Showing papers on "Bovine serum albumin published in 2012"
TL;DR: The crystal structures of serum albumins isolated from bovine, equine and leporine blood plasma revealed different amino-acid compositions and conformations in comparison to HSA in some cases; however, much more significant differences were observed on the surface of the molecules.
Abstract: Serum albumin first appeared in early vertebrates and is present in the plasma of all mammals. Its canonical structure supported by a conserved set of disulfide bridges is maintained in all mammalian serum albumins and any changes in sequence are highly correlated with evolution of the species. Previous structural investigations of mammalian serum albumins have only concentrated on human serum albumin (HSA), most likely as a consequence of crystallization and diffraction difficulties. Here, the crystal structures of serum albumins isolated from bovine, equine and leporine blood plasma are reported. The structure of bovine serum albumin (BSA) was determined at 2.47 A resolution, two crystal structures of equine serum albumin (ESA) were determined at resolutions of 2.32 and 2.04 A, and that of leporine serum albumin (LSA) was determined at 2.27 A resolution. These structures were compared in detail with the structure of HSA. The ligand-binding pockets in BSA, ESA and LSA revealed different amino-acid compositions and conformations in comparison to HSA in some cases; however, much more significant differences were observed on the surface of the molecules. BSA, which is one of the most extensively utilized proteins in laboratory practice and is used as an HSA substitute in many experiments, exhibits only 75.8% identity compared with HSA. The higher resolution crystal structure of ESA highlights the binding properties of this protein because it includes several bound compounds from the crystallization solution that provide additional structural information about potential ligand-binding pockets.
587 citations
TL;DR: The optical trapping of a single bovine serum albumin (BSA) molecule that has a hydrodynamic radius of 3.4 nm is experimentally demonstrated using a double-nanohole in an Au film, which shows that the setup is extremely sensitive to detect the presence of a protein, even at the single molecule level.
Abstract: We experimentally demonstrate the optical trapping of a single bovine serum albumin (BSA) molecule that has a hydrodynamic radius of 3.4 nm, using a double-nanohole in an Au film. The strong optical force in the trap not only stably traps the protein molecule but also unfolds it. The unfolding of the BSA is confirmed by experiments with changing optical power and with changing solution pH. The detection of the trapping event has a signal-to-noise ratio of 33, which shows that the setup is extremely sensitive to detect the presence of a protein, even at the single molecule level.
430 citations
TL;DR: The displacement experiment shows that these Pt complexes can bind to the subdomain IIA (site I) of albumin, and synchronous fluorescence spectroscopy studies revealed some changes in the local polarity around the tryptophan residues.
Abstract: The interactions of two organoplatinum complexes, [Pt(C^N)Cl(dppa)], 1, and [Pt(C^N)Cl(dppm)], 2 (C^N = N(1), C(2')-chelated, deprotonated 2-phenylpyridine, dppa = bis(diphenylphosphino)amine, dppm = bis(diphenylphosphino)methane), as antitumor agents, with bovine serum albumin (BSA) and human serum albumin (HSA) have been studied by fluorescence and UV-vis absorption spectroscopic techniques at pH 7.40. The quenching constants and binding parameters (binding constants and number of binding sites) were determined by fluorescence quenching method. The obtained results revealed that there is a strong binding interaction between the ligands and proteins. The calculated thermodynamic parameters (ΔG, ΔH, and ΔS) confirmed that the binding reaction is mainly entropy-driven, and hydrophobic forces played a major role in the reaction. The displacement experiment shows that these Pt complexes can bind to the subdomain IIA (site I) of albumin. Moreover, synchronous fluorescence spectroscopy studies revealed some changes in the local polarity around the tryptophan residues. Finally, the distance, r, between donor (serum albumin) and acceptor (Pt complexes) was obtained according to Forster theory of nonradiation energy transfer.
275 citations
TL;DR: The data reveal that the polyphenol structures significantly affect the binding process: the binding affinity generally decreases with glycosylation and reduced numbers of hydroxyl groups on the second aromatic ring.
211 citations
TL;DR: 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).
Abstract: 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 Cu2+ 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 Cu2+ 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 Cu2+ is discussed.
195 citations
TL;DR: Docking studies showed the participation of several amino acids in drug-protein complexation, which stabilized by H-bonding systems, which altered protein conformation by a major reduction of α-helix and inducing a partial protein destabilization.
