Showing papers on "Bovine serum albumin published in 1976"
TL;DR: The Lowry protein assay is a sensitive but highly nonspecific procedure that has been modified so that protein can be assayed in the presence of interfering chemicals.
3,135 citations
TL;DR: A simple and rapid method for a highly sensitive radioimmunoassay of cyclic AMP and GMP is described, based on the observation that the affinity of the cyclic nucleotide antibodies for the 2′-0-succinyl or acetyl derivatives is considerably greater than that for the nonacylated cyclicucleotides.
325 citations
TL;DR: The sensitivity of binding to pH suggests a means whereby immunoglobulins which are selectively absorbed by the cells can be released efficiently at the abluminal surface.
Abstract: Rat and rabbit IgG immunoglobulins conjugated to horseradiah peroxidase as a histochemical marker bind at 0 degrees C to the luminal surface of absorptive cells in isolated segments of jejunum from 10-12-day old rats. Binding is observed at pH 6.0, near the normal luminal pH of the duodenum and jejunum at this age, but not at pH 7.4. Furthermore, no binding occurs when cells are exposed at pH 6.0 to either free peroxidase or peroxidase conjugated to chicken or sheep IgG immunoglobulins or bovine serum albumin. The sensitivity of binding to pH suggests a means whereby immunoglobulins which are selectively absorbed by the cells can be released efficiently at the abluminal surface.
273 citations
TL;DR: The reversible denaturations of bovine serum albumin solutions by heat, acid's, and alkali were studied and a new mechanism for heat denaturation has been proposed based on a continuous unfolding of the α‐helices.
Abstract: The Raman Spectra of bovine serum albumin have been obtained in the solute state, in alkaline and acidic solutions, and in the gel. The reversible denaturations of bovine serum albumin solutions by heat, acid's, and alkali were studied and a new mechanism for heat denaturation has been proposed based on a continuous unfolding of the α-helices.
256 citations
TL;DR: Bovine serum albumin, gelatin, fibrinogen and pepsin impaired the attachment of a marine pseudomonad to polystyrene Petri dishes, apparently through adsorption on the dish surface.
Abstract: Summary: Bovine serum albumin, gelatin, fibrinogen and pepsin impaired the attachment of a marine pseudomonad to polystyrene Petri dishes, apparently through adsorption on the dish surface. Serum albumin also appeared to affect the bacterial surface. The basic proteins protamine and histone did not markedly inhibit attachment. These findings are discussed in relation to comparative experiments using tissue cells.
202 citations
TL;DR: The behavior of neoglycoprotein toward rabbit liver membranes closely paralleled that of serum glycoproteins (Ashwell and Morell, 1974) with respect to sugar specificity.
Abstract: Thioglycosides of D-galactose, D-glucose, N-acetyl-D-glucosamine, and D-mannose were covalently attached to Aspergillus oryzae alpha-amylase, hen's eggs lysozyme, and bovine serum albumin by amidination, diazo coupling, and amide formation. The binding of the newly formed glycoproteins (neoglycoproteins) to rabbit liver membranes was measured, using asialoorosomucoid as a reference. Attachment of D-galactosides by any of the three methods enhanced binding by several orders of magnitude. Coupling of a comparable number of D-mannosides or N-acetyl-D-glucosaminides had little or no effect. Attachment of D-glucosides also enhanced binding but to a variable extent depending on the method of attachment. Thus, the behavior of neoglycoproteins toward rabbit liver membranes closely paralleled that of serum glycoproteins (Ashwell and Morell, 1974) with respect to sugar specificity.
167 citations
TL;DR: An experimentally induced Escherichia coli infection of a bovine mammary gland resulted in a 30-fold increase in lactoferrin (Lf) concentration in the mammary secretion by 90 h postinoculation and a 4-fold rise in total daily production of Lf by 264 h post inoculation in the infected quarter.
