Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum components with binding activity towards free human beta 2 microglobulin (beta 2m) were investigated in healthy adults. The binding activity increased after treatment of the serum components by dissociating buffers (acid pH, 2-8 M urea, 3 M NaSCN, 6 M guanidine hydrochloride). This activity resided in serum IgG as shown by the following evidence: (1) recovery in the 160 K region after AcA 44 filtration, (2) association with the IgG fraction after purification by DEAE chromatography and AcA 34 filtration, (3) after immunopurification on beta 2m-Sepharose immunosorbent, the labeled eluted fraction was shown to bind to beta 2m-Sepharose and to protein A or anti-IgG-Sepharose. Pepsin-digested F(ab')2 fragments from serum IgG were treated by 3 M urea, then passed on beta 2m-Sepharose immunosorbent in order to prepare specific anti-beta 2m F(ab')2. Those fragments retained all the beta 2m binding capacity of the IgG fraction. Saturation analysis studies showed estimated K values between 1.5 and 9.5 X 10(9) L/M, depending on the preparation it was concluded that normal human serum contains minute amounts of auto-antibodies of relatively high affinities, specific for beta 2m.
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PMID:Auto-antibodies specific for beta 2 microglobulin in normal human serum. 635 5

To investigate the nature of the 140 kDa glycoprotein in the trabecular meshwork, polypeptides were extracted with either urea/sodium dodecyl sulfate (SDS)/beta-2-mercaptoethanol (BME) or guanidine hydrochloride followed by pepsin digestion. After electrophoresis and immunoblotting with anti-type-VI-collagen antibodies, a single fraction of molecular weight 140 kDa was identified in the urea/SDS/BME extracts. Pepsin solubilization revealed two immunoreactive fractions (molecular weights 75 and 85 kDa) that comigrated with purified, pepsin-solubilized type VI collagen. By using the polymerase chain reaction (PCR) and primers specific for the alpha 2(VI) chain of type VI collagen, a single PCR product was obtained, which corresponded to the expected size of 137 base pairs, from the total RNA extracted from the trabecular meshwork ex vivo. Southern hybridization with the antisense oligonucleotide probe of the alpha 2(VI) chain confirmed that the amplified sequence was specific. The results show that the trabecular meshwork contains a significant amount of type VI collagen and that trabecular cells express the mRNA coding for the alpha 2(VI) chain of this glycoprotein. The presence of type VI collagen in the trabecular meshwork is implicated in cell-extracellular matrix interactions at this site, and its abnormal accumulation in glaucomatous and aging eyes probably signifies a defect in the function of the trabecular cells in these eyes.
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PMID:Identification of type VI collagen in the trabecular meshwork and expression of its mRNA by trabecular cells. 815 10

Peptides from a Staphylococcus aureus (V8) proteinase digest of human pepsin 3b have been identified by amino acid sequence analysis. Only 137 out of 326 expected residues were detected from the C and N terminal regions of the molecule. Comparison with amino acid sequences derived from nucleotide analysis of three different pepsinogen A genes, identified 2 out of 4 possible substitutions. The presence of valine at position 30 and leucine at 291 indicates that the major pepsin component of gastric juice, pepsin 3b, corresponds to pepsinogen genotype PGA-3. Reversed-phase chromatography of native human pepsin 3b on C4 (300 A), C18 (300 A) or polymer (1000 A) columns was optimal on the C4 column and gradient elution with 2-propanol rather than acetonitrile. Denaturation of the protein in guanidinium hydrochloride, urea or high pH resulted in irreversible column retention. The marked hydrophobicity of denatured pepsin 3b may thus explain why the central segment of the protein was not revealed by peptide map analysis.
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PMID:Human pepsin 3b peptide map sequence analysis, genotype and hydrophobic nature. 840 29

Pepsin successfully catalyzed the synthesis of several hydrophobic octa- and decapeptides in dimethylformamide-water solutions containing concentrated urea at pH 4.65. The factors that influence peptide synthesis in the presence of urea were studied using condensation of the tripeptides Z-Ala-Ala-Phe-OH and H-Leu-Ala-Ala-OCH3 as a model. The dependence of Z-Ala-Ala-Phe-Leu-Ala-Ala-OCH3 yield on pepsin concentration and pH, as well as the behavior of pepsin during peptide synthesis were studied. It was shown that pepsin catalyzed the synthesis of Z-Ala-Ala-Phe-Leu-Ala-Ala-OCH3 in guanidine hydrochloride and sodium dodecyl sulfate solutions. Other proteinases, subtilisin and thermolysin, were applied for the synthesis of p-nitroanilides of tri- and tetrapeptides in urea solutions. Proteinase-catalyzed peptide synthesis in the presence of denaturing agents might help to overcome the limitations caused by poor solubility of the starting peptide derivatives, although this effect is sometimes counterbalanced by the product solubility.
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PMID:Proteinase-catalyzed peptide synthesis in concentrated solutions of urea and other denaturing agents. 890 96

