Showing papers on "Bovine serum albumin published in 2015"
TL;DR: The present study will be helpful in understanding the binding mechanism of limonene and associated stability and conformational changes.
Abstract: 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 ∼104 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.
213 citations
TL;DR: This study demonstrates the ability to hijack neutrophils to deliver nanoparticles to targeted diseased sites and markedly mitigated the lung inflammation induced by LPS (lipopolysaccharide) or infection by Pseudomonas aeruginosa.
Abstract: Endothelial cells form a monolayer in lumen of blood vessels presenting a great barrier for delivery of therapeutic nanoparticles (NPs) into extravascular tissues where most diseases occur, such as inflammation disorders and infection. Here, we report a strategy for delivering therapeutic NPs across this blood vessel barrier by nanoparticle in situ hitchhiking activated neutrophils. Using intravital microscopy of TNF-α-induced inflammation of mouse cremaster venules and a mouse model of acute lung inflammation, we demonstrated that intravenously (iv) infused NPs made from denatured bovine serum albumin (BSA) were specifically internalized by activated neutrophils, and subsequently, the neutrophils containing NPs migrated across blood vessels into inflammatory tissues. When neutrophils were depleted using anti-Gr-1 in a mouse, the transport of albumin NPs across blood vessel walls was robustly abolished. Furthermore, it was found that albumin nanoparticle internalization did not affect neutrophil mobility and functions. Administration of drug-loaded albumin NPs markedly mitigated the lung inflammation induced by LPS (lipopolysaccharide) or infection by Pseudomonas aeruginosa. These results demonstrate the use of an albumin nanoparticle platform for in situ targeting of activated neutrophils for delivery of therapeutics across the blood vessel barriers into diseased sites. This study demonstrates our ability to hijack neutrophils to deliver nanoparticles to targeted diseased sites.
190 citations
TL;DR: The 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.
Abstract: 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.
146 citations
TL;DR: The hybrid nanoflower-based IMER was applicable to the digestion of a complex human sample, showing great promise for proteome analysis and the residual activity of the nanoflowers decreased slightly even after eight repeated use, demonstrating promising stability.
Abstract: A facile approach for the synthesis of enzyme–inorganic hybrid nanoflowers and their application as an immobilized α-chymotrypsin (ChT) reactor (IMER) for highly efficient protein digestion was described. The hybrid nanoflowers were room-temperature synthesized in aqueous solution using calcium phosphate (Ca3(PO4)2) as the inorganic component and ChT as the organic component. The effects of reaction parameters on the formation of the enzyme-embedded hybrid nanoflowers and their growth mechanism were investigated systematically. By monitoring the reaction of N-benzoyl-L-tyrosine ethyl ester (BTEE), the enzymatic activity of the immobilized ChT was calculated and the results showed 266% enhancement in enzymatic activity. The performance of such a nanoreactor was further demonstrated by digesting bovine serum albumin (BSA) and human serum albumin (HSA), with a stringent threshold for unambiguous identification of these digests, the yielding sequence coverages for nanoflower-based digestion were 48% and 34%, higher than those obtained with the free enzyme. The digestion time of BSA and HSA in the former case was less than 2 min, about 1/360 of that performed in the latter case (12 h). Furthermore, the residual activity of the nanoflowers decreased slightly even after eight repeated use, demonstrating promising stability. In addition, the hybrid nanoflower-based IMER was applicable to the digestion of a complex human sample, showing great promise for proteome analysis.
145 citations
TL;DR: 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.
Abstract: 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 evid...
135 citations
TL;DR: The developed method facilitates in situ, sensitive, and more in-depth probing of protein secondary structures, which represents a significant advancement compared to conventional characterization methods.
