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)

Specific glycosidase activities were determined in samples of gingival crevicular fluid (GCF) collected from eight predetermined sites in two groups, each of 20 adult patients, with either gingivitis or periodontitis. The total activities (as units of enzyme activity per sample) of alpha-L-fucosidase, sialidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase and alpha-glucosidase were significantly greater in the periodontitis group. In contrast, the total beta-mannosidase and hexosaminidase A activities were significantly greater in the gingivitis group, while there was no significant difference in the total alpha-mannosidase activity between the groups. Only the specific activities (as units of enzyme activity per min per microliter of GCF) of beta-mannosidase and hexosaminidase A were significantly different between the groups being greater in the gingivitis group. When used to predict the clinical status of individual periodontal sites, the total enzyme activities had specificity and sensitivity values of 91.9 and 61.3%, respectively. Measurement of glycosidase activities might thus have a role in monitoring the efficacy of periodontal treatment or in predicting future periodontal disease but this will require further investigation.
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PMID:Glycosidase activities in gingival crevicular fluid in subjects with adult periodontitis or gingivitis. 161 Mar 3

Human von Willebrand factor (vWF) immobilized on a polyvinylidene difluoride membrane was subjected to binding assay with a series of horseradish peroxidase-conjugated lectins. The protein was reactive with concanavalin A, Ricinus communis agglutinin 120, wheat germ agglutinin and Ulex europaeus agglutinin I (UEA-I) but not with peanut agglutinin before sialidase treatment. These reactivities were consistent with the major oligosaccharide structure reported except for UEA-I. The reactivity with UEA-I was greatly decreased after digestion of the protein with either alpha-L-fucosidase or peptide-N-glycosidase F, but no significant decrease was observed after mild alkaline treatment or delipidation. vWF and UEA-I have been independently used as a good marker for human endothelial cells. Our results indicate that vWF itself contains UEA-I reactive sugar chains in its Asn-linked oligosaccharides.
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PMID:Carbohydrate analysis of human von Willebrand factor with horseradish peroxidase-conjugated lectins. 187 45

Exogenous gangliosides are known to affect the metabolism when administered to the body. To study the mechanism of this effect three types of gangliosides were administered intraperitoneally to mice and the changes in the enzyme activity of the cerebral tissues studied. The effect of GM2 from bovine brain was characterized by a decrease in the activity of various aminopeptidases, while GD3 from cow's milk caused an increase in the activity of sugar-related enzymes such as sialidase, glucosidase, and fucosidase. GM3 from horse erythrocytes showed intermediate effects between GM2 and GD3. Multivariate analysis showed that the effects of the three gangliosides are clearly separable statistically. These results which demonstrate the sugar moiety-specificity of gangliosides are discussed in relation to the A and B pathways of ganglioside synthesis.
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PMID:Gangliosides administration causes sugar moiety-specific enzymatic changes in brain. 188 33

We examined the distribution of blood group-related antigens using an indirect immunoperoxidase method with monoclonal antibodies (MAb) directed to A, B, H, Lewis a (Lea), Lewis b (Leb), Lewis x (Lex), and Lewis y (Ley) antigens and Type 1 precursor chain in human pancreas. Effects of prior digestion with exoglycosidases on MAb stainings were simultaneously investigated. A, B, H, Leb, and Ley antigens were detected in acinar cells and interlobular duct cells but not in centroacinar cells, intercalated duct cells, and islet of Langerhans cells. The expression of these antigens in acinar cells was not dependent on Lewis type and secretor status of the tissue donors, whereas that in interlobular duct cells was strictly dependent on secretor status. The distribution pattern of these antigens in acinar cells was not homogeneous, i.e., cells producing H antigens expressed both Leb and Ley antigens but not A or B antigens, whereas those producing A or B antigens did not secrete Leb and Ley as well as H antigens. Digestion with alpha-N-acetylgalactosaminidase or alpha-galactosidase resulted in the appearance of Leb and Ley antigens as well as H antigen in acinar cells producing A and/or B antigens. Type 1 precursor chain was not detected in pancreatic tissues from secretors but appeared in acinar cells producing H antigen after alpha-L-fucosidase digestion, which also disclosed Lex but not Lea antigen in acinar cells expressing both Leb and Ley. In some non-secretors, MAb against Type 1 precursor chain reacted with acinar cells without enzyme digestion. Although Lea antigen was not detected in acinar cells, it was found in centroacinar cells, intercalated duct cells, and interlobular duct cells from all individuals examined except two Le(a-b-) secretors. After sialidase digestion, Lex antigen appeared in centroacinar and intercalated duct cells from some individuals. Sialidase digestion also elicited reactivity with MAb against Type 1 precursor chain in islet of Langerhans cells from some individuals. These results demonstrate the complexity in the pattern of expression and regulation of blood group-related antigens in different cell types of human pancreas. Such complexity may largely be ascribed to differences in individual genotypes and in gene expression patterns of different cell types.
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PMID:Histochemical localization and analysis of blood group-related antigens in human pancreas using immunostaining with monoclonal antibodies and exoglycosidase digestion. 238 86

