Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.1.53 (sialidase)
2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gangliosides of hepatomas have been analyzed by using a monoclonal antibody directed to N-acetylneuraminosyl(alpha 2-6)lactoneotetraosylceramide (sialyl(alpha 2-6)paragloboside), which was prepared by injecting the monosialoganglioside fraction of human meconium into BALB/c mice. The monoclonal antibody, named MSG-15, was found to bind sialyl(alpha 2-6)paragloboside, but it failed to react with other gangliosides, including N-acetylneuraminosyl(alpha 2-3)lactoneotetraosylceramide (sialyl (alpha 2-3)paragloboside) and "Ii"-type gangliosides. MSG-15 was found to recognize NeuAc alpha 2-6Gal beta structure of the ganglioside. Gangliosides obtained from human hepatomas were analyzed by immunostaining on high-performance thin-layer chromatography plates using the monoclonal antibody MSG-15. All primary hepatoma samples used in this study (nine samples) were found to contain sialyl(alpha 2-6)paragloboside, which accounted for 13-31% of the monosialoganglioside fractions in the hepatomas. Furthermore, MSG-15 recognized several monosialogangliosides in addition to sialyl(alpha 2-6)paragloboside. These gangliosides apparently also contain a terminal NeuAc alpha 2-6Gal beta structure. Other ganglioside fractions obtained from hepatoma and meconium were immunostained on thin layer chromatography plates with MSG-15. Additionally, another monoclonal antibody (H-11), which recognizes terminal lactosamine structure, was used to immunostain these fractions after sialidase treatment. Bands stained with both monoclonal antibodies showed similar mobilities to each other in the di- and trisialoganglioside fractions as well as monosialoganglioside fraction. In control liver, GM3 ganglioside accounted for 92% of monosialoganglioside fraction, and sialyl(alpha 2-6)paragloboside accounted for less than 1% of the fraction. Immunohistochemical study by using MSG-15 in tissue sections from hepatocellular carcinoma and normal liver tissues demonstrated that only hepatocellular carcinoma cells gave a positive reaction. These results suggest that the biosynthetic pathway of gangliosides containing NeuAc alpha 2-6Gal beta 1-4GlcNAc beta structure is activated in hepatoma cells.
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PMID:Accumulation of gangliosides with N-acetylneuraminosyl(alpha 2-6)lactosamine structure in primary human hepatoma. 215 56

Human beta-mannosidosis urine was fractionated by gel permeation chromatography on Bio-Gel P-2 and by high performance liquid chromatography on Partisil 10 SAX. Besides the disaccharide Man beta 1-4GlcNAc as the major component, a sialic acid-containing compound was detected in an amount of 10% compared to that of Man beta 1-4GlcNAc. Structural characterization of the oligosaccharide and of its reduced analogue by sugar composition analysis, methylation analysis, gas-liquid chromatography-mass spectrometry, and 500-MHz 1H NMR spectroscopy gave conclusive evidence for a novel urinary constituent: NeuAc alpha 2-6Man beta 1-4GlcNAc. This linear trisaccharide can be considered as the result of an alpha 2-6-sialylation of the major accumulating compound, Man beta 1-4GlcNAc. The hitherto unknown linkage between sialic acid and mannose was shown to be susceptible to sialidase digestion.
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PMID:Sialyl-alpha 2-6-mannosyl-beta 1-4-N-acetylglucosamine, a novel compound occurring in urine of patients with beta-mannosidosis. 224 52

