechnology can be an importante tool to improve the quercetin properties and increase its bioavailability. In this study, bovine serum albumin (BSA) nanoparticles containing quercetin were developed by desolvation technique, characterized the mean particle size, polydispersity, zeta potential, encapsulation efficiency, physical state of drug in nanoparticles and drug release profile as well as their antioxidant activity was evaluated. The influence of glutaraldehyde percentage in nanoparticles properties was evaluated and did not influence the nanoparticles parameters. Nanoparticles presented a mean size around 130 nm and encapsulation efficiency around 85%. Results from X-ray diffractometry showed that the crystal of the drug was converted to an amorphous state in polymeric matrix. Quercetin release profile demonstrated a biphasic pattern and after 96 h approximately 18% of drug was released. Kinetic models demonstrated that the quercetin release followed a second-order model and the release was governed by Fickian diffusion. After 96 h, quercetin-loaded nanoparticles were more effective than free quercetin for scanvenger of radical ABTS + and hypochlorous acid. BSA nanoparticles represents potential carriers for improve quercetin properties.

  16. Effect of geometry and scale for axial and radial flow membrane chromatography-Experimental study of bovin serum albumin adsorption.

    PubMed

    Teepakorn, Chalore; Fiaty, Koffi; Charcosset, Catherine

    2015-07-17

    During the last 10 years, membrane chromatography (MC) has been increasingly reported for biomolecule purification at both small and large scales. Although, several axial and radial flow MC devices are commercialized, the effect of the device dimensions on the adsorption performance has not been fully investigated. In this study, axial and radial flow anion ion-exchange MC devices were used for bovine serum albumin (BSA) adsorption. For both axial and radial flow, three devices at different scales were compared, two having similar diameter and two similar bed height. The pressure drop and the flow distribution using acetone as a non-binding solute were measured, as well as BSA breakthrough curves at different flow rates and BSA loading concentrations. For all devices, it was observed that the flow rate had no effect on the breakthrough curve, which confirms the advantage of MC to be used at high flow rates. In addition, the BSA binding capacity increased with increasing BSA concentration, which suggests that it could be preferable to work with concentrated solutions rather than with very dilute solutions, when using buffer at high phosphate concentration. For both axial and radial flow, the bed height had a negative impact on the binding capacity, as the lowest binding capacities per membrane volume were obtained with the devices having the highest bed height. Radial flow MC has potential at large-scale applications, as a short bed thickness can be combined with a large inlet surface area.

  17. 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.

  18. Bovine serum albumin-meloxicam nanoaggregates laden contact lenses for ophthalmic drug delivery in treatment of postcataract endophthalmitis.

    PubMed

    Zhang, Wenji; Zu, Dongni; Chen, Jianting; Peng, Junjie; Liu, Yun; Zhang, Hefeng; Li, Sanming; Pan, Weisan

    2014-11-20

    Postcataract endophthalmitis treatment through eye drops is of low corneal bioavailability and short residence time. The dominant NSAIDs therapy also suffers from severe ocular irritancy and low patients compliance. This study dispersed bovine serum albumin (BSA) coated meloxicam (MX) nanocrystals encapsulating nanoaggregates (BSA-MX-NA) in contact lenses to reduce drug ocular irritancy and increased drug release duration. The BSA-MX-NA (∼100 nm) were prepared using acid-base neutralization in aqueous solutions and were dispersed in poly(hydroxylethyl methacrylate) gels, which are common contact lens materials. Drug release studies showed that the gels released the drug for about 5 days. The proposed drug transport mechanism is a diffusion process which can be described by the Ritger-Peppas model with the diffusional exponent n of 0.4768. The drug release can be affected by the gel thickness and the cross-linking degree. A 400 micro thick gels with 100 μL cross-linker TEGDMA leads to an adequate meloxicam release for therapeutic application. The ocular irritation studies showed that BSA-MX-NA loaded p-HEMA gels are significantly less irritating to the ocular tissues as compared to marketed MX solutions. The developed contact lenses loaded with BSA-MX-NA could be very useful for extended delivery in postcataract endophthalmitis treatment.

