Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously reported the isolation of a 66 kDa melanoma-associated antigen, identified by autologous antibody, in serum and unfractionated spent tissue culture media by Western blot analysis. The antigen, detected by autologous serum S150, was found to be broadly represented on melanoma, glioma, renal cell carcinoma, neuroblastoma and head and neck carcinoma cell lines. S150 did not react with bladder or colon carcinoma, fetal fibroblasts, pooled platelets, lymphocytes and red blood cells, autologous cultured lymphocytes or fetal calf serum. To further characterize the antigen, spent tissue culture media, obtained from autologous melanoma cell line, Y-Mel 84:420, was separated by an isoelectric focusing column. Unabsorbed control serum S150 was noted to have a maximum titer of 1:2040 against autologous melanoma cells as measured by protein A hemadsorption. Following isoelectric focusing the greatest decrease in autologous antibody titer (30-fold) occurred with fractions having a pI between 2 and 3. Further resolution of the antigen was accomplished with high-pressure ion-exchange chromatography. One of these fractions showed a significantly higher concentration of antigen and was distinctly resolved from bulk serum albumin. Subsequent Western blot analysis, with autologous antibody, of the isolated antigen-containing fraction, confirmed the presence of a single 66 kDa band. Exposure of the antigen, purified by high-pressure ion-exchange chromatography, to neuraminidase ablated recognition by autologous antibody and suggests that sialic acid is present on the protein and may be part of the antigenic epitope. Binding of antigen, obtained following DEAE anion exchange chromatography, was noted to lectins derived from Triticum vulgaris, Dolichos biflorus and Lycopersicon esculentum. Preparative purification of the antigen was accomplished by anion exchange followed by lectin affinity chromatography with a Dolichos biflorus column. Antigen obtained following lectin affinity chromatography subjected to SDS-PAGE and silver stain revealed a single band at 66 kDa. We conclude that a melanoma-associated antigen detected by autologous antibody in spent tissue culture media is an unusually acidic glycoprotein (pI 2-3).
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PMID:Purification and partial characterization of a shed 66 kDa melanoma-associated antigen identified by autologous antibody. 193 77

Processing of the measles virus haemagglutinin (H) protein was analysed by the pulse-chase method, immunoprecipitation with an anti-H monoclonal antibody and SDS-polyacrylamide gel electrophoresis, combined with the addition of carbonyl cyanide m-chlorophenylhydrazone (CCCP) or monensin (inhibitors of intracellular processing of secretory proteins) to cultures and digestion of the protein with endoglycosidase H or neuraminidase. The apparent Mr of the H protein was increased from 74K to 78K during the chase period. Addition of either CCCP or monensin to the chase medium inhibited the appearance of the 78K H protein, but not the immunoreactivity of the H protein or dimer formation, suggesting that these two events occur in the rough endoplasmic reticulum. The 74K H protein processed in the presence of CCCP was fully sensitive to endoglycosidase H digestion, whereas the 74K H protein processed in the presence of monensin was partially resistant to endoglycosidase H. In experiments using 3H-labelled sugars, [3H]galactose was incorporated into the 74K H protein in the presence of monensin. Neuraminidase treatment increased the electrophoretic mobility of the 78K H protein to 74K. Only the 78K H protein was detected on the surface of untreated cells, and it was resistant to endoglycosidase H digestion. These data suggest that after galactose addition sialic acid is added to the H protein in the trans-Golgi complex and then the mature 78K H protein is transported to the cell surface.
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PMID:Glycosylation of measles virus haemagglutinin protein in infected cells. 194 Aug 65

Hanganutziu-Deicher (HD) antigen is a heterophile antigen that is widely distributed in many animals other than humans and chickens and is highly immunogenic in humans and chickens. In the present study, we demonstrated expression of HD-antigenic glycoproteins in activated T lymphocytes by SDS-PAGE and immunoblotting. Treatment with IL-2 plus PMA induced 29kD glycoprotein antigen detected under reducing condition. It contained sialic acid epitope of HD antigen because of the expression being neuraminidase-sensitive. Treatment with PMA plus A 23187 or PHA treatment and then PHA plus IL-2 treatment also induced two proteins of Mr 50kD and 70kD. These expressions were not detected in all individuals examined. These results indicate that HD antigen is an activated T cell antigen and expressed as an isoantigen as it is expressed in cancerous tissues from some patients.
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PMID:Expression of Hanganutziu-Deicher antigen in activated human T lymphocytes. 195 1

