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)

A peanut lectin-horseradish peroxidase (PL-HRP) conjugate has been applied to histochemical staining of paraffin sections of various mouse organs. The PL-HRP conjugate has selectively reacted with secretory bodies, the Golgi zone, and the apical cell surface in various cell types. Some positive sites, including lingual and tracheal serous glands, Brunner's glands, and the brush border of the proximal straight nephron, contained periodic acid-Schiff (PAS)-positive glycoconjugate with no affinity for basic reagents. The stored secretion in these sites was interpreted as containing neutral glycoprotein with terminal galactose residues which could, in part at least, account for the PAS reactivity. Duodenal goblet cells, which exhibited basophilia attributable to sulfate esters, also bound PL-HRP. As the binding was affected by prior sialidase digestion, the secretory glycoprotein in the duodenal goblet cells was judged to contain oligosaccharides with sulfate esters and terminal galactose uncapped by sialic acid. All sites known from their basophilia to form sialomucin failed to stain with the PL-HRP conjugate, but consistently gained reactivity following sialidase digestion and were inferred, therefore, to possess glycoproteins with oligosaccharide side chains containing subterminal galactose and terminal sialic acid. Lingual mucous glands, known to secrete a mucosubstance with basophilic properties indicative of the presence of sulfate esters but not sialic acid, stained with PL-HRP only after sialidase digestion and, accordingly, were reinterpreted as containing both sulfate esters and terminal galactose-sialic acid dimers. Staining of gastric surface epithelium demonstrated a srongly PAS-reactive neutral glycoprotein, and that of goblet cells in the cecum disclosed PAS-positive sulfated glycoprotein. The latter two sites lacked PL-HRP affinity without or with prior sialidase treatment and apparently possessed neither terminal galactose residues nor galactose-sialic acid dimers. PL-HRP affinity was observed exclusively in the Golgi cisternae of some epithelial cells, thus indicating that galactose occurs transiently as a terminal residue in this site. A few histologic sites, such as pancreatic and gastric zymogen cells and renal tubules, were devoid of both PAS reactivity and basophilia indicative of the presence of complex carbohydrate but stained strongly with the PL-HRP conjugate by means which are not understood. Galactose in the PL-HRP solution blocked or reversed the PL-HRP binding in most of the structures with an affinity for the conjugate, supporting the conclusions that the reagent is specific for galactosyl residues.
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PMID:Histochemical reactivity of peanut lectin-horseradish peroxidase conjugate. 741 Aug 18

This paper presents a sensitive assay for sialidase activity based on the specific binding of lecting to N-acetyllactosamine. The substrate used for sialidase assay is fetuin (30-100 ng/50 microliters) with sialylated oligosaccharides, which was then coated on a 96-well microtiterplate. After removing sialic acids from the terminal positions of the glycoconjugate glycans by sialidase, it was subjected to biotin-labeled lectin (Ricinus communis agglutinin 120), which binds specifically to N-acetyllactosamine. This was followed by the addition of a peroxidase conjugated avidin-biotin complex. The amount of bound peroxidase was determined by a colorimetric assay. The sensitivity was enhanced 1000- to 10,000-fold compared to the colorimetric assay using a synthetic substrate such as 2-O-(p-nitrophenyl)-N-acetyl-alpha-D-neuraminic acid (PNPN). In the established method, only very small amounts of substrate and sialidase were required; therefore, it can be applied to the quantitative assay of some sialidases from Vibrio cholerae, streptococcus, the influenza virus and rat liver.
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PMID:A microplate assay for sialidase activity using plant lectin binding to N-acetyllactosamine. 751 58

The glycosidic residues in the mandibular glands of five adult dogs were studied by using seven different lectin-horseradish peroxidase conjugates. In some cases a treatment with sialidase preceded the lectin staining. The mucous acinar cells contained oligosaccharides with alpha- and beta-N-acetylgalactosamine, N-acetylglucosamine and fucose residues, whereas the demilunar cells contained glycoconjugates rich in sialic acid linked to the penultimate disaccharide galactosyl-(beta 1-->3) N-acetylgalactosamine.
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PMID:Glycoconjugates in the mandibular salivary gland of adult dogs revealed by lectin histochemistry. 753 71

