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Showing papers on "Bovine serum albumin published in 2005"


Journal ArticleDOI
TL;DR: The ability of simple tailor-made monochemical surfaces to influence binding rates and conformation of bound proteins through protein-surface interactions is demonstrated, with the effect observed greatest for albumin.
Abstract: Protein adhesion plays a major role in determining the biocompatibility of materials. The first stage of implant integration is the adhesion of protein followed by cell attachment. Surface modification of implants (surface chemistry and topography) to induce and control protein and cell adhesion is currently of great interest. This communication presents data on protein adsorption (bovine serum albumin and fibrinogen) onto model hydrophobic (CH3) and hydrophilic (OH) surfaces, investigated using a quartz crystal microbalance (QCM) and grazing angle infrared spectroscopy. Our data suggest that albumin undergoes adsorption via a single step whereas fibrinogen adsorption is a more complex, multistage process. Albumin has a stronger affinity toward the CH3 compared to OH terminated surface. In contrast, fibrinogen adheres more rapidly to both surfaces, having a slightly higher affinity toward the hydrophobic surface. Conformational assessment of the adsorbed proteins by grazing angle infrared spectroscopy (GA...

1,324 citations


Journal ArticleDOI
TL;DR: The data suggested that the association between flavonoids and BSA did not change molecular conformation of BSA and that hydrogen bonding, ionic, and hydrophobic interaction are equally important driving forces for protein-flavonoid association.
Abstract: The interaction between four flavonoids (catechin, epicatechin, rutin, and quercetin) and bovine serum albumin (BSA) was investigated using tryptophan fluorescence quenching. Quenching constants were determined using the Stern-Volmer equation to provide a measure of the binding affinity between the flavonoids and BSA. The binding affinity was strongest for quercetin and ranked in the order quercetin > rutin > epicatechin = catechin. The pH in the range of 5-7.4 does not affect significantly (p < 0.05) the association of rutin, epicatechin, and catechin with BSA, but quercetin exhibited a stronger affinity at pH 7.4 than at lower pH (p < 0.05). Quercetin has a total quenching effect on BSA tryptophan fluorescence at a molar ratio of 10:1 and rutin at approximately 25:1. However, epicatechin and catechin did not fully quench tryptophan fluorescence over the concentration range studied. Furthermore, the data suggested that the association between flavonoids and BSA did not change molecular conformation of BSA and that hydrogen bonding, ionic, and hydrophobic interaction are equally important driving forces for protein-flavonoid association.

838 citations


Journal ArticleDOI
TL;DR: Overall, flavonoids display moderate affinities for albumins (binding constants in the range 1-15 x 10(4) M(-1), flavones and flavonols being most tightly bound), and it can be proposed that the binding of flavonol primarily takes place in subdomain IIA.

496 citations


Journal ArticleDOI
TL;DR: It is demonstrated that bioactive "smart" polymer conjugates can be synthesized by polymerizing from defined initiation sites on proteins, thus preparing the polymer conjUGates in situ.
Abstract: Protein−polymer conjugates are widely used in biotechnology and medicine, and new methods to prepare the bioconjugates would be advantageous for these applications In this report, we demonstrate that bioactive “smart” polymer conjugates can be synthesized by polymerizing from defined initiation sites on proteins, thus preparing the polymer conjugates in situ In particular, free cysteines, Cys-34 of bovine serum albumin (BSA) and Cys-131 of T4 lysozyme V131C, were modified with initiators for atom transfer radical polymerization (ATRP) either through a reversible disulfide linkage or irreversible bond by reaction with pyridyl disulfide- and maleimide-functionalized initiators, respectively Initiator conjugation was verified by electrospray-ionization mass spectroscopy (ESI-MS), and the location of the modification was confirmed by μLC-MSMS (tandem mass spectrometry) analysis of the trypsin-digested protein macroinitiators Polymerization of N-isopropylacrylamide (NIPAAm) from the protein macroinitiators

439 citations


Journal ArticleDOI
Yan-Jun Hu1, Yi Liu1, Li-Xia Zhang1, Ru-Ming Zhao1, Song-Sheng Qu1 
TL;DR: In this article, the interaction between colchicine and bovine serum albumin (BSA) was investigated by fluorescence and UV-Vis absorption spectroscopy, and the modified Stern-Volmer quenching constant K a and corresponding thermodynamic parameters Δ H, Δ G, Δ S at different temperatures were calculated.