Abstract: Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy using a special waveguide based on a silver halide fiber was used for probing the heat-induced secondary structure and conformation changes of bovine serum albumin (BSA). From the secondary derivative and the curve fitting of the obtained ATR-FTIR spectra, the changes of the BSA secondary structure with temperature were clearly identified. Two different thermal denaturation temperature ranges (i.e., 50-52 and 80-82 °C, at which a change of the protein structure occurred) were determined, while only one denaturation temperature was previously identified via classical FTIR measurements. Additionally, taking advantage of two-dimensional correlation spectroscopy more detailed information on changes of the protein secondary structure was revealed. The developed method facilitates in situ, sensitive, and more in-depth probing of protein secondary structures, which represents a significant advancement compared to conventional characterization methods.
125 citations
TL;DR: This study characterizes the formation of a PC on AgNPs and demonstrates its influence on cytotoxicity and cell activation through a cell surface receptor.
125 citations
TL;DR: A series of N-substituted isatin thiosemicarbazone ligands and their nickel(II) complexes [Ni(L)2] (1-5) were synthesized and characterized by elemental analyses and UV-Visible, FT-IR, 1H & 13C NMR, and mass spectroscopic techniques as discussed by the authors.
Abstract: A series of N-substituted isatin thiosemicarbazone ligands (L1–L5) and their nickel(II) complexes [Ni(L)2] (1–5) were synthesized and characterized by elemental analyses and UV-Visible, FT-IR, 1H & 13C NMR, and mass spectroscopic techniques. The molecular structure of the ligands (L1 and L2) and complex 1 was confirmed by single crystal X-ray crystallography. The single crystal X-ray structure of 1 showed distorted octahedral geometry. The interaction of calf thymus (CT) DNA and bovine serum albumin (BSA) with the nickel(II) complexes was explored using absorption and emission spectral methods. A DNA cleavage study showed that the complexes cleaved DNA without any external agents. The alterations in the secondary structure of the protein by the nickel(II) complexes (1–5) were confirmed by synchronous and three dimensional fluorescence spectroscopic studies. The interaction of the complexes with DNA/protein also has been supported by molecular docking studies. An in vitro cytotoxicity study of the complexes found significant activity against human breast (MCF7) and lung (A549) cancer cell lines, with the best results for complexes 4 and 2 respectively, where the IC50 value is less than 0.1 μM concentration.
123 citations
TL;DR: It is demonstrated that RuII(CO)2–protein complexes, formed by the reaction of the hydrolytic decomposition products of [fac-RuCl(κ2-H2NCH2CO2)(CO)3) with histidine residues exposed on the surface of proteins, spontaneously release CO in aqueous solution, cells, and mice.
Abstract: We demonstrate that RuII(CO)2–protein complexes, formed by the reaction of the hydrolytic decomposition products of [fac-RuCl(κ2-H2NCH2CO2)(CO)3] (CORM-3) with histidine residues exposed on the surface of proteins, spontaneously release CO in aqueous solution, cells, and mice. CO release was detected by mass spectrometry (MS) and confocal microscopy using a CO-responsive turn-on fluorescent probe. These findings support our hypothesis that plasma proteins act as CO carriers after in vivo administration of CORM-3. CO released from a synthetic bovine serum albumin (BSA)–RuII(CO)2 complex leads to downregulation of the cytokines interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α in cancer cells. Finally, administration of BSA–RuII(CO)2 in mice bearing a colon carcinoma tumor results in enhanced CO accumulation at the tumor. Our data suggest the use of RuII(CO)2–protein complexes as viable alternatives for the safe and spatially controlled delivery of therapeutic CO in vivo.
118 citations
TL;DR: The interaction between N‐acetyl cysteine and bovine serum albumin was investigated by UV–vis, fluorescence spectroscopy, and molecular docking methods and hydrogen bonding and van der Waals force were the major intermolecular forces and it was spontaneous.