TNF-alpha and lymphotoxin (LT or TNF-beta) are structurally related cytokines that share several proinflammatory and immunomodulatory activities. The shared biologic activities of TNF and LT have been attributed to their binding to a common cell surface receptor(s). We observed that rTNF enhanced the expression of MHC class I proteins on the human T cell hybridoma, II-23.D7, however LT was largely unable to regulate MHC expression. To determine the molecular basis of this disparity between LT and TNF the receptor binding characteristics of rTNF and rLT were investigated by direct and competitive radioligand assays on the II-23.D7 T hybridoma, and for comparison, anti-CD3 activated human T lymphocytes. Specific 125I-rTNF binding to the II-23.D7 line revealed a single class of sites with a Kd = 175 pM and 3000 sites/cell; anti-CD3 activated T cells exhibited specific TNF binding with similar properties. The relationship of receptor occupancy to the induction of MHC class I Ag yielded a hyperbolic curve indicating a complex relationship between rTNF binding and biologic response. LT appeared to function like a partial agonist in that rLT was 10- to 20-fold less effective than rTNF in competitively inhibiting 125I-rTNF binding on the II-23.D7 line. Scatchard type analysis revealed a single class of low affinity binding sites for 125I-rLT. No differences in the competitive binding activity of rTNF and rLT were observed on the anti-CD3-activated T cells. Receptors for rTNF and rLT were immunoprecipitated from the II-23.D7 and activated T cells with anticytokine antibodies after cross-linking of radioiodinated rTNF or rLT to intact cells by using chemical cross-linking reagents. Analysis of the cross-linked adducts by SDS-PAGE and autoradiography indicated a major adduct of 92 kDa for rTNF and 104 kDa for rLT. Enzymatic digestion with neuraminidase or V8 protease revealed a unique structure to these adducts consistent with the cross-linking of a single chain of cytokine to a cell surface glycoprotein. rTNF inhibited the formation of the 104-kDa adduct formed with 125I-rLT on the II-23.D7 line, indicating these two cytokines bind to the same receptor of approximately 80 kDa. These results suggest that the disparate activities of LT and TNF to induce MHC class I proteins on the II-23.D7 cells are, in part, associated with a modified state of a common receptor.
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PMID:Characterization of the receptor for tumor necrosis factor (TNF) and lymphotoxin (LT) on human T lymphocytes. TNF and LT differ in their receptor binding properties and the induction of MHC class I proteins on a human CD4+ T cell hybridoma. 196 53

Fluorescent lectin binding to cell surfaces was quantitatively analysed by flow cytometry on mortal human breast epithelial cells MCF-10M, the immortalized cell line MCF-10A derived from MCF-10M and sublines of MCF-10A transfected with the neomycin resistance gene (MCF-10Aneo), the c-Ha-ras protooncogene (MCF-10AneoN), or transfected and transformed with the c-Ha-ras activated oncogene (MCF-10AneoT). Immortal MCF-10A cells bound 10-fold more peanut agglutinin (PNA) and soy bean agglutinin (SBA) than did MCF-10M cells. Transformed MCF-10AneoT cells bound approximately ten times more PNA than did non-transformed cells transfected with protooncogene (MCF-10AneoN). Treatment of the transfectants with neuraminidase abrogated the differences in PNA-binding and reduced the differences in SBA binding. SDS-PAGE separation of PNA binding glycoproteins revealed different patterns for all MCF-10A derived sublines.
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PMID:Cell surface glycosylation changes accompanying immortalization and transformation of normal human mammary epithelial cells. 202 77

In this study we demonstrate that haptoglobin, a serum glycoprotein secreted by the liver, has altered structure in the BB/Wor diabetic rat. SDS-PAGE of haptoglobin (a tetramer composed of two glycosylated beta-chains each containing two sites for Asn-linked oligosaccharides connected by disulfide bonds with two nonglycosylated alpha-chains) clearly shows that the beta-chain of haptoglobin from diabetic rats is smaller than normal, with a molecular mass of 39 instead of 40 kDa. Both acute and chronic diabetic rats exhibit the defect. Defective haptoglobin appears in the serum within 4 days of onset of the disease, but insulin therapy prevents the defect. Removal of Asn-linked oligosaccharides with peptide: N-glycosidase F from Flavobacterium meningosepticum abolished the size difference between the beta-chains from normal and diabetic haptoglobin, with the molecular mass in both cases shifting to 30 kDa. Haptoglobin from both normal and diabetic rats was resistant to digestion by endoglycosidase H from Streptomyces griseus, which cleaves high mannose-type chains. Removal of sialic acid with neuraminidase treatment resulted in a reduction in the molecular mass in both cases, but without eliminating the size difference between the two. These results demonstrate that haptoglobin from diabetic BB/Wor rats contains a structural abnormality which correlates with onset of the disease. The defect is most likely due to an alteration in Asn-linked oligosaccharides, probably involving a change in the neutral sugars of complex-type oligosaccharide chains. This finding represents the first example of an altered Asn-linked oligosaccharides in diabetes.
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PMID:Diabetic BB/Wor rat haptoglobin exhibits a probable structural abnormality in Asn-linked oligosaccharides. 202 25

