Showing papers on "Human serum albumin published in 1981"
323 citations
TL;DR: A recombinant plasmid has been constructed which contains the mature protein coding region of the human serum albumin (HSA) gene and predicts a mature protein of 585 amino acids preceded by a 24 amino acid "prepro" peptide.
Abstract: A recombinant plasmid has been constructed which contains the mature protein coding region of the human serum albumin (HSA) gene. Bacteria containing this plasmid synthesize HSA protein under control of the E. coli trp promoter-operator. The DNA sequence and predicted protein sequence of HSA were determined from the cDNA plasmid and are compared to existing data obtained from direct protein sequencing. The DNA sequence predicts a mature protein of 585 amino acids preceded by a 24 amino acid "prepro" peptide.
209 citations
TL;DR: Unlike the usually employed thiobarbituric acid assay the present procedure is truly specific for the detection of ketoamine linkages of glycosylated proteins.
Abstract: A specific and sensitive method for quantification of the fructose-lysine linkages present in non-enzymatically glycosylated albumin and other proteins is described. Protein is hydrolyzed for 18 h in 6 mol/l HCl at 95 degrees C to yield furosine (epsilon-N-(2-furoylmethyl)-L-lysine) known as a specific degradation product of fructose-lysine. Furosine is then separated on HPLC and quantified by its UV-absorbance against a prepared fructose-lysine standard. The method has been successfully used for the determination of glycosyl-albumin in diabetic patients starting from 100 microliter serum or less, as well as for various other proteins. Unlike the usually employed thiobarbituric acid assay the present procedure is truly specific for the detection of ketoamine linkages of glycosylated proteins.
122 citations
TL;DR: Plasma albumin concentration and degree of binding do not correlate, but in normal hypoalbuminemic subjects the free fraction of dl‐methadone correlates negatively with the concentration of α1‐acid glycoprotein (α1‐AGP), an acute‐phase reactant protein.
Abstract: The distribution of basic drugs in blood differs qualitatively from that of acidic drugs. The binding of racemic, d-methadone, and l-methadone to human plasma and isolated protein fractions was studied by equilibrium dialysis at 37°. In plasma samples from 29 healthy subjects free fraction of dl-methadone was (x% ± SD) 10.62 ± 1.43. There were significant variations among subjects (p < 0.001). The free fraction of the d-isomer was 9.24 ± 1.61% and of the l-isomer, 12.44 ± 1.53%. Plasma albumin concentration and degree of binding do not correlate, but in normal hypoalbuminemic subjects the free fraction of dl-methadone correlates negatively with the concentration of α1-acid glycoprotein (α1-AGP), an acute-phase reactant protein. Percentage dl-methadone bound to purified human serum albumin (HSA) (4.1 gm/dl) was 36.60% (x ± SD). Isolated α1-AGP bound dl-methadone more avidly. As the α1-AGP increased from 0.05 to 2.0 gm/l, free fraction fell from 92.40% to 8.80%. Addition of α1-AGP (0.05 to 2.0 gm/l) to a physiologic concentration of purified HSA or to whole plasma progressively increased methadone binding. In eight monozygotic twin pairs, within-pair differences in binding of dl-methadone were less than in eight dizygotic twin pairs. Less than 20% of naloxone, codeine, morphine, heroin, pentazocine, and diphenoxylate bound to α1-AGP. Elevations of α1-AGP that occur in a variety of diseases may alter the kinetic and pharmacologic activity of methadone.
Clinical Pharmacology and Therapeutics (1981) 29, 211–217; doi:10.1038/clpt.1981.34
111 citations
TL;DR: The formation of protein-bound aggregates with defined stoichiometries and a high local vesicles concentration, as well as changes in the local degree of hydration, are proposed to be the driving forces for the protein-induced vesicle fusion in this system.
83 citations
TL;DR: The results establish that cathechols responsible for the production of the poison oak/ivy contact dermatitis in humans undergo a sequence of reactions in the presence of human serum albumin that lead to covalent attachment of the catechols to the protein via carbon-nitrogen bonds.
Abstract: Attempts to characterize potential biologically important covalent interactions between electrophilic quinones derived from catechols present in poison oak/ivy (urushiol) and biomacromolecules have led to the analysis of model reactions involving sulfur and amino nucleophiles with 3-heptadecylbenzoquinone. Characterization of the reaction products indicates that this quinone undergoes regiospecific attack by (S)-N-acetylcysteine at C-6 and by 1-aminopentane at C-5. The red solid obtained with 1-aminopentane proved to be 3-heptadecyl-5-(pentylamino)-1,2-benzoquinone. Analogous aminobenzoquinones were obtained with the quinones derived from the 4- and 6-methyl analogues of 3-pentadecylcatechol. All three adducts absorbed visible light at different wavelengths. When the starting catechols were incubated with human serum albumin almost identical chromophores were formed. These results establish that cathechols responsible for the production of the poison oak/ivy contact dermatitis in humans undergo a sequence of reactions in the presence of human serum albumin that lead to covalent attachment of the catechols to the protein via carbon-nitrogen bonds. Estimations of the extent of this binding indicate that, at least with human serum albumin, the reaction is quantitative.