Abstract: The interaction between N-acetyl cysteine (NAC) and bovine serum albumin (BSA) was investigated by UV–vis, fluorescence spectroscopy, and molecular docking methods. Fluorescence study at three different temperatures indicated that the fluorescence intensity of BSA was reduced upon the addition of NAC by the static quenching mechanism. Binding constant (Kb) and the number of binding sites (n) were determined. The binding constant for the interaction of NAC and BSA was in the order of 103 M−1, and the number of binding sites was obtained to be equal to 1. Enthalpy (ΔH), entropy (ΔS), and Gibb's free energy (ΔG) as thermodynamic values were also achieved by van't Hoff equation. Hydrogen bonding and van der Waals force were the major intermolecular forces in the interaction process and it was spontaneous. Finally, the binding mode and the binding sites were clarified using molecular docking which were in good agreement with the results of spectroscopy experiments. © 2015 Wiley Periodicals, Inc. Biopolymers 103: 638–645, 2015.
101 citations
TL;DR: The binding interaction of sorafenib with bovine serum albumin (BSA) was studied using fluorescence, circular dichrosim (CD) and molecular docking methods and 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 B SA.
TL;DR: Formation of distinct amorphous aggregates by disulfide-reduced BSA and lysozyme suggests an alternate pathway for protein aggregation that may be relevant to several proteins.
Abstract: Disulfide bonds are naturally formed in more than 50% of amyloidogenic proteins, but the exact role of disulfide bonds in protein aggregation is still not well-understood. The intracellular reducing agents and/or improper use of antioxidants in extracellular environment can break proteins disulfide bonds, making them unstable and prone to misfolding and aggregation. In this study, we report the effect of disulfide-reducing agent dithiothreitol (DTT) on hen egg white lysozyme (lysozyme) and bovine serum albumin (BSA) aggregation at pH 7.2 and 37 °C. BSA and lysozyme proteins treated with disulfide-reducing agents form very distinct amorphous aggregates as observed by scanning electron microscope. However, proteins with intact disulfide bonds were stable and did not aggregate over time. BSA and lysozyme aggregates show unique but measurable differences in 8-anilino-1-naphthalenesulfonic acid (ANS) and 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) fluorescence, suggesting a loose and flexible aggregate structure for lysozyme but a more compact aggregate structure for BSA. Scrambled disulfide-bonded protein aggregates were observed by nonreducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for both proteins. Similar amorphous aggregates were also generated using a nonthiol-based reducing agent, tris(2-carboxyethyl)phosphine (TCEP), at pH 7.2 and 37 °C. In summary, formation of distinct amorphous aggregates by disulfide-reduced BSA and lysozyme suggests an alternate pathway for protein aggregation that may be relevant to several proteins.
TL;DR: A simple electrostatic model is developed that can qualitatively explain the observed adsorption behaviour based on charge-induced pH modifications near the charged nanoparticle surfaces.
Abstract: Understanding the interaction of proteins with charged diamond nanoparticles is of fundamental importance for diverse biomedical applications. Here we present a thorough study of protein binding, adsorption kinetics and structure on strongly positively (hydrogen-terminated) and negatively (oxygen-terminated) charged nanodiamond particles using a quartz crystal microbalance by dissipation and infrared spectroscopy. By using two model proteins (bovine serum albumin and lysozyme) of different properties (charge, molecular weight and rigidity), the main driving mechanism responsible for the protein binding to the charged nanoparticles was identified. Electrostatic interactions were found to dominate the protein adsorption dynamics, attachment and conformation. We developed a simple electrostatic model that can qualitatively explain the observed adsorption behaviour based on charge-induced pH modifications near the charged nanoparticle surfaces. Under neutral conditions, the local pH around the positively and negatively charged nanodiamonds becomes very high (11–12) and low (1–3) respectively, which has a profound impact on the protein charge, hydration and affinity to the nanodiamonds. Small proteins (lysozyme) were found to form multilayers with significant conformational changes to screen the surface charge, while larger proteins (albumin) formed monolayers with minor conformational changes. The findings of this study provide a step forward toward understanding and eventually predicting nanoparticle interactions with biofluids.
TL;DR: This paper examined the stability of liposomes loaded with negatively charged protein (bovine serum albumin, BSA) during in vitro digestion and found that BSA-loaded liposome exhibited lower stability in simulated intestinal fluid, as shown by damaged membranes and the release of free fatty acids.