Cultured epithelial cells isolated from guinea pig trachea were treated with Vibrio cholerae sialidase. The treatment was not cytotoxic and resulted in membrane desialylation as assessed by measurement of sialic acids released, along with an increased fixation of the galactose-specific lectin peanut agglutinin. After incubation in serum from normal guinea pigs, membrane-bound immunoglobulins were detected using peroxidase-labelled antibodies. Sialidase-treated cells bound significantly more IgM than controls (P < 0.0005), whereas binding of IgG was not significantly different between treated and untreated cells (0.1 < P < 0.375); IgA were never detected. In influenza-infected guinea-pigs, as assessed by reactivity with peanut agglutinin, the tracheal and lung epithelium, as well as alveolar cells were hyposialylated. In these animals, the level of serum IgG autoantibodies capable to bind sialidase treated cultured cells increased, while the level of IgM autoantibodies did not change. These autoantibodies may participate in cellular dysfunctions and modified bronchoreactivity that occur during infection of the respiratory tract by sialidase-producing microorganisms, either through activation of the complement system, or subsequently to their reaction with cells expressing membrane complement and/or Fc receptors.
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PMID:Binding of serum autoantibodies to sialidase-treated tracheal epithelial cells. Determination of autoantibodies isotypes in normal and influenza virus infected guinea pig sera. 782 32

Myelinated nerve fibres isolated from Wistar rats chronically exposed to 2,5-hexanedione (0.8 ml/kg/day, intraperitoneally) over a period of 20 days, were stained with lectin-horseradish peroxidase conjugates. The lectins with high affinity for terminal D-galactopyranosyl residues, Bandeiraea simplicifolia-B4 (BSA I-B4) and peanut agglutinin (PNA), showed glycoconjugates in the control nodes of Ranvier. In the treated animals, application of PNA-HRP caused weak reactivity to the node of Ranvier; digestion with sialidase prior to the application of PNA-HRP conjugate enhanced reactivity, thus revealing the presence of a sialoglycoprotein. The results indicate that glycoconjugates of the Ranvier node undergo a rearrangement during exposure to 2,5-hexanedione. In particular, neutral glycoproteins with terminal galactose are replaced by sialoglycoproteins. These findings are consistent with the proposed role of polysialic acid as a regulator of axonal behaviour during regeneration.
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PMID:Up-regulation of polysialic acid in peripheral myelinated axons of rat chronically exposed to 2,5-hexanedione. 837 40

In the present work, gustatory glands (von Ebner's glands) of the horse tongue were examined by means of five peroxidase-conjugated lectins (PNA, DBA, SBA, UEA I, WGA), with and without prior sialidase digestion, in order to investigate the presence and distribution of carbohydrate residues in secretory cells and duct cells. The most intense staining of secretory cells was observed with PNA after pre-treatment with neuraminidase. This indicates that the terminal trisaccharide sequence sialic acid- (alpha 2-->3, 6) galactosyl (beta 1-->3) N-acetylgalactosamine is the most frequent oligosaccharide chain present in glycoproteins secreted by horse gustatory glands. Secretory cells also contained oligosaccharides with terminal alpha-N-acetylgalactosamine and N-acetylglucosamine, whereas fucose was found in only a few glandular cells. The apical cytoplasm of duct lining cells reacted with all the lectins except WGA.
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PMID:A lectin histochemical study of gustatory (von Ebner's) glands of the horse tongue. 858 3

We investigated the lectin cytochemistry of control and sialidase-digested sections of the mouse parotid gland by postembedding techniques. PNA and DBA lectins were used and their affinity sites were localized by employing conjugates with horseradish peroxidase that then reacted with anti-horseradish peroxidase antibody and protein A-gold. Potassium hydroxide pretreatment also was used before sialidase/PNA and DBA binding to investigate sialic acid acetylation. Ultrathin sections were obtained from specimens embedded in the acrylic hydrophilic resin, Bioacryl. The acini of mouse parotid gland contained polymorphous secretory granules differentially stained by the two lectins; the use of sialidase digestion and KOH deacetylation revealed that the sialic acids linked to beta-galactose are restricted to the electron-dense concentric areas of target granules, whereas the sialic acids linked to alpha-N-acetylgalactosamine contain C4-acetylated groups and are preferentially located in the electron-lucent regions of bizonal granules.
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PMID:Sialylation patterns of the mouse parotid secretory granules. Combined deacetylation, enzymatic degradation and lectin-gold binding. 887 93