We analyzed the tissue-type plasminogen activator (TPA)-binding proteoglycans (PGs) on human umbilical vein endothelial cells (HUVECs), which were metabolically labeled with [35S]NA2SO4. Cell extracts were then prepared and subjected to affinity chromatography on diisopropyl fluorophosphate (DFP)-inactivated TPA-Sepharose 4B. Approximately 6% of the incorporated 35S radioactivity bound to DFP-treated TPA-Sepharose 4B and was eluted with 2 mol/L NaCl. In addition to NaCl, heparin, arginine, and lysine but not glycine, epsilon-amino-n-caproic acid or aspartic acid inhibited this binding and eluted the bound 35S radioactivity. Urea-containing polyacrylamide gel electrophoresis of the eluted material consistently revealed two main signals of 35S radioactivity (one with an M(r) between 600,000 and 750,000 [PGA] and the other with an M(r) between 120,000 and 180,000 [PGC]). Occasionally a less intense signal with an M(r) between 340,000 and 440,000 (PGB) was seen. Heparitinase treatment markedly decreased the intensities of both 35S signals (PGA and PGB), and chondroitinases AC and ABC abolished the 35S signal of PGC, indicating that most of the HUVEC-incorporated radioactivity with an affinity for TPA could be attributed to heparan sulfate- and chondroitin sulfate-like structures. Reductive elimination, which was performed to separate the possible glycosaminoglycan moieties from the core proteins, confirmed the PG-like nature of this material and again revealed heparan sulfate and chondroitin sulfate as the major glycosaminoglycan components. We therefore conclude that HUVECs synthesize TPA-binding, heparan sulfate- and chondroitin sulfate-containing PGs. In vivo, similar PGs may play a role in TPA binding to endothelial cells and thereby possibly influence TPA activity and/or provide an intravascular storage pool of TPA.
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PMID:Isolation and characterization of tissue-type plasminogen activator- binding proteoglycans from human umbilical vein endothelial cells. 896 24

The hydrolysis kinetics of native and denatured haemoglobin, using pepsin immobilized on aluminium oxide, was studied in order to produce hydrolysates containing bioactive peptides. Pepsin was immobilized on acidic alumina and on 2-ethanolamine- O -phosphate (2-EAOP)-modified acidic alumina. Surface charge of the two supports was determined as a function of pH. Kinetic studies were performed at 23 degrees C in 0.1 M acetate buffer, pH 4.5. At this pH, the surface charge of the two supports was almost the same. The coating of alumina by 2-EAOP only introduced a two carbon spacer between alumina surface and the reaction medium. Adsorption on the two supports of haemoglobin, haem and peptides produced in the course of hydrolyses were compared. Fixation of 2-EAOP on a pepsin-alumina complex gave hydrolysis kinetics of urea-denatured haemoglobin close to that obtained with the same amount of pepsin in solution, but with comparatively less adsorption of peptides and complete adsorption of haem. Heterogeneous hydrolyses of haemoglobin with pepsin, immobilized on functionalized alumina, resulted in the presence of VV-haemorphin-4, VV-haemorphin-7 and neokyotorphin in the supernatants without haem, the presence of which makes further purification difficult.
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PMID:A kinetic study of bovine haemoglobin hydrolysis by pepsin immobilized on a functionalized alumina to prepare hydrolysates containing bioactive peptides. 1503 40

This study describes the synthesis of urea formaldehyde (UF) microspheres by a dispersion polycondensation polymerization method. These microspheres with proper F/U molar ratio can provide highly reactive groups, capable of further condensation with the amino acid residues of enzyme/proteins. Presence of methylols groups in UF microspheres was confirmed by 13C NMR study. Pepsin, a proteolytic enzyme, was immobilized on the UF microspheres to form bioconjugate system. As compared to the free enzyme in solution, the pepsin in the bioconjugate system exhibited significantly enhanced pH and temperature stability. The urea-formaldehyde-pepsin bioconjugate system also exhibited excellent proteolytic activity over eight successive reuse cycles with more than 50% of initial activity. A highlight of this new biocatalyst is the ease with which separation of this biocatalyst from the reaction medium may be achieved by mild centrifugation.
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PMID:Preparation and characterization of urea-formaldehyde-pepsin bioconjugate: a new biocatalyst system. 1713 5

