Showing papers on "Bovine serum albumin published in 2000"
TL;DR: The first use of pulsed terahertz spectroscopy to examine low-frequency collective vibrational modes of biomolecules was reported in this paper, which indicated that a large number of the lowfrequency collective modes for these systems are IR active.
677 citations
TL;DR: The interaction of the surfactants with HSA showed an enhancement of fluorescence at low concentrations, opposite to the effect on BSA, consistent with the existence of a unique buried tryptophan residue in this protein with considerable static quenching in the native state.
412 citations
TL;DR: This review will concentrate on the critical description of the structural properties of experimentally tested protein scaffolds and of the novel functions that have been achieved on their basis, rather than on the methodology of how to best select a particular mutant with a certain activity.
Abstract: The use of so-called protein scaffolds has recently attracted considerable attention in biochemistry in the context of generating novel types of ligand receptors for various applications in research and medicine. This development started with the notion that immunoglobulins owe their function to the composition of a conserved framework region and a spatially well-defined antigen-binding site made of peptide segments that are hypervariable both in sequence and in conformation. After the application of antibody engineering methods along with library techniques had resulted in first successes in the selection of functional antibody fragments, several laboratories began to exploit other types of protein architectures for the construction of practically useful binding proteins. Properties like small size of the receptor protein, stability and ease of production were the focus of this work. Hence, among others, single domains of antibodies or of the immunoglobulin superfamily, protease inhibitors, helix-bundle proteins, disulphide-knotted peptides and lipocalins were investigated. Recently, the scaffold concept has even been adopted for the construction of enzymes. However, it appears that not all kinds of polypeptide fold which may appear attractive for the engineering of loop regions at a first glance will indeed permit the construction of independent ligand-binding sites with high affinities and specificities. This review will therefore concentrate on the critical description of the structural properties of experimentally tested protein scaffolds and of the novel functions that have been achieved on their basis, rather than on the methodology of how to best select a particular mutant with a certain activity. An overview will be provided about the current approaches, and some emerging trends will be identified. (c) 2000 John Wiley & Sons, Ltd. Abbreviations used: ABD albumin-binding domain of protein G APPI Alzheimer's amyloid beta-protein precursor inhibitor BBP bilin-binding protein BPTI bovine (or basic) pancreatic trypsin inhibitor BSA bovine serum albumin CBD cellulose-binding domain of cellobiohydrolase I CD circular dichroism Cdk2 human cyclin-dependent kinase 2 CDR complementarity-determining region CTLA-4 human cytotoxic T-lymphocyte associated protein-4 FN3 fibronectin type III domain GSH glutathione GST glutathione S-transferase hIL-6 human interleukin-6 HSA human serum albumin IC(50) half-maximal inhibitory concentration Ig immunoglobulin IMAC immobilized metal affinity chromatography K(D) equilibrium constant of dissociation K(i) equilibrium dissociation constant of enzyme inhibitor LACI-D1 human lipoprotein-associated coagulation inhibitor pIII gene III minor coat protein from filamentous bacteriophage f1 PCR polymerase-chain reaction PDB Protein Data Bank PSTI human pancreatic secretory trypsin inhibitor RBP retinol-binding protein SPR surface plasmon resonance TrxA E. coli thioredoxin
353 citations
TL;DR: It is concluded that the formation of soluble primary protein-polymer complexes is initiated at pHcrit and proceeds until "pH'crit", and a maximum in scattering intensity at pH phi is observed coincident with the appearance of turbidity and also corresponding to the first microscopic observation of coacervate droplets.
267 citations
TL;DR: It is suggested that patients can be sensitized with an IgE response against BSA leading to anaphylactic reactions and dendritic cells cultured in autologous serum or under serum-free conditions are recommended for therapeutic applications in vivo.
