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)

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

We had previously shown that the human colon produces at least two immunochemically distinct mucins, one neutral and the other a sialomucin [Gold et al. J. biol. Chem. 256, 6354-6358 (1981)]. In addition, the sialomucin was shown to contain an immunodeterminant restricted to colonic epithelium and may thus prove useful as a tissue-specific marker. In the current study we have shown that a specific linkage of sialic acid to the oligosaccharide backbone has a major role in the organ-specific immunodeterminant structure. Treatment of intact colonic mucin with sialidase (Cl. perfringens) cleaved 20-80% of the sialic acid as measured colorimetrically. Immunoreactivity was decreased by 0-42% with respect to the untreated material. Saponification (0.1 N KOH, 20 min at room temp) caused an approximate 90% decrease in immunoreactivity for each mucin. Subsequent to saponification, neuraminidase cleaved most of the sialic acid from the mucins. The majority of sialic acid was observed to be O-acetylated, thus making it sialidase-insensitive. Gas chromatography-mass spectrometric analyses of the trimethylsilyl sialic acid derivatives indicated the presence of NeuNAc; NeuNAc, 9-OAc; and NeuNAc, 7,9 diOAc as the major sialyl derivatives. The radioimmunoassay data appeared to indicate that O-acetylated sialic acid was necessary for immunoreactivity. It should be noted that jejunal mucin and bovine submaxillary mucin also contain O-acetylated sialic acid, but did not inhibit in our radioimmunoassay. This may have been due to differences in the O-acetylation pattern or the linkage of sialic acid to the core carbohydrate. Analyses of the partially methylated alditol acetate derivatives by gas chromatography-mass spectrometry of the untreated, as well as the saponified and neuraminidase treated, mucins revealed that sialic acid was attached to the carbohydrate core either to galactose, N-acetylglucosamine, and/or N-acetylgalactosamine. Linear regression analyses comparing immunoreactivity with specific epitope concns, in conjunction with RIA analyses of known structures, suggested that the organ-specific immunodeterminant was (or was dependent upon the presence of) the structure GlcNAc (1,3)[O-acetylated Neu5Ac(2,6)] GalNAc.
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PMID:Studies on the structure of the organ-specific determinant of human colonic mucin. 247 76

The present study investigated some lectin affinities of human dental pulps, especially of odontoblasts and pulp cells. The materials were obtained from clinically intact teeth that were caries-free, attrition and/or abrasion-free. Mucopolysaccharide staining was carried out with applied PAS and alcian blue (AB) (pH 1.0 and 2.5). Lectins used were Con A, WGA, RCA-1, UEA-1, DBA, SBA, MPA, LFA, HPA, PNA, and GS-1, and the avidin-biotin peroxidase complex method was employed. Some specimens were tested for PNA binding after treatment with sialidase. The following results were obtained: 1) On PAS and AB staining, the pulp tissue was very weakly or borderline positive. 2) Lectin binding in odontoblasts was intensely positive with Con A, WGA, RCA-1, MPA, and LFA, but negative or very weakly positive with the other lectins examined. 3) Lectin localization in odontoblasts was localized diffusely throughout the cytoplasm. 4) On PNA staining, odontoblasts were negative, but changed to positive after treatment with sialidase. 5) Odontoblast processes showed negative or borderline staining with all lectins used in this study. 6) The pulp cells were clearly positive with Con A, MPA, LFA, RCA-1, and SBA and especially LFA showed an intense reaction with the pulp cells. 7) WGA affinity for odontoblasts was very strong but that for pulp cells was very weak. 8) Lectin binding in pulp cells was observed mainly in the processes of the cells. From the above results, it is clear that the lectin binding pattern of odontoblasts differs from that of pulp cells. The data suggest that D-mannose, N-acetyl-D-glucosamine, D-galactose, and N-acetyl-D-galactosamine residues are localized in the odontoblasts and sialic acid is localized in the pulp cells.
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PMID:[Lectin histochemical study on human dental pulp. Special reference to odontoblasts and pulp cells]. 248 77

A total of 378 streptococcal isolates of Lancefield groups B, C, D and G were tested for their ability to hemagglutinate untreated, sialidase-treated, and endo-beta-galactosidase-treated human erythrocytes. Of the 43 strains showing positive hemagglutination, 9 were inhibitable with neutral monosaccharides. Four strains were inhibited with galactose and N-acetylgalactosamine, whereas five were inhibited with galactose only. A third, sialic acid-specific adhesion activity was suggested for two additional strains on the basis of their agglutination of native and endo-beta-galactosidase-treated but not sialidase-treated erythrocytes. All the sugar-specific agglutination activities detected were confined to Streptococcus suis strains of group D streptococci, whereas streptococci of other groups did not exhibit these types of hemagglutination activities. The adhesins were sensitive to proteases and heat treatment, which indicates that they were proteins. The hemagglutinating isolates of S. suis originated from pig brain and lung, human brain, and the tonsils of healthy pigs. No clear correlation with a particular serotype was observed. These results demonstrate the occurrence of unique sugar-specific adherence activities in S. suis, an important pig pathogen with occasional human pathogenicity.
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PMID:Hemagglutination activities of group B, C, D, and G streptococci: demonstration of novel sugar-specific cell-binding activities in Streptococcus suis. 249 58

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

The IgG2a monoclonal antibody TH-1, which reacts specifically with blood group A1 but with neither A2 nor O erythrocytes, has been established. The antibody reacted only with A1 erythrocytes in hemagglutination and antibody absorption assays; it did not react with A2 erythrocytes, even after trypsin or sialidase treatment. This antibody detected, on TLC immunostaining, a series of glycolipids from A1 erythrocytes but virtually none or very weak bands from A2 erythrocytes. It did not react with type 1 or type 2 chain A, or with globo-A. The simplest reactive component was isolated from a previously assigned Ab fraction by HPTLC of acetylated compounds. The structure of the reactive component was characterized by 1H NMR spectroscopy, methylation analysis, and enzymatic degradation, as shown below: (Formula: see text). The structure is essentially a repetitive A epitope attached to type 2 chain and is hereby called type 3 chain A. The determinant can be carried on extended and/or branched structures, but it was not detectable in glycoproteins. The structure was characteristic of A1 erythrocytes and present in only trace amounts in A2 erythrocytes. The precursor H (Fuc alpha 1----2Gal beta 1----3GalNAc alpha 1----3[Fuc alpha 1----2]Gal beta 1----4GlcNAc beta 1----R; type 3 chain H) was present in greater quantity in A2 erythrocytes than in A1 erythrocytes, but it was absent in both O and B erythrocytes. The A1 transferase apparently can transfer alpha-GalNAc to type 3 chain H, while the A2 transferase may not have this ability.
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PMID:Repetitive A epitope (type 3 chain A) defined by blood group A1-specific monoclonal antibody TH-1: chemical basis of qualitative A1 and A2 distinction. 257 90

Sites of binding of eight different lectins (LTA, UEA I, WGA, SBA, DBA, CON A, PNA, RCA I) to cat submandibular gland were studied after exposure of tissue sections to sialidase, alpha-fucosidase, beta-galactosidase, alpha-mannosidase, beta-N-acetylglucosaminidase. All lectins were affected by enzymatic predigestion and the labeling of individual lectins was highly dependent upon the glycosidase used to pretreat the sections. Glycoconjugates of demilunar, acinar and ductal cells exhibited a different composition of terminal sequences. For example, fucose proved to form the disaccharide fucose-galactose in demilunar and acinar cells, whereas it was present with the sequence fucose-N-acetyl-D-glucosamine in striated duct cells. Sialic acid participated both to the terminal sequence sialic acid-galactose and sialic acid-N-acetyl-D-galactosamine either in demilunar or in ductal cells. Lectin labeling combined with glycosidase digestion was also helpful in verifying the influence of neighbouring oligosaccharides on the affinity of lectins for the respective sugars.
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PMID:Enzymatic degradation and quantitative lectin labeling for characterizing glycoconjugates which act as lectin acceptors in cat submandibular gland. 271 45