  19. The influence of common metal ions on the interactions of the isoflavone genistein with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Singha Roy, Atanu; Tripathy, Debi Ranjan; Chatterjee, Angshuman; Dasgupta, Swagata

    2013-02-01

    The interaction of genistein with bovine serum albumin (BSA) has been characterized via UV-vis, fluorescence spectroscopy and Circular Dichroism (CD) measurements under physiological conditions. In this study, we have investigated the effect of some common metal ions on the binding of genistein with BSA using fluorescence studies. The fluorescence data reveal that the binding affinity of genistein to BSA increases in presence of certain metal ions. The possibility of non-radiative energy transition from the donor tryptophan to the acceptor genistein has been observed in absence and presence of metal ions. The observed similarities in the values of efficiency of energy transfer (E) and the separation between the donor and acceptor (r) in both the cases may be correlated with the complexation between the genistein and metal ions, which is also observed from the UV-vis studies. The changes in enthalpy (ΔH°) and entropy (ΔS°) of the interaction were found to be -14.64 kJ mol-1 and +42.75 J mol-1 K-1 respectively. These values indicate the involvement of electrostatic interactions along with a hydrophobic association that results in a positive entropy change. CD analysis shows that there is a slight increase in the% α-helical content of BSA on binding with genistein at lower molar ratios. Warfarin and ibuprofen displacement studies in accordance with the molecular docking show that genistein binds to site I (subdomain IIA) of BSA.

  20. Using resonance light scattering and UV/vis absorption spectroscopy to study the interaction between gliclazide and bovine serum albumin.

    PubMed

    Zhang, Qiu-Ju; Liu, Bao-Sheng; Li, Gai-Xia; Han, Rong

    2016-08-01

    At different temperatures (298, 310 and 318 K), the interaction between gliclazide and bovine serum albumin (BSA) was investigated using fluorescence quenching spectroscopy, resonance light scattering spectroscopy and UV/vis absorption spectroscopy. The first method studied changes in the fluorescence of BSA on addition of gliclazide, and the latter two methods studied the spectral change in gliclazide while BSA was being added. The results indicated that the quenching mechanism between BSA and gliclazide was static. The binding constant (Ka ), number of binding sites (n), thermodynamic parameters, binding forces and Hill's coefficient were calculated at three temperatures. Values for the binding constant obtained using resonance light scattering and UV/vis absorption spectroscopy were much greater than those obtained from fluorescence quenching spectroscopy, indicating that methods monitoring gliclazide were more accurate and reasonable. In addition, the results suggest that other residues are involved in the reaction and the mode 'point to surface' existed in the interaction between BSA and gliclazide. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Study on the interaction between 21-(Ph-Ndbnd N)-NCTPP and bovine serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    The interaction between 21-(Ph-Ndbnd N)-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-Ndbnd N)-NCTPP. The binding constants (Ka) and the binding sites (n) were obtained at three different temperatures (298, 304, and 310 K). 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-Ndbnd N)-NCTPP]-BSA binding process. Based on the Förster non-radiation energy transfer theory, the binding distance from 21-(Ph-Ndbnd N)-NCTPP to BSA was estimated to be about 3.51 nm. What's more, the synchronous fluorescence spectra indicated that the conformation of BSA has not been changed.

  2. Studying the denaturation of bovine serum albumin by a novel approach of difference-UV analysis.

    PubMed

    Nikolaidis, Athanasios; Moschakis, Thomas

    2017-01-15

    A novel approach in the analysis of difference-UV spectrophotometric data for determining the heat denaturation degree of bovine serum albumin (BSA) was assessed. Five different parameters of difference-UV spectra were obtained by subtracting spectra of unheated and denatured protein solutions at different temperature-time combinations. BSA was found to exhibit a maximum degree of heat denaturation of about 17% compared to the complete unfolding caused by 6M guanidine hydrochloride. This low degree of heat denaturation is probably caused by the aggregation of the initially unfolded protein molecules. The kinetic analysis exhibited discontinuities in the Arrhenius plots, distinguishing the unfolding and aggregation phases of the denaturation process, whereas such a discrimination could not be obtained by differential scanning calorimetry analyses. The proposed method is accurate, fast, simple and sensitive enough to detect changes in the protein heat denaturation even at short temperature-time intervals. PMID:27542472

  3. Experimental immune complex glomerulonephritis and the nephrotic syndrome in cats immunised with cationised bovine serum albumin.