Abstract: Dendritic cells are professional antigen-presenting cells that can be generated in vitro either from monocytes or from CD34+ peripheral blood progenitor cells by using recombinant cytokines These cells have potential implications for immunotherapeutic approaches in the treatment of cancer and other diseases We have conducted a phase I study in melanoma patients using peptide-pulsed dendritic cells cultured in medium supplemented with 10% fetal calf serum (FCS) and a cocktail of cytokines Peptide-pulsed dendritic cells were injected intravenously at 2-week intervals Here we report on a case of type I hypersensitivity anaphylactic reaction after repetitive vaccination with autologous peptide-pulsed cells Pre-vaccination and post-vaccination serum samples were evaluated for the presence of antibodies to FCS and bovine serum albumin (BSA) A retrospective study in 7 patients vaccinated with FCS-cultured dendritic cells demonstrated the presence of IgG and IgM antibodies to FCS and BSA after vaccination in 6 out of 7 patients However, IgE antibodies were absent in all patients with the exception of the patient developing anaphylaxis The patient's serum was demonstrated to contain a strong IgE response directed against BSA In contrast, 2 patients vaccinated with dendritic cells cultured under serum-free conditions developed no antibodies to FCS and BSA after repetitive vaccination We suggest that patients can be sensitized with an IgE response against BSA leading to anaphylactic reactions On the basis of these data, dendritic cells cultured in autologous serum or under serum-free conditions are recommended for therapeutic applications in vivo
229 citations
TL;DR: The interaction between bovine serum albumin (BSA) and several surfactants has been investigated by light scattering as discussed by the authors, showing that cooperative binding of DTAB occurs at higher surfactant concentrations than in comparative solutions of SDS and C12E8.
Abstract: The interaction between bovine serum albumin (BSA) and several surfactants has been investigated by light scattering. Anionic (sodium dodecyl sulfate, SDS), cationic (dodecyl trimethylammonium bromide, DTAB), and nonionic (polyoxyethylene 8 lauryl ether, C12E8) surfactants, all containing a C12 alkyl chain, were used to study the effect of different headgroups on the complex formation. The hydrodynamic radii of the complexes obtained by dynamic light scattering indicate that cooperative binding of DTAB occurs at higher surfactant concentrations than in comparative solutions of SDS and C12E8. The effect of chain length is shown for the cationic surfactants DTAB and cetyl trimethylammonium bromide (CTAB, C16 alkyl chain). The higher surface activity of CTAB results in complex formation at a lower surfactant concentration compared to DTAB. The hydrodynamic radii of the BSA−SDS and BSA−DTAB complexes at saturation were determined as ∼5.9 nm and ∼4.8 nm, respectively. The hydrodynamic radius of the reduced BSA...
220 citations
TL;DR: The results emphasize the importance of electrostatic interactions in both adsorption processes, and the forces that attract hydrophobic side chains toward the protein-clay interface are large enough to distort peripheral amphiphilic helical domains.
219 citations
TL;DR: The present observations suggest that the two receptors cubilin and megalin are both involved in the endocytic uptake of albumin in renal proximal tubule cells.
201 citations
TL;DR: These findings demonstrate that melanin is a potent inhibitor of thermostable DNA polymerase in vitro and that the inhibitory effect is conferred by a direct and reversible polymerase-melanin interaction.
200 citations
TL;DR: This study developed four types of non-CML AGE anti-AGE antibodies that recognized proteins modified by incubation with short chain sugars and dicarbonyl compounds that enable us to identify such compounds created by the Maillard reaction in vivo.
Abstract: The Maillard reaction that leads to the formation of advanced glycation end-products (AGE) plays an important role in the pathogenesis of angiopathy in diabetic patients and in the aging process. Recently, it was proposed that AGE were not only created by glucose, but also by dicarbonyl compounds derived from the Maillard reaction, autoxidation of sugars and other metabolic pathways of glucose. In this study, we developed four types of non-carboxymethyllysine (CML) anti-AGE antibodies that recognized proteins modified by incubation with short chain sugars and dicarbonyl compounds. AGE-modified serum albumins were prepared by incubation of rabbit serum albumin with glyceraldehyde, glycolaldehyde, methylglyoxal or glyoxal. After immunization of rabbits, four types of AGE-specific antisera were obtained that were specific for the AGE modification. To separate non-CML AGE antibodies (Ab) (non-CML AGE-Ab-2, -3, -4, and -5), these anti-AGE antisera were subjected to affinity chromatography on a matrix coupled with four kinds of AGE bovine serum albumin (BSA) or CML-BSA. These non-CML AGE antibodies were used to investigate the AGE content of serum obtained from diabetic patients on hemodialysis. Characterization of the four types of non-CML AGE antibodies obtained by immunoaffinity chromatography was performed by competitive ELISA and immunoblot analysis. Non-CML AGE-Ab-2 cross-reacted with the protein modified by glyceraldehyde or glycolaldehyde. Non-CML AGE-Ab-3 and -Ab-4 specifically cross-reacted with protein modified by glycolaldehyde and methylglyoxal, respectively. Non-CML AGE-Ab-5 cross-reacted with protein modified with glyoxal as well as methylglyoxal and glycolaldehyde. Three kinds of non-CML AGE (AGE-2, -4, and -5) were detected in diabetic serum as three peaks with apparent molecular weights of 200, 1.15, and 0.85 kD; whereas, AGE-3 was detected as two peaks with apparent molecular weights of 200 and 0.85 kD. We propose that various types of non-CML AGE are formed by the Maillard reaction, sugar autoxidation and sugar metabolism. These antibodies enable us to identify such compounds created by the Maillard reaction in vivo.