The sugar residues in glycoconjugates present in the parotid and mandibular glands of the adult fallow-deer were detected and characterized by using a battery of eight different lectin-horseradish peroxidase conjugates. In some cases a treatment with sialidase preceded the lectin staining. Parotid secretory cells produced glycoconjugates with N-acetylgalactosamine, N-acetylglucosamine and mannose residues. Mucous acinar cells were the most reactive sites of the mandibular gland and contained conspicuous quantities of oligosaccharides with terminal sialic acid radicals. Galactosil-(beta 1-->3)N-acetylgalactosamine was the most abundant penultimate sugar linked to N-acetylneuraminic acid. Mandibular mucous cells also presented N-acetylglucosamine and sialylated components with the terminal dimer sialic acid-N-acetylgalactosamine. Demilunar cells contained glycoconjugates with fucose and mannose residues. The apical surface of duct cells was stained by all the lectins.
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PMID:Histochemical study of lectin binding in the major salivary glands of adult fallow-deer (Dama dama L.). 915 Aug

The Bovine tongue possesses numerous circumvallate papillae (8-16 each side). The troughs around the papillae are the openings of the ducts of the gustatory (von Ebner's) glands. In this study, we have characterized in situ the glycosidic composition of the secretion of bovine gustatory glands using traditional histochemical methods and lectin histochemistry with and without prior neuraminidase (sialidase) digestion. The lectin-horseradish peroxidase conjugates employed were: PNA, DBA, SBA, WGA, LTA, UEA I and ConA. Acinar cells show a diffuse positivity towards PAS and Alcian blue at pH 2.5 and the most intense and homogeneous lectin staining was obtained with PNA. This indicates that bovine gustatory glands secrete glycoproteins with 1,2-glycol containing hexoses and carboxyl-rich glycoconjugates and that galactosyl (beta 1-->3) Nacetylgalactosamine is the most frequent sugar residue present in these glycoproteins. Results were compared with data reported in the literature on the same glands of other species.
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PMID:Basic and lectin histochemical characterization of bovine gustatory (von Ebner's) glands. 933 2

A battery of horseradish peroxidase-conjugated lectins (Con A, WGA and DBA), as well as conventional histochemical techniques (PAS, saponification, Alcian Blue pH 0.1, 1, 2.5, chlorhydric hydrolisis, sialidase, Bromophenol blue, Tioglycollate reduction and Ferric-ferricyanide-FeIII) were used to study the content and distribution of carbohydrates, proteins and glycoconjugate sugar residues on the skin and on the lymphocystis-infected cells of gilthead seabream, Sparus aurata. Variable amounts of glycoproteins containing sialic acid, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, mannose and/or glucose residues were observed in the cuticle and mucous cells of the corporal skin, tails and fins. Germinative and epithelial cells of the epidermis contained glycogen, proteins, carboxylated groups, as well as glycoproteins with mannose and/or glucose and N-acetyl-D-galactosamine residues. Hyaline capsule of the mature lymphocystis-infected cells was strongly stained with PAS, Alcian Blue (pH 0.5 and 2.5) and weakly positive with Alcian Blue (pH 1). Con A reacted with the granular cytoplasm, specially around hyaline capsule, and with the basophilic intracytoplasmic inclusions developed in mature lymphocystis-infected cells of Sparus aurata skin. These sugar residues (mannose and/or glucose), as well as N-acetyl-D-glucosamine and/or sialic acid and N-acetyl-D-galactosamine were not detected in the hyaline capsule of the lymphocystis disease.
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PMID:Histochemical study of lymphocystis disease in skin of gilthead seabream, Sparus aurata L. 947 32


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