    PubMed

    Nash, A S; Mohammed, N A; Wright, N G

    1990-11-01

    Membranous nephropathy was induced in four cats by repeated intravenous injections of 120 mg cationic bovine serum albumin (BSA, pI 9.5). All four cats developed diffuse granular deposits of IgG and C3 along the glomerular capillary walls as early as five weeks which persisted until the end of the experiment at 17 weeks. Ultrastructural studies revealed many subepithelial electron dense deposits. Two cats developed severe proteinuria and the nephrotic syndrome characterised by hypoalbuminaemia and oedema. An additional four cats received repeated injections of unmodified native BSA (pI 4.5) and remained basically normal. This is the first report of membranous nephropathy and the nephrotic syndrome in an experimental animal model which, unlike other animal models, is subject to the spontaneously occurring disease. PMID:2148430

  4. The complexity of condensed tannin binding to bovine serum albumin--An isothermal titration calorimetry study.

    PubMed

    Kilmister, Rachel L; Faulkner, Peta; Downey, Mark O; Darby, Samuel J; Falconer, Robert J

    2016-01-01

    Isothermal titration calorimetry was applied to study the binding of purified proanthocyanidin oligomers to bovine serum albumin (BSA). The molecular weight of the proanthocyanidin oligomer had a major impact on its binding to BSA. The calculated change in enthalpy (ΔH) and association constant (Ka) became greater as the oligomer size increased then plateaued at the heptameric oligomer. These results support a model for precipitation of proteins by proanthocyanidin where increased oligomer size enhanced the opportunity for cross linkages between proteins ultimately forming sediment-able complexes. The authors suggest tannin binding to proteins is opportunistic and involves multiple sites, each with a different Ka and ΔH of binding. The ΔH of binding comprises both an endothermic hydrophobic interaction and exothermic hydrogen bond component. This suggests the calculated entropy value (ΔS) for tannin-protein interactions is subject to a systematic error and should be interpreted with caution.

  5. Synthesis of gold nanorods and their functionalization with bovine serum albumin for optical hyperthermia.

    PubMed

    Zhang, Liming; Xia, Kai; Bai, Ying-Ying; Tang, Yongjun; Deng, Yan; Chen, Juan; Qian, Weiping; Shen, He; Zhang, Zhijun; Ju, Shenghong; He, Nongyue

    2014-08-01

    Although gold nanorods (GNRs) have been investigated extensively for optical hyperthermia therapies, the synthesis of rods is far from ideal. In this report, we optimized the synthesis of gold nanorods using hydroquinone as a reducing agent. Compared with the GNRs prepared by traditional ways, the as-synthesized rods have a flexibly tunable size and wider range of longitudinal surface plasmon resonance (LSPR). Furthermore, a series of small-length gold nanorods with length ranging from 30 to 90 nm were synthesized and they are more suitable for in vivo biomedical applications. Finally, we exploited a convenient approach for preparing water-soluble GNRs with less toxicity, better dispersion and flexible functionalization by exchanging hexadecyltrimethylammonium bromide (CTAB) on the surface of the rods with carboxylated bovine serum albumin (BSA) derivative, the BSA modified GNRs showed significant anticancer efficacy through near infrared (NIR) hyperthermia. We believe that the as-prepared gold nanorods will find promising applications in biomedical fields, especially in cancer therapy.

  6. Insights into the interactions between tetracycline, its degradation products and bovine serum albumin.

    PubMed

    Tong, Xingyu; Mao, Manfei; Xie, Jingqian; Zhang, Kefeng; Xu, Dongmei

    2016-01-01

    Tetracyclines (TCs) are the most widely used antibiotics in the world. Because antibiotics have low bioavailability and are difficult to completely remove using current sewage treatment facilities, residual TCs and their degradation products in the environment, animal and plant foodstuffs and personal care products may enter the body through the food chain, thus causing unpredictable effects on human health. We studied bovine serum albumin (BSA) (a functional protein) as a target of tetracycline-induced toxicity by examining its interactions with TC, anhydrotetracycline (ATC) and epitetracycline (ETC), based on a fluorescence spectroscopy and molecular docking method under simulated physiological conditions. The interaction mechanism was elucidated at the molecular level. The results show that TC, ATC and ETC bind at site II of BSA and interact mainly through hydrogen bonding interactions and van der Waals interactions. The binding affinities can be ranked in the order ATC > TC > ETC. PMID:27462521

  7. Enzymic and immunochemical properties of lysozyme. X. Conformation, enzymic activity and immunochemistry of lysozyme reduced at two carboxyl groups.