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

Fibronectins from human adult plasma, fetal plasma and from amniotic fluid obtained during early and late gestation were compared with respect to (i) their reactivity with lectins, (ii) their binding to the physiological ligands gelatin and heparin, and (iii) the role of the carbohydrate residues in the binding to these two ligands. The two fibronectin isoforms displayed distinct developmental differences in both glycosylation and binding properties: (i) Proportions of tri/tetraantennary complex glycans compared to the fraction of biantennary structures, as inferred from the reactivity with concanavalin A, were highest in amniotic fluid fibronectin from late pregnancy, lower in amniotic fluid fibronectin from early gestation, and even lower in fetal and adult plasma fibronectins. Likewise, fucose (alpha 1-6) linked to the innermost N-acetylglucosamine of the chitobiosyl core, defined by reactivity with Lens culinaris agglutinin (LCA), was present primarily in amniotic fluid fibronectin, and decreased in content during gestation from the 2nd. to the 3rd. trimenon. Both fetal and adult plasma fibronectins were only weakly reactive with LCA, indicating a low content of (alpha 1-6) linked fucose residues. After prior treatment with sialidase, both plasma and amniotic fluid fibronectins strongly reacted with erythrocyte phytohaemagglutinin (E-PHA), indicating that both fibronectin isoforms contain bisecting (beta 1-4) N-acetylglucosamine residues. Amniotic fluid fibronectins showed much greater reactivity than adult and fetal plasma fibronectins with wheat germ agglutinin; binding of this lectin to amnion fluid fibronectins was not decreased by desialylation indicating the presence of poly(N-acetyllactosamine) units. Whereas amniotic fluid fibronectins were strongly reactive with peanut agglutinin, neither adult nor fetal plasma fibronectins did bind to this lectin unless after prior desialylation. Hence, both fibronectin isoforms contain O-glycan residues that are fully sialylated in fetal and adult plasma fibronectins, but only partly sialylated in amniotic fluid fibronectins. According to these differences, glycosylation of plasma and amniotic fluid fibronectins is under developmental regulation. (ii) Amniotic fluid fibronectins had a significantly lower binding activity for both heparin and gelatin than plasma fibronectins. Moreover, amnion fibronectin from late gestation displayed a significantly lower binding to these two ligands than amnion fibronectin from early gestation. Fetal plasma fibronectins had a lower binding activity for gelatin than adult plasma fibronectin. (iii) Treatment of fibronectins with sialidase, fucosidase and removal of N-glycans with endoglycosidases H and F did not affect binding to gelatin and heparin, indicating that the interaction of plasma and amnion fibronectin with these two ligands is not influenced by their oligosaccharide moieties.
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PMID:Developmental changes in the glycosylation and binding properties of human fibronectins. Characterization of the glycan structures and ligand binding of human fibronectins from adult plasma, cord blood and amniotic fluid. 261 23