Abstract: We located the binding sites of doxorubicin (DOX) and N-(trifluoroacetyl) doxorubicin (FDOX) with bovine serum albumin (BSA) and human serum albumins (HSA) at physiological conditions, using constant protein concentration and various drug contents. FTIR, CD and fluorescence spectroscopic methods as well as molecular modeling were used to analyse drug binding sites, the binding constant and the effect of drug complexation on BSA and HSA stability and conformations. Structural analysis showed that doxorubicin and N-(trifluoroacetyl) doxorubicin bind strongly to BSA and HSA via hydrophilic and hydrophobic contacts with overall binding constants of K(DOX-BSA) = 7.8 (± 0.7) × 10(3) M(-1), K(FDOX-BSA) = 4.8 (± 0.5)× 10(3) M(-1) and K(DOX-HSA) = 1.1 (± 0.3)× 10(4) M(-1), K(FDOX-HSA) = 8.3 (± 0.6)× 10(3) M(-1). The number of bound drug molecules per protein is 1.5 (DOX-BSA), 1.3 (FDOX-BSA) 1.5 (DOX-HSA), 0.9 (FDOX-HSA) in these drug-protein complexes. Docking studies showed the participation of several amino acids in drug-protein complexation, which stabilized by H-bonding systems. The order of drug-protein binding is DOX-HSA > FDOX-HSA > DOX-BSA > FDOX>BSA. Drug complexation alters protein conformation by a major reduction of α-helix from 63% (free BSA) to 47-44% (drug-complex) and 57% (free HSA) to 51-40% (drug-complex) inducing a partial protein destabilization. Doxorubicin and its derivative can be transported by BSA and HSA in vitro.
176 citations
TL;DR: Fluorescent carbon dots are prepared directly via a simple hydrothermal method using bovine serum albumin as a carbon source in the presence of surface passivation reagents, demonstrating that their features are good for application in cell imaging.
Abstract: Fluorescent carbon dots (C-dots) are prepared directly via a simple hydrothermal method using bovine serum albumin (BSA) as a carbon source in the presence of surface passivation reagents. The obtained C-dots have low cytotoxicity and good biocompatibility, demonstrating that their features are good for application in cell imaging.
168 citations
TL;DR: The fluorescence spectra revealed that CPF causes the quenching of the fluorescence emission of serum albumin, and the alterations of protein secondary structure in the presence of CPF were confirmed by the evidences from UV and CD spectra.
Abstract: Chlorpyrifos (CPF) is a widely used organophosphate insecticide which could bind with human serum albumin (HSA) and bovine serum albumin (BSA). The binding behavior was studied employing fluorescence, three-dimensional fluorescence, Circular dichroism (CD) spectroscopy, UV-vis absorption spectroscopy, electrochemistry and molecular modeling methods. The fluorescence spectra revealed that CPF causes the quenching of the fluorescence emission of serum albumin. Stern-Volmer plots were made and quenching constants were thus obtained. The results suggested the formation of the complexes of CPF with serum albumins, which were in good agreement with the results from electrochemical experiments. Association constants at 25°C were 3.039 × 10(5) mol L(-1) for HSA, and 0.3307 × 10(5) mol L(-1) for BSA, which could affect the distribution, metabolism, and excretion of pesticide. The alterations of protein secondary structure in the presence of CPF were confirmed by the evidences from UV and CD spectra. Site competitive experiments also suggested that the primary binding site for CPF on serum albumin is close to tryptophan residues 214 of HSA and 212 of BSA, which was further confirmed by molecular modeling.
165 citations
TL;DR: Some of the important physiochemical aspects needed for an appropriate synthesis of BSA-conjugated NPs where unfolded BSA is an essential reaction component are shown.
Abstract: Bovine serum albumin (BSA) conjugated gold (Au) nanoparticles (NPs) were synthesized to explore their applications as drug delivery vehicles in systemic circulation. They showed little hemolysis and cytotoxic responses essentially required for such applications. This study shows some of the important physiochemical aspects needed for an appropriate synthesis of BSA-conjugated NPs where unfolded BSA is an essential reaction component. Unfolding of BSA was carried out under different experimental conditions in the presence of different ionic/zwitterionic surfactants and monitored simultaneously by UV–visible studies. Cationic surfactants induced unfolding at relatively lower temperatures than anionic and zwitterionic surfactants due to stronger electrostatic interactions with BSA. TEM analysis revealed the presence of NPs with almost similar shapes and sizes for different samples, and all NPs were stabilized by a coating of unfolded BSA. Isoelectric point of unfolded BSA coating on NP surface was close to 4...
163 citations
TL;DR: It is found that BSA did not induce colloidal aggregation, a relevant result from the toxicological viewpoint, and the thermodynamics of the gold nanoparticle-BSA association was elucidated, best described by an anticooperative binding model.