74 citations
TL;DR: The optimal conditions for the thiobarbituric acid assay of ketoamine adducts on human serum albumin have been established and results were reproducible to within 6% over seven separate studies.
68 citations
TL;DR: Fluorescence spectra of protoporphyrin bound to its most affinitive site on human serum albumin, bound to human haemopexin and dissolved in human plasma reveal that, when present in plasma, at least 90% of this porphyrIn is bound to albumin.
Abstract: Fluorescence spectra of protoporphyrin bound to its most affinitive site on human serum albumin, bound to human haemopexin and dissolved in human plasma reveal that, when present in plasma, at least 90% of this porphyrin is bound to albumin. Human serum albumin binds protoporphyrin with an affinity KA = 3 X 10(9)M-1 in phosphate-buffered saline. The affinity of haemopexin for protoporphyrin is 4 times smaller. From these data it is concluded that less than 1% of plasma protoporphyrin is bound to haemopexin. Implications of the data for protoporphyrin transport and clearance are discussed.
63 citations
TL;DR: The structure of a new variant of serum albumin characterized by an abnormal propeptide is reported: Arg -Gly -Va l -Phe -Hi s -Arg , that appears not cleaved in vivo, but is easily Cleaved in vitro by incubation with trypsin.
62 citations
TL;DR: It is concluded that configurational isomerization of bilirubin is the predominant nonradiative pathway that competes with pigment fluorescence, that photoisomerization proceeds via a short-lived (much less than 18 ps) partially twisted excited-singlet-state intermediate, and that bilirutin remains relatively unihibited with respect to photoisomersomerization when bound to human serum albumin.
Abstract: We measure the fluorescence quantum yield of bilirubin bound to its highest-affinity site on human serum albumin to increase from about 0.001 near room temperature to 0.5 at 77 K. The quantum yield for configurational (Z leads to E) photoisomerization about the meso double bonds concomitantly decreases from about 0.22 to less than 0.01 over the same temperature range in reciprocal relationship to the fluorescence yield. Transient absorption spectra recorded after excitation with a 0.5-ps pulse of 305-nm light decay with a lifetime of 19 +/- 3 ps at 22 degrees C and 35 +/- 7 ps at 2 degrees C. Bilirubin undergoes the same photoisomerization reaction in chloroform solution, in which a similar short-lived (17 +/- 3 ps at 22 degrees C) transient is observed. From these and other data we conclude that configurational isomerization of bilirubin is the predominant nonradiative pathway that competes with pigment fluorescence, that photoisomerization proceeds via a short-lived (much less than 18 ps) partially twisted excited-singlet-state intermediate, and that bilirubin remains relatively unihibited with respect to photoisomerization when bound to human serum albumin.
58 citations
TL;DR: The predominant immunoglobulin class with polymerized albumin binding activity was IgG in sera from patients with chronic active hepatitis and alcoholic liver disease, and IgM in acute viral hepatitis, chronic persistent hepatitis, and primary biliary cirrhosis.
TL;DR: These results and those from inhibition studies with L-phenylalanine, L-homoarginine, phosphate and vanadate support the 3-gene hypothesis advanced from structural studies.
TL;DR: A two-state model describing this transition is presented and is used to describe results such as the cooperativity in proton binding, most clearly observable when Ca2+ is present, and the difficulty of measuring experimentally this cooperativity.
TL;DR: The distinct pH dependence of the esr signals observed in human and dog serum albumin complexes could be correlated to their respective optical spectra changes as a function of pH.
TL;DR: Phenol Red-binding curves in the presence of 1 mol of octanoate, 8 mol of stearate and 6 or 7 mol of linolenate per mol of albumin respectively indicated that the dye and the fatty acids do not complete for a common primary binding site.
