Showing papers on "Bovine serum albumin published in 2004"
TL;DR: The results of synchronous fluorescence spectra and UV-vis absorption spectra show that the conformation of bovine serum albumin has been changed, and the quenching mechanism of fluorescence of BSA by monoammonium glycyrrhizinate was discussed.
586 citations
TL;DR: The distance constraints obtained for lysine residues using various cross-linkers should be valuable in assisting the determination of the 3-D structure of BSA.
478 citations
TL;DR: By the analysis of fluorescence spectrum and fluorescence intensity, it was showed that BCPT has a strong ability to quench the intrinsic fluorescence of both bovine serum albumin and human serumalbumin through a static quenching procedure.
337 citations
TL;DR: A new adsorption model for BSA on Al2O3 particles was introduced on the basis of observations and it was shown that approximately one monolayer of BSA was needed to fully mask the surface and to compromise the charge of Al2 O3.
Abstract: 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.
296 citations
TL;DR: Overall, assay pH did not influence the time to disappearance of the full-length protein or protein fragments, however, results across laboratories were more consistent at pH 1.2 than pH 2.0, demonstrating that this common protocol for evaluating the in vitro digestibility of proteins is reproducible and yields consistent results when performed using the same proteins at different laboratories.
259 citations
TL;DR: This all-aqueous procedure was used for the encapsulation of model proteins, such as bovine serum albumin and human hemoglobin, or of a vaccine protein, and the level of immunization against H. pylori infection in mice was assessed.
214 citations
TL;DR: In this study, CA has been mixed with PEG 600 as an additive in a polar solvent to prepare membranes with improved properties and the efficiency of protein separation by the developed CA membranes have been quantified using model proteins.
211 citations
TL;DR: Results suggest that the primary binding site for methyl parathion on albumin is close to tryptophan residues 214 of human serum albumin and 212 of bovine serum albumIn, and suggest that this pesticide is potentially toxic for both vertebrates and invertebrates.
204 citations
TL;DR: The results point to a weak attractive interaction between PEO and protein, with protein repellency of a densely PEO-brushed surface ascribed to a high activation energy for the protein molecules to enter the brush.
Abstract: Solid surfaces are modified by grafting poly(ethylene oxide), PEO, to influence their interaction with indwelling particles, in particular molecules of bovine serum albumin and human plasma proteins. As a rule, the grafted PEO layers suppress protein adsorption. The suppression is most effective when the PEO layer is in a molecular brush conformation having a reciprocal grafting density (area per grafted PEO chain) less than the dimensions of the protein molecules. Nevertheless, the protein molecules may penetrate the PEO brush to some extent. For a given grafting density, the penetration is facilitated by increasing thickness of the brush. Tenuous brushes of reciprocal grafting densities exceeding the protein molecular dimensions enhance protein adsorption. The results point to a weak attractive interaction between PEO and protein. The protein repellency of a densely PEO-brushed surface is ascribed to a high activation energy for the protein molecules to enter the brush. Varying the temperature between 2...
199 citations
TL;DR: A novel nanoparticle film modified electrode has been constructed using a glassy carbon electrode (GCE) coated with a carbon nanotube-dihexadecylphosphate (DHP) film that exhibits an enhanced effectiveness for the oxidation of azithromycin.
187 citations
TL;DR: Detailed protocols for the generation of AGEs that reproducibly bind RAGE with high affinity were developed, which will allow for further study of the RAGE-AGE interaction.
TL;DR: High-abundant protein removal, combined with 2-D DIGE, is a practical approach for enriching and characterizing lower abundant proteins in human serum and offers advances in proteomic characterization, and therefore, in the identification of biomarkers from human serum.
Abstract: Two-dimensional differential gel electrophoresis (2-D DIGE) was used to analyze human serum following the removal of albumin and five other high-abundant serum proteins. After protein removal, serum was analyzed by SDS-PAGE as a preliminary screen, and significant differences between four high-abundant protein removal methods were observed. Antibody-based albumin removal and high-abundant protein removal methods were found to be efficient and specific. To further characterize serum after protein removal, 2-D DIGE was employed, enabling multiplexed analysis of serum through the use of three fluorescent protein dyes. Comparison between crude serum and serum after removal of high-abundant proteins clearly illustrates an increase in the number of lower abundant protein spots observed. Approximately 850 protein spots were detected in crude serum whereas over 1500 protein spots were exposed following removal of six high-abundant proteins, representing a 76% increase in protein spot detection. Several proteins that showed a 2-fold increase in intensity after depletion of high-abundant proteins, as well as proteins that were depleted during abundant protein removal methods, were further characterized by mass spectrometry. This series of experiments demonstrates that high-abundant protein removal, combined with 2-D DIGE, is a practical approach for enriching and characterizing lower abundant proteins in human serum. Consequently, this methodology offers advances in proteomic characterization, and therefore, in the identification of biomarkers from human serum.