The asparagine-linked sugar chain of glucose transporter from human erythrocytes was quantitatively released as oligosaccharides from the polypeptide backbone by hydrazinolysis. They were converted to radioactive oligosaccharides by NaB3H4 reduction after N-acetylation and fractionated by anion-exchange column chromatography and Bio-Gel P-4 column chromatography after sialidase treatment. Structural study of each oligosaccharide by exo- and endoglycosidase digestion and methylation analysis indicated that the glycoprotein contains a high-mannose-type oligosaccharide, Man9.GlcNAc.GlcNAc, and biantennary complex-type oligosaccharides with Man alpha 1----6(+/- GlcNAc beta 1----4)(Man alpha 1----3) Man beta beta 1----4GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAc as their cores and the poly-N-acetyllactosamine composed of about 16 N-acetyllactosaminyl units as their outer chains. These structural features of the sugar moiety of glucose transporter are quite different from those of two major intrinsic glycoproteins of human erythrocytes, glycophorin A and band 3.
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PMID:Structures of the asparagine-linked sugar chain of glucose transporter from human erythrocytes. 227 82

Asparagine-linked oligosaccharides were quantitatively released by hydrazinolysis from an alkaline phosphatase, Kasahara isozyme, which was purified from FL amnion cells. Almost all of the oligosaccharides (98%) were acidic components, all of which can be converted to neutral oligosaccharides upon sialidase digestion. Structural analysis of the oligosaccharides by sequential exoglycosidase digestion in combination with methylation analysis revealed that the alkaline phosphatase of FL cells contains sialylated mono-, bi-, tri-, and tetraantennary complex type sugar chains with the Gal beta 1----4GlcNAc beta 1---- outer chains. Some of the tetraantennary sugar chains contain a single Gal beta 1----4GlcNAc beta 1----3Gal beta 1----4GlcNAc beta 1---- outer chain on their Man alpha 1----6 arm. Both fucosylated and nonfucosylated trimannosyl cores were found in the sugar chains. However, it is of interest that the core portion of monoantennary oligosaccharide was not fucosylated and that of the tetraantennary oligosaccharide with a tetrasaccharide outer chain was completely fucosylated.
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PMID:Structures of the asparagine-linked oligosaccharides of an alkaline phosphatase, kasahara isozyme, purified from FL amnion cells. 229 56

The two kinds of glycoprotein hormone alpha subunit ectopically produced by an undifferentiated carcinoma of the left femoral region (TM-alpha) and an adenocarcinoma of the right external genitalia (FS-alpha) were examined for amino acid composition, isoelectric focusing, molecular weight, the ability to combine with standard hCG beta and affinity with lectins (Con A, Ricin and PNA). Both TM-alpha and FS-alpha exhibited immunoantigenicity similar to standard hCG alpha. Furthermore, there were no significant differences in the amino acid compositions of TM-alpha, FS-alpha or standard hCG alpha. In isoelectric focusing, while standard hCG alpha exhibited a neutral charge, both TM-alpha and FS-alpha exhibited strong negative charges. FS-alpha was as sensitive to sialidase as standard hCG alpha, whereas most of the TM-alpha exhibited resistance to sialidase. TM-alpha contains sialidase-insensitive peripheral material with a negative charge. The affinity with Ricin-Sepharose indicated that most of the FS-alpha and some of the TM-alpha may contain terminal sialic acid and the penultimate structure, Gal beta 1----4G1cNAc; the affinity with PNA-Sepharose indicated that both may also contain terminal sialic acid and the penultimate structure, Gal beta 1----3GalNAc. These observations suggest that dissimilar glycosylation processes are present in the carcinoma ectopic biosynthesis of glycoprotein hormone alpha subunit.
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PMID:Free alpha subunits of glycoprotein hormone with dissimilar carbohydrates produced by pathologically different carcinomas. 241 29