Abstract: Binding of Phenol Red to human serum albumin at pH 7.0 was studied by ultrafiltration (n1 = 1, K1 = 3.9 X 1-(4) M-1, n2 = 5, K2 = 9.6 X 10(2) M-1). The presence of 1 mol of octanoate or decanoate per mol of albumin caused a decrease in dye binding (dye/protein molar ratio 1:1), which, in contrast with additional fatty acid, was very pronounced: 1-8 mol of palmitate or stearate resulted in a small, and apparently linear, displacement of Phenol Red. The displacement effect of 1-5 mol of oleate, linoleate or linolenate per mol of albumin was comparable with that of the equimolar concentrations of palmitate or stearate. A higher molar ratios the unsaturated acids caused a drastic decrease in dye binding. The different Phenol Red-displacement effects of low molar ratios of medium-chain and long-chain fatty acids indicate that these acids have different high-affinity binding sites. In accordance with this proposal, low concentrations of stearate had only a small effect on the Phenol Red-displacement effect of octanoate. Phenol Red-binding curves in the presence of 1 mol of octanoate, 8 mol of stearate and 6 or 7 mol of linolenate per mol of albumin respectively indicated that the dye and the fatty acids do not complete for a common primary binding site. In contrast, a secondary Phenol Red-binding site could be identical with the primary octanoate-binding site. Furthermore, the primary Phenol Red-binding site could be the same as a secondary linolenate-binding site. Assignment of the different primary binding sites for Phenol Red and for medium-chain and long-chain fatty acids to a model of the secondary structure of albumin is attempted.
TL;DR: The purified enzyme was stable at 4°C, but it was temperature sensitive, losing one-half of its activity in 20 min when stored at 45°C and the availability of purified active LCATase should permit further investigations into the enzyme's molecular and catalytic properties.
TL;DR: Polymerization of a commercial human serum albumin was investigated by two different techniques, high-performance liquid chromatography and gel electrophoresis and showed a concentration-dependent aggregation.
TL;DR: The biological half-life of prostacyclin in Krebs solution, human cell-free plasma or whole blood was measured by bracket assay on ADP-induced platelet aggregation by finding the protective effect of plasma was greater than that of whole blood.
Abstract: The biological half-life of prostacyclin in Krebs solution, human cell-free plasma or whole blood was measured by bracket assay on ADP-induced platelet aggregation. At 37 degrees C, pH 7.4, plasma and blood reduced the rate of loss of antiaggregatory activity compared with Krebs solution. The protective effect of plasma was greater than that of whole blood. This effect could be partially mimicked by the addition of human or bovine serum albumin to the Krebs solution. The stabilisation afforded by human serum albumin was dependent on the fatty acid content of the albumin, although this was less important for bovine serum albumin.
TL;DR: The binding to human serum albumin of some drugs (warfarin, furosemide and phenylbutazone) has been studied by high-performance liquid chromatography using the equilibrium saturation method and the obtained total affinities are in accordance with previous results.
TL;DR: The physiological importance of the N-B transition in changing albumin binding parameters for drugs and endogeneous compounds caused by small changes in blood concentrations of hydrogen and other ions is discussed.
TL;DR: Human Z protein from liver was purified to homogeneity and revealed that Z protein was localized in the cytoplasm of hepatocytes, proximal tubular epithelium, and epithelial cells of the small intestine.
TL;DR: The interaction of the immobilized triazine dye Cibacron Blue 3G-A with rat, rabbit, sheep, goat, bovine and human serum albumins was studied by affinity gel electrophoresis and showed human serumalbumin to have a significantly higher affinity for the dye than did albumin from any other species.
Abstract: The interaction of the immobilized triazine dye Cibacron Blue 3G-A with rat, rabbit, sheep, goat, bovine and human serum albumins was studied by affinity gel electrophoresis. Dissociation constants were estimated in each instance and showed human serum albumin to have a significantly higher affinity for the dye than did albumin from any other species. Pretreatment of the defatted proteins with bilirubin (3 mol of bilirubin/mol of protein) did not increase the dissociation constants of the serum albumins, whereas pretreatment with palmitate (7 mol of palmitate/mol of protein) increased the dissociation constant in all cases: 3-fold for human serum albumin, 15-fold for other serum albumins. Increasing the bilirubin/albumin ratio (to 7:1) did not affect the dissociation constant of the albumins studied. Decreasing the palmitate/albumin ratio decreased the dissociation constant for human serum albumin, but did not affect those of bovine and rat albumins. Altering the chain length of the presaturating fatty acid dramatically changed the dissociation constant of both human and bovine serum albumins. Butyrate, hexanoate, octanoate and decanoate did not significantly influence the dissociation constants of bovine and human serum albumins for Cibacron Blue, whereas laurate, myristate and palmitate greatly increased the dissociation constant. These data are discussed in relationship to the behaviour of albumins during dye--agarose column chromatography. In Addendum the effect of nucleotide presaturation on the interaction between Bacillus stearothermophilus 6-phosphogluconate dehydrogenase and the immobilized triazine dyes Cibacron Blue 3G-A and Procion Red HE-3B was examined, and the implications for dye--ligand chromatography are discussed.