438 citations


Journal ArticleDOI
Shuyun Bi1, Daqian Song1, Yuan Tian1, Xin Zhou1, Zhongying Liu1, Hanqi Zhang1 
TL;DR: A molecular spectroscopic investigation of the interaction between tetracyclines antibiotics and human serum albumin or bovine serumalbumin was reported and the action distances and the energy transfer efficiencies between donor-acceptor were calculated based on the Foster energy transference.

418 citations


Journal ArticleDOI
Wei Lu1, Yan Zhang1, Yu-Zhen Tan1, Kaili Hu1, Xinguo Jiang1, Shoukuan Fu1 
TL;DR: The significant results in vitro and in vivo showed that CBSA-NP was a promising brain drug delivery carrier with low toxicity.

290 citations


Journal ArticleDOI
TL;DR: Micropolarities in the two proteinous environments have been determined following the polarity sensitivity of the CT emission and addition of urea to the protein-bound systems leads to a reduction in the fluorescence anisotropy indicating the denaturation of the proteins.
Abstract: Interaction of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ), a biologically active molecule, with model transport proteins, bovine serum albumin (BSA) and human serum albumin (HSA) have been studied using steady state and picosecond time-resolved fluorescence and fluorescence anisotropy. The polarity dependent intramolecular charge transfer (ICT) process is responsible for the remarkable sensitivity of this biological fluorophore to the protein environments. The CT fluorescence exhibits appreciable hypsochromic shift along with an enhancement in the fluorescence yield, fluorescence anisotropy (r) and fluorescence lifetime upon binding with the proteins. The reduction in the rate of ICT within the hydrophobic interior of albumins leads to an increase in the fluorescence yield and lifetime. Marked increase in the fluorescence anisotropy indicates that the probe molecule is located in a motionally constrained environment within the proteins. Micropolarities in the two proteinous environments have been determined following the polarity sensitivity of the CT emission. Addition of urea to the protein-bound systems leads to a reduction in the fluorescence anisotropy indicating the denaturation of the proteins. Polarity measurements and fluorescence resonance energy transfer (FRET) studies throw light in assessing the location of the fluorophore within the two proteinous media.

286 citations


Journal ArticleDOI
TL;DR: The structures of the proteins as determined by circular dichroism indicate changes in the tertiary structure with the secondary structure remaining intact.
Abstract: In the context of this study, the noncovalent binding of selected phenolic compounds (chlorogenic, ferulic, and gallic acids, quercetin, rutin, and isoquercetin) to different proteins (human serum albumin, bovine serum albumin, soy glycinin, and lysozyme) was studied with direct (Hummel-Dreyer/size exclusion chromatography) and/or indirect methods (fluorescence absorbance properties of the binding components) In the latter case, the measurement of the phenol binding was achieved by exploiting the intrinsic fluorescence emission properties of quercetin as a probe From the data obtained, the binding constants and the number of binding sites were calculated The binding parameters were influenced by different factors, where, eg, increasing temperature and ionic strength as well as decreasing pH cause a diminished binding The structures of the proteins as determined by circular dichroism indicate changes in the tertiary structure with the secondary structure remaining intact

261 citations


Journal ArticleDOI
TL;DR: The studied results by FT-IR and CD experiment indicated that the secondary structures of protein have been perturbed by the interaction of wogonin with BSA.

246 citations


Journal ArticleDOI
Yan-Jun Hu1, Yi Liu1, Xuesong Shen, Xian-Yang Fang1, Song-Sheng Qu1 
TL;DR: In this paper, the interaction between 1-hexylcarbamoyl-5-fluorouracil (Carmofur) and bovine serum albumin (BSA) was studied by spectroscopic methods including fluorescence spectroscopy, circular dichroism (CD) and UV-Visible absorption spectrum.

Journal ArticleDOI
TL;DR: The structure of all three proteins, when adsorbed to the surface of an aluminum salt, was altered in such a way as to render the proteins less thermally stable, and it is considered that this phenomenon may facilitate the presentation of antigens and thus contribute to the adjuvant activity of the aluminum salts.

Journal ArticleDOI
TL;DR: It was found that at pH 7 a protein oppositely charged to the oxide surface adsorbs in significantly higher amounts, and electrostatic interactions dominate the adsorption process at the investigated experimental conditions.

