Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The major macromolecular component of the porcine oocyte zona pellucida is a Mr = 55,000 antigen, termed ZP3, comprised of greater than 25 charge isomers. ZP3 was purified to apparent electrophoretic homogeneity from nonreduced, sodium dodecyl sulfate-treated porcine zonae pellucidae by chromatography on Sephacryl S-400 and hydroxylapatite resins. The carbohydrate moiety of purified ZP3 was comprised of a heterogeneous population of acidic lactosaminoglycans as evidenced by the saccharide composition and size distribution of glycopeptides produced by Pronase digestion of ZP3, as well as by the sensitivity of ZP3 to digestion with Escherichia freundii endo-beta-galactosidase. Endo-beta-galactosidase-digested ZP3 was resolved by gel electrophoresis into two components, termed alpha-glycoprotein and beta-glycoprotein, with Mr values (nonreduced) of 46,000 and 42,000, respectively. Each was comprised of fewer and more neutral charge isomers than ZP3. Following purification by reverse phase high performance liquid chromatography, the alpha- and beta-glycoproteins of endo-beta-galactosidase-digested ZP3 were distinguished on the basis of amino acid and carbohydrate compositions, amino-terminal sequence analyses and peptide mapping experiments, thus suggesting differences in the primary structures of their respective polypeptide moieties. Corresponding dissimilarities in the immunoreactivities of the alpha- and beta-glycoproteins toward polyclonal antisera raised against ZP3, alpha-glycoprotein, and beta-glycoprotein were revealed by competitive binding radioimmunoassays as well as by immunoblotting experiments. Collectively, the data were interpreted to indicate that the Mr = 55,000 antigen of porcine oocyte zona pellucida is in fact comprised of overlapping families of charge isomers corresponding to two structurally and immunologically distinct lactosaminoglycan-containing glycoproteins.
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PMID:Structural characterization of the Mr = 55,000 antigen (ZP3) of porcine oocyte zona pellucida. Purification and characterization of alpha- and beta-glycoproteins following digestion of lactosaminoglycan with endo-beta-galactosidase. 310 May 14

Endo-beta-galactosidase treatment of glycopeptides derived from the trypsinate and membranes of PC12 pheochromocytoma cells and cultured sympathetic neurons demonstrated the presence of poly(N-acetyllactosaminyl) units on tri- and tetraantennary oligosaccharides, some of which have a core fucose residue and a 2,6-substituted alpha-linked mannose residue. Nerve growth factor induced differentiation of the PC12 cells led to a small but significant decrease in the proportion of these oligosaccharides. Poly(N-acetyllactosaminyl) oligosaccharides were also identified in a major 230 000-Da cell-surface glycoprotein (the nerve growth factor inducible large external, or NILE, glycoprotein) of PC12 cells and appear to account for much or all of the difference in size between this glycoprotein as compared to the immunochemically cross-reactive 205 000-Da species present in postnatal brain. Glycoproteins containing poly(N-acetyllactosaminyl) oligosaccharides were selectively labeled by treatment of PC12 cells with endo-beta-galactosidase to expose N-acetylglucosamine residues, followed by incubation with galactosyltransferase and UDP-[14C]galactose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography revealed the presence of a number of distinct PC12 cell glycoproteins that contain these oligosaccharides and have apparent molecular weights in the range of 25 000-250 000. Treatment of PC12 cells with nerve growth factor (NGF) altered the relative labeling of several of the glycoprotein bands, with a time course similar to the effects of NGF on neurite outgrowth.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Poly(N-acetyllactosaminyl) oligosaccharides in glycoproteins of PC12 pheochromocytoma cells and sympathetic neurons. 375 58