    PubMed

    Atassi, M Z; Suliman, A M; Habeeb, A F

    1975-10-20

    Reduction of lysozyme by diborane, followed by air oxidation of the reduced disulfides and chromatography on CM-cellulose, yielded a homogeneous derivative. In the derivative, the carboxyl groups of aspartic acid 119 and the end-chain leucine residue were reduced to their corresponding alcohols. Correct re-forming of the disulfide bonds was demonstrated by peptide mapping of the tryptic hydrolysates of the derivative and lysozyme without breaking the disulfide bonds, followed by identification of the disulfide-containing peptides. Correct disulfide pairing in the two-disulfide peptide in the tryptic hydrolysate was established from its immunochemical behavior. Preparations of the two-disulfide fragment from lysozyme and derivative had equal inhibitory activities (26 or 32%) of the reaction of lysozyme with two homologous antisera. In ORD measurements, lysozyme and the derivative had equal rotatory powers at neutral pH. However, the bo value for the derivative decreased by about 10%. Below pH 6.4 and above pH 8.0, the derivative was less rotatory than native lysozyme. In CD measurements at neutral pH, the negative ellipticity bands at 220 and 208 nm showed little or no decrease in the derivative relative to the native protein. Although conformational differences between the derivative and its parent protein were almost undetectable by ORD and CD measurements, they were readily detected by chemical monitoring of the conformation. In the derivative, both accessibility to tryptic hydrolysis and reducibility of the disulfide bonds increased markedly. The enzymic activity of the derivative was decreased but retained the same pH optimum. With antisera to lysozyme or antisera to the derivative, lysozyme and its derivative possessed equal antigenic reactivities. The immunochemical findings further confirm the correct refolding of the disulfides. Also, they indicate that aspartic acid 119 and the C-terminal leucine residue are not part of an antigenic reactive region in

  8. Enhanced extraction of bovine serum albumin with aqueous biphasic systems of phosphonium- and ammonium-based ionic liquids

    PubMed Central

    Pereira, Matheus M.; Pedro, Sónia N.; Quental, Maria V.; Lima, Álvaro S.; Coutinho, João A. P.; Freire, Mara G.

    2016-01-01

    Novel aqueous biphasic systems (ABS) composed of phosphonium- or ammonium-based ionic liquids (ILs), combined with a buffered aqueous solution of potassium citrate/citric acid (pH=7.0), were investigated for the extraction of proteins. For that purpose, the phase diagrams, tie-lines and tie-line lengths were determined at 25ºC, and the performance of these ABS for the extraction of bovine serum albumin (BSA) was then evaluated. The obtained results reveal that, with the exception of the more hydrophobic ILs, most of the systems investigated allow the complete extraction of BSA for the IL-rich phase in a single-step. These remarkable extraction efficiencies are far superior to those afforded by more conventional extraction systems previously reported. The composition of the biphasic systems, i.e., the amount of phase-forming components, was also investigated aiming at reducing the overall costs of the process without losing efficiency on the protein extraction. It is shown that the extraction efficiencies of BSA are maintained at 100% up to high protein concentrations (at least up to 10 g.L-1). The recovery of the BSA from the IL-rich phase by dialysis is also shown in addition to the demonstration of the IL recyclability and reusability, at least for 3 times. In the sequential three-step extractions (BSA recovery/IL reusability), the extraction efficiencies of BSA for the IL-rich phase were maintained at 100%. For the improved ABS, the preservation of the protein native conformation was confirmed by Size Exclusion High-Performance Liquid Chromatography (used also as the quantification method) and by Fourier Transform Infra-Red spectroscopy. According to the results herein reported, ABS composed of phosphonium- or ammonium-based ILs and a biodegradable organic salt represent an alternative and remarkable platform for the extraction of BSA and may be extended to other proteins of interest. PMID:25865275

  9. Enhanced extraction of bovine serum albumin with aqueous biphasic systems of phosphonium- and ammonium-based ionic liquids.

    PubMed

    Pereira, Matheus M; Pedro, Sónia N; Quental, Maria V; Lima, Álvaro S; Coutinho, João A P; Freire, Mara G

    2015-07-20

    Novel aqueous biphasic systems (ABS) composed of phosphonium- or ammonium-based ionic liquids (ILs), combined with a buffered aqueous solution of potassium citrate/citric acid (pH=7.0), were investigated for the extraction of proteins. For that purpose, the phase diagrams, tie-lines and tie-line lengths were determined at 25 °C, and the performance of these ABS for the extraction of bovine serum albumin (BSA) was then evaluated. The obtained results reveal that, with the exception of the more hydrophobic ILs, most of the systems investigated allow the complete extraction of BSA for the IL-rich phase in a single-step. These remarkable extraction efficiencies are far superior to those afforded by more conventional extraction systems previously reported. The composition of the biphasic systems, i.e., the amount of phase-forming components, was also investigated aiming at reducing the overall costs of the process without losing efficiency on the protein extraction. It is shown that the extraction efficiencies of BSA are maintained at 100% up to high protein concentrations (at least up to 10 g L(-1)). The recovery of the BSA from the IL-rich phase by dialysis is also shown in addition to the demonstration of the IL recyclability and reusability, at least for 3 times. In the sequential three-step extractions (BSA recovery/IL reusability), the extraction efficiencies of BSA for the IL-rich phase were maintained at 100%. For the improved ABS, the preservation of the protein native conformation was confirmed by Size Exclusion High-Performance Liquid Chromatography (used also as the quantification method) and by Fourier Transform Infra-Red spectroscopy. According to the results herein reported, ABS composed of phosphonium- or ammonium-based ILs and a biodegradable organic salt represent an alternative and remarkable platform for the extraction of BSA and may be extended to other proteins of interest. PMID:25865275