Abstract: An experimentally induced Escherichia coli infection of a bovine mammary gland resulted in a 30-fold increase in lactoferrin (Lf) concentration in the mammary secretion by 90 h postinoculation and a 4-fold increase in total daily production of Lf by 264 h postinoculation in the infected quarter A simultaneous rise and fall of bovine serum albumin (BSA) and immunoglobulin G (IgG) concentrations occurred during the acute phase of the infection Peak BSA and IgG levels were reached 36 h before peak Lf levels BSA concentrations declined rapidly after the acute phase, whereas IgG and Lf levels remained elevated and decreased slowly as the infection subsided A decline in alpha-lactalbumin concentration by 48 h postinoculation indicated decreased synthetic capability The increased Lf production may be a result of a specific response of secretory tissue to inflammatory agents and thus the infectious process Analogous changes in Lf, IgG, and BSA were observed during a natural coliform infection Sephadex G-200 chromatography of mastitis skim milk showed that Lf approximated the monomer (molecular weight 77,100) early in infections progressed and abated, the apparent molecular weight of Lf increased to approximately that of the trimer and subsequently decreased to about 15 times that of the monomer
155 citations
TL;DR: The receptor-mediated binding steps in the transport process are most easily studied in the chicken because of the enormous amount of oocyte membrane available from a given oocyte and because up to 1 gm of protein is normally transported per day per oocyte.
Abstract: Proteins are selectively sequestered by a number of cell types. However, only in oocytes is the process sufficiently aggravated and specific to be readily studied. In these cells certain serum proteins are taken up in proportions different from those found in the serum. In vitro incubations of hormonally stimulated and synchronous mosquito oocytes show that the only protein capable of initiating the transport process is the female specific yolk protein. Heterologous proteins such as IgG, bovine serum albumin, cytochrome C, and ferritin are inactive. The female specific protein is a phosphoglycolipoprotein. It is synthesized in the fat body, a liver analog in the insect, and passed into the serum before being transported into the oocytes. Preliminary kinetic analysis shows the uptake process to be specific with an apparent Km of about 10(-7) M. Glycolytic inhibitors stop protein uptake. The receptor-mediated binding steps in the transport process are most easily studied in the chicken because of the enormous amount of oocyte membrane available from a given oocyte and because up to 1 gm of protein is normally transported per day per oocyte. IgG and the hen specific phosvitin lipovitellin are two of the physiologically important proteins that are transported intact into the chicken oocytes. The uptake appears selective as shown by studies with iodinated proteins. Ferritin conjugated to IgG is shown by electron microscopy to bind to isolated plasma membranes only where coated pits have formed, whereas ferritin alone is not seen localized on any membrane surface. These very specialized regions of the membrane are similar to micropinocytotic pits but, in addition, possess on their cytoplasmic side dense ridges that form the coat. Transport involves binding to the coated pits, the pinching off of the pits, and the subsequent movement of the coated vesicles in the cytoplasm.
154 citations
TL;DR: No direct evidence for H2O2 formation during preincubation could be found, however, indirect evidence was obtained by the spectrophotometric detection of choleglobin formation from hemoglobin present in the lung supernatant fluid.
146 citations
TL;DR: It was decided to reisolate this modified peptide and to determine its amino acid sequence and to establish the identity of an amino acid residue in one of the binding sites of the albumin molecule.
109 citations
TL;DR: It is proposed that thrombin may play a role in wound healing by stimulating proliferation of not only fibroblasts but also B lymphocytes, a process of possible physiological significance in defending the host against pathogens and during inflammations.
Journal Article•
TL;DR: The antisera produced in rabbits immunized with propranolol conjugated to bovine serum albumin were used to develop radioimmunoassays for dl-proprolol and l-proPRanolol, which were able to discriminate the l- Propranolols selectively.