TL;DR: Using this method, transcobalamin II, transferrin, or insulin linked to minibeads was incubated with mouse L1210 cells, rat reticulocytes, and adipocytes and evidence for receptor-mediated transport process was also obtained.
TL;DR: Monomer and dimer fractions of human serum albumin obtained from charcoal-treated Fraction V HSA have very similar fluorescence and circular dichroism spectra, but the dimer neither binds l -tryptophan nor reacts rapidly with p -nitrophenyl acetate.
Journal Article•
TL;DR: The binding parameters of valproic acid to human serum albumin (HSA) were determined by equilibrium dialysis and computed using non-linear regression, however unclassic, it was observed that thebinding parameters of VPA varied according to the concentration of the HSA solutions used.
Abstract: The binding parameters of valproic acid (VPA) to human serum albumin (HSA) were determined by equilibrium dialysis and computed using non-linear regression. However unclassic, it was observed that the binding parameters of VPA varied according to the concentration of the HSA solutions used. At 580 microM HSA, VPA is bound to two classes of binding sites with the association constants K1 = 56000 M(-1) and K2 = 750 M(-1), and their respective numbers of binding sites n1 = 2 and n2 = 5. Free serum fraction of VPA is significantly increased by 500, 1000 and 1500 microM palmitate, 250 microM clofibrate, 320 microM phenylbutazone, or 360 microM salicylate. In any case, the increase of the VPA serum free fraction is highly correlated with the inhibitor concentration. On the other hand, the free serum fraction of warfarin is increased by 600 microM VPA (100 micrograms/ml). In patients with liver disease, the variations of the free serum fraction of VPA are correlated to the albumin and to the bilirubin concentrations. Serum binding of VPA is significantly decreased in the two groups of patients as compared with the control group.
TL;DR: The effect of albumin therapy was mainly an unexpected increase of the non‐binding fraction of serum albumin, while the increase ofthe serum reserve albumin concentration was small and the concentration of bilirubin‐albumin was not changed.
Abstract: Fifty-nine jaundiced light treated newborn infants with low birth weight were studied. At onset of phototherapy 30 infants received 1 g human serum albumin per kg body weight as a 9% solution containing sodium caprylate and N-acetyltryptophan as stabilizers. 29 infants did not receive human serum albumin and served as controls. Blood samples were taken before initiation of the therapy and again 24 and 48 h thereafter, and the following determinations were made: Serum concentrations of unconjugated bilirubin, albumin, reserve albumin for binding of bilirubin by the [14C]-MADDS method, packed cell volume and pH. Before infusion of albumin it was found that the binding fraction of serum albumin, i.e. the sum of the serum concentrations of bilirubin-albumin and reserve albumin, constituted about half of the total serum albumin concentration. The other half was non-binding, in agreement with previous findings in neonates. The effect of albumin therapy was mainly an unexpected increase of the non-binding fraction of serum albumin, while the increase of the serum reserve albumin concentration was small and the concentration of bilirubin-albumin was not changed.
TL;DR: Evidence is presented suggesting that denaturation of the albumin may adversely affect the endothelium and functional capabilities of preserved and autotransplanted canine kidneys.
Journal Article•
TL;DR: In this article, albumin anti-albumin immune complexes (IC) have been shown to bind to freshly isolated human peripheral blood monocytes and polymorphonuclear leucocytes (PMN) in vitro.
Abstract: Soluble human serum albumin anti-albumin immune complexes (IC) have been shown to bind to freshly isolated human peripheral blood monocytes and polymorphonuclear leucocytes (PMN) in vitro. Binding sites on both cell types were saturable and specifically inhibited by heat aggregated IgG1 and IgG3 subclasses. PMN contained a greater number of binding sites than monocytes although the affinity was similar for both cell types. The enhanced binding of IC by both cell types observed after incubation at low pH (pH 6.0) was a consequence of increased affinity of the PMN binding site and an increase in the number of sites in monocytes. Binding of IC by both cell types was inhibited by normal human serum. Enhanced IC binding associated with enhanced affinity and number of sites was observed in PMN and monocytes preincubated in suspension with trypsin. However, monocytes exposed to trypsin while adherent to microexudate coated flasks demonstrated a marked increase in affinity without any change in the number of sites.
Journal Article•
TL;DR: The hypothesis that the drug-binding defect in uremia is due to accumulation of endogenous metabolic products rather than to an intrinsic structural abnormality in serum albumin is strongly supported.
TL;DR: The results indicate that the first step in the conformational change of human serum albumin from the alkaline to the neutral form of the albumin-bilirubin complex is caused by electrostatic attraction between a carboxylate group of bilirub in and a histidine residue of albumin.