Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0393754 (HSA)
 2,996 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As an advanced stage of glycation, glycated human serum albumin (G-HSA; glucose content, 2 mol of 5-hydroxymethylfurfural equivalent/mol of HSA) was incubated at 37 degrees C up to 30 d in 0.2 M phosphate buffer, pH 7.4, with 100 microM Fe3+. G-HSA incubated for 30 d (G-HSA-30(Fe)) was subsequently hydrolyzed at 110 degrees C for 24 h in 6 N HCl. In the hydrolysate, N epsilon-carboxymethyllysine (CML) was identified by cochromatography with synthesized CML on an amino acid analyzer. pI of HSA (4.8) shifted to 4.5 in G-HSA. A more acidic fraction, pI 4.3, appeared in G-HSA-30(Fe). CML content (mol of CML/mol of HSA) of HSA and G-HSA was as follows; 0 in HSA, 0.2 in HSA-30(Fe), 0.4 in G-HSA and 1.5 in G-HSA-30(Fe) pI 4.3. The amino acid compositions also changed in lysine, arginine and tyrosine at the advanced stage of the reaction.
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PMID:Identification of the carboxymethyllysine residue in the advanced stage of glycated human serum albumin. 161 83

The binding of ritodrine HCl in whole plasma from healthy nonpregnant women, parturients and matched umbilical venous plasma and in solutions of HSA and alpha 1-AGP has been studied by equilibrium dialysis. Binding to plasma from nonpregnant subjects and HSA was independent of ritodrine concentration over a wide range. The free fraction in plasma was high and significantly different between groups of nonpregnant (alpha = 0.64), parturient (alpha = 0.68) and matched umbilical venous plasma (alpha = 0.75). It would seem that variability in transplacental transfer of ritodrine, as a result of plasma binding fluctuations, will be minor.
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PMID:Plasma protein binding of ritodrine at parturition and in nonpregnant women. 402 53

We studied the effect of various anions (of acids and salts) on the acid denatured state of HSA by near-UV circular dichroism (CD), far-UV CD, 1-anilinonaphthalene-8-sulfonate (ANS) binding, tryptophan fluorescence and thermal transition. Addition of different acids and salts caused an induction of alpha-helical structure as evident from the increase in the mean residue ellipticity (MRE) value at 222 nm and loss of ANS binding sites exhibited by the decrease in the ANS fluorescence intensity at 480 nm. However, the concentration range of acids/salts required to bring about the transition varied greatly among different acids and salts. Among various acids/salts tested, K(3)Fe(CN)(6) was found to be most effective whereas HCl and KCl were least effective in inducing the properties close to native structure. Further, they followed the electroselectivity series. The near-UV CD spectra showed an increase in MRE towards the native state, whereas the tryptophan fluorescence emission spectra produced a red shift of about 6 nm on addition of KClO(4). The temperature-induced transition in the presence of 40 mM KClO(4) monitored by ellipticity measurements at 222 nm was characterized by the presence of an intermediate state in the temperature range 30-50 degrees C having abundant secondary structure. These results suggest that human serum albumin at low pH and in the presence of acids or salts exists in a partially folded state characterized by native-like secondary structure and tertiary folds.
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PMID:Anion-induced refolding of human serum albumin under low pH conditions. 1060 75

In pH 7.40 Tris-HCl buffer solution, PMA is light yellow and has no absorption peak in the visible region. HSA has no color and no absorption peak in the visible region either. There is a fluorescence peak at 350 nm for HSA in pH 7.40 Tris-HCl buffer solution. HSA and PMA can combine into HSA-PMA association nanoparticles with a diameter about 80 nm by means of static gravitation. HSA has both hypochromic and color enhancement effects on PMA through our research. The fluorescence of Trp, Tyr and HSA can be quenched by PMA, but their quenching mechanisms are different. The fluorescence quenching of Trp and Tyr by PMA is due to molecule absorption in the range of emission wavelength, namely because of energy transfer often reported. The investigation results demonstrated that the formation of HSA-PMA associated nanoparticle and interface is the ultimate reason for fluorescence quenching, resonance scattering, and enhanced and hypochromic color.
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PMID:[Study on fluorescence quenching mechanism of HSA-PMA associated nanoparticle system]. 1576 22