Abstract: Antisera against propranolol were produced in rabbits immunized with propranolol conjugated to bovine serum albumin. The antiserum against dl-propranolol recognized both d- and l-propranolol to the same degree. However, antiserum against l-propranolol was able to discriminate the l-propranolol selectively. The antisera were used to develop radioimmunoassays for dl-propranolol and l-propranolol. The assay can detect as little as 10 pg of propranolol. Metabolites of propranolol do not interfere with the assay unless concentrations are very high. Serum and heart levels of l-propranolol and the d-isomer were determined in the rat after i.v. injection (1 mg/kg) of dl-propranolol. l-Propranolol declines rapidly in the blood after the injection. Concomitantly, there is a rapid accumulation of l-propranolol by the heart. The d-form of propranolol remains in the blood and is metabolized rapidly as reflected by a shorter half-life (23.8 minutes) than the one found for l-propranolol (5.20 minutes).
TL;DR: It is suggested that displacement is essentially non-competitive and that glibenclamide is less susceptible to displacement by acidic drugs than tolbutamide or chlorpropamide.
TL;DR: The paradoxical effects of pyruvate on cysteine are probably due to the formation of a dissociable complex between these two compounds, which is not cytotoxic and resistant to oxidation.
Abstract: When added to Eagle's Minimum Essential Medium supplemented with 10% bovine serum (MEM-10BS), 1mM cysteine was highly toxic to cultured cells. This toxicity was eliminated by (a) preincubation of the medium at 37 degrees C for 24 hr before use, or (b) presence of 5mM pyruvate. Similar results were obtained with freshly prepared CMRL 1066 supplemented with 10% bovine serum (CMRL-10BS), which contains 1.5 mM cysteine as an original ingredient. Medium L 15 supplemented with 10% bovine serum (L-10BS), which contains both 1 mM cysteine and 5 mM pyruvate, supported cell growth. On incubation of MEM-10BS supplemented with 1 mM cysteine (MEM-10BS-1CySH) or CMRL-10BS without cells for one day, the cysteine concentrations decreased to about one-tenth or less of the original concentrations. The cysteine concentration in L-10BS did not decrease so much on similar incubation. Pyruvate reduced the rate of disappearance of the cysteine in MEM-10BS-1CySH or CMRL-10BS as assayed with p-chloromercuribenzoate, although less than that in L-10BS. This effect of pyruvate was concentration dependent. These paradoxical effects of pyruvate on cysteine, i.e. the reduction of its cytotoxicity and the stabilization as an SH compound, are probably due to the formation of a dissociable complex between these two compounds, which is not cytotoxic and resistant to oxidation.
Journal Article•
TL;DR: An oxygen-dependent, covalent interaction of radioactive 6-hydroxydopamine, 5,6-dihydroxtryptamine, and related compounds with several model proteins in vitro is described, suggesting that in the native proteins certain sulfhydryl and/or disulfide bonds are inaccessible to the amine.