Journal ArticleDOI
TL;DR: In this paper, the best experimental conditions for the production of amino acids from bovine serum albumin (BSA) by continuous sub-critical water hydrolysis were determined.
Abstract: The aim of this work was the determination of the best experimental conditions for the production of amino acids from bovine serum albumin (BSA) by continuous sub-critical water hydrolysis. The results were compared with conventional acid hydrolysis in HCl. At a residence time of 30 s and a pressure of 25 MPa, the highest amount of amino acids was obtained at 583 K. An increase in residence time to 90 s led to a shift of the temperature optimum to 543 K. The highest amino acid yield in sub-critical water was obtained at 563 K and 65 s. No significant influence of operating pressure (15–27 MPa) could be observed at the tested temperature (523 K) and residence time (30 s). The addition of carbon dioxide led to an increase in amino acid yield due to the acceleration of acid hydrolyzed catalysis steps. This protein treatment may provide a practical and economical solution for the disposal of protein-rich sources like marine wastes, hairs, and feathers, which are considered as waste so far.

Journal ArticleDOI
TL;DR: In this paper, a simple and convenient method for the synthesis of gold, silver and their alloy nanoparticles in a foam matrix using the protein bovine serum albumin (BSA) is reported.
Abstract: A simple and convenient method for the synthesis of gold, silver and their alloy nanoparticles in a foam matrix using the protein bovine serum albumin (BSA) is reported. BSA is an excellent foaming agent and,by virtue of its zwitterionic character at the protein isoelectric point, may be used to bind to either cationic silver (Ag+) or anionic gold (AuCl4−) ions in the foam. The metal ions in the foam are thereafter reduced in situ to yield silver and gold nanoparticles. The versatility of an amphoteric foaming agent is further demonstrated by the simultaneous binding of Ag+ and AuCl4− ions with zwitterionic BSA leading to the possibility of obtaining Au–Ag alloy nanoparticles in the foam. The BSA molecules coat and stabilize the nanoparticles thus prepared eliminating the necessity of employing an additional stabilizing agent in the experimental recipe.

Journal ArticleDOI
TL;DR: This work has been able to refine the albumin depletion protocols and establish a modified albumin removal method using trichloroacetic acid (TCA)/acetone, which may offer a rapid method for purifying serum albumin in large scale.
Abstract: Proteomic analysis of sera and the quest for identifying serum proteins as disease markers have often been hampered by the predominance of several highly abundant proteins including albumin and immunoglobulins. Prior albumin depletion so as to enrich for otherwise undetectable serum components is therefore a prerequisite in mining the serum proteome. In the course of evaluating several available methods and commercial kits, we have been able to refine the albumin depletion protocols and establish a modified albumin removal method using trichloroacetic acid (TCA)/acetone. Changes in major protein bands were monitored by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (1-D SDS-PAGE) and used as the first screening strategy to evaluate and optimize for the precipitation experimental conditions. Our method showed better performance in efficiency, specificity, and costs in comparison with two commercially available albumin removal kits, and provides a simple pre-fractionation step for the proteomic analysis of serum biomarkers. Albumin isolated by the modified method is in the native state. Our method may offer a rapid method for purifying serum albumin in large scale.

Journal ArticleDOI
TL;DR: For the slightly less hydrophilic zirconia particles high amounts of protein adsorption are observed even under repulsive electrostatic conditions, one reason could be that the hydrophobic effect plays a more important role for zIRconia than electrostatic interaction.
Abstract: The amounts of negatively charged bovine serum albumin and positively charged lysozyme adsorbed on alumina, silica, titania, and zirconia particles (diameters 73 to 271 nm) in aqueous suspensions are measured. The adsorbed proteins change the ζ potentials and the isoelectric points (IEP) of the oxide particles. The added to adsorbed protein ratios at pH 7.5 are compared with the protein treated particle ζ potentials. It is found that the amounts of adsorbed proteins on the alumina, silica, and titania (but not on the zirconia) particle surfaces are highly correlated with the ζ potential. For the slightly less hydrophilic zirconia particles high amounts of protein adsorption are observed even under repulsive electrostatic conditions. One reason could be that the hydrophobic effect plays a more important role for zirconia than electrostatic interaction.

Journal ArticleDOI
TL;DR: The effect of calcium phosphate surface deposit and the surface adsorption of the serum proteins, bovine serum albumin (BSA) and fibrinogen, on the corrosion resistance and electrochemical behavior of (cp)titanium in phosphate buffer saline solution was investigated.