Recent work indicates that subpopulations of human fecal bacteria, averaging approximately 1% of the total viable fecal flora, degrade the oligosaccharide side chains of hog gastric mucin, which structurally resembles human epithelial mucins. Here we report studies to determine whether degradation of mucin oligosaccharides is related to glycosidase production by bacteria growing in anaerobic fecal cultures. Triplicate cultures containing hog gastric mucin were inoculated with serially diluted feces from each of seven healthy subjects. When the stationary growth phase was attained, mucin oligosaccharide degradation and both cell-bound and extracellular activities of four glycosidases were measured in each culture. Cell-bound beta-d-galactosidase, beta-N-acetylglucosaminidase, and sialidase were present in bacteria growing at all levels of fecal inocula, including 10(-11) g. In contrast, extracellular activities were present in every culture inoculated with 10(-4)-10(-7) g feces, but were diminished or absent in cultures inoculated with 10(-8)-10(-11) g feces. Bacterial autolysis was an unlikely cause of extracellular glycosidase activity, since p-nitrophenyl-alpha-l-fucosidase remained cell bound in cultures at every level of fecal inoculum. Degradation of mucin oligosaccharides was associated with extracellular, but not with cell-bound beta-d-galactosidase, beta-N-acetylglucosaminidase, and sialidase. Among the seven subjects, the estimated most probable numbers (MPN) of fecal bacteria producing extracellular beta-d-galactosidase, beta-N-acetylglucosaminidase, and sialidase ranged from 10(6)-10(10)/g dry fecal wt, were comparable to the MPN of mucin-degrading bacteria, and were significantly smaller than the MPN of total fecal bacteria. We interpret these findings as evidence for the existence of bacterial subpopulations in the normal fecal flora that produce extracellular glycosidases, and that these subpopulations have a major role in degrading the complex oligosaccharides of mucin in the gut lumen.
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PMID:Mucin degradation in human colon ecosystems. Evidence for the existence and role of bacterial subpopulations producing glycosidases as extracellular enzymes. 616 Nov 36

To probe the potential for extracellular degradation of glycoprotein oligosaccharides in conjunction with Chinese hamster ovary (CHO) cell culture, an initial characterization of several CHO cell glycosidases was performed using 4-methylumbelliferyl substrates. CHO cell lysates contained sialidase, beta-galactosidase, beta-hexosaminidase, and fucosidase activities with pH optimums near 5.5, 4, 6, and 6.5, respectively. These glycosidase activities were also present in cell-free supernatant samples from commercial CHO cell cultures. The sialidase activity was further characterized. In contrast to previous reports concerning mammalian sialidases, the sialidase activity in CHO cell lysate retained considerable activity at pH 7 and was very stable, with a half-life of 57 h at 37 degrees C. Both the Km and Vmax of CHO lysate sialidase for 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid (4MU-NeuAc) varied with pH, and this activity was competitively inhibited by 2,3-dehydro-2-deoxy-N-acetylneuraminic acid and by free N-acetylneuraminic acid. The kinetic characteristics and pH-activity profiles of the CHO cell lysate and cell culture supernatant sialidase activities were essentially identical, and both released sialic acid from the glycoprotein fetuin at pH 7.5. These results suggest that the oligosaccharides of glycoproteins secreted by CHO cells can potentially be modified extracellularly by sialidase under culture conditions which promote the release and extracellular accumulation of this enzyme.
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PMID:Glycosidase activities in Chinese hamster ovary cell lysate and cell culture supernatant. 776 7

Pig brain cytosolic sialidase purified to homogeneity, showed a single protein band on SDS-PAGE under non-reducing conditions, and three bands using reducing conditions, suggesting a complex of different units. The sialidase complex (molecular mass, M(r), 180 kDa) was resolved into a catalytic unit (M(r) 30 kDa), active but very liable upon storage at 4 degrees C and freezing and thawing, and two protective units (66 kDa and 42 kDa), inactive, but capable to stabilize the catalytic unit. Recombination of the catalytic and protective units (optimal ratio, 1:1, by weight) gave rise to a stable active complex. Using GD1a as substrate, the catalytic unit showed a Michaelis-Menten kinetics, and the complex a sigmoid-shaped kinetics, whereas a Michaelis-Menten kinetics was exhibited with MU-NeuAc in both cases. The apparent Vmax and Km values of the catalytic unit for MU-NeuAc and GD1a were 105.1 and 110.0 mU/mg protein, and 4.2 x 10(-5) and 1.6 x 10(-5) M, respectively. The model we propose for cytosolic sialidase complex is one of each protective units and 2-3 catalytic units. The sialidase complex and protective units did not display any beta-D-galactosidase, beta-D-N- acetylglucosaminidase, alpha-L-fucosidase, alpha-D-glucosidase and carboxypeptidase activities.
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PMID:Cytosolic sialidase from pig brain: a 'protein complex' containing catalytic and protective units. 794 53


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