Resonance light scattering (RLS) of Congo red (CR) was greatly enhanced by BSA (HSA) in the presence of Triton X-100 (TX-100). In sodium citrate-HCl buffer (pH 2.7-3.0), the enhanced intensity of resonance light scattering at 360 nm was in proportion to the concentration of proteins [corrected] The linear relationship was obtained between the resonance light scattering intensity and proteins in the range 5.0 x 10(-8)-8.0 x 10(-6) g/mL and 1.0 x 10(-9)-6.0 x 10(-6) g/mL for BSA and HSA, respectively. Their detection limits were 1.4 x 10(-8) g/mL and 2.8 x 10(-10) g/mL (S:N = 3), respectively. Synthetic and actual samples were analysed satisfactorily.
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PMID:Resonance light scattering technique for the determination of proteins with Congo red and Triton X-100. 1620 50

A new fluorescence method for the detection of proteins with novel composite nanoparticles (CdS/PPA) has been developed. The composite nanoparticles have been prepared through an in-situ polymerization method under ultrasonic irradiation. The surface of the composite nanoparticles was covered with functional groups (-COOH). These groups may play a major role in the improving the water solubility and biocompatibility of the nanoparticles. The composite particles is combined with proteins in NaAc-HCl buffer solution (pH=1.99), which can result in strong fluorescence, and the response is linearly proportional to the concentration of proteins. In lambdaem/lambdaex=650 nm/365 nm place (the stoke' shift is 285 nm), its fluorescent strength reaches the maximum. Under the optimum conditions, the linear range is 0.10-20.0 microg.ml(-1) with the detection limit of 41 ng.ml(-1) for HSA, and 0.10-15.0 microg.ml(-1) with the detection limit of 35 ng.ml(-1) for Human gamma-IgG . The method has been applied to the determination of the total protein in human serum samples collected from the hospital and the results are satisfactory.
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PMID:Preparation of a novel composite particles and its application in the fluorescent detection of proteins. 1680 2

Magnetic poly(ethylene glycol dimethacrylate-N-methacryloyl-(L)-histidine methyl ester) [mag-poly(EGDMA-MAH) beads, 50-100 microm in diameter, were produced by suspension polymerization for affinity depletion of immunoglobulin G (IgG) from human serum. Cu2+ ions were complexed directly via MAH groups (Cu2+ loading: 4.1 micromol/g). IgG depletion studies were performed by magnetically stabilized fluidized bed column. Acetate, Tris-HCl, MES and phosphate buffers all allow adsorption of similar quantities of IgG (27.3-45.6 mg/g). MOPS and HEPES allow higher adsorption quantities (79.6 mg/g and 74.1mg/g, respectively). Maximum adsorption capacities in MOPS buffer were 46.8 mg/g for mag-poly(EGDMA-MAH) and 102.1mg/g for Cu2+ chelated mag-poly(EGDMA-MAH) beads. The adsorption capacity decreased drastically from 102.1mg/g to 30.7 mg/g with the increase of the flow rate from 0.2 ml/min to 3.5 ml/min. The elution studies were performed by 1.0M NaCl. The elution results demonstrated that the adsorption of IgG to the adsorbent was reversible. To test the efficiency of IgG depletion from human serum, proteins in the serum and eluted portion were analyzed by two-dimensional gel electrophoresis. The depletion efficiency for IgG was above 99.4%. Eluted proteins include mainly IgG, and a small number of non-albumin proteins such as apo-lipoprotein A1, sero-transferrin, haptoglobulin and alpha1-antitrypsin. When anti-HSA-sepharose adsorbent is used together with our metal-chelated mag-beads, IgG and HSA can be depleted in a single step.
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PMID:Immunoglobulin G depletion from human serum with metal-chelated beads under magnetic field. 1697 89