  10. Albumin-Mediated Biomineralization of Paramagnetic NIR Ag2S QDs for Tiny Tumor Bimodal Targeted Imaging in Vivo.

    PubMed

    Zhang, Jing; Hao, Guangyu; Yao, Chenfei; Yu, Jiani; Wang, Jun; Yang, Weitao; Hu, Chunhong; Zhang, Bingbo

    2016-07-01

    Bimodal imaging has captured increasing interests due to its complementary characteristics of two kinds of imaging modalities. Among the various dual-modal imaging techniques, MR/fluorescence imaging has been widely studied owing to its high 3D resolution and sensitivity. There is, however, still a strong demand to construct biocompatible MR/fluorescence contrast agents with near-infrared (NIR) fluorescent emissions and high relaxivities. In this study, BSA-DTPA(Gd) derived from bovine serum albumin (BSA) as a novel kind of biotemplate is employed for biomineralization of paramagnetic NIR Ag2S quantum dots (denoted as Ag2S@BSA-DTPA(Gd) pQDs). This synthetic strategy is found to be bioinspired, environmentally benign, and straightforward. The obtained Ag2S@BSA-DTPA(Gd) pQDs have fine sizes (ca. 6 nm) and good colloidal stability. They exhibit unabated NIR fluorescent emission (ca. 790 nm) as well as high longitudinal relaxivity (r1 = 12.6 mM(-1) s(-1)) compared to that of commercial Magnevist (r1 = 3.13 mM(-1) s(-1)). In vivo tumor-bearing MR and fluorescence imaging both demonstrate that Ag2S@BSA-DTPA(Gd) pQDs have pronounced tiny tumor targeting capability. In vitro and in vivo toxicity study show Ag2S@BSA-DTPA(Gd) pQDs are biocompatible. Also, biodistribution analysis indicates they can be cleared from body mainly via liver metabolism. This protein-mediated biomineralized Ag2S@BSA-DTPA(Gd) pQDs presents great potential as a novel bimodal imaging contrast agent for tiny tumor diagnosis. PMID:27300300

  11. Comprehensive study on the structure of the BSA from extended-to aged form in wide (2-12) pH range.

    PubMed

    Varga, N; Hornok, V; Sebők, D; Dékány, I

    2016-07-01

    In this work we studied the structure of the bovine serum albumin (BSA) and the protein-ligand interactions since researchers prefer to use them as carriers in drug delivery systems. Systematic study (between pH 2-12, in double distilled water and physiological salt solution) was carried out to determine the changes in the secondary and the tertiary structures of the BSA, the apparent molecular weight (Mw), the size (dLS) and the electrokinetic potential (ζ). At pH 7, the BSA has higher stability in the absence (ζ=-69mV, dLS=2.2nm, A2=1.4×10(-3)mlmol/g(2)) than in the presence of salt solution (ζ=-2.4mV, dLS=5.3nm, A2=-3.2×10(-4)mlmol/g(2)). The Mw strongly depends on the pH and the ionic strength (at pH 3 in the absence of salt, the Mw is 54.6kDa while in the presence of salt is 114kDa) which determines the geometry of the protein. The protein-ligand interactions were characterized by fluorescence (FL) and isothermal microcalorimetry (ITC) methods; these independent techniques provided similar thermodynamic parameters such as the binding constant (K) and the Gibbs free energy (ΔG). PMID:26995614

