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

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

The objective of this study was to characterize the glycoconjugates present in the zona pellucida of the follicular oocytes in sheep, goats and pigs. The zona pellucida was stained with periodic acid-Schiff, low iron diamine, high iron diamine, and nine different lectin horseradish conjugates: Con-A, SBA, DBA, PNA, RCA-I, GSA-II, WGA, LTA and UEA-I. Staining with DBA, PNA, SBA and RCA-I was performed with and without saponification with KOH and sialidase digestion. The results showed the presence of neutral and acidic glycoconjugates with different terminal sugars and also sialic acid radicals in the zona pellucida of all the animal studied. In particular, the positive staining with WGA, SBA, PNA and RCA-I suggests the presence of oligosaccharides with N-acetyl-D-glucosamine and sialic acid linked to the penultimate beta-N-acetyl-D-galactosamine and to the disaccharide galactosyl-(beta 1-3)-N-acetyl-D-galactosamine. The terminal trisaccharide sialic acid galactosyl-(beta 1-4)-N-acetyl-D-glucosamine was identified only in the zona pellucida of ovine and porcine oocytes. Thus, the zona pellucida exhibited species-specific variations in the content and distribution of lectin-binding patterns that may reflect the species specificity of gamete interaction.
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PMID:Characterization of the complex carbohydrates in the zona pellucida of mammalian oocytes using lectin histochemistry. 873 21

This paper describes an approach for studying the structure of glycoconjugates found in the principal cells lining the epididymal duct in adult and prepubertal horses, using ten different lectin horseradish conjugates: Con-A, LCA, WGA, GSA-II, SBA, PNA, RCA-I, DBA, UEA-I, and LTA. Saponification and sialidase procedures, followed by lectin binding, were employed to visualize the distribution and to reveal the sequence of sialoglycoconjugates in ductus epididymis. In the adult horse the results demonstrated variations in the content and distribution of glycosidic residues of glycoconjugates in different epididymal regions (caput, corpus, cauda) and vas deferens, suggesting that each epididymal segment has a specific function. In particular, staining of the Golgi-zone in the principal cells lining corpus epididymis was interpreted as evidence for synthesis and secretion of glycoconjugates and sialoglycoconjugates. In the prepubertal horse, only the glycocalyx of the epithelial cells lining the epididymal duct showed reactivity toward the different lectins used, suggesting hormonal regulation of the epididymis activity. Additional, the heterogeneity of the lectin staining pattern of the adult horse epididymis reported in this investigation also suggests the existence of different functional segments along the epididymal duct.
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PMID:Detection of glycoconjugates in the ductus epididymis of the prepubertal and adult horse by lectin histochemistry. 922 52

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

This study was undertaken to determine the lectin affinity of the extratesticular rete testis and ductuli efferentes epithelial cells in adult and prepubertal horses, using ten different lectin horseradish peroxidase conjugates: Con-A, LCA, WGA, GSA-II, SBA, PNA, RCA-I, DBA, UEA-I, and LTA. In some cases, treatments with sialidase and KOH preceded the lectin staining. In sexually mature and immature horses the results showed the presence of different kinds of sialoglycoconjugates with the terminal sialic acid linked to D-GalNAc and beta-D-Gal residues in the rete testis. In the apical surface and cytoplasm of epithelial cells lining the ductuli efferentes of the adult horse, glycoconjugates with alpha-D-Man and/or alpha-D-Glc, GlcNAc, D-GalNac and beta-D-Gal residues were evidenced, whereas in the prepubertal horse only the apical surface of the ductuli efferentes epithelial cells resulted reactive toward some lectins. The differences observed in the presence of glycoconjugates between adult and prepubertal horse ductuli efferentes, suggest a hormonal control of the function of these tracts of the post-testicular ducts.
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PMID:Lectin-staining pattern in extratesticular rete testis and ductuli efferentes of prepubertal and adult horses. 958 88

A lectin histochemical study was performed to investigate the glycoconjugate saccharidic moieties on the endometrial epithelium and stroma in 12 women undergoing controlled ovarian hyperstimulation (COH) for in-vitro fertilisation for embryo transfer (IVF-ET) in early luteal phase. 7 control subjects were also evaluated. For this purpose a battery of seven horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, WGA, ConA, LTA and UEA I) was used. Cytochemical controls were performed for specificity of lectin-sugar reaction. As far as the endometrial glands and stroma are concerned, the obtained data showed no differences in the endometrial lectin binding between the subjects of the control group and the ones undergoing COH, with the exception of PNA reactivity at the level of the apical portion of the glandular cells, which was detected only in COH women. It is noteworthy that, although the endometrial dating using the Noyes's criteria showed marked dissynchronies between the stroma and the glands in COH subjects, a uniformity of lectin binding, revealing the same type and localization of terminal oligosaccharides, was observed in all the examined subjects. The uniformity in distribution of the sugar residues detected in the endometrial specimens following COH might be due to the massive FSH and/or hCG treatment which probably determines an endometrial environment almost equal in all the examined subjects. In all the treated subjects reactivity with sialidase-WGA and ConA, revealing the presence of N-acetyl-D-glucosamine and D-mannose respectively, was detected at the level of the lining epithelium.
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PMID:Lectin binding in the human endometrium in early luteal phase following controlled ovarian hyperstimulation. 969 Jan 31