187 citations
TL;DR: GA serves as an important intermediate for the generation of AGE structure(s) responsible for recognition by MSR-A, which is effectively inhibited by glucose-derived AGE-BSA, acetylated LDL, and oxidized LDL.
Abstract: Long-term incubation of proteins with glucose leads to the formation of advanced glycation end products (AGEs) that are recognized by AGE receptors. Glyoxal, glycolaldehyde (GA), and methylglyoxal are potential intermediates for the formation of AGE structures such as Nomega-(carboxymethyl)lysine (CML). We evaluated the contribution of these aldehydes to the formation of AGE structure(s), particularly the structure important for the receptor-mediated endocytic uptake of AGE proteins by macrophages. GA-modified bovine serum albumin (BSA), methylglyoxal-modified BSA (MG-BSA), and glyoxal-modified BSA (GO-BSA) were prepared, and their physicochemical, immunological, and biologic properties were compared with those of glucose-derived AGE-BSA. CML contents were high in GO-BSA and low in GA-modified BSA (GA-BSA) but did not exist in MG-BSA. The fluorescence patterns of GA-BSA and MG-BSA were similar to those of glucose-derived AGE-BSA but were weak in GO-BSA. Immunochemically, the antibody against non-CML structures of glucose-derived AGE-BSA reacted strongly with GA-BSA and weakly with GO-BSA but did not react with MG-BSA. The negative charge of these ligands increased to a similar extent. However, GA-BSA, but not MG-BSA or GO-BSA, underwent receptor-mediated endocytosis by the macrophage-derived cell line RAW 264.7, which was effectively inhibited by glucose-derived AGE-BSA, acetylated LDL, and oxidized LDL, which are well-known ligands for the macrophage type I and type II class A scavenger receptors (MSR-A). The endocytic uptake of GA-BSA by mouse peritoneal macrophages was also significant, but that by peritoneal macrophages from MSR-A-deficient mice was markedly reduced. Our results suggest that GA serves as an important intermediate for the generation of AGE structure(s) responsible for recognition by MSR-A.
TL;DR: The efficiency of photoactivated cross-linking of the proteins bovine serum albumin and fibrinogen, using rose bengal, have been determined and found to vary with photosensitizer concentration, which suggests that the mechanism for protein cross- linking is a direct hydrogen transfer between an amino acid residue of the protein and the dye molecule itself.
Abstract: Nonlinear multiphoton photo-cross-linking and photopolymerization of proteins and polymers in solution have been used to direct the three-dimensional assembly of micron scale objects. Two aspects of fabricated proteinatious matrixes are examined in this paper: the efficiency of protein photopolymerization and the application of fabricated matrixes as sustained release devices. The efficiency of photoactivated cross-linking of the proteins bovine serum albumin and fibrinogen, using rose bengal, have been determined and found to vary with photosensitizer concentration. This concentration dependence suggests that the mechanism for protein cross-linking is a direct hydrogen transfer between an amino acid residue of the protein and the dye molecule itself. A comparison of the surface structure of single and multiple protein oligomers is undertaken and shown to vary significantly depending on fabrication materials. Alkaline phosphatase bioactivity, upon entrapment in a protein structure, is maintained. The pro...
TL;DR: It is suggested that small amounts of protein are present in deproteinized cancellous bovine bone in close association with the mineral phase, and some of the extracted material has osteoinductive potential and may contain growth factors.