Abstract: An oxygen-dependent, covalent interaction of radioactive 6-hydroxydopamine, 5,6-dihydroxtryptamine, and related compounds with several model proteins in vitro is described. 6-Hydroxydopamine and 5,6-dihydroxytryptamine react with bovine serum albumin in the presence of oxygen to yield a total of about 12 moles of amine bound per mole of protein. The nature of the oxidation product which reacts rapidly has not been defined, but in the case of 6-hydroxydopamine the amine moiety of the side chain, and hence cyclization to a dihydroxyindole, is not required. 5,7-Dihydroxytryptamine, norepinephrine, and dopamine react much more slowly, and tyramine, serotonin, and nonphenolic amines, not at all. The reaction of 6-hydroxydopamine and 5,6-dihydroxytryptamine appears to occur almost exclusively with sulfhydryl groups of proteins, but both amines appear capable of generating additional free sulfhydryl groups by reduction of disulfide bonds in proteins. Denaturation of proteins such as albumins or hemoglobins with 6 M urea results in a marked increase in the amount of radioactive amine bound per mole of protein. This binding approaches the theoretical number of potential free sulfhydryl groups, suggesting that in the native proteins certain sulfhydryl and/or disulfide bonds are inaccessible to the amine. In proteins which do not contain disulfide bonds, blockade of free sulfhydryl groups with N-ethylmaleimide renders the protein resistant to interaction with 6-hydroxydopamine. Polylysine reacts only slowly with 6-hydroxydopamine. The reaction product of radioactive 6-hydroxydopamine and bovine serum albumin consists primarily not of monomeric protein but of a series of polymeric proteins as determined by gel filtration and polyacrylamide gel electrophoresis. The cross-linking of bovine serum albumin to form polymers which occurred with both 6-hydroxydopamine and 5,6-dihydroxytryptamine was irreversible. Incorporation of more than 2 moles of amine per mole of protein appeared to be required for cross-linking. Acid hydrolysis of 6-hydroxydopamine-cross-linked bovine serum albumin yielded two radioactive, ninhydrin-positive products, which are suggested to be cysteine derivatives. The covalent binding and induction of cross-linking of proteins in vitro by 6-hydroxydopamine and 5,6-dihydroxytryptamine is discussed from a mechanistic standpoint and as a possible model for the mechanism of the cytotoxic actions of these compounds in vivo.
TL;DR: Immersion of juvenile rainbow trout in a solution containing either urea or sodium chloride at 1650 milliosmoles and 2 percent of bovine serum albumin resulted in an uptake of BSA into the blood of the fish after a 3-minute exposure.
Abstract: Immersion of juvenile rainbow trout (Salmo gairdneri) in a solution containing either urea or sodium chloride at 1650 milliosmoles and 2 percent of bovine serum albumin (BSA) resulted in an uptake of BSA into the blood of the fish after a 3-minute exposure. Similar blood levels of BSA were also obtained by placing the fish in 1650 millosmoles of sodium chloride for about 2 minutes, and then immersing them in 2 percent BSA solution for 3 minutes. Uptake of BSA into the fish appeared to be primarily through the lateral line system and secondarily through the gills.
TL;DR: T1 and T2 dispersion measurements of proton spin relaxation on aqueous solutions of bovine serum albumin as a function of both protein concentration and temperature will be presented as a most conclusive test for a three-phase fast-exchange relaxation model.
Journal Article•
TL;DR: Comparison of human plasma and saliva levels by the radioimmunoassay procedure indicated approximately equal concentrations in the two fluids, in agreement with previous work.
Abstract: Caffeine was analyzed in human plasma and saliva by a simple, rapid, and sensitive radioimmunoassay procedure. Immunization of rabbits with an antigen prepared by coupling 7-(5-carboxypentyl)-1,3-dimethylxanthine to bovine serum albumin resulted in the formation of antibodies selective for caffeine as opposed to various mono- and dimethylxanthines, mono-, di-, and trimethyluric acids and a variety of common drugs. The radioligand used for competitive binding studies was 7-(2,3-3H2-propyl)-1,3-dimethylxanthine. The procedure permits direct analysis of caffeine in plasma or saliva without extraction. Comparison with a high pressure liquid chromatography method for the analysis of caffeine gave satisfactory results and showed no evidence for interference by metabolites. A caffeine half-life of 4.0 hours determined by the radioimmunoassay was in agreement with previous work. Comparison of human plasma and saliva levels by the radioimmunoassay procedure indicated approximately equal concentrations in the two fluids.
Journal Article•
TL;DR: The data indicated that the aminoterminal region of type III collagen contains strong antigenic determinants located in a non-helical sequence of about sixteen amino acids that were purified and rendered specific fortype III collagen by immunoadsorption.