TL;DR: The present study shows that both human- and bovine albumin could take up part of the transferrin bound Cu(II), the second order rate constant for the reaction estimated to 12 mM−1 min−1 for both species.
Abstract: Serum albumin (human, bovine) has a specific Cu(II)-ion binding site, and is proposed to act as a copper transport protein in blood plasma. Human transferrin, normally about 30% saturated with iron in vivo, has two sites/molecule capable of complexing Cu(II); one more strongly than the other (Hirose et al. 1996). The present study shows that this binding site has a slightly stronger affinity for Cu(II) than that on the albumins. However, both human- and bovine albumin could take up part of the transferrin bound Cu(II), the second order rate constant for the reaction estimated to 12 mM−1 min−1 for both species. In vivo the albumin concentration is considerably higher than that of iron-free transferrin, and it seems unlikely that the latter can compete with albumin for non-ceruloplasmin cupric ions.
TL;DR: This synthesis method is a new technique for directly attaching gold nanoparticles to macromolecular proteins and demonstrates that the disulfide bonds in the conjugated protein are broken and thus are available for interaction with the nanoparticle surface.
Abstract: We report the synthesis of gold nanoparticles directly conjugated to bovine serum albumin protein by chemical reduction in aqueous solution. Transmission electron microscopy reveals that the gold nanoparticles are well dispersed with an average diameter less than 2 nm, and elemental analysis verifies the composition of the gold-protein conjugates. Infrared spectroscopy confirms that the polypeptide backbone is not cleaved during the conjugation process and that the side chain functional groups remain intact. Raman spectroscopy demonstrates that the disulfide bonds in the conjugated protein are broken and thus are available for interaction with the nanoparticle surface. This synthesis method is a new technique for directly attaching gold nanoparticles to macromolecular proteins.
TL;DR: Results showed that there was no significant size effect of Nano-Se from 5 to 200 nm in the induction of glutathione peroxidase (GPx), phospholipid hydroperoxide glutathieno-enzyme (PHGPx) and thioredoxin reductase-1 (TrxR-1) in human hepatoma HepG2 cells and the livers of mice.
TL;DR: In this paper, the effect of different procyanidins, anthocyanins, and their aglycons (10 and 20 μM) on lactalbumin oxidation was investigated in a liposome system.
Abstract: Oxidation of bovine serum albumin, casein, and lactalbumin and the effect of different procyanidins, anthocyanins, and their aglycons (10 and 20 μM) on lactalbumin oxidation were investigated in a liposome system. Samples were incubated in the dark at 37 °C with copper, and the extent of oxidation was measured by determining the loss of tryptophan fluorescence and the formation of protein carbonyls, conjugated diene hydroperoxides, and hexanal. The correlation between different protein and lipid oxidation measurements was good and statistically significant. Casein was the most stable protein in the liposome model, and it was also the best inhibitor of liposome oxidation. All tested anthocyanins and other phenolic compounds inhibited both lipid and protein oxidation. There were no systematic differences with anthocyanins and their aglycons in relation to the concentrations used or glycosylation with either glucose or rutinose. Procyanidins B1 and B2 and ellagic acid were potentially better antioxidants tha...
TL;DR: In this paper, the binding of kaempferol with bovine serum albumin (BSA) was investigated at three temperatures, 296, 310 and 318 K, by the fluorescence, circular dichroism (CD) and Fourier transform infrared spectroscopy (FT-IR) at pH 7.40.
TL;DR: Poly(SA) and 20:80 (CPH:SA) microspheres were found to conserve the primary structure of the released protein and the secondary structure ofThe encapsulated protein, and showed a sustained delivery for approximately 15 and 30 days, respectively.
TL;DR: It is shown that Lys525 is a predominant site of N-homocysteinylation in human serum albumin in vitro and in vivo and that the reactivity of albumin lysine residues, including Lys525, is affected by the status of Cys34.