Abstract: Background: Preclinical and clinical studies indicate that deproteinized cancellous bovine bone is osteoconductive and may be osteopromotive. Previous studies using commercial preparations failed to demonstrate the presence of protein, implicating bone-mineral composition and 3-dimensional structure as reasons for clinical success; however, these studies did not examine whether osteoinductive factors might be present in close association with the mineral phase. Methods: Deproteinized cancellous bovine bone was decalcified and any protein present released by chaotropic solvents using the protocol described for purification of bone morphogenetic proteins (BMPs). Three extracts were obtained and tested for their ability to support osteoinduction in the calf muscle of nude mice. Results: Protein content averaged 11 µg/g based on absorbance at 280 nm using bovine serum albumin as a standard. All extracts contained material that stained positively with silver stain after sodium dodecyl sulfate polyacrylamide ge...
TL;DR: In this paper, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were used to examine the adsorption behavior of bovine serum albumin and fibrinogen on titanium in phosphate buffer pH 7.4.
Abstract: Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were used to examine the adsorption behavior of bovine serum albumin (BSA) and bovine fibrinogen on titanium in phosphate buffer pH 7.4, over the temperature range 295−343 K. It was shown that the surface charge density is directly proportional to the amount of the adsorbed protein (surface concentration), thus indicating that the adsorption is accompanied by the transfer of charge, i.e. chemisorption. On the other hand, the resulting adsorption pseudocapacitance obtained under the potentiostatic conditions not only depends on the protein surface concentration but also is a very complex function of parameters that are, in turn, dependent on structural, physical, and chemical properties of the proteins. Both techniques were shown to be very sensitive to the conformational behavior of the proteins. The adsorption of BSA onto a Ti surface resulted in a bimodal isotherm at all the temperatures studied, while the adsorption of fibrinogen resul...
TL;DR: Two high-pressure liquid chromatography-purified peptides from the 32-kDa tryptic digest showed complete homology to galectin-3 (previously designated Mac-2 antigen), an endogenous lectin with pleiotropic functions which is expressed in a wide variety of cell types with which C. albicans interacts as a saprophyte or a parasite.
Abstract: beta-1,2-linked oligomannoside residues are present, associated with mannan and a glycolipid, the phospholipomannan, at the Candida albicans cell wall surface. beta-1,2-linked oligomannoside residues act as adhesins for macrophages and stimulate these cells to undergo cytokine production. To characterize the macrophage receptor involved in the recognition of C. albicans beta-1,2-oligomannoside we used the J774 mouse cell line, which is devoid of the receptor specific for alpha-linked mannose residues. A series of experiments based on affinity binding on either C. albicans yeast cells or beta-1,2-oligomannoside-conjugated bovine serum albumin (BSA) and subsequent disclosure with biotinylated conjugated BSA repeatedly led to the detection of a 32-kDa macrophage protein. An antiserum specific for this 32-kDa protein inhibited C. albicans binding to macrophages and was used to immunoprecipitate the molecule. Two high-pressure liquid chromatography-purified peptides from the 32-kDa tryptic digest showed complete homology to galectin-3 (previously designated Mac-2 antigen), an endogenous lectin with pleiotropic functions which is expressed in a wide variety of cell types with which C. albicans interacts as a saprophyte or a parasite.
TL;DR: The separation of drug enantiomers using proteins as the chiral selectors in capillary electrophoresis (CE) is considered in this review and the advantages and limitations of the two modes and the factors affecting theChiral separations of various drugs by protein-based CE are discussed.
TL;DR: The specific binding to bovine serum albumin of anionic and non-ionic surfactants with C12 acyl chains has been studied by high sensitivity isothermal titration calorimetry and suggests that binding to low affinity sites exhibits energetic parameters; in particular, a large negative change in heat capacity, which is characteristic of hydrophobic interactions.
TL;DR: The blocking effects of Tween 20 and bovine serum albumin (BSA) were estimated using an original novel approach and the magnitude of saturation of the microwells was quantitated by measuring the enzymatic activity of alkaline phosphatase adsorbed to residual vacant sites in the microwell.