Abstract: We present in situ observations of adsorption of bovine serum albumin (BSA) on citrate-stabilized gold nanospheres. We implemented scattering correlation spectroscopy as a tool to quantify changes in the nanoparticle Brownian motion resulting from BSA adsorption onto the nanoparticle surface. Protein binding was observed as an increase in the nanoparticle hydrodynamic radius. Our results indicate the formation of a protein monolayer at similar albumin concentrations as those found in human blood. Additionally, by monitoring the frequency and intensity of individual scattering events caused by single gold nanoparticles passing the observation volume, we found that BSA did not induce colloidal aggregation, a relevant result from the toxicological viewpoint. Moreover, to elucidate the thermodynamics of the gold nanoparticle–BSA association, we measured an adsorption isotherm which was best described by an anticooperative binding model. The number of binding sites based on this model was consistent with a BSA...
159 citations
TL;DR: The results indicate that serum albumins are capable of transporting retinoids in vitro and in vivo, and the complexation of bovine serum albumin with retinol and retinoic acid at physiological conditions is reported.
TL;DR: The results suggested that the fluorescence quenching of BSA by maltol was a static procedure forming a maltol-BSA complex, and indicated that hydrophobic interactions played a predominant role in the interaction of maltol with BSA.
TL;DR: In this article, a surface imprinting biosensor was used for bovine serum albumin detection using chitosan-coated magnetic nanoparticles modified multi-walled carbon nanotubes (MNPs/CS-MWNTs) as a signal amplifier.
Abstract: A surface-imprinting biosensor was prepared for bovine serum albumin (BSA) detection using chitosan-coated magnetic nanoparticles modified multi-walled carbon nanotubes (MNPs/CS-MWNTs) as a signal amplifier. The property of the MNPs/CS-MWNTs was studied using infrared spectra and their configurations were characterized with scanning electron microscopy. The molecularly imprinted biosensor was tested by differential pulse voltammetry to investigate the relationship between the response current and BSA concentration. The results showed that a wide detection linear range (1.0 × 10 −4 –1.0 × 10 −10 g mL −1 ) for the determination of bovine serum albumin with the low detection limit of 2.8 × 10 −11 g mL −1 for S/N = 3 was obtained. The surface imprinted biosensor exhibited excellent selectivity, high sensitivity, and good reproducibility. The proposed biosensor also exhibited fast balance response time of 30 s, which is propitious to rapid detect protein in spot specimens. The merits of the imprinted biosensor suggested an attractive and broadly applicable way for developing biosensors.
TL;DR: Results indicated that the surface modification by blending citric acid grafted polyurethane provided practical application of the membranes with good biocompatibility, especially the anticoagulant property; and the membranes could be used in blood purification fields, such as hemodialysis and bioaritificial liver assist devices.
TL;DR: In this article, the authors used QCM-D to characterize the adsorption of the model proteins, bovine serum albumin (BSA) and fibronectin (FN), to polypyrrole doped with dextran sulfate (PPy-DS) as a function of DS loading and surface roughness.
Abstract: Quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to characterize the adsorption of the model proteins, bovine serum albumin (BSA) and fibronectin (FN), to polypyrrole doped with dextran sulfate (PPy-DS) as a function of DS loading and surface roughness. BSA adsorption was greater on surfaces of increased roughness and was above what could be explained by the increase in surface area alone. Furthermore, the additional mass adsorbed on the rough films was concomitant with an increase in the rigidity of the protein layer. Analysis of the dynamic viscoelastic properties of the protein adlayer reveal BSA adsorption on the rough films occurs in two phases: (1) arrival and initial adsorption of protein to the polymer surface and (2) postadsorption molecular rearrangement to a more dehydrated and compact conformation that facilitates further recruitment of protein to the polymer interface, likely forming a multilayer. In contrast, FN adsorption was independent of surface roughness. However, films prepared from solutions containing the highest concentration of DS (20 mg/mL) demonstrated both an increase in adsorbed mass and adlayer viscoelasticity. This is attributed to the higher DS loading in the conducting polymer film resulting in presentation of a more hydrated molecular structure indicative of a more unfolded and bioactive conformation. Modulating the redox state of the PPy-DS polymers was shown to modify both the adsorbed mass and viscoelastic nature of FN adlayers. An oxidizing potential increased both the total adsorbed mass and the adlayer viscoelasticity. Our findings demonstrate that modification of polymer physicochemical and redox condition alters the nature of protein-polymer interaction, a process that may be exploited to tailor the bioactivity of protein through which interactions with cells and tissues may be controlled.