TL;DR: For the first time studies on the binding of daphnetin to bovine serum albumin (BSA) under physiological conditions with BSA concentration of 1.5 x 10(-6) mol l(-1) and drug concentration in the range of 6.7 x 10 (-6) to 2.0 x 10-5 mol l (-1) are reported.
TL;DR: Twenty carbonylated proteins were identified in the proteome of yeast following oxidative stress with hydrogen peroxide, and Matrix‐assisted laser desorption/ionization‐mass spectrometry analysis of tryptic peptides was used to identify peptides extracted from gels.
Abstract: A method for detecting carbonylated proteins in two-dimensional electrophoresis (2-DE) was developed using biotinylation and avidin-fluorescein isothiocyanate (FITC) affinity staining. The method was used to examine oxidatively modified proteins associated with oxidative stress. Carbonyl formation in proteins was first examined in a model system by subjecting bovine serum albumin (BSA) and ribonuclease A (RNase A) to metal-catalyzed oxidation (MCO). Carbonyl group formation was found to occur at multiple sites along with a small amount of polypeptide chain cleavage. In vivo studies were conducted in yeast cell cultures using 5 mM hydrogen peroxide to induce oxidative stress. Biotinylation of yeast protein was accomplished during extraction at 4 degrees C in a lysis buffer containing 5 mM biotin-hydrazide. Biotin-hydrazide forms a Schiff base with a carbonyl group on an oxidized protein that is subsequently reduced before electrophoresis. Proteins were separated by either 2-DE or sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Biotinylated species were detected using avidin-FITC affinity staining. Detection sensitivity with biotinylated proteins was five times higher than achieved by silver staining. The limit of detection with avidin-FITC staining approached 0.64 pmol of protein-associated carbonyls. Twenty carbonylated proteins were identified in the proteome of yeast following oxidative stress with hydrogen peroxide. Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis of tryptic peptides was used to identify peptides extracted from gels. Aconitase, heat shock protein SSA1 and SSC1, pyruvate decarboxylase isozyme 1, pyruvate kinase 1, enolase 1 and 2, phosphoglycerate kinase, fructose-bisphosphate aldorase, and glyceraldehyde-3-phosphate dehydrogenase were among the major targets of oxidative stress.
TL;DR: The binding of gatifloxacin to bovine serum albumin (BSA) in aqueous solution was studied using fluorescence spectroscopy and absorbance spectra, and practical formulas for small molecule ligands to bio-macromolecules have been proposed.
Abstract: The binding of gatifloxacin to bovine serum albumin (BSA) in aqueous solution was studied using fluorescence spectroscopy and absorbance spectra, Further, the interactions influenced by Fe3+ and Cu2+ were also explored in this work. Based on Scatchard's site-binding model and florescence quenching, practical formulas for small molecule ligands to bio-macromolecules have been proposed. The binding parameters were measured according to suggested models, and the binding distance and the transfer efficiency of energy between gatifloxacin and BSA were also obtained in view of the Forster theory of non-radiation energy transfer. The effect of gatifloxacin on the conformation of BSA has also been analyzed using synchronous fluorescence spectroscopy.
TL;DR: This work reports the specific removal of 98% of albumin and 80% of immunoglobulin heavy chain from human plasma by affinity chromatography, and the subsequent improvement in the number of spots detected and their resolution following two‐dimensional gel electrophoresis.
Abstract: In studies of the plasma proteome, the high abundance of proteins such as albumin and immunoglobulin impedes the investigation of lower abundance proteins that may be more suitable as biomarkers of disease. We report the specific removal of 98% of albumin and 80% of immunoglobulin heavy chain from human plasma by affinity chromatography, and the subsequent improvement in the number of spots detected and their resolution following two-dimensional gel electrophoresis.
Journal Article•
TL;DR: In this paper, the effect of crosslinking the enzyme esperase (E.C. 3.4.62) and the proteins bovine serum albumin and casein with the bifunctional compound glutaraldehyde on molecular mass increase was studied.