TL;DR: ESCA provides a direct, quantitative measure of the surface composition of spray-dried trehalose/protein/surfactant particles and shows how and why the addition of a surfactant reduces protein adsorption, and by thisMechanism could reduce protein instability during Spray-drying.
Abstract: Purpose. To characterize via electron spectroscopy for chemical analysis(ESCA) the surface of spray-dried particles of trehalose plus aprotein (bovine serum albumin). Additionally, to show how and whythe addition of a surfactant reduces protein adsorption, and by thismechanism could reduce protein instability during spray-drying.
TL;DR: The reaction of Na[transRuCl4Me2SO(Im)] (NAMI; where Im is imidazole), a novel anti-neoplastic ruthenium(III) complex, with BSA was studied in detail by various physico-chemical techniques and suggested that the described NAMI-BSA adducts may form in vivo and may be relevant for the biological properties of this complex.
Abstract: The reaction of Na[transRuCl4Me2SO(Im)] (NAMI; where Im is imidazole), a novel anti-neoplastic ruthenium(III) complex, with BSA, was studied in detail by various physico-chemical techniques. It is shown that NAMI, following chloride hydrolysis, binds bovine serum albumin tightly; spectrophotometric and atomic absorption data point out that up to five ruthenium ions are bound per albumin molecule when BSA is incubated for 24 h with an eightfold excess of NAMI. CD and electronic absorption results show that the various ruthenium centers bound to albumin exhibit well distinct spectroscopic features. The first ruthenium equivalent produces a characteristic positive CD band at 415 nm whereas the following NAMI equivalents produce less specific and less marked spectral effects. At high NAMI/BSA molar ratios a broad negative CD band develops at 590 nm. Evidence is provided that the bound ruthenium centers remain in the oxidation state +3. By analogy with the case of transferrins it is proposed that the BSA-bound ruthenium ions are ligated to surface histidines of the protein; results from chemical modification experiments with diethylpyrocarbonate seem to favor this view. Spectral patterns similar to those shown by NAMI are observed when BSA is reacted with two strictly related ruthenium(III) complexes Na[transRuCl4(Me2SO)2] and H(Im)[transRuCl4(Im)2] (ICR), implying a similar mechanism of interaction in all cases. It is suggested that the described NAMI-BSA adducts may form in vivo and may be relevant for the biological properties of this complex; alternatively NAMI/BSA adducts may be tested as specific carriers of the ruthenium complex to cancer cells. Implications of these findings for the mechanism of action of NAMI and of related ruthenium(III) complexes are discussed.
TL;DR: In this paper, the second virial coefficient (B2) of globular proteins in the presence of poly (ethylene glycol) (PEG) was measured for four molecular weights (400, 1000, 6000, and 12'000), providing an opportunity for quantitative comparison of measurements and theoretical predictions.
Abstract: The interactions between globular proteins in the presence of poly (ethylene glycol) (PEG) are probed through the measurement of the protein solution second virial coefficient (B2). The solution properties of PEG are characterized for four molecular weights (400, 1000, 6000, and 12 000), providing an opportunity for quantitative comparison of measurements and theoretical predictions of B2. PEG displays a buffer and molecular weight-dependent lower critical solution temperature. As the polymer solution approaches phase separation, the consequences of depletion attractions increase significantly. For lysozyme and bovine serum albumin in sulfate buffers with PEG, B2 is not well described by standard depletion models. This failure is accentuated in acetate buffers where B2 is a nonmonotonic function of polymer concentration. The attractive minima in B2 are closely associated with the proximity of the heating-induced phase separation of aqueous PEG solutions. The experimental data for both proteins in the pres...
TL;DR: Quantitative data obtained by the RP-HPLC method compared very favourably with data obtain by alternative methods of whey protein analysis.
TL;DR: In situ perfusion showed that brain uptake was improved by up to 98% for several of the glycosylated peptides, and the nociceptive profiles of the peptides followed the rank order of peptide entry to the brain with up to a 39-fold increase in A.C.U.
TL;DR: At Atomic force microscopy and surface plasmon resonance (SPR) analysis revealed that the surface coverage of the dextran monolayers increased with an increasing degree of thiol substitution, but conversely decreased with increasing molecular weight.
TL;DR: The results suggest that hypoalbuminemia is not due to reduced albumin synthesis during sepsis, andalbumin synthesis measured in the plasma is a good indicator of liver albumin Synthesis.