Journal ArticleDOI
TL;DR: A new method involving SA as fluorescence-enhancing reagent for estimation of BRD in aqueous samples has been suggested, and selective excitation of tryptophan residue results in emission from bromadiolone, thereby indicating a Förster type energy transfer from Trp to BRD.

Journal ArticleDOI
Changxia Sun1, Jinghe Yang1, Xia Wu1, Xirong Huang1, Fei Wang1, Shufang Liu1 
TL;DR: It was found that CPB at low and high concentrations could induce the unfolding and refolding of BSA, respectively and it was suggested that in the unfolding process, there existed BSA-CPB complex with the "necklace and bead" structure in which the unfolded BSA wrapped around CPB micelles, and that the hydrophobic interaction between the complexes led to the formation of large aggregates.

Journal ArticleDOI
TL;DR: It was concluded that CBSA-NP preferentially transported across BBB with little toxicity, which offered the possibility to deliver therapeutic agents to CNS.

Journal ArticleDOI
TL;DR: Human serum albumin species with a bound Cys34 account for a large percentage of the composition of human serumalbumin preparations used for the treatment of critically ill patients, and the variability within lots from the same manufacturer is significant.
Abstract: Objective:Human serum albumin is indicated for the treatment of shock, acute restoration of blood volume, and in hypoalbuminemia. Conflicting reports are found in the literature for the clinical safety and efficacy of human serum albumin administration to critically ill patients. We sought to analyz

Journal ArticleDOI
TL;DR: The kinetics for exchange between an aromatic disulphide and the thiol group in human and bovine albumin as well as in glutathione were investigated in the pH range 2.5--9.8 and it was concluded that the pK of the thiola group in albumin is significantly below that of SH in glutATHione, and ionization of this thiol Group, Cys-34, is independent of the neutral transition.
Abstract: The kinetics for exchange between an aromatic disulphide and the thiol group in human and bovine albumin as well as in glutathione were investigated in the pH range 2.5--9.8. For both albumins the rate constants exhibit a maximum near pH 3, confirming the results of Svenson and Carlsson's investigation of bovine albumin [A. Svenson and J. Carlsson (1975) Biochim. Biophys Acta, 400, 433--438]. This was related to the well known N--F conformational change of the protein. At pH 5--8 the reactivity of the thiol group in both albumins and glutathione changes sharply, probably due to ionization of the thiol group. At pH above 8, however, the reactivity of the thiol group in albumins, but not in glutathione, becomes nearly independent of pH. In addition, a conformational change at pH 6.5--8.5 was studied by means of differential spectroscopy of bilirubin, liganded to human albumin. This neutral transition appeared to proceed identically in mercaptalbumin and nonmercaptalbumin. It is concluded that (a) the pK of the thiol group in albumin is significantly below that of SH in glutathione, and (b) ionization of this thiol group, Cys-34, is independent of the neutral transition.

Journal ArticleDOI
12 Jul 2005-Langmuir
TL;DR: The results imply that the use of charged conjugated polymers as biosensors, while an attractive proposition, has to take into account strong nonspecific interactions between conjugate polymers and the host of proteins that is found in cells and complex biological fluids.
Abstract: Two carboxylate-substituted, fluorescent (Φ = 0.08), water-soluble poly(p-phenyleneethynylene)s (PPE) and a water-soluble model compound were exposed to a series of proteins and bovine serum. While the anionic PPEs do not have any specific binding sites, they form stable complexes with histone, lysozyme, myoglobin, and hemoglobin. The complex formation was evidenced by fluorescence quenching. Bovine serum albumin does not quench the fluorescence of the PPEs but enhances it, probably due to its surfactant character. These results imply that the use of charged conjugated polymers as biosensors, while an attractive proposition, has to take into account strong nonspecific interactions between conjugated polymers and the host of proteins that is found in cells and complex biological fluids.

Journal ArticleDOI
TL;DR: Results show that papain, creatine phosphokinase, and glyceraldehyde-3-phosphate dehydrogenase were significantly both S-nitrosated and S-glutathionylated by GSNO, whereas alcohol dehydrogenases, bovine serum albumin, and actin appeared nearly only S-Nitrosated.
Abstract: S-Nitrosation of protein sulfhydryl groups is an established response to oxidative/nitrosative stress. The transient nature and reversibility of S-nitrosation, as well as its specificity, render this posttranslational modification an attractive mechanism of regulation of protein function and signal transduction, in analogy to S-glutathionylation. Several feasible mechanisms for protein S-nitrosation have been proposed, including transnitrosation by S-nitrosothiols, such as S-nitrosoglutathione (GSNO), where the nitrosonium moiety is directly transferred from one thiol to another. The reaction between GSNO and protein sulfhydryls can also produce a mixed disulfide by S-glutathionylation, which involves the nucleophilic attack of the sulfur of GSNO by the protein thiolate anion. In this study, we have investigated the possible occurrence of S-glutathionylation during reaction of GSNO with papain, creatine phosphokinase, glyceraldehyde-3-phosphate dehydrogenase, alcohol dehydrogenase, bovine serum albumin, a...

