Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: HUMANGGP:003450 (mucin)
 15,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuraminidases have been purified from the culture medium of two microorganisms, one aerobic, Diplococcus neumoniae, the other anaerobic, Clostridium perfringens. The enzymatic properties of the 2 neuraminidases have been studied (pH optimum; effect of cations; activity toward different substrates: neuraminyllactose, dilactaminyllacto-N-tetraose, gangliosides, alpha1-acid glycoprotein, Collocalia glycoprotein, ovine submaxillary mucin, porcin intestinal and human bronchial mucins).
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PMID:[Comparative study of neuraminidases from "Diplococcus pneumoniae" and "Clostridium perfringens"]. 0 29

An endo-beta-galactosidase acting on blood group A and B substances was found in the culture fluid of Diplococcus pneumoniae. The enzyme was purified 1000-fold, and its properties were studied in detail. The enzyme preparation, thus obtained, was practically free from various exoglycosidases, endo-beta-N-acetylglucosaminidase and proteases. The enzyme releases trisaccharides from blood group A and B active mucins purified from ovarian cyst fluid. The structures of the trisaccharides liberated from A and B active mucins were elucidated to be GalNAcalpha1 leads to 3(Fucalpha1 leads to 2)Gal and Galalpha1 leads to 3(Fucalpha1 leads to 2)Gal, respectively. The enzyme also hydrolyzes blood group A and B active oligosaccharides composed of type 2 chains, yielding the same products as in the case of ovarian cyst blood group substances. An H active mucin from ovarian cyst fluid, H active oligosaccharides, and A and B active oligosaccharides with type 1 chains were not hydrolyzed by the enzyme. Consequently, the enzyme catalyzes the following reaction, resulting in the degradation of blood type A and B determinants. (see article).
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PMID:Purification and characterization of an endo-beta-galactosidase produced by Diplococcus pneumoniae. 0 59

An alpha-L-fucosidase had been purified approximately 300-fold from the liver (hepatopancreas) of the marine mollusc Chamelea gallina L. (= Venus gallina L.). During the different steps of the purification procedure it was difficult to remove the contaminant N-acetylglucosaminidase activity; but, after electrofocusing, a final preparation free of this and other glycosidades present in the crude extract was obtained. The purified enzyme has a broad specificity; it hydrolyzes p-nitrophenyl alpha-L-fucoside and natural substrates such as oligosaccharides containing fucosidic residues with alpha 1--2, alpha 1--3 and alpha 1--4 linkages; also it hydrolyzes fucose-containing glycopeptides, such as thyroglobulin glycopeptide, and glycoproteins as procine submaxillary mucin (previously rendered free of sialic acid). The enzyme has a pH optimum of 5.2 +/- 0.2, with a Km of 7 X 10(-5) M using p-nitrophenyl L-fucoside as substrate. It is inhibited by Hg2+ and some sugars, and activated by CN-, Zn2+, Ca2+ and EDTA. It shows two peaks by isoelectric focusing (at 6.3 and 6.6). The molecular weight of the alpha-L-fucosidase by gel filtration was over 2000000.
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PMID:Glycosidases of molluscs. Purification and properties of alpha-L-fucosidase from Chamelea gallina L. 0 58

Changes in the fine structure of the gastric mucosa following exposure to graded concentrations of ethanol were studied in dogs. 300 ml of 12.5, 20, and 40%, vol/vol, were instilled intragastrically for 30 min. Mucosa from the midbody and midantrum along the greater curvature was examined by light and electron microscopy. Ethanol produced a gradation of changes in the surface epithelial cells and in the lamina propria without affecting the parietal cells and chief cells. 12.5% ethanol produced widened and irregular intercellular spaces while 20 and 40% disrupted the apical cell membrane with concomitant exudation of mucin into the gastric lumen. These changes were more severe after 40% ethanol. The tight junction between cells remained intact following exposure to the lower concentrations of ethanol, but focal separation of cell junctions was observed in severely damaged areas. Quantitation of protein, sodium, and potassium concentrations in the gastric contents revealed marked increases following exposure to ethanol which correlated with the concentration. These studies provide additional morphological data on the relationship between structural changes and functional abnormalities induced by agents which break the gastric mucosal barrier.
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PMID:Ultrastructural changes of the canine gastric mucosa after topical application of graded concentrations of ethanol. 0 53

The culture medium of Diplococcus pneumoniae contains enzymic activity that cleaves Galbeta1 leads to 3GalNAc from desialized human erythrocyte membrane glycoprotein. The enzyme was purified 180-fold by ammonium sulfate fractionation, gel filtration through a Sephadex G-200 column, and DEAE A-25 Sephadex chromatography. The purified enzyme liberates Galbeta1 leads to 3GalNAc from glycopeptides and glycoproteins with Galbeta1 leads to 3GalNAcalpha1 leads to Ser and Thr moieties. The optimum pH of this enzyme is 6.0. Using glycopeptides obtained by trypsin digestion of human erythrocyte membrane glycoprotein as a substrate, a Km of 0.20 mM (on the basis of the amount of Galbeta1 leads to 3GalNAc residues) was obtained. So far, the enzyme appears to have a strict specificity for Galbeta1 leads to 3GalNAcalpha1 leads to Ser and Thr structures, because no oligosaccharides larger than trisaccharides were liberated from porcine submaxillary mucin.
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PMID:Partial purification and characterization of an endo-alpha-N-acetylgalactosaminidase from the culture of medium of Diplococcus pneumoniae. 0 74