The carbohydrate-binding properties of wheat-germ agglutinin (WGA) have been studied by using glycopeptides isolated from the cell surfaces of a cultured murine myeloid cell line (416B). The glycopeptides were passed through affinity columns of lentil lectin (LCA), concanavalin A (Con A) and WGA arranged in series so that material reaching the WGA column had failed to bind to LCA or Con A. WGA-binding glycopeptides were step-eluted with 0.01 M, 0.1 M and 0.5 M-N-acetylglucosamine (GlcNAc), to yield weak (WGA-W), intermediate (WGA-I) and strong (WGA-S) affinity fractions. WGA-W and WGA-I contained 'N'- and 'O'-linked oligosaccharides bound to separate polypeptides. WGA-S consisted almost entirely of N-linked components. Our analytical work was concentrated mainly on the N-linked fractions. In these carbohydrates WGA affinity was directly proportional to molecular size but inversely related to N-acetylneuraminic acid content. The binding of the weak-affinity fraction was dependent on N-acetylneuraminic acid, but the intermediate- and strong-binding species interacted with the lectin by N-acetylneuraminic acid-independent mechanisms. N-linked glycopeptides in each WGA-binding class were almost totally degraded to monosaccharides by the concerted action of the exoglycosidases neuraminidase, beta-galactosidase and beta-N-acetylglucosaminidase. Treatment with endo-beta-galactosidase caused partial depolymerization, yielding some disaccharides but also a heterogeneous population of partially degraded components. These findings suggest that WGA binds with high affinity to internal GlcNAc residues in large oligosaccharides containing repeat sequences of Gal beta(1----4)GlcNAc beta(1----3) (i.e. polylactosamine-type glycans). N-Acetylneuraminic acid is involved only in low-affinity interactions with WGA. WGA therefore displays an intricate pattern of saccharide specificities that can be profitably utilized for structural analysis of complex carbohydrates.
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PMID:Identification of two binding sites for wheat-germ agglutinin on polylactosamine-type oligosaccharides. 384 Jun 82

Escherichia coli strains isolated from patients with different levels of urinary tract infection and from healthy persons were tested for their ability to haemagglutinate endo-beta-galactosidase-treated human erythrocytes. Among the 104 strains studied one revealed a strong agglutination reaction with the enzyme-treated erythrocytes. From the monosaccharides tested N-acetyl-D-glucosamine inhibited agglutination most effectively. Orosomucoid and asialo-orosomucoid had no effect on the haemagglutination whereas beta-galactosidase treated asialo-orosomucoid was inhibitory. These findings indicate that the E. coli strain studied contains a novel cell-binding activity with specificity for terminal N-acetyl-D-glucosamine residues.
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PMID:Novel cell-binding activity specific for N-acetyl-D-glucosamine in an Escherichia coli strain. 640 69

A new strain of Escherichia freundii was isolated from human feces. Compared with the previous strain (Kitamikado, M., and Ueno, R. (1970) Bull. Jpn. Soc. Sci. Fish. 36, 1175-1180), this strain releases comparable levels of endo-beta-galactosidase with lower levels of exoglycosidases in the culture medium containing 0.3% of keratan sulfate. Endo-beta-galactosidase was purified by an improved purification procedure involving Amicon H1P10 hollow fiber filtration, QAE-Sephadex A-50, and CM-Sephadex C-50 chromatographies. The purified enzyme is completely free from proteases and exoglycosidases. The general properties of this enzyme are: molecular weight, 28,000; optimal pH, 5.5 TO 5.8; PI, pH 8.0. This enzyme hydrolyzed keratan sulfates isolated from different sources to produce 6-O-sulfo-GlcNAc beta1 leads to 3Gal as the major product. In addition, the specificity of this enzyme toward various glycoconjugates was also studied.
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PMID:Isolation and characterization of an endo-beta-galactosidase from a new strain of Escherichia freundii. 676 23