TL;DR: There was a transition in the mechanism of adsorption to allow for vertically oriented antibodies, as evidenced by the binding of both Protein G' and streptavidin as well as looser mechanical coupling with the surface.
Abstract: The orientation of a monoclonal, anti-streptavidin human IgG1 antibody on a model hydrophobic, CH(3)-terminated surface (1-dodecanethiol self-assembled monolayer on gold) was studied by monitoring the mechanical coupling between the adsorbed layer and the surface as well as the binding of molecular probes to the antibodies. In this study, the streptavidin antigen was used as a probe for the Fab portions of the antibody, while bacteria-derived Protein G' was used as a probe for the Fc region. Bovine serum albumin (BSA) acted as a blocking protein. Monolayer coverage occurred around 468 ng/cm(2). Below 100 ng/cm(2), antibodies were found to adsorb flat-on, tightly coupled to the surface and unable to capture their antigen, whereas the Fc region was able to bind Protein G'. At half-monolayer coverage, there was a transition in the mechanism of adsorption to allow for vertically oriented antibodies, as evidenced by the binding of both Protein G' and streptavidin as well as looser mechanical coupling with the surface. Monolayer coverage was characterized by a reduced level in probe binding per antibody and an even less rigid coupling to the surface.
TL;DR: A detailed investigation on the interaction of bovine serum albumin with polyethyleneimine-functionalized ZnO nanoparticles (ZnO-PEI) revealed that the complexation is enthalpy-driven, indicating the possible involvement of electrostatic interaction.
Abstract: In biological fluids, nanoparticles are always surrounded by proteins. As the protein is adsorbed on the surface, the extent of adsorption and the effect on the protein conformation and stability are dependent on the chemical nature, shape, and size of the nanoparticle (NP). We have carried out a detailed investigation on the interaction of bovine serum albumin (BSA) with polyethyleneimine-functionalized ZnO nanoparticles (ZnO-PEI). ZnO-PEI was synthesized using a wet chemical method with a core size of ∼3–7 nm (from transmission electron microscopy). The interaction of BSA with ZnO-PEI was examined using a combination of calorimetric, spectroscopic, and computational techniques. The binding was studied by ITC (isothermal titration calorimetry), and the result revealed that the complexation is enthalpy-driven, indicating the possible involvement of electrostatic interaction. To investigate the nature of the interaction and the location of the binding site, a detailed domain-wise surface electrostatic pote...
TL;DR: The chaperone-like activity of serum albumin suggests it protects against protein misfolding and aggregation, and may have implications for protein mis Folding disorders of the extracellular compartment.
TL;DR: While studying the interactions of the vaccinia virus complement control protein (VCP) with complement, non-specific binding of VCP to BSA is found and the need to perform critical controls to ensure that ELISA reactants do not inappropriately bind to the blocking agent is highlighted.
TL;DR: A thermo-responsive poly{γ-2-[2-(2-methoxyethoxy)ethoxy]ethoxy-ε-caprolactone}-b-poly(γ-octyloxy-�- caprolact one) diblock copolymer was synthesized by ring-opening polymerization using tin octanoate (Sn(Oct)(2)) catalyst and a fluorescent dansyl initiator to prepare thermally responsive micelles.
TL;DR: This is the first work to graft gold surfaces with polyacrylamide brushes via ATRP to achieve ultralow fouling surfaces, demonstrating that polyacylamide is a promising alternative to traditional PEG-based antifouling materials.
TL;DR: It is demonstrated that antibody-modified field effect transistors (FETs), which were treated with bovine serum albumin (BSA) blocking, had quantitative capability for tumor marker detection in blood serum.
Abstract: This paper demonstrates that antibody-modified field effect transistors (FETs), which were treated with bovine serum albumin (BSA) blocking, had quantitative capability for tumor marker detection in blood serum. Antibody-modified surface covered with 0.1% BSA effectively minimized nonspecific adsorption of blood proteins. Tumor markers with their isoelectric points of around 5 generated strong signals in body environmental pH (pH 7.4) in proteins with isoelectric points ranging from 3 to 10. Detection of a tumor marker alpha-fetoprotein in blood serum at required level for clinical diagnosis (10 ng/mL) was achieved. The obtained results suggest that the fabricated FETs be expected to practical application in medical fields for direct detection of multi-tumor markers from blood.
TL;DR: The particles presented provide an excellent prerequisite for further investigation of fundamental particle-protein interactions and the design of functionally graded materials for biomedical and biotechnological applications, e.g. as drug carriers or for protein purification.