Conformational transitions and functional stability of the bile salt hydrolase (BSH; cholylglycine EC: 3.5.1.24) from Bifidobacterium longum (BlBSH) cloned and expressed in E. coli were studied under thermal, chemical and pH-mediated denaturation conditions using fluorescence and CD spectroscopy. Thermal and Gdn-HCl-mediated denaturation of BlBSH is a multistep process of inactivation and unfolding. The inactivation and unfolding of the enzyme was found to be irreversible. Enzyme activity seems sensitive to even minor conformational changes at the active site. Thermal denaturation as such did not result in any insoluble protein aggregates. However, on treating with 0.25 - 1 M Gdn-HCl the enzyme showed increasing aggregation at temperatures of 40 - 55 degrees C indicating more complex structural changes taking place in the presence of chemical denaturants. The enzyme secondary structure was still intact at acidic pH (pH 1 - 3). The perturbation in the tertiary structure at the acidic pH was detected through freshly formed solvent exposed hydrophobic patches on the enzyme. These changes could be due to the formation of an acid-induced molten globule-like state.
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PMID:Bile salt hydrolase, the member of Ntn-hydrolase family: differential modes of structural and functional transitions during denaturation. 1745 5

In this paper, a sensitive resonance light scattering (RLS) method for the determination of protein is reported. In the Tris-HCl (pH 7.50) buffer, protein enhanced the RLS intensity of the Y(3+)-2-thenoyltrifluoroacetone (TTA)-sodium dodecyl sulphate (SLS) system. The enhanced RLS intensities were in proportion to the concentrations of proteins in the range 8.0 x 10(-9)-1.0 x 10(-5) g/mL for BSA, 1.0 x 10(-8)-1.0 x 10(-5) g/mL for HSA and 1.0 x 10(-8)-1.0 x 10(-6 )g/mL for EA, and their detection limits were 5.0, 5.4 and 6.7 ng/mL, respectively. Actual samples were satisfactorily determined. The interaction mechanism was also studied.
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PMID:Resonance light-scattering enhancement effect of the protein-Y3+-TTA-SLS system and its analytical application. 1854 50

Gold nanoparticles the size of about 10 nm were prepared by improved trisodium citrate reduction procedure, and were used to label goat anti-human IgG to obtain a sensitive spectral probe for IgG in the condition of pH 6.5. The immune reaction of nanogold-labeled IgG antibody (anti-IgG) with the antigen IgG took place to form the nanogold immune complex in pH 7.O Na2HPO4-C6H8O7 buffer solution and in the presence of polyethylene (PEG). The optimal immunoreaction conditions were pH 7.0, 10.76 microg x mL(-1) nanogold-labeled anti-IgG, 8.0% PEG 6000 and incubation time of 30 min under the ultrasonic irradiation. After centrifuging for 15 min at 16000 rpm, the excess nanogold-labeled anti-IgG in the upper solutions was obtained, and was used to catalyze the colored particle reaction of HAuCl4 with NH2 OH x HCl to produce gold particles with bigger size. The influence of pH value, HAuCl4 and NH2OH x HCl concentration, and reaction temperature and time on the immunonanogold catalytic reaction was considered spectrophotometrically. A pH 2.27 Na3C6H5O7-HCl buffer solution, 0.094 mmol x L HAuCl4, 1.92 mmol x L NH22OH x HCl, and reaction time of 6 min at 30 degrees C water bath were chosen for use. Results demonstrated that with increasing IgG, the concentration of gold labeled anti-IgG in the upper solution decreased, and the absorbance decreased linearly. Linear relationships between the decreased absorbance at 700 nm and the IgG concentration CIgG in the range of 0.10-10 ng x mL(-1) were obtained. Its regress equation was deltaA(760 nm) = 0.0144c(IgG) + 0.0042, the related coefficient was 0.9926, and the detection limit reached 0.06 ng x mL(-1) IgG. The influence of foreign substances on the determination of 3 ng x mL(-1) IgG was examined, with the relative error +/-10%. Results showed that the following coexistent substances had no impact on the assay: 6000 ng x mL(-1) HSA, 6000 ng x mL(-1) gluocose, 6000 ng x ml(-1) Zn(II), 3000 ng x mL(-1) IgA, 3000 ng x mL(-1) Ca(II), 3000 ng x mL(-1) L-arginine, 3000 ng x mL(-1) beta-phenylalanine, 2400 ng x mL(-1) Cu(II), 2400 ng x mL(-1) EDTA, 2400 ng x mL(-1) L-cystinol etc. This showed that the assay has high selectivity. The sensitive, rapid and highly specific assay was applied to the quantification of IgG in human sera, with satisfactory results.
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PMID:[Immunonanogold catalytic spectrophotometric determination of trace IgG]. 1924 17


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