Gangliosides were isolated from purified preparations of human peripheral blood lymphocytes and neutrophils. Structural analyses and comparisons were performed by direct probe mass spectrometry and by degradation studies with the following enzymes: Escherichia freundii endo-beta-galactosidase; Clostridium perfringens and Arthrobacter ureafaciens neuraminidase; and jack bean beta-N-acetylhexosaminidase and beta-galactosidase. This combination of techniques allowed us to obtain carbohydrate composition and sequence information without the aid of methylation or carbohydrate compositional analyses using only 1-2 mg of purified gangliosides. On the basis of these studies we propose that human lymphocytes and neutrophils have gangliosides with the following structures. NeuAc alpha 2 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure A NeuAc alpha 2 leads to ? GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure B NeuAc alpha 2 leads to ? Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1Cer Structure C All three compounds were isolated from both cell types with structure A being the major lymphocyte ganglioside and structure C the major neutrophil ganglioside. Structure B is a novel ganglioside and may represent a leukocyte-specific glycosphingolipid. Neuraminidase degradation studies demonstrated that only one ganglioside species of each cell type contains an internally linked sialic acid residue, and on the basis of thin layer chromatographic analysis this component is the same as the major brain ganglioside, GM1 (II3-N-acetylneuraminosyl-gangliotetraosylceramide). In addition, large gangliosides with the general structure NeuAc alpha 2 leads to ?(Gal beta 1 leads to 3,4GlcNAc beta 1 leads to 3)n Gal beta 1 leads to 4Glc beta 1 leads to 1Cer were isolated. These results are discussed as they relate to blood group antigens and specific cell surface markers in human leukocytes.
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PMID:Isolation and structural characterization of human lymphocyte and neutrophil gangliosides. 678 May 55

A new procedure for inducing and purifying endo-beta-galactosidase from Escherichia freundii was described. The enzyme was found to be induced with high efficiency in culture medium containing Smith-degraded hog gastric mucin, which was prepared from a commercially available starting material. Endo-beta-galactosidase was then purified by ammonium sulfate fractionation, DEAE-Sephadex chromatography, and affinity chromatography on Sepharose conjugated with the Smith-degraded mucin. The enzyme thus purified by only three steps showed no other glycosidase or protease activities and had higher specific activity compared to the previous method. This new method has a great advantage since the gastric mucin is abundantly available and the efficiency of enzyme production was high without significant induction of exoglycosidase. The hydrolysis of oligosaccharides, glycosphingolipid, and keratansulfate was studied by using this newly purified enzyme. Kinetic data indicate that hydrolyzability of these substrates is largely affected by substrate concentration, enzyme concentration and the structure of substrates. Based on these results, the specificity of E. freundii endo-beta-galactosidase was discussed.
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PMID:Purification and characterization of endo-beta-galactosidase from Escherichia freundii induced by hog gastric mucin. 678 49

The present study deals with the biochemical properties of high-molecular-weight glycopeptides isolated from the surface of human teratocarcinoma cells. This cell surface material released by mild trypsin digestion from galactose-labeled human teratocarcinoma cells, Tera I and PA1, was digested extensively with pronase. Most of the resulting glycopeptides were large and were excluded from a Sephadex G-50 column. The properties of these large cell surface glycopeptides isolated from Tera I cells have been examined in detail. It is clear from these experiments that they are neither acidic mucopolysaccharides nor mucin-type glycopeptides with short oligosaccharide chains. Although the glycopeptides are hardly hydrolyzed by beta-galactosidase even after prior digestion with neuraminidase, around 30% of the glycopeptides are depolymerized by treatment with endo-beta-galactosidase from Escherichia freundii. The large cell surface glycopeptides from Tera I cells therefore appear to be very similar to the large glycopeptides seen on mouse embryonal carcinoma cells, which have core structures composed of galactose and N-acetylglucosamine. Like the mouse cell glycopeptides, a fraction of the large glycopeptides from these human cells bind to agarose-conjugated fucose-binding proteins and peanut agglutinin.
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PMID:Biochemical properties of the high-molecular-weight glycopeptides released from the cell surface of human teratocarcinoma cells. 680 82

Neutral glycosