Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.53 (sialidase)
 2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sugar specific lectins (PNA, RCA I, LPA, SBA, DBA, GSA IB4, GSA II, WGA, LTA, UEA I, Con A, LCA) with and without prior selective glycosidase digestion (sialidase, alpha-fucosidase, alpha-mannosidase, beta-N-acetylglucosaminidase, alpha- and beta-galactosidase, beta-glucosidase) were used in order to investigate the distribution of native accessible carbohydrates and obtain information dealing with the composition of terminal disaccharides within glycoconjugates present in acinar compartments and ductal segments of mammalian (mouse, rat, hare, and rabbit) parotid glands. Glycoconjugates containing variable amounts of mannose, glucose, N-acetylgalactosamine and N-acetylglucosamine were present in the parotid glands of all species. However, these carbohydrate chains exhibited a different composition of terminal sequences within each type of gland. For example, sialylated components having the terminal dimers sialic acid-galactose and sialic acid-N-acetylgalactosamine were found in all acinar cells, whereas fucoglycoconjugates with terminal disaccharide fucose-galactose were localized in the rat striated ducts and hare acinar cells. The terminal sequence alpha-galactose-beta-galactose was demonstrated in the mouse acinar cells. Finally, glycoconjugates characterized by the terminal dimer beta-galactose-N-acetylgalactosamine were demonstrated in the mouse acinar and ductal cells and the rat ductal ones. Thus, present findings outlined and further confirmed the possibility to elucidate the oligosaccharide structure in situ using lectin histochemistry combined with enzymatic degradation.
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PMID:Glycoconjugate composition of mammalian parotid glands elucidated in situ by lectins and glycosidases. 137 7

Borrelia burgdorferi glycoconjugates with different oligosaccharide structures were characterized by a blotting technique with peroxidase-labelled lectins. The localization of surface carbohydrates was studied using electron microscopy with lectin-gold complexes. A high-mannose glycan structure was detected in 83 kDa glycoprotein (major extracellular protein); at least four carbohydrates (glucose or mannose, galactose, N-acetylgalactosamine and N-acetylglucosamine) were present in other Borrelia glycoconjugates. N-acetylneuraminic (sialic) acid was detected on the Borrelia surface. Two sialidases with different specificities were used in an attempt to cleave off the Borrelia N-acetylneuraminic acid. The attempt was successful by using Vibrio cholerae sialidase which has a broad substrate specificity, while the mumps-virus sialidase with restricted substrate specificity had no effect. Endogenous activity of N-acetylneuraminidase was not demonstrated in B. burgdorferi K 5 and B 31 strains.
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PMID:Characterization of Borrelia burgdorferi glycoconjugates and surface carbohydrates. 161 Dec 4

The involvement of the carbohydrate moiety of the human erythrocyte glucose transporter in glucose transport activity was previously demonstrated (Feugeas et al. (1990) Biochim. Biophys. Acta 1030, 60-64): N-glycanase treatment of the transport glycoprotein reconstituted in proteoliposomes resulted in a dramatic decrease of the Vmax. In this study, kinetic measurements of glucose equilibrium influx confirm our previous results. In order to investigate that a minimum glycosidic structure is required to maintain glucose transport activity, proteoliposomes were respectively treated with either sialidase, or sialidase and endo-beta-galactosidase, or a pool of exo-glycosidases which allows the release of all the sugar residues, except the proximal N-acetylglucosamine. Kinetic measurements of zero-trans influx made on sialidase- and (sialidase + endo-beta-galactosidase)-treated proteoliposomes did not reveal any significant changes in the glucose transport activity. On the contrary, treatment of the same proteoliposomes by a pool of exoglycosidases led to a complete abolition of activity, suggesting that a minimum glycosidic structure is required for glucose transport activity.
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PMID:Glycosylation of the human erythrocyte glucose transporter: a minimum structure is required for glucose transport activity. 206 69

Synthetic thioglycoside-analogs of gangliosides such as Neu5Ac alpha(2-S-6)Glc beta(1-1)Ceramide (1) and the GM3 analog Neu5Ac alpha(2-S-6)Gal beta(1-4)Glc beta(1-1)Ceramide (2), competitively inhibited GM3 hydrolysis by the sialidase of different subtypes of human and animal influenza viruses with an apparent Ki value of 2.8 x 10(-6) and 1.5 x 10(-5) M, respectively. The inhibitory activity of the ganglioside GM4 analog [Neu5Ac alpha(2-S-6)Gal beta(1-1)Ceramide (3)], in which the glucose of 1 was substituted by galactose, was lower than that of 1 (Ki = 1.0 x 10(-4) M). The thioglycoside-analogs (1, 2, 3) of the gangliosides were non-hydrolyzable substrates for influenza virus sialidase. The inhibitory activity of 1 to bacterial sialidases from Clostridium perfringens and Arthrobacter ureafaciens was considerably lower than that to influenza virus sialidase, indicating that the structure of the active site in bacterial and influenza virus sialidase may be different and the analogs may be useful to determine the orientation of the substrate to the active site of sialidases, especially of influenza viruses.
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PMID:New ganglioside analogs that inhibit influenza virus sialidase. 213 50

The antigen designated as Chol-1 beta, detected by an antiserum specific for cholinergic neurons, has been purified to homogeneity from ganglioside mixtures extracted from Torpedo electric organ and pig brain. The final products from the two sources behaved identically in a wide range of tests and gave coincident immunopositive and Ehrlich-positive spots after thin layer chromatography in seven different solvent systems; they were thus considered to be identical and to constitute a single, pure chemical species. Gas-chromatographic analysis revealed the presence of long-chain bases, glucose, galactose, N-acetylgalactosamine, and sialic acid in integral molar ratios of 1:1:2:1:3; the compound's reactivity to cholera toxin after Vibrio cholerae sialidase treatment on thin layer chromatography and the recovery of GM1 as sole product of exhaustive sialidase treatment identified it as a member of the gangliotetrahexosyl series. From the products of partial enzymatic desialylation and treatment with beta-galactosidase and a comparison of the compound's immunoreactivity to anti-Chol-1 antisera with that of other trisialogangliosides of defined molecular structure, we were able to assign a disialosyl residue alpha-Neu5Ac-(2----8)-alpha-Neu5Ac-(2----3)- to the inner galactose, and we suggest GalNAc as a possible site of linkage of the third sialic acid.
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PMID:Further studies on the gangliosidic nature of the cholinergic-specific antigen, Chol-1. 235 21

1) The content and accessibility of terminal sialic acid and galactose residues as well as the incorporation of [3H]fucose into glycoconjugates were determined in 48-h cultures of Ehrlich ascites tumor cells in a glucose-free medium supplemented with uridine, a compound which can fulfil the necessary functions of glucose. 2) Sialic-acid residues accessible to sialidase cleavage were reduced from 695 +/- 80 nmol/10(9) cells (controls) to 284 +/- 22 nmol/10(9) cells (43% of controls). In situ labeling using periodate oxidation followed by sodium borotritiide reduction revealed a tritium incorporation of 47 +/- 11% that of controls (= 4.1 x 10(5) cpm/mg protein). 3) Labeling of galactose residues of 80-90% of that of controls was achieved after treatment of the cells with galactose oxidase/sodium borotritiide. A nearly six-fold enhancement of tritium incorporation into galactose of control cells was observed after sialidase/galactose oxidase treatment and sodium borotritiide reduction (1.5----8.8 x 10(5) cpm/mg protein); only a 3.6-fold increase (1.2 x 10(5)----4.3 x 10(5) cpm/mg protein) was found with glucose-free cultured cells. It is concluded that the galactose content of the cell surface is reduced to about 50% of controls. 4) The incorporation of tritium into acid-insoluble precipitate after 24 h incubation with [3H]fucose and the activity of the acid-soluble fraction were enhanced by about 85% as compared to controls. The pattern of inhibition by tunicamycin of [3H]fucose uptake and incorporation was the same in glucose-containing standard medium and in glucose-free uridine medium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sialic acid, galactose and fucose on the surface of Ehrlich ascites tumor cells grown in glucose-free medium in the presence of uridine. 254 Jul 68

An esterase was isolated from influenza C virus with a specific activity from 1.7-5 U/mg protein, and its substrate specificity was tested with various naturally occurring O-acylated sialic acids, synthetic carbohydrate acetates, and other esters. The enzyme hydrolyses only acetic acid esters at significant rates. The non-natural substrates 4-methyl-umbelliferyl acetate, 4-nitrophenyl acetate, and alpha-naphthyl acetate are cleaved at highest hydrolysis rates, followed by the natural substrate N-acetyl-9-O-acetylneuraminic acid. The esterase also acts on N-glycoloyl-9-O-acetylneuraminic acid and, much slower, on N-acetyl-4-O-acetylneuraminic acid; N-acetyl-7-O-acetylneuraminic acid is not hydrolysed. 2-Deoxy-2,3-didehydro-N-acetyl-9-O-acetylneuraminic acid is also a substrate for this enzyme, however, 6-O-acetylated N-acetylmannosamine and glucose are not. Esterification of the carboxyl function of sialic acids strongly reduces or prevents esterase action on O-acetyl groups. The carboxyl ester is not hydrolysed. The relative cleavage rates also depend on the type of the non-sialic acid part of the molecule. N-Acetyl-9-O-acetylneuraminic acid as component of sialyllactose and rat serum glycoprotein shows hydrolysis rates close to the free form of this sugar, while acetyl ester groups of bovine submandibular gland mucin and rat erythrocytes are hydrolysed at slower rates. Gangliosides and 4-O-acetylated glycoproteins are no substrates for the purified enzyme. A slow hydrolysis is observed by incubation of 9-O-acetylated GD1a with intact influenza C viruses. As other natural acetyl esters (acetyl-CoA and acetylthiocholine iodide) are not hydrolysed, the enzyme can be classified as sialate 9(4)-O-acetylesterase (EC 3.1.1.53).
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PMID:Isolation and characterization of sialate 9(4)-O-acetylesterase from influenza C virus. 324 42

An oligosaccharide alditol, dHex-GalNAc-Gal-Gal-GalNAcol, has been isolated from polysialoglycoprotein, which was derived from the unfertilized eggs of Savelinus leucomaenis pluvius (a salmonid fish, Iwana in Japanese), by alkaline borohydride treatment followed by exhaustive digestion with sialidase. First, the structure of the terminal dHex residue in the above pentasaccharide has been assigned as 6-deoxyaltrose (= dAlt in pyranoid form) by a combination of structural methods (GLC, TLC, mass spectrometry, and 400-MHz 1H-NMR spectroscopy). The occurrence of a 6-deoxyhexose other than L-fucose in glycoprotein has not been previously reported. Next, the absolute configuration of this unusual sugar residue has been assigned as D on the basis of the exciton-splitting study of tris-p-bromobenzoate derivatives of methyl 6-deoxyaltrosides. The usefullness of this circular dichroic exciton-splitting method in the determination of the absolute configuration of carbohydrate components, only available in minute amounts, is emphasized. The anomeric configuration of the glycosidic linkage of the D-altropyranosyl residue was deduced from 400-MHz 1H NMR spectroscopy. The 6-deoxy-beta-D-altropyranosyl residue thus established has the same configuration as alpha-L-fucose but with the C-5 methyl group inverted, suggesting that the biosynthetic incorporation of D-dAlt parallels that of L-fucose, and a possible pathway is also considered.
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PMID:Identification and determination of absolute and anomeric configurations of the 6-deoxyaltrose residue found in polysialoglycoprotein of Salvelinus leucomaenis pluvius eggs. The first demonstration of the presence of a 6-deoxyhexose other than fucose in glycoprotein. 366 14

Two gangliosides, representing 85% of total lipid-bound sialic acid, have been isolated from bovine buttermilk and characterized. Both contained long-chain base, glucose, galactose and sialic acid in the molar ratio 1:1:1:2, and gave, upon sialidase treatment, a neutral glycolipid, characterized as lactosylceramide. Partial acid hydrolysis, permethylation analysis and chromium trioxide oxidation indicated their basic oligosaccharide portion to be NeuAc alpha 2----8NeuAc alpha 2----3Gal beta 1----4Glc. The difference between the two forms was exclusively in the ceramide moiety of the molecule, one containing mainly long-chain (C22-C25) fatty acids and an equimolar proportion of C16 and C18 long-chain bases, and the other mainly palmitic acid and C18 long-chain base.
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PMID:Characterization of two molecular species GD3 ganglioside from bovine buttermilk. 397 Sep 56

A survey has been made of the activity of a wide variety of standard strains of streptococci against bovine submaxillary mucin. Strain 6646 (group K) and strain D 168A "X" (group M) completely broke down and strain H 60R (group F) incompletely broke down bound sialic acid of bovine submaxillary mucin added to the growth medium. Among these strains, strain 6646 (group K) produced sialidase in the cell and in the culture fluid. An appropriate amount of glucose in the culture medium stimulated growth and the production of enzyme, but an excess of glucose in the culture medium caused abundant growth without production of the enzyme. The streptococcal sialidase was precipitated from the culture fluid by ammonium sulfate at 50% saturation, and further purification was achieved by diethylaminoethyl cellulose chromatography. Ca(++) and Co(++) stimulated the sialidase activity, and Mn(++), Zn(++), and ethylenediaminetetraacetate inhibited it. With acetate buffer, the optimal pH lay between 5 and 6. Sialic acid was detected in the reaction product of the streptococcal sialidase and bovine submaxillary mucin.
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PMID:Streptococcal sialidase. I. Isolation and properties of sialidase produced by group K Streptococcus. 496 Aug 91


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