Carpal glands are compound tubuloalveolar glands, located on the medial surface of the carpus. This study was carried out on samples from carpal glands of adult wild and domestic pigs of both sexes. We elucidated the glycosidic composition of carpal gland secretion in situ using traditional histochemical methods and lectin histochemistry. Some secretory cells exhibited an intense reaction with PAS in both wild and domestic pigs. Lectin histochemistry showed differences in the localization and composition of glycoconjugates secreted by carpal glands. A cytoplasmic positivity was revealed in the wild pig by the sequence sialidase-PNA and WGA, whereas in the domestic pig the reactivity was localized at the apical surface of some cells. LTA positive cells were found only in the carpal glands of the domestic pig.
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PMID:Detection of glycosidic residues in carpal glands of wild and domestic pig revealed by basic and lectin histochemistry. 1036 9

The carbohydrate expression in the epithelium lining the oesophagus of the toadfish Halobatrachus didactylus was studied by means of conventional and lectin histochemistry. The stratified epithelium was constituted by basal cells, polymorphous cells in the intermediate layer, pyramidal and flattened cells in the outer layer and contained two types of large secretory cells: goblet cells and sacciform cells. PAS, Alcian blue pH 2.5 and pH 1.0 stained very strongly the goblet cells, weakly the surface of the other epithelial cells but did not stain the sacciform cells. The goblet cells cytoplasm contained oligosaccharides with terminal Galbeta1,3GalNAc, alpha/betaGalNAc, Galbeta1,4GlcNAc, alphaL-Fuc and internal betaGlcNAc residues (PNA, SBA, RCA120, UEA I, LTA and KOH-sialidase-WGA affinity). Galbeta1,4GlcNAc, alphaL-Fuc and internal betaGlcNAc were also found in the glycocalyx. The sacciform cells expressed sialyloligosaccharides terminating with Neu5Acalpha2,3Galbeta1,4GlcNac, Neu5Acbeta2,6Gal/GalNAc, Neu5AcForssman pentasaccharide (MAL II, SNA, KOH-sialidase-DBA staining) as well as asialo-glycoconjugates with terminal/internal alphaMan (Con A affinity) and with terminal Galbeta1,3GalNAc, Forssman pentasaccharide, Galbeta1,4GlcNAc, GalNAc (HPA and SBA reactivity), alphaGal (GSA I-B4 reactivity), D-GlcNAc (GSA II labelling), alphaL-Fuc. The basal cells cytoplasm exhibited terminal/internal alphaMan and terminal Neu5Acalpha2,6Gal/GalNAc, Galbeta1,4GlcNAc, alpha/betaGalNAc, alphaGal, GlcNAc, alphaL-Fuc. Intermediate cells showed oligosaccharides with terminal/internal alphaMan and/or terminating with Neu5Acalpha2,6Gal/GalNAc, Galbeta1,4GlcNAc in the cytoplasm and with Neu5Acalpha2,3Galbeta1,4GlcNac, alpha/betaGalNAc, alphaGal, GlcNAc, alphaL-Fuc in the glycocalyx. The pyramidal cells expressed terminal/internal alphaMan and terminal Neu5Acalpha2,6Gal/GalNAc, alpha/betaGalbeta1,4NAc, alphaGal, alphaL-Fuc in the entire cytoplasm, terminal Neu5Acalpha2,3Galbeta1,4GlcNac and Forssman pentasaccharide in the apical extension, internal betaGlcNAc and/or terminal alphaL-Fuc in the luminal surface, Neu5Acalpha2,3Galbeta1,4GlcNac, Neu5Acalpha2,6Gal/GalNAc, Galbeta1,4GlcNAc, alphaGal in the basolateral surface. The flattened cells displayed glycans with terminal/internal alphaMan and terminal Neu5Acalpha2,6Gal/GalNAc, alpha/betaGalNAc, alphaGal, D-GlcNAc in the entire cytoplasm, glycans terminating with Galbeta1,3GalNAc and/or internal betaGlcNAc in the sub-nuclear cytoplasm.
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PMID:Histochemical study of glycoconjugates in the toadfish Halobatrachus didactylus oesophagus epithelium. 1712 8

Mucins in the gastrointestinal tract of Rhinolophus ferrumequinum were investigated by histochemistry and lectin histochemistry to evaluate morphofunctional variations of different regions and their possible physiological and evolutionary implications. Histochemical methods included periodic acid-Schiff (PAS), Alcian blue (AB) at pH 2.5 and 1.0 and high-iron-diamine AB pH 2.5. Binding of lectins Con A, DBA, WGA, LTA, LFA, PNA and SBA; LFA, PNA and SBA with prior sialidase treatment; and paradoxical Con A were evaluated. The oesophagus lacked glands. The stomach was divided into a short cardias, a wide fundus and a brief pylorus. The surface muciparous cells secreted sulpho- and sialomucins with N-acetylgalactosamine (GalNAc) residues, N-acetyllactosamine and (beta1,4 N-acetylglucosamine)(n) chains. Towards the pylorus, N-acetylgalactosamine residues disappeared and acidity decreased. Cardiac glands, neck cells in the fundic glands, pyloric and duodenal Brunner's glands all shared neutral, stable class-III mucins, mainly with N-acetylgalactosamine sequences. The intestine was divided into a duodenum, a jejuno-ileum and a short rectum. The goblet cells produced sulpho- and sialomucins with sialylated N-acetylgalactosamine sequences, (beta1,4 N-acetylglucosamine)(n) and N-acetyllactosamine, whose sialylation increased towards the rectum. The main features of the mucins are probably associated with the requirements of fast absorption and food passage and in protection against mechanical and pathogenic injuries.
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PMID:Lectin histochemistry of gastrointestinal glycoconjugates in the greater horseshoe bat, Rhinolophus ferrumequinum (Schreber, 1774). 1757 Apr 76


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