The membrane-bound N-acetylgalactosaminyltransferase from porcine submaxillary glands which provides A blood group specificity to mucin has been purified 38,000-fold by affinity chromatography on UDP-hesanolamine-agarose in aqueous Triton X-100. Design of a suitable purification procedure was developed by assessing the strength of interaction between enzyme and affinity adsorbent using batch desorption. The pure transferase has an apparent molecular weight of 100,000 as judged by zonal centrifugation and by sodium dodecyl sulfate polyacrylamide gel electrophoresis in the absence of a reducing agent. The reduced and carboxymethylated protein has an apparent molecular weight of 46,000 and 57,000 as judged by sedimentation equilibrium and sodium dodecyl sulfate polyacrylamide gel electrophoresis, respectively, suggesting that the native enzyme contains two subunits. It is a glycoprotein with a specific activity of 30 micronmol/min/mg of enzyme, which is 55,000 times that reported for the same enzyme isolated from human serum.
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PMID:Porcine A blood group-specific N-acetylgalactosaminyltransferase. I. Purification from porcine submaxillary glands. 1 62

Porcine A blood group-specific N-acetylgalactosaminyl-transferase required either Mn2+, Cd2+, or Zn2+ for activity and 2'-O-alpha-fucosylgalactosides as acceptor substrates. The presence of detergent stabilizes the enzyme but is not essential for catalysis. To obtain information about the kinetic mechanism of the transferase reaction, initial rate parameters have been determined using 2'-fucosyllactose or A--mucin as acceptors, and Mn2+ or Cd2+ as cosubstrates. 2'-Fucosyllactose is a competitive inhibitor with respect to A--mucin and a noncompetitive inhibitor with respect to UDP-N-acetylgalactosamine. UDP inhibits noncompetively with respect to acceptor; thus UDP-N-acetylgalactosamine or acceptor can bind to the transferase via an equilibrium random pathway. The transferase converts human O blood type erythrocytes of A blood types. After exhaustive glycosylation, 3 X 10(6) N-acetylgalactosaminyl residues were incorporated per cell. Gel electrophoretic analysis of the labeled erythrocyte membranes indicates that glycoproteins with apparents molecular weights from 30,000 to 100,000 have been glycosylated; glycolipids account for only 15% of the labeled material, although pure H-glycolipid is a good acceptor. The transferase, with its strict acceptor specificity, can thus be used as a tool to study the biosynthesis and function of glycolipids and glycoproteins.
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PMID:Porcine A blood group-specific N-acetylgalactosaminyltransferase. 1 63

The specific enzymic properties, membrane or particle binding capacities, and the total activities of certain acid hydrolases, including cathepsin D, acid phosphatase, arylsulfatase, and five acid glycosidases have been compared in normal canine antral and fundic mucosae and in liver. The two major regions of the gastric mucosa, whose cell populations are comparable in type but have very distinct functions, also differ in many properties of their lysosomal enzymes. These differences necessitate several major modification in their method of assay. Using optimal conditions, the activities of most of these enzymes were found to differ: levels in the antrum, in spite of its high water and mucin-glycoprotein content, were significantly greater, suggesting that the high lysosomal hydrolytic activity may be associated with the rapid autophagic processes of normal turnover of its surface epithelial and mucous neck cells. Lysosomal membrane stability or latency is also greater in the antrum; this may account, in part at least, for antral resistance to erosions brought about by stress.
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PMID:Acid hydrolases. Assay of activity and latency in the varied mixed cell populations of canine gastric mucosa. 1 64

A number of barium sulphate suspensions showed varying patterns of stability when provoked with gastric secretion. The stability of the suspensions was affected by the pH, the mucin content and the volume of secretion used. These studies indicate that flocculation of the suspension in the presence of gastric residue decreases as the amount of undiluted barium sulphate in the mixture is increased.
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PMID:Observations on the behaviour of barium sulphate suspensions in gastric secretion. 1 44

The hemolymph of the Japanese horseshoe crab, Tachypleus tridentatus contains lectins which agglutinate mammalian erythrocytes. Affinity chromatographic purification of the lectins using bovine submaxillary gland mucin-conjugated Sepharose resulted in the separation of the lectins into four fractions; one major and three minor lectins. Protein subunits revealed by polyacrylamide gel electrophoresis and the immunoprecipitin line of these lectins against antiserum to crude lectins were unique to each fraction. The activities of all the lectins were optimal at pH values between 6 and 8, and were destroyed by heating at 60 degrees C. Calcium chloride augumented the activities of three lectins, but the major lectin was not influenced by the salt. Bovine erythrocytes were not agglutinated by any of the lectins and comparative agglutination titers for other erythrocytes from various sources were different among these lectins. The activities of all the lectins were inhibited by N-acetylamino sugars. They were more effectively inhibited by glycoproteins which contain sialic acid.
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PMID:Lectins in the hemolymph of Japanese horseshoe crab, tachypleus tridentatus. 2 4


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