  12. Comprehensive study on the structure of the BSA from extended-to aged form in wide (2-12) pH range.

    PubMed

    Varga, N; Hornok, V; Sebők, D; Dékány, I

    2016-07-01

    In this work we studied the structure of the bovine serum albumin (BSA) and the protein-ligand interactions since researchers prefer to use them as carriers in drug delivery systems. Systematic study (between pH 2-12, in double distilled water and physiological salt solution) was carried out to determine the changes in the secondary and the tertiary structures of the BSA, the apparent molecular weight (Mw), the size (dLS) and the electrokinetic potential (ζ). At pH 7, the BSA has higher stability in the absence (ζ=-69mV, dLS=2.2nm, A2=1.4×10(-3)mlmol/g(2)) than in the presence of salt solution (ζ=-2.4mV, dLS=5.3nm, A2=-3.2×10(-4)mlmol/g(2)). The Mw strongly depends on the pH and the ionic strength (at pH 3 in the absence of salt, the Mw is 54.6kDa while in the presence of salt is 114kDa) which determines the geometry of the protein. The protein-ligand interactions were characterized by fluorescence (FL) and isothermal microcalorimetry (ITC) methods; these independent techniques provided similar thermodynamic parameters such as the binding constant (K) and the Gibbs free energy (ΔG).

  13. Preparation, characterization and in vitro release study of BSA-loaded double-walled glucose-poly(lactide-co-glycolide) microspheres.

    PubMed

    Ansary, Rezaul H; Rahman, Mokhlesur M; Awang, Mohamed B; Katas, Haliza; Hadi, Hazrina; Mohamed, Farahidah; Doolaanea, Abd Almonem; Kamaruzzaman, Yunus B

    2016-09-01

    The aim of this study was to prepare a model protein, bovine serum albumin (BSA) loaded double-walled microspheres using a fast degrading glucose core, hydroxyl-terminated poly(lactide-co-glycolide) (Glu-PLGA) and a moderate-degrading carboxyl-terminated PLGA polymers to reduce the initial burst release and to eliminate the lag phase from the release profile of PLGA microspheres. The double-walled microspheres were prepared using a modified water-in-oil-in-oil-in-water (w/o/o/w) method and single-polymer microspheres were prepared using a conventional water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The particle size, morphology, encapsulation efficiency, thermal properties, in vitro drug release and structural integrity of BSA were evaluated in this study. Double-walled microspheres prepared with Glu-PLGA and PLGA polymers with a mass ratio of 1:1 were non-porous, smooth-surfaced, and spherical in shape. A significant reduction of initial burst release was achieved for the double-walled microspheres compared to single-polymer microspheres. In addition, microspheres prepared using Glu-PLGA and PLGA polymers in a mass ratio of 1:1 exhibited continuous BSA release after the small initial burst without any lag phase. It can be concluded that the double-walled microspheres made of Glu-PLGA and PLGA polymers in a mass ratio of 1:1 can be a potential delivery system for pharmaceutical proteins.

  14. Influence of metal ions on phosphatidylcholine bovine serum albumin model membrane, an FTIR study

    NASA Astrophysics Data System (ADS)

    Wang, Fan; Yang, Zhanlan; Zhou, Yong; Weng, Shifu; Zhang, Li; Wu, Jinguang

    2006-08-01

    FTIR spectroscopy was used to study the interaction of K +, Ca 2+ and Eu 3+ ions and the Phosphatidylcholine (PC)-bovine serum albumin (BSA) complex. First, a PC-BSA interaction system was constructed. The analytical results of transmission electron microscope (TEM), quasi-elastic light scattering (QELS) techniques and FTIR-ATR spectroscopy indicated that PC molecules interacted with BSA in aqueous solutions. However, IR inspection was limited for aqueous solutions. Solid experimental condition was then employed, and FTIR spectra showed that the PC and BSA molecules incorporated with each other, which could represent their interactions in solutions. Then, the influence of metal ions on PC-BSA system was studied in solid experimental conditions, and FTIR spectroscopy was used in this study. The spectral results showed that: (1) K +, Ca 2+ and Eu 3+ ions all decreased the rigidities of acyl chains of PC in PC-BSA systems. (2) The interactions between Ca 2+, Eu 3+ ions and the hydrophilic phosphate ester and carbonyl ester groups of PC were stronger than that of K + ions, while the influent modes of Ca 2+ and Eu 3+ ions on these regions were different. (3) When the relative molar content of Eu 3+ ions to PC ( Ri/p) reached 2, the coordination effect between Eu 3+ ions and PO2- groups of PC was saturated. (4) The addition of these ions increased the content of α-helix structures of BSA, and decreased the content of β-turn structures. By comparing these results with the interactions of K +, Ca 2+, Eu 3+ ions with phospholipid system in the absence of protein, some special characters were discovered in the acyl regions of PC, while their interactions results with the hydrophilic regions of PC were alike. It might be interpreted that these metal ions influenced the acyl chains of PC mediated from BSA molecules, and coordinated directly with the hydrophilic regions of PC. As for biological membrane was a system included both phospholipid and proteins, these characters