Aiming at the introduction of a fluorescent sialic acid into glycoconjugates, 5-acetamido-9-(3-fluoresceinylthio-ureido)-3,5,9-trideoxy-2-non ulosonic acid (9-fluoresceinyl-NeuAc) was synthesized which has an intact carbon chain. a) Despite the space-filling substituent at C-9, the fluorescent NeuAc analogue was activated to the corresponding CMP-glycoside by CMP sialic acid synthase from bovine brain. Whereas the Km value of the synthase was little affected by the modification (Km = 2.1 mM, for NeuAc Km = 1.4 mM), the V value decreased to 7.5%. b) CMP-9-fluoresceinyl-NeuAc was synthesized on a preparative scale (17% overall yield), and characterized by analytical HPLC, absorption and fluorescence spectra. c) 9-Fluoresceinyl-NeuAc was transferred onto asialo-alpha 1-acid glycoprotein by both Gal beta 1, 4GlcNAc alpha 2, 6sialyltransferase and Gal beta 1,4(3)GlcNAc alpha 2,3sialyltransferase (rat liver), and onto antifreeze glycoprotein by GalNAc alpha 2,6-sialyltransferase (porcine submaxillary glands). Using analytical HPLC, transfer was confirmed after release of the fluorescent sialic acid by Vibrio cholerae sialidase. d) Initial rate studies indicated a low Km value of Gal beta-1,4GlcNAc alpha 2,6sialyltransferase, and GalNAc alpha 2,6sialyltransferase (specific for O-linked oligosaccharide chains) for CMP-9-fluoresceinyl-NeuAc.
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PMID:Enzymatic introduction of a fluorescent sialic acid into oligosaccharide chains of glycoproteins. 284 3

The adherence of Actinomyces naeslundii to human epithelial (KB) cells is mediated by the interaction of a fimbrial lectin on this oral bacterium with epithelial cell receptors exposed by sialidase. The D-galactose- and N-acetyl-D-galactosamine-reactive plant lectins from peanut and from Bauhinia purpurea inhibit this interaction. This report describes the partial purification and characterization of a 160-kilodalton (kDa) cell surface glycoprotein which is the principal receptor for these lectins. Radioiodinated lectins detected a band of 160 kDa on sialidase-treated Western blots of epithelial cell extracts but did not detect bands on nontreated filters. However, wheat germ agglutinin was reactive with the 160-kDa band on filters that were not treated with sialidase, suggesting that this lectin recognizes the sialic acid residues of this molecule. The 160-kDa component was partially purified from n-octylglucoside extracts of the epithelial cells by wheat germ agglutinin affinity chromatography. This molecule was metabolically labeled with D-[14C]glucosamine and labeled at the cell surface by lactoperoxidase-catalyzed iodination or periodate oxidation followed by sodium borotritide reduction. Incubation of epithelial cells with sialidase before extraction resulted in the loss of the 160-kDa band and the appearance of a band at 200 kDa which was directly reactive with 125I-labeled peanut agglutinin. These results indicate that the 160-kDa glycoprotein on the surface of the epithelial cell serves as a receptor for the agglutinins from the peanut and B. purpurea and presumably the fimbrial lectin of actinomyces.
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PMID:A 160-kilodalton epithelial cell surface glycoprotein recognized by plant lectins that inhibit the adherence of Actinomyces naeslundii. 287 66

The two varieties of fimbriae identified on oral strains of actinomyces have distinct functional properties. The type 1 fimbriae of Actinomyces viscosus T14V mediate attachment to saliva-treated hydroxyapatite. Type 2 fimbriae--on A. viscosus and the only fimbriae detected on A. naeslundii WVU45--are associated with lectin activity. Interaction of these fimbriae with complementary receptors initiates bacterial attachment to Streptococcus sanguis 34 and sialidase-treated epithelial cells and the killing of actinomyces by polymorphonuclear leukocytes (PMNs). Galactose, N-acetylgalactosamine (GalNAc), and related oligosaccharides inhibit these processes, and mutants lacking type 2 fimbriae do not participate in them. The actinomyces lectin is similar to lectins from Ricinus communis and Bauhinia purpurea that agglutinate certain strains of oral streptococci, block attachment of actinomyces to epithelial cells, and inhibit killing of actinomyces by PMNs. The S. sanguis receptor for the actinomyces lectin comprises repeating hexasaccharide units with GalNAc termini. Used as probes, the peanut agglutinin, with specificity for Gal(beta-3)GalNAc, and the lectin from B. purpurea detect a 160-kilodalton (kdal) band in SDS-PAGE-separated epithelial cell extracts and a 100-kdal band in PMN extracts. These may be receptors for type 2 fimbriae. A. viscosus genes encoding subunits of types 1 and 2 fimbriae have been cloned in Escherichia coli; the type 1 subunit is 65 kdal and the type 2 subunit is 59 kdal. Submandibular immunization of mice with a mixture of type 1 and type 2 fimbriae evokes the production of IgA and IgG antibodies in serum and saliva that inhibit in vitro adsorption of A. viscosus to SHA. These antibodies may modulate colonization of teeth by this organism.
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PMID:Molecular basis of bacterial adhesion in the oral cavity. 289 Nov 80


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