TL;DR: Naphthalimide moiety of compound 1 greatly contributed to the hydrophobic interaction between compound 1 and BSA protein, as confirmed by experimental data.
Abstract: 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.
TL;DR: It is found that erucic acid can quench the intrinsic fluorescence of BSA by dynamic quenching and there is a single class of binding site on BSA, and hydrogen bonding is also an acting force.
TL;DR: DP-TPPNa was successfully applied for the quantitative detection of BSA in fetal bovine serum and the mechanism of fluorescent turn-on behavior was elucidated utilizing an unfolding process induced by guanidine hydrochloride, which revealed a capture process via selective hydrophobic interaction and hydrogen bonding between luminogen and SA.
Abstract: An aggregation-enhanced emission active luminogen named as sodium 4,4′4″-(3,4-diphenyl-1H-pyrrole-1,2,5-triyl)tribenzoate (DP-TPPNa) with propeller construction was synthesized and developed as a “turn on” fluorescent probe for in situ quantitation of albumin in blood serum. The DP-TPPNa fluorescence intensity was linearly correlated with the concentration of two serum albumins, bovine serum albumin (BSA) and human serum albumin (HSA), in pure PBS buffer in the ranges of 2.18–70 and 1.68–100 μg/mL, respectively. The detection limits were as low as 2.18 μg/mL for BSA and 1.68 μg/mL for HSA. The response time of fluorescence to serum albumin (SA) was very short (below 6 s), which achieved real-time detection. It also showed high selectivity to SA because other components in serum barely interfere with the detection of DP-TPPNa to SA, enabling in situ quantitative detection of SA without isolation from serum. DP-TPPNa was successfully applied for the quantitative detection of BSA in fetal bovine serum. The m...
TL;DR: Thermodynamic investigations revealed the interaction between the two carotenoids and HSA/BSA is synergistically driven by enthalpy and entropy, and hydrophobic forces and electrostatic attraction have a significant role in the reactions.
TL;DR: Through conjugation of Cdots with the transacting activator of transcription (TAT) peptide (CPP) derived from human immunodeficiency virus (HIV), it is possible to directly monitor the dynamic interactions of CPP with living cell membrane at single particle level.
Abstract: In this work, we demonstrated a convenient and green strategy for the synthesis of highly luminescent and water-soluble carbon dots (Cdots) by carbonizing carbon precursors, i.e., Bovine serum albumin (BSA) nanoparticles, in water solution. Without post surface modification, the as-synthesized Cdots exhibit fluorescence quantum yield (Q.Y.) as high as 34.8% and display superior colloidal stability not only in concentrated salt solutions (e.g. 2 M KCl) but also in a wide range of pH solutions. According to the FT-IR measurements, the Cdots contain many carboxyl groups, providing a versatile route for further chemical and biological functionalization. Through conjugation of Cdots with the transacting activator of transcription (TAT) peptide (a kind of cell penetration peptide (CPP)) derived from human immunodeficiency virus (HIV), it is possible to directly monitor the dynamic interactions of CPP with living cell membrane at single particle level. Furthermore, these Cdots also exhibit a dosage-dependent selectivity toward Fe(3+) among other metal ions, including K(+), Na(+), Mg(2+), Hg(2+), Co(2+), Cu(2+), Pb(2+) and Al(3+). We believed that the Cdots prepared by this strategy would display promising applications in various areas, including analytical chemistry, nanomedicine, biochemistry and so on.
TL;DR: The findings point to limited validity of the colloidal protein model and to the need for further consideration and quantification of the effects of conformational changes on protein solution viscosity, protein association, and the phase behavior.
TL;DR: Specific ion effects on the Brownian molecular motion of BSA protein under physiological conditions are investigated and new useful insights into Hofmeister phenomena related to electrolyte-protein interactions are presented.