  15. NO forms an adduct with serum albumin that has endothelium-derived relaxing factor-like properties.

    PubMed Central

    Keaney, J F; Simon, D I; Stamler, J S; Jaraki, O; Scharfstein, J; Vita, J A; Loscalzo, J

    1993-01-01

    Recent evidence suggests that sulfhydryl species can react with oxides of nitrogen under physiologic conditions and thereby stabilize endothelium-derived relaxing factor (EDRF) activity, but the presence of a specific in vivo thiol carrier for nitric oxide (NO) remains controversial. The single free sulfhydryl of serum albumin is the most abundant thiol species in plasma (approximately 0.5 mM) and is particularly reactive towards NO. To examine the potential role of serum albumin in endogenous nitric oxide metabolism, we synthesized S-nitroso-BSA (S-NO-BSA), a model S-nitroso-protein, and examined its effects on platelet function and coronary and systemic vascular tone in 16 mongrel dogs. Intravenous bolus S-NO-BSA markedly reduced mean arterial pressure in a dose-dependent manner and proved seven and a half-fold less potent than intravenous nitroglycerin and 10-fold less potent than intravenous S-nitroso-cysteine (half-maximal response of 75 nmol/kg compared to 10 and 7.5 nmol/kg, respectively; P < 0.05); when given by intravenous infusion (half-maximal response = 10 nmol/kg per min), however, S-NO-BSA and nitroglycerin were equipotent. Intravenous bolus S-NO-BSA had a greater duration of action than either nitroglycerin or S-nitroso-cysteine and produced marked prolongation of the template bleeding time associated with dose-dependent inhibition of ex vivo platelet aggregation (half-maximal response approximately 70 nmol/kg). Intracoronary S-NO-BSA increased coronary blood flow (mean +/- SEM) less effectively than nitroprusside, acetylcholine, or S-nitroso-cysteine (165% +/- 24% vs. 315% +/- 82%, 483% +/- 55%, or 475% +/- 66%, respectively; P < 0.05) although with much longer duration of action. On a molar basis, S-nitroso-cysteine proved more effective than S-nitroso-BSA, nitroprusside, or acetylcholine as an epicardial coronary vasodilator. Thus, serum albumin reacts with oxides of nitrogen to form a stable S-nitroso-thiol with properties reminiscent of

  16. The conformation of serum albumin in solution: a combined phosphorescence depolarization-hydrodynamic modeling study.

    PubMed Central

    Ferrer, M L; Duchowicz, R; Carrasco, B; de la Torre, J G; Acuña, A U

    2001-01-01

    There is a striking disparity between the heart-shaped structure of human serum albumin (HSA) observed in single crystals and the elongated ellipsoid model used for decades to interpret the protein solution hydrodynamics at neutral pH. These two contrasting views could be reconciled if the protein were flexible enough to change its conformation in solution from that found in the crystal. To investigate this possibility we recorded the rotational motions in real time of an erythrosin-bovine serum albumin complex (Er-BSA) over an extended time range, using phosphorescence depolarization techniques. These measurements are consistent with the absence of independent motions of large protein segments in solution, in the time range from nanoseconds to fractions of milliseconds, and give a single rotational correlation time phi(BSA, 1 cP, 20 degrees C) = 40 +/- 2 ns. In addition, we report a detailed analysis of the protein hydrodynamics based on two bead-modeling methods. In the first, BSA was modeled as a triangular prismatic shell with optimized dimensions of 84 x 84 x 84 x 31.5 A, whereas in the second, the atomic-level structure of HSA obtained from crystallographic data was used to build a much more refined rough-shell model. In both cases, the predicted and experimental rotational diffusion rate and other hydrodynamic parameters were in good agreement. Therefore, the overall conformation in neutral solution of BSA, as of HSA, should be rigid, in the sense indicated above, and very similar to the heart-shaped structure observed in HSA crystals. PMID:11325741