A fusion of human lymphocytes released from regional lymph nodes of papillary adenocarcinoma of lung cancer with mouse myeloma P3-X63-Ag8-U1 cells resulted in a stable hybridoma-secreting human IgM antibody (NCC-1004) that reacts with a large proportion of squamous cell carcinomas of lung and esophagus as well as carcinoma of thyroid glands. However, the antibody also reacts with normal red blood cells, B lymphocytes, and a few other limited loci in normal tissues such as the basal cells of bronchial epithelium and the basal cell layer of stratified squamous epithelium, as well as endothelium and alveolar lining epithelium. The antigen defined by NCC-1004 has been characterized as blood group i antigen on the basis of the following results. The antibody preferentially agglutinates cord erythrocytes in contrast to adult erythrocytes. The agglutination was obvious at 4 degrees C, but diminished greatly at 37 degrees C, and was enhanced after sialidase treatment. The antibody specifically reacts with lacto-norhexaosylceramide (nLc6) and sialosyllacto-norhexaosylceramide (IV3NeuAcnLc6), but does not react with lacto-neotetraosylceramide (nLc4), sialosyllacto-neotetraosylceramide (IV3NeuAcnLc4), lacto-isooctaosylceramide (IV6Gal beta 1----4GlcNAcnLc6; I antigen), and other standard glycolipids so far tested. The properties of the antibody and its antigen are identical to those previously described for the i blood group system. Inasmuch as the hybridoma was established by hybridization of lymphocytes derived from regional lymph nodes of lung cancer, and the antigen was found in the patient's lung cancer tissue, the i antigen in lung cancer is probably recognized as a tumor-associated antigen by the host's immune cell system.
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PMID:A human monoclonal antibody directed to blood group i antigen: heterohybridoma between human lymphocytes from regional lymph nodes of a lung cancer patient and mouse myeloma. 242 74

Fibronectins purified from human plasma (termed pFN), spent culture media of human fibroblasts WI38 (termed cFN), and SV40 virus-transformed WI38/VA13 cells (termed tFN) and their cleavage fragments were compared with respect to their binding activities to lectins and anti-carbohydrate antibodies reacting with chemically well-defined structures. The following findings were of particular interest. About 25-35% of cFN and tFN carried a binary sialosyl type 2 chain (NeuAc alpha 2----3/or 6Gal beta 1----4GlcNAc) linked beta 1----3/beta 1----6 to the galactose residue and defined by monoclonal antibody C6. This structure was not detected in pFN. In cFN, the C6-defined structure was localized within the gelatin-binding domain, whereas in tFN the same structure was absent from this domain but was located at the NH2-terminal region of the central domain. Other carbohydrate determinants, defined by Ricinus communis lectin and concanavalin A before and after sialidase treatment, showed essentially identical domain distribution patterns among cFN, tFN, and pFN and were all located at the gelatin-binding domain (44 kDa), its precursor (60 kDa), and the Cell/Hep-2 domain (155/145 kDa). Although both cFN and tFN were reactive with lentil lectin, pFN was not. Fibronectin from transformed cells (tFN) showed much greater reactivity than cFN and pFN with wheat germ lectin before sialidase treatment and showed enhanced reactivity with R. communis lectin and peanut lectin after sialidase treatment, indicating that tFN is more highly sialylated than cFN and pFN. All fibronectins examined were strongly reactive with monoclonal antibody AH8-28, which binds to Gal beta 1----3GalNAc residues, and this reactivity was localized to both the NH2-terminal half and COOH-terminal half of the S-cyanylation-cleaved fibronectin molecule.
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PMID:Domain-specific distribution of carbohydrates in human fibronectins and the transformation-dependent translocation of branched type 2 chain defined by monoclonal antibody C6. 242 70

A panel of lectins was used to study surface carbohydrate expression on myeloma cells with the aim of finding a possible agent for in vitro bone marrow purging. Peanut agglutinin (PNA, galactose beta 1,3 N-acetylgalactosamine-binding) bound to all plasma cells in 33/34 bone marrow samples from myeloma patients and to all plasma cells in 11 bone marrow from patients with monoclonal gammopathy of undetermined significance and 10 normal bone marrow samples. Bone marrow and peripheral blood monocytes reacted weakly with PNA except in one case of acute monoblastic leukaemia and two of chronic myelomonocytic leukaemia in which monocytes were strongly positive. The only case of plasma cell leukaemia studied was PNA negative. All other bone marrow mononuclear cells were negative for PNA but became positive after sialidase treatment. Peanut agglutinin may have potential as an agent to be used in myeloma for in vitro marrow purging prior to autologous transplantation in combination with high dose chemotherapy.
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PMID:Peanut agglutinin shows specificity for bone marrow plasma cells. 246 73