Abstract: A cross-linked fragment (peptide T1X) with a molecular weight of 13,000 could be isolated from a tryptic digest of insoluble type III collagen of calf skin. Peptide T1X was conjugated on to bovine serum albumin by glutaraldehyde and used for immunization of rabbits. The antisera reacted in passive haemagglutination and radioimmune assay with peptide T1X, type III collagen and its constituent alpha1(III) chain. Little or no reaction was observed with type I collagen and alpha1(I) chain. While rabbit antisera to neutral salt-soluble type III Collagen also showed a strong binding for 125I-labelled peptide T1X much less reaction was observed with antisera to type I collagen. The antigenicity of type III collagen was largely destroyed by pepsin treatment suggesting that it resided in non-helical segments. A fragment of peptide T1X produced by digestion with collagenase retained antigenic activity. The data indicated that the aminoterminal region of type III collagen contains strong antigenic determinants located in a non-helical sequence of about sixteen amino acids. Antibodies to these antigenic determinants were purified and rendered specific for type III collagen by immunoadsorption. The antibodies stained in indirect immunofluorescence tests particularly those regions in various connective tissues which are rich in reticulin fibres. Different staining patterns were observed with antibodies to type I collagen.
TL;DR: It is concluded that a) luminal peptides of four or more amino acids can stimulate the pancreas and b) during protein alimentation a wide array of luminal protein products may evoke pancreatic secretion.
Abstract: Pancreatic bicarbonate and protein secretory responses to intestinally perfused proteins or digests of proteins were measured in dogs with chronic gastric and pancreatic fistulas when luminalpancreatic protease concentrations were reduced to undetectable levels. Protein digests were analyzed for amino acid content, and various other indirect met-ods were used to assess the composition of the digest mixtures. Of five undigested proteins, none evoked more pancreatic secretion than a control perfusion with saline. Peptic digestion of these same proteins converted four of them to polypeptides that were poten stimuli of a pancreatic juice similar in HCO3-/protein ratios to that evoked by luminal amino acids. Dialyzed peptic digests of one of the proteins, bovine serum albumin (BSA), retained potency. Likewise, digestion of BSA with endogenous or exogenous pancreatic proteases converted the protein to a stimulus about equipotent with the peptic digest, though the composition of the pancreatic digests differed markedly from that of the peptic digests. We conclude that a) luminal peptides of four or more amino acids can stimulate the pancreas and b) during protein alimentation a wide array of luminal protein products may evoke pancreatic secretion.
TL;DR: In this article, the presence of antibodies against a dietary protein, bovine serum albumin (BSA), was investigated in the serum of normal subjects and patients with inflammatory bowel disease and celiac disease.
TL;DR: It is concluded that a pH difference across the lysosomal membrane (more acidic inside than outside) is maintained by the presence of indiffusible negatively charged groups within theLysosomes, and by the permeation across the LYSOSomal membrane of protons together with permeant anions.
TL;DR: The conversion site of proalbumin into serum albumin was investigated in the subcellular fractions of rat liver labeled with [3H] leucine in vivo, and more than 70% of the labeledalbumin was found as serum type, indicating that conversion of pro albumin into Serum albumin occurs within the secretory vesicles in rat liver.
TL;DR: In this paper, a rat liver albumin messenger RNA has been purified to apparent homogeneity by means of polysome immunoprecipitation and poly(U)-Sepharose affinity chromatography.
TL;DR: It is proposed that high turnover of cellular NAD+ is the source of aldehydic metabolites which may regulate macromolecular metabolism by covalent modification of nuclear proteins, whereas polyamines serve as modulators of this control cycle.
Abstract: Covalently bound adducts of ply(L-lysine), bovine serum albumin, lysine rich histone (f1) and deoxyribonucleotidase I (DNase, EC 3.1.4.5) with adenosine diphosphoribose and ribose-5-phosphate were prepared at pH 7.4 and 9.5. Macromolecular adducts of bovine serum albumin and histone (f1) were isolated by gel filtration and electrophoresis. Reduction of products by NaBH4 did not dissociate the ribose-5-phosphate moiety from macromolecules. Specific introduction of 3H into the adducts also indicated Schiff base formation. The reaction of ribose-5-phosphate with epsilon-amino groups of histone (f1) approached 70-90% saturation. Spermine and spermidine also react with adenosine diphosphoribose and ribose-5-phosphate to form 1:1 Schiff bases. It is proposed that high turnover of cellular NAD+ is the source of aldehydic metabolites which may regulate macromolecular metabolism by covalent modification of nuclear proteins, whereas polyamines serve as modulators of this control cycle.