  17. Preferential binding of fisetin to the native state of bovine serum albumin: spectroscopic and docking studies.

    PubMed

    Singha Roy, Atanu; Pandey, Nitin Kumar; Dasgupta, Swagata

    2013-04-01

    We have investigated the binding of the biologically important flavonoid fisetin with the carrier protein bovine serum albumin using multi-spectroscopic and molecular docking methods. The binding constants were found to be in the order of 10(4) M(-1) and the number of binding sites was determined as one. MALDI-TOF analyses showed that one fisetin molecule binds to a single bovine serum albumin (BSA) molecule which is also supported by fluorescence quenching studies. The negative Gibbs free energy change (∆G°) values point to a spontaneous binding process which occurs through the presence of electrostatic forces with hydrophobic association that results in a positive entropy change (+51.69 ± 1.18 J mol(-1) K(-1)). The unfolding and refolding of BSA in urea have been studied in absence and presence of fisetin using steady-state fluorescence and lifetime measurements. Urea denaturation studies indicate that fisetin is gradually released from its binding site on the protein. In the absence of urea, an increase in temperature that causes denaturation of the protein results in the release of fisetin from its bound state indicating that fisetin binds only to the native state of the protein. The circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopic studies showed an increase in % α-helix content of BSA after binding with fisetin. Site marker displacement studies in accordance with the molecular docking results suggested that fisetin binds in close proximity of the hydrophobic cavity in site 1 (subdomain IIA) of the protein. The PEARLS (Program of Energetic Analysis of Receptor Ligand System) has been used to estimate the interaction energy of fisetin with BSA and the results are in good correlation with the experimental findings.

  18. Molecular dynamics simulations of lysozyme in water/sugar solutions

    NASA Astrophysics Data System (ADS)

    Lerbret, A.; Affouard, F.; Bordat, P.; Hédoux, A.; Guinet, Y.; Descamps, M.

    2008-04-01

    Structural and dynamical properties of the solvent at the protein/solvent interface have been investigated by molecular dynamics simulations of lysozyme in trehalose, maltose and sucrose solutions. Results are discussed in the framework of the bioprotection phenomena. The analysis of the relative concentration of water oxygen atoms around lysozyme suggests that lysozyme is preferentially hydrated. When comparing the three sugars, trehalose is seen more excluded than maltose and sucrose. The preferential exclusion of sugars from the protein surface induces some differences in the behavior of trehalose and maltose, particularly at 50 and 60 wt% concentrations, that are not observed experimentally in binary sugar/mixtures. The dynamical slowing down of the solvent is suggested to mainly arise from the homogeneity of the water/sugar matrices controlled by the percolation of the sugar hydrogen bonds networks. Furthermore, lysozyme strongly increases relaxation times of solvent molecules at the protein/solvent interface.

  19. Effect of Lysozyme on Resting Spores of Bacillus Megaterium

    PubMed Central

    Suzuki, Yahiko; Rode, L. J.

    1969-01-01

    Resting spores of Bacillus megaterium ATCC 9885 were found to be markedly affected by lysozyme. Exposure to as little as 1.5 μg of lysozyme per ml caused the spores to lose refractility, the darkened spores to shed their coat structures, and the spore central bodies to lyse. The spores of seven other strains of B. megaterium and seven other Bacillus species were not similarly affected by lysozyme. Proteolytic enzymes such as pronase, trypsin, pepsin, and subtilisin did not induce the change. The action of lysozyme differed in certain important respects from that of common “physiological” germinants. Its action was considered to be direct via its enzymatic attack on exposed sites directly accessible in the resting spores of B. megaterium ATCC 9885. Images PMID:4977688

  20. Location of Bromide Ions in Tetragonal Lysozyme Crystals

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

    1998-01-01

    Anions have been shown to play a dominant role in the crystallization of chicken egg white lysozyme from salt solutions. Previous studies employing X-ray crystallography had found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystal grown in bromide and chloride solutions. Five possible anion binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four of these sites corresponded to four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion binding sites in lysozyme remain unchanged, even when different anions and different crystal forms of lysozyme are employed.

  1. A spectroscopic study on interaction between bovine serum albumin and titanium dioxide nanoparticle synthesized from microwave-assisted hybrid chemical approach.

    PubMed

    Ranjan, Shivendu; Dasgupta, Nandita; Srivastava, Priyanka; Ramalingam, Chidambaram

    2016-08-01

    The use of nanoparticles in food or pharma requires a molecular-level perceptive of how NPs interact with protein corona once exposed to a physiological environment. In this study, the conformational changes of bovine serum albumin (BSA) were investigated in detail when exposed to different concentration of titanium dioxide nanoparticle by various techniques. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin and titanium dioxide nanoparticles at different concentrations were investigated. The interaction, BSA conformations, kinetics, and adsorption were analyzed by dynamic light scattering, Fourier transform infrared spectroscopy and fluorescence quenching. Dynamic light scattering analysis confirms the interaction with major changes in the size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.1 molecules of serum albumin to titanium dioxide nanoparticles. Further, pseudo-second order kinetics was determined with equilibrium contact time of 20min. The spectroscopic analysi