Polyelectrolyte multilayers of poly(L-glutamic acid) (PGA) and poly(L-lysine) (PLL) were built up using the layer-by-layer (LbL) technique in low pH (3.6, PM3.6) and in neutral pH (7.4, PM7.4) solutions. The multilayers were then treated with a concentrated urea (one kind of denaturant for proteins and polypeptides) solution (8M) and rinsed with corresponding buffer. The buildup and treatment processes were investigated by ultraviolet visible spectroscopy and ellipsometry. The surface morphology was observed by scanning force microscopy (SFM). The inner structures were determined by X-ray reflectometry and circular dichroism spectroscopy (CD). An exponential growth of the optical mass and the layer thickness was observed for both PM3.6 and PM7.4. After urea treatment, a significant mass loss for PM3.6 was found, while no mass change was recorded for PM7.4. The dominant driving force for PM7.4 is electrostatic interaction, resulting in multilayers with an abundant beta-sheet structure, which has higher stability against urea treatment. By contrast, the dominant driving force for PM3.6 is hydrogen bonding and hydrophobic interaction, which are sensitive to the urea treatment. The mechanism is substantiated by molecular mechanics calculation. This has offered a convenient pathway to mediate the multilayer properties, which is of great importance for potential applications.
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PMID:Influence of assembling pH on the stability of poly(L-glutamic acid) and poly(L-lysine) multilayers against urea treatment. 1806 58

Tissue engineering of the small intestine remains experimental despite worldwide attempts to develop a functional substitute for short bowel syndrome. Most published studies have reported predominant use of PLLA (poly-L-lactide acid)/PGA (polyglycolic acid) copolymer as the scaffold material, and studies have been limited by in vivo experiments. This lack of progress has inspired a fresh perspective and provoked further investigation and development in this field of tissue engineering. In the present paper, we exploit a relatively new nanocomposite of POSS (polyhedral oligomeric silsesquioxane) and PCL [poly(caprolactone-urea)urethane] as a material to develop porous scaffolds using a solvent casting/particulate leaching technique to fabricate porous scaffolds in different pore sizes and porosities. Scaffolds were characterized for pore morphology and porosity using scanning electron microscopy and micro-computed tomography. Rat intestinal epithelial cells were then seeded on to the polymer scaffolds for an in vitro study of cell compatibility and proliferation, which was assessed by Alamar Blue and lactate dehydrogenase assays performed for 21 days post-seeding. The results obtained demonstrate that POSS-PCL nanocomposite was produced as a macroporous scaffold with porosity over the range of 40-80% and pore size over the range of 150-250 microm. This scaffold was shown to support epithelial cell proliferation and growth. In conclusion, as a further step in investigating small intestinal tissue engineering, the nanocomposite employed in this study may prove to be a useful alternative to poly(lactic-co-glycolic acid) in the future.
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PMID:In vitro small intestinal epithelial cell growth on a nanocomposite polycaprolactone scaffold. 1986 Jul 39

The main objective of this study was to eliminate the hemagglutination activity of an antinutritional factor in soybeans, soybean agglutinin (SBA). A series of experiments was designed to enzymatically modify SBA structure and to use other physical treatments to reduce activity. SBA extract was prepared from soy flour and used as the substrate for all treatments. Deglycosylation by enzyme decreased activity of SBA by 21%, but not to the level of denaturation by heat or by denaturing reagents (47-77% residual activity). Single enzymes, such as trypsin, chymotrypsin, thermolysin, and endoproteinase Glu-C, did not hydrolyze native SBA, but they hydrolyzed heat- or organic solute-denatured SBA. Even after hydrolysis, SBA still had 44-62% residual activity. Combinations of enzymes with thermolysin fully deactivated heat- or guanidine hydrochloride- and urea-treated SBA. Pepsin and pancreatin hydrolysis fully deactivated not only heated but also native SBA. Tea polyphenols, metal ions, and chelating agents were also tested, and they showed no significant effect on SBA activity. N-Acetylgalactosamine-agarose beads specifically but not fully removed SBA from the soy protein mixture. In general, SBA needs to be denatured first for an effective enzymatic hydrolysis, and multiple enzymes are needed to fully deactivate SBA. Pepsin and pancreatin treatment showed great promise in fully reducing SBA activity, and it would be further tested using soy flour as a model system.
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PMID:Deactivation of soybean agglutinin by enzymatic and other physical treatments. 2094 44


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