TL;DR: The protein corona bound to the surface of SiO2-NPs suppresses their biological effects, an issue which needs to be more carefully considered for in vitro–in vivo extrapolations.
Abstract: In cell culture studies, foetal calf serum (FCS) comprising numerous different proteins is added, which might coat the surface of engineered nanomaterials (ENMs) and thus could profoundly alter their biological activities. In this study, a panel of industrially most relevant metal oxide nanoparticles (NPs) was screened for toxic effects in A549 lung epithelial cells and RAW264.7 macrophages in the presence and absence of FCS. In medium without FCS amorphous SiO2-NPs were the most cytotoxic NPs and induced a significant pro-inflammatory response in both cell types. An increased anti-oxidative response after exposure to SiO2-NPs was, however, only observed in RAW264.7 macrophages. Furthermore, pre-coating of SiO2-NPs with FCS proteins or simply bovine serum albumin abrogated responses in A549 lung epithelial cells. Thus, the protein corona bound to the surface of SiO2-NPs suppresses their biological effects, an issue which needs to be more carefully considered for in vitro-in vivo extrapolations.
TL;DR: It is found for the first time that the complexation could take place well above the critical pH(c), the value that most previous studies had regarded as the onset occurrence of complexation.
Abstract: The complexation between bovine serum albumin (BSA) and sugar beet pectin (SBP) was studied in situ by coupling glucono-δ-lactone (GDL) induced acidification with dynamic light scattering and turbidity measurements. Individual measurements at specific pHs and mixing ratios were also carried out using zeta potentiometry, gel permeation chromatography-multiangle laser light scattering (GPC-MALLS), and isothermal titration calorimetry (ITC). These investigations together enabled the establishment of a phase diagram of BSA/SBP and the identification of the molecular events during protein/polysaccharide complexation in relation to the phase diagram, which showed five regions: (I) a stable region of mixed individual soluble polymers, (II) a stable region of intramolecular soluble complexes, (III) a quasi-stable region of intermolecular soluble complexes, (IV) an unstable region of intermolecular insoluble complexes, and (V) a second stable region of mixed individual soluble polymers, on lowering pH. We found for the first time that the complexation could take place well above the critical pH(c), the value that most previous studies had regarded as the onset occurrence of complexation. A model of structural transitions between the regions was proposed. The borderline between region II and region III represents the BSA/SBP stoichiometry for intramolecular soluble complex at a specific pH, while that between region III and region IV identifies the composition of the intermolecular insoluble complex. Also studied was the effect of NaCl and CaCl(2) on the phase diagram and structural transitions.
TL;DR: A new type of molecularly imprinted polymer (MIP)-based fluorescent artificial receptor was developed by anchoring MIP on the surface of denatured bovine serum albumin (dBSA) modified CdTe quantum dots (QDs) using the surface molecular imprinting process.
TL;DR: Highly concentrated antibody dispersions comprising dense equilibrium nanoclusters of protein molecules which, upon dilution in vitro or administration in vivo, remain conformationally stable and biologically active are created.
Abstract: Stabilizing proteins at high concentration is of broad interest in drug delivery, for treatment of cancer and many other diseases. Herein, we create highly concentrated antibody dispersions (up to 260 mg/mL) comprising dense equilibrium nanoclusters of protein (monoclonal antibody 1B7, polyclonal sheep immunoglobulin G, and bovine serum albumin) molecules which, upon dilution in vitro or administration in vivo, remain conformationally stable and biologically active. The extremely concentrated environment within the nanoclusters (∼700 mg/mL) provides conformational stability to the protein through a novel self-crowding mechanism, as shown by computer simulation, while the primarily repulsive nanocluster interactions result in colloidally stable, transparent dispersions. The nanoclusters are formed by adding trehalose as a cosolute which strengthens the short-ranged attraction between protein molecules. The protein cluster diameter was reversibly tuned from 50 to 300 nm by balancing short-ranged attraction ...
TL;DR: The interaction of a food colourant, quinoline yellow (Qy), and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorometry, FT-IR and circular dichroism techniques and indicated that the quenching mechanism of BSA by the dye was a static procedure.
TL;DR: In this article, it has been shown that a mononuclear nickel-II-Schiff base complex exhibits greater binding affinity for bovine serum albumin (BSA) than that of its human counterpart (HSA).
TL;DR: The aptasensor showed a high selectivity to LPS despite the presence of pDNA, RNA and bovine serum albumin (BSA) and could be regenerated in low pH condition, offering a promising option for detecting LPS often present in a complex milieu.