TL;DR: F folate functionalized nanoparticles confer enhance cellular uptake and cytotoxicity for gemcitabine and exhibited improved anti-tumor activity in Ehrlich solid tumor model in mice.
TL;DR: In vivo MR imaging conducted on nude mice bearing the Bel-7402 xenografts after bolus intravenous administration reveals excellent tumor targeting and MR imaging capabilities, especially at 24h post-injection.
01 Jan 2015
TL;DR: The stability of liposomes loaded with negatively charged protein (bovine serum albumin, BSA) during in vitro digestion and lipolysis kinetics revealed that bile salts and ionic strength could facilitate a high level of free fatty acid release.
TL;DR: Investigation of the interaction between polyethylene (glycol) (PEG) and human (HSA) and bovine serum albumin (BSA) in aqueous solution and molecular modeling showed that the interaction process is spontaneous at room temperature.
TL;DR: 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.
TL;DR: Thermolysin hydrolyzates of freshly isolated, extensively stored and heated bovine serum albumin samples were analyzed and heat-induced extractability loss of BSA was linked to the impact of protein unfolding on the involvement of specific cysteine residues in intermolecular and intramolecular thiol-disulfide interchange and thiol oxidation reactions.
Abstract: Thermolysin hydrolyzates of freshly isolated, extensively stored (6 years, 6 °C, dry) and heated (60 min, 90 °C, in excess water) bovine serum albumin (BSA) samples were analyzed with liquid chromatography (LC) electrospray ionization (ESI) tandem mass spectrometry (MS/MS) using alternating electron-transfer dissociation (ETD) and collision-induced dissociation (CID). The positions of disulfide bonds and free thiol groups in the different samples were compared to those deduced from the crystal structure of native BSA. Results revealed non-enzymatic posttranslational modifications of cysteine during isolation, extensive dry storage, and heating. Heat-induced extractability loss of BSA was linked to the impact of protein unfolding on the involvement of specific cysteine residues in intermolecular and intramolecular thiol-disulfide interchange and thiol oxidation reactions. The here developed approach holds promise for exploring disulfide bond formation and reshuffling in various proteins under conditions relevant for chemical, biochemical, pharmaceutical and food processing.
TL;DR: Covalent and non-covalent binding of BSA to ZnO NPs reduces Zn O NPs cytotoxicity and ROS generation, however changes in BSA conformation makes corona less protective against Zn o NPs.
TL;DR: Good's buffers ionic liquids (GB-ILs), composed of cholinium-based cations and Good's buffers anions, display self-buffering characteristics in the biological pH range, and their polarity and hydrophobicity can be easily tuned by a proper manipulation of their ions chemical structures.
TL;DR: It is reported that Cu2(C9H3O6)4/3 MOF (which is well known as HKUST-1 and denoted as Cu-MOF here), possesses an intrinsic enzyme mimicking activity similar to that found in natural trypsin to bovine serum albumin (BSA) and casein.
Abstract: The construction of efficient enzyme mimetics for the hydrolysis of peptide bonds in proteins is challenging due to the high stability of peptide bonds and the importance of proteases in biology and industry. Metal-organic frameworks (MOFs) consisting of infinite crystalline lattices with metal clusters and organic linkers may provide opportunities for protease mimic which has remained unknown. Herein, we report that Cu2(C9H3O6)4/3 MOF (which is well known as HKUST-1 and denoted as Cu-MOF here), possesses an intrinsic enzyme mimicking activity similar to that found in natural trypsin to bovine serum albumin (BSA) and casein. The Michaelis constant (Km) of Cu-MOF is about 26,000-fold smaller than that of free trypsin indicating a much higher affinity of BSA for Cu-MOF surface. Cu-MOF also exhibited significantly higher catalytic efficiency than homogeneous artificial metalloprotease Cu(II) complexes and could be reused for ten times without losing in its activity. Moreover, Cu-MOF was successfully used to simulate trypsinization in cell culture since it dissociated cells in culture even without EDTA.