Journal ArticleDOI
TL;DR: In this article, the adsorption of bovine serum albumin (BSA) from aqueous solutions was studied with in situ ATR-IR spectroscopy, and with ex situ ATr-IR, ellipsometry, and water wettablity measurements.

Journal ArticleDOI
TL;DR: Viscoelastic behavior indicated a tenuous network, solidlike at low strain but re-forming after breakage by shear, and high MW sensitivity was observed by rheology for the terminal time, which increased as well with the strength of polyelectrolyte-protein interaction.

Journal ArticleDOI
Yan-Jun Hu1, Yi Liu1, Wei Jiang2, Ru-Ming Zhao1, Song-Sheng Qu1 
TL;DR: The result of synchronous fluorescence spectra shows that the conformation of bovine serum albumin has been changed at the present of 6-mercaptopurine, which indicates dynamic quenching mechanism.
Abstract: Fluorescence quenching in solutions of bovine serum albumin has been investigated in the presence of 6-mercaptopurine and ionic surfactants. Spectroscopic analysis of the emission quenching at different temperatures revealed that the quenching mechanism of bovine serum albumin by 6-mercaptopurine was dynamic quenching mechanism. The Stern–Volmer quenching model has been successfully applied, and the activation energy of the interaction between 6-mercaptopurine and bovine serum albumin as much as 4.26 kJ mol−1 was calculated. The distance r between donor (bovine serum albumin) and acceptor (6-mercaptopurine) was obtained according to fluorescence resonance energy transfer (FRET). The result of synchronous fluorescence spectra shows that the conformation of bovine serum albumin has been changed at the present of 6-mercaptopurine.

Journal ArticleDOI
TL;DR: The results clearly demonstrate that the visible-light form of the surfactant causes a greater degree of protein unfolding than the UV- light form, providing a means to control protein folding with light that, within the resolution of SANS, appears to be completely reversible.
Abstract: The photoresponsive interaction of light-sensitive azobenzene surfactants with bovine serum albumin (BSA) at neutral pH has been investigated as a means to control protein folding with light irradiation. The cationic azobenzene surfactant undergoes a reversible photoisomerization upon exposure to the appropriate wavelength of light, with the visible-light (trans) form of the surfactant being more hydrophobic than the UV-light (cis) form. As a consequence, the trans form exhibits enhanced interaction with the protein compared to the cis form of the surfactant, allowing photoreversible control of the protein folding/unfolding phenomena. Small-angle neutron-scattering (SANS) measurements are used to provide detailed information on the protein conformation in solution. A fitting of the protein shape to a low-resolution triaxial ellipsoid model indicates that three discrete forms of the protein exist in solution depending on the surfactant concentration, with lengths of approximately 90, 150, and 250 A, respec...

Journal ArticleDOI
TL;DR: Far UV circular dichroism and fluorescence spectroscopy were used to investigate the interaction between bovine serum albumin (BSA) and metallothionein (MT) and a decrease in KSV values were observed which indicates conformational changes in BSA upon binding MT.
Abstract: Far UV circular dichroism (CD) and fluorescence spectroscopy were used to investigate the interaction between bovine serum albumin (BSA) and metallothionein (MT). Both spectroscopic probes gave proofs on the interaction of the two proteins. At pH 4.0, 7.0 and 9.0, BSA showed a negative increase in ellipticity at the far-UV range in the presence of MT indicating an increase in α-helical content and a decrease in β-sheet structure. In the presence of MT at pH 4.0 and 9.0, a decrease in fluorescence intensity was observed. Tryptophan fluorescence quenching experiments were also performed using acrylamide and KI as quenchers. Under acidic conditions, a four-fold increase in Stern-Volmer constant (KSV) was observed for BSA + MT. At neutral and basic conditions, a decrease in KSV values were observed which indicates conformational changes in BSA upon binding MT. These changes are close to the region where the tryptophan residues are located in the protein.