Abstract: Summary In this work the effect of crosslinking the enzyme esperase (E.C. 3.4.21.62) and the proteins bovine serum albumin and casein with the bifunctional compound glutaraldehyde on molecular mass increase was studied. Two common techniques for measuring molecular mass of proteins were used: SEC and SDS-PAGE. These techniques revealed that the proteins bovine albumin and casein, when subjected to chemical crosslinking with glutaraldehyde, volume fraction 0.25 %, increased their molecular mass by 20- and 40-fold, respectively. It was also observed that Mr increased proportionally to the increase of glutaraldehyde concentration in the solution, and that the addition of glutaraldehyde should be done slowly, in small amounts, in order to attain bigger protein aggregates. When the proteolytic enzyme esperase was subjected to glutaraldehyde, no increase in its Mr was achieved. Several assumptions can be made to explain these results, the most reasonable being the low amount of free lysine groups available for crosslinking. This study confirms that glutaraldehyde is not an adequate crosslinker for esperase.
TL;DR: Thermodynamic parameters obtained from data at different temperatures showed that the binding of phenothiazine drugs to BSA involve hydrophobic bonds predominantly and the CD spectrum of BSA in presence of drugs shows that binding of drugs leads to change in the helicity of the protein.
TL;DR: A new linker system has been designed and applied to neoglycoprotein synthesis that is well suited for the coupling of very small amounts of oligosaccharide and protein.
TL;DR: The results are consistent with the interpretation that immunochemically nonreactive albumin has a limited number of polypeptide chain scissions and is held together by noncovalent intrachain bonding and disulfide bonds.
Abstract: Background: Conventional immunoassays underestimate the urinary albumin concentration because intact albumin in urine exists in two forms, immunoreactive and immunochemically nonreactive
Methods: Urinary albumin concentration measured by HPLC (which measures total albumin, ie, the sum of immunoreactive albumin + immunochemically nonreactive albumin) or RIA was compared with densitometric analysis of albumin bands in diabetic urine samples separated by either native polyacrylamide gel electrophoresis (PAGE) or reducing sodium dodecyl sulfate (SDS)-PAGE Immunochemically nonreactive albumin was also isolated from diabetic urine (relative amount detected, 70–80% of the expected) and was tested for contamination by common urinary proteins by native PAGE, ELISA, and capillary electrophoresis
Results: Urinary albumin concentrations measured by native PAGE and HPLC were better correlated ( r 2 = 083) than concentrations measured by native PAGE and RIA ( r 2 = 062) because under native conditions both native PAGE and HPLC detect total albumin and not only the immunoreactive albumin alone that is measured by RIA Urinary albumin concentrations measured by reducing SDS-PAGE and RIA were better correlated ( r 2 = 084) than concentrations measured by reducing SDS-PAGE and HPLC ( r 2 = 065) because under reducing conditions immunochemically nonreactive albumin is unstable and fragments into many smaller peptides The partially purified preparation was found to contain <1% contamination by common urinary proteins and is stable to freezing and frequent freeze/thaw cycles
Conclusions: The results are consistent with the interpretation that immunochemically nonreactive albumin has a limited number of polypeptide chain scissions and is held together by noncovalent intrachain bonding and disulfide bonds Detection of this molecule is likely to be of clinical importance in diagnosing kidney disease as well as cardiovascular disease
TL;DR: 6-Nitro-L-tryptophan in proteins can be measured as an additional biomarker of protein nitration as well as under physiological conditions.
TL;DR: Microspheres with a double-walled morphology have the potential for therapeutic use where a high burst might be detrimental and a significantly lower initial release rate compared to microspheres where the drug was located in the outer layer, or compared tomicrospheres made from PLA only.
TL;DR: The mechanism of protein uptake is similar to that earlier proposed for linear polyelectrolytes and involves a “relay-race” transfer of protein molecules from one...
Abstract: Sorption of proteins such as cytochrome c, lysozyme or protamine by slightly cross-linked poly(acrylic acid) and bovine serum albumin by slightly cross-linked poly(N,N-dimethyl-N-ethylaminoethyl methacrylate bromide) hydrogels in salt-free and saline aqueous solutions was studied. The polyanionic hydrogel uptakes the proteins at pH below their isoelectric points while polycationic one at pH above them. As a result highly swollen original hydrogel transforms into relatively compact cross-linked polyelectrolyte−protein complex. Sorption of proteins by slightly cross-linked polyelectrolyte hydrogels is a chemically drawn diffusion process. The driving force of the process comes from the gain in the free energy of the interpolyelectrolyte coupling reaction between the protein and oppositely charged segments of the polyelectrolyte network. Apparently the mechanism of protein uptake is similar to that earlier proposed for linear polyelectrolytes. It involves a “relay-race” transfer of protein molecules from one...