Histochemical analyses of the chemical structures of sugar sequences with or without blood group specificity were carried out by combined stepwise digestion of tissue sections with exo- and endoglycosidases and subsequent lectin stainings in formalin-fixed, paraffin-embedded human pancreas. In acinar cells from blood group A or AB secretor individuals, sequential digestion with alpha-N-acetylgalactosaminidase and alpha-L-fucosidase imparted reactivity with peanut agglutinin (PNA) in cells reactive with Dolichos biflorus agglutinin as well as those with Ulex europaeus agglutinin I(UEA-I). Simple fucosidase digestion imparted the PNA reactivity only in UEA-I reactive cells. Sequential digestion with alpha-galactosidase and fucosidase likewise liberated the PNA binding sites in Griffonia simplicifolia agglutinin I-B4 reactive cells from blood group B and AB secretors. Sialidase digestion liberated the PNA binding sites not only in acinar cells but also intercalated duct cells, islet cells of Langerhans and endothelial cells. The PNA reactivity obtained by these enzyme digestions was eliminted by endo-alpha-N-acetylgalactosaminidase (endo-GalNAcdase) digestion. Preexisting PNA affinity in acinar cells from non-secretors was also susceptible to endo-GalNAcdase treatment. Following the endo-GalNAcdase digestion, fucosidase or sialidase digestion recovered the PNA reactivity in acinar cells from nonsecretors. These results show that ABH determinants carried on O-glycosidically linked type 3 chain (D-galactose-(beta 1-3)-N-acetyl-D-galactosamine alpha 1-serine or threonine) are secreted in pancreatic acinar cells and suggest that product coded by the secretor gene is required for the complete conversion of type 3 precursor chains into H determinants.
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PMID:Histochemical demonstration of O-glycosidically linked, type 3 based ABH antigens in human pancreas using lectin staining and glycosidase digestion procedures. 247 5

Using lectin staining methods in combination with exo- and endo-glycosidase digestion procedures, we analyzed the chemical structure of different types of blood group-related substances in serous cells of formalin-fixed, paraffin-embedded human submandibular glands. Serous cells produced only H antigen; A and B antigens were not present, and the expression of H antigen is dependent on the secretor status of the tissue donor. Although reactivity with Ulex europaeus agglutinin I (UEA-I) was not markedly reduced by alpha-L-fucosidase digestion, an affinity for peanut agglutinin (PNA) was seen after fucosidase digestion in the cells from secretors. In those from nonsecretors, no PNA reactivity appeared after enzyme digestion. On the other hand, sialidase digestion elicited PNA reactivity in serous cells irrespective of the donor's secretor status. PNA reactivity observed after fucosidase or sialidase digestion was susceptible to endo-alpha-N-acetylgalactosaminidase (endo-GalNAc-dase) digestion. SBA reactivity in UEA-I-negative cells from secretors, or in cells from fetuses and newborn infants, was markedly reduced by beta-galactosidase digestion. After galactosidase digestion, reactivity with Griffonia simplicifolia agglutinin II (GSA-II) appeared in the corresponding cells. This GSA-II reactivity was almost completely eliminated by subsequent beta-N-acetylhexosaminidase digestion. Whereas PNA reactivity in these cells was not reduced by beta-galactosidase treatment, it was significantly diminished by endo-GalNAc-dase digestion. These results suggest that at least two kinds of precursor disaccharides are produced in submandibular serous cells, i.e., SBA-reactive D-galactose-(beta 1-3,4)-N-acetyl-D-glucosamine and PNA-reactive D-galactose-(beta 1-3)-N-acetyl-D-galactosamine alpha 1-serine or threonine (O-glycosidically linked Type 3 chain or T antigen). Final fucosylation and synthesis of these two types of precursor chain appear to be under the control of the secretor gene.
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PMID:Histochemical analysis of the chemical structure of blood group-related carbohydrate chains in serous cells of human submandibular glands using lectin staining and glycosidase digestion. 249 20


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