TL;DR: Isolated domains of albumin refolded to native antigenic structure demonstrating that the entire polypeptide chain was not necessary for reformation of native structure, but there does seem to be some interdomain influence on the rate of refolding of a particular domain within the intact protein.
TL;DR: The inactivation os six strains from three different groups of viruses with 0.001 M binary ethyleneimine at 37 C proceeded at the same rate in either bovine serum or cell culture medium and did not affect the antibody activity of guinea pig hyperimmune serum.
Abstract: The inactivation os six strains from three different groups of viruses with 0.001 M binary ethyleneimine at 37 C proceeded at the same rate in either bovine serum or cell culture medium. The inactivant did not impair the growth-promoting capacity of bovine serum used in cell culture, nor did it affect the antibody activity of guinea pig hyperimmune serum.
TL;DR: Results suggest that rat sperm cells failed to capacitate in the absence of albumin, the protein exerted more than a nonspecific macromolecular effect, and lipids associated with albumin may modify its ability to promote sperm capacitation.
Abstract: Under defined conditions, in the presence of 10 mg/ml of bovine serum albumin, cauda epididymal rat spermatozoa displayed vigorous motility, and a high proportion (81%) of eggs were fertilized. In contrast, no fertilization was observed after omission of albumin, or replacement of the protein by 10 mg/ml of cytochrome c, beta-globulin, gamma-globulin, hemoglobin, lysozyme, and polyvinylpyrrolidone, and 5 mg/ml of ribonuclease. However, high motility occurred in suspensions containing 3 x 10(6) spermatozoa/0.1 ml of medium with cytochrome c, beta-globulin, or gamma-globulin. In medium with 1 mg/ml of ovalbumin, 7% (2/29) eggs were fertilized. Use of defatted albumin resulted in a higher rate of fertilization than unmodified albumin (87 vs 70%), and this difference approached statistical significance. No fertilization was obtained in the presence of albumin presaturated with cholesterol. These results suggest that: (a) rat sperm cells failed to capacitate in the absence of albumin; (b) the protein exerted more than a nonspecific macromolecular effect; and (c) lipids associated with albumin may modify its ability to promote sperm capacitation.
TL;DR: Measurements of the distribution of label in mice up to 23 days after injection suggest that metabolism of the labeled protein does not lead to binding of indium ions by transferrin, and demonstrates the kinetic inertness of the chelate.
Abstract: Human serum albumin has been conjugated to 1-(p-bnezenediazonium)-(ethylenedinitrilo)tetraacetic acid, a powerful chelating agent, and radioactive 111indium ions have been added specifically to the chelating groups. The product, with a specific radioactivity of about 1 mCi/mg of protein, was employed as a radiotracer in scintillation scanning studies with human volunteers. Results show that 48 hr after injection, practically all of the label remains attached to albumin. This is confirmed by electrophoresis of serum proteins; 7 days after injection, 85% of the radioactivity in the serum is still in the albumin fraction. These observations agree with in vitro studies of the labeled albumin in human serum, where loss of the metal ion from the chelating group to the protein transferrin amounts to less than 3% after 1 week and less than 5% after 2 weeks. Measurements of the distribution of label in mice up to 23 days after injection suggest that metabolism of the labeled protein does not lead to binding of indium ions by transferrin. The binding of indium and other metal ions by transferrin has previously posed a major impediment to the use of metal chelates for in vivo diagnostic procedures. Demonstration of the kinetic inertness of the chelate in these experiments suggests the use of related chelates as physical probes of biological systems.