Abstract: Plasma albumin is well known to decrease in response to inflammation. The rate of albumin synthesis from both liver and plasma was measured in vivo by use of a large dose ofl-[2H3-14C]valine in rat...
TL;DR: This study has quantified the contribution of the N-terminal imidazole of HisGlyHis to the stability of the Cu(II) and Ni(ii) complexes of this protein sequence and has provided new insight about Cu( II) binding to albumin.
Abstract: The binding of Ni(II) and Cu(II) to histidine, to the tripeptides GlyGlyHis and HisGlyHis, and to the protein bovine serum albumin has been studied by isothermal titration calorimetry (ITC) to determine the experimental conditions and data analysis necessary to reproduce literature values for the binding constants and thermodynamic parameters. From analysis of the ITC data, we find that there are two major considerations for the use of this method to accurately quantify metal ion interaction with biological macromolecules. First, to determine true pH-independent binding constants, ITC data must be corrected for metal ion competition with protons by accounting for the experimental pH and pKa values of the metal-binding residues. Second, metal interaction with the buffer (stability and enthalpy of formation of metal−buffer complex(es)) must be included in the analysis of the ITC data to determine the binding constants and the change in enthalpy. While it may be possible to use a buffer that forms only weak,...
TL;DR: Targeted intracellular delivery of photosensitizers with real-time radiolysis enhances the chances of successful delivery of drugs to patients with high levels of inflammation.
Abstract: Targeted intracellular delivery of photosensitizers Alexander S. Sobolev*, David A. Jans, Andrey A. Rosenkranz Department of Biophysics, Biological Faculty, Moscow State University, 119899, Moscow, Russia Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Russian Academy of Science, Vavilov St. 34/5, 117984, Moscow, Russia Nuclear Signaling Laboratory, Division for Biochemistry and Molecular Biology, John Curtin School of Medical Research, Canberra, ACT 2601, Australia
TL;DR: The method has been successfully used to confirm illegal hormone administration for regulatory purposes and is reported to be high sensitivity and specificity based on tandem mass spectrometry with on-line high-performance liquid chromatography with atmospheric pressure chemical ionisation.
TL;DR: The present study suggests a dynamic, unusually flexible high affinity binding site for bilirubin on human serum album in aqueous solutions saturated with chloroform.
TL;DR: A single medium can be used successfully throughout maturation, fertilization and pre-implantation embryo development of bovine oocytes and embryos and inclusion of serum during maturation in the single medium system resulted in significantly greater cell numbers, possibly reflecting increased quality of the embryos produced.
Abstract: Oocytes and embryos are typically exposed sequentially to varying culture media in standard in-vitro protocols. Expenditures of energy may be required following each medium change to adjust to the changing environment. Therefore, a single base medium was evaluated for its ability to support in-vitro maturation, fertilization and pre-implantation development (IVM/F/C) of bovine oocytes and embryos. Four treatments were examined: a standard maturation [tissue culture medium (TCM) 199 with bovine calf serum (BCS)], fertilization (modified Tyrode's medium with albumin, lactate and pyruvate) and culture (hamster embryo culture medium/TCM with BCS) system (control) and three synthetic oviductal fluid (SOF) treatments; maturation in SOF with bovine serum albumin (SOFBSA), SOF with bovine calf serum (SOFBCS) or the control maturation medium (TCM199 with BCS; SOF199), followed by fertilization and culture in SOF medium. The percentage of total inseminated oocytes successfully developing to the morula and blastocyst stage did not differ (P > 0. 05) between treatments (control, 30.5 +/- 3.5; SOFBSA, 24.6 +/- 3.2; SOFBCS, 22.4 +/- 4.7; SOF199, 27.3 +/- 3.2). Embryos cultured in SOFBCS (92.1 +/- 6.4) had significantly higher cell numbers (P < 0. 05) than those cultured in control (74.8 +/- 4.8) and SOFBSA (71.6 +/- 6.6) but not SOF199 (81.2 +/- 6.8). In conclusion, a single medium can be used successfully throughout maturation, fertilization and pre-implantation embryo development. Moreover, inclusion of serum during maturation in the single medium system resulted in significantly greater cell numbers, possibly reflecting increased quality of the embryos produced.