Natural human interferon alpha 2 (IFN-alpha 2) was isolated from a preparation of partially purified human leucocyte IFN by monoclonal-antibody immunoaffinity chromatography. The purified protein had a specific activity of 1.5 x 10(8) i.u./mg; it was estimated to constitute 10-20% of the total antiviral activity of leucocyte IFN. N-Terminal amino-acid-sequence analysis identified the subspecies IFN-alpha 2b and/or IFN-alpha 2c, whereas IFN-alpha 2a was not detectable. The structure of natural IFN-alpha 2 was found to differ from that of its recombinant (Escherichia coli-derived) equivalent. First, reverse-phase h.p.l.c. showed that natural IFN-alpha 2 was significantly more hydrophilic then expected. Secondly, the apparent molecular mass of the natural protein determined by SDS/PAGE was higher than that of recombinant IFN-alpha 2; incubation under mild alkaline conditions known to eliminate O-linked carbohydrates resulted in a reduction of the apparent molecular mass to that of the recombinant protein. On sequence analysis of proteolytic peptides, Thr-106 was found to be modified. These results suggested that Thr-106 of natural IFN-alpha 2 carries O-linked carbohydrates. Reverse-phase h.p.l.c. as well as SDS/PAGE of natural IFN-alpha 2 showed that glycosylation is heterogeneous. For characterization of the carbohydrate moieties, the protein was treated with neuraminidase and/or O-glycanase and analysed by gel electrophoresis; in addition, glycopeptides obtained by proteinase digestion and separated by h.p.l.c. were characterized by sequence analysis and m.s. Further information on the composition of the glycans was obtained by monosaccharide analysis. The results indicate that natural IFN-alpha 2 contains the disaccharide galactosyl-N-acetylgalactosamine (Gal-GalNAc) linked to Thr-106. In part of the molecules, this core carbohydrate carries (alpha-)N-acetylneuraminic acid, whereas a disaccharide, probably N-acetyl-lactosamine, is bound to Gal-GalNAc in another proportion of the protein. Further glycosylation isomers are present in small amounts. As IFN-alpha 2 is the only IFN-alpha species with a threonine residue at position 106, it may represent the only O-glycosylated human IFN-alpha protein.
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PMID:Natural human interferon-alpha 2 is O-glycosylated. 204 76

1. Human, bovine and equine transferrins have been characterized with respect to mol. wt, and behavior on urea-polyacrylamide gels, and isoelectric focussing gels. 2. As shown by SDS-polyacrylamide gel electrophoresis human transferrin has one major polypeptide whereas both bovine and equine transferrins have two polypeptides. 3. The transferrins show multiple banded patterns on urea-polyacrylamide and isoelectric focussing gels, particularly when iron saturated. The various forms are not resolved by neuraminidase treatment.
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PMID:Electrophoretic characterization of human, equine and bovine transferrins. 206 Feb 80

A murine monoclonal antibody (E10) was made against cultured cartilage cells. The E10 antibody binding is localized to the surface of cultured cartilage cells in suspension and is present in the cytoplasm in paraffin embedded sections. There is no reactivity with cartilage matrix, or with the matrix of cartilaginous tumors. Reactivity is removed by treatment with trypsin and hyaluronidase, but not by treatment with heparinase, neuraminidase, and chondroitinase. Regeneration of E10 antigen after trypsinization takes 48 hours in chondrocytes in tissue culture. SDS-polyacrylamide gel electrophoresis of an E10 immune precipitate of cultured chondrocytes results in two peaks: one at a very high molecular weight and a small fragment at approximately 250 kd. Specificity has been demonstrated by cytofluorometry, immunofluorescence, and immunohistochemistry, in both frozen and paraffin-embedded tissues. Positive reactivity was seen in cultured cartilage cells, chondrocytes in fetal and adult cartilage, chondrosarcomas, and chordomas. Minimal reactivity was found in a chondromyxoid liposarcoma. Acinar cells of salivary and sweat glands and mast cells in various tissues and tumors were also positive. There was no reactivity with other tissues and tumors, including myxoid and mucinous tumors and epithelial tissues.
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PMID:Monoclonal antibody to human cartilage cells and its reactivities to chondrocytic tumors. 206 41

Rat liver macrophages express a galactose-specific receptor which mediates endocytosis of particles or neuraminidase-treated blood cells. From rat serum we now have isolated and purified a galactose-specific lectin by affinity chromatography. Comparative analysis of this serum galactose-binding protein with the galactose-particle receptor protein purified from rat liver macrophages and with C-reactive protein (CRP) reveals close relation or identity of these proteins. An apparent m.w. of 30,000 was determined for all three proteins by SDS-PAGE under reducing conditions and m.w. of about 130,000 by native PAGE. All three proteins exhibit the same pentameric, ring-shaped structure in electron microscopy after negative staining. Antibodies raised against the serum galactose-binding protein or against the macrophage receptor cross-react. A mAb specific for rat neo-CRP labels liver macrophages but not hepatocytes and reacts with the isolated protein in a Western blot assay. Furthermore, the galactose-particle receptor can be functionally replaced by purified CRP: the binding capacity for neuraminidase-treated E of receptor-depleted liver macrophages can be restored by preincubation with purified rat CRP. We therefore conclude that CRP occurs as a membrane-associated protein constitutively expressed on liver macrophages functioning as a receptor mediating galactose-specific binding of particulate ligands.
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PMID:A membrane-associated form of C-reactive protein is the galactose-specific particle receptor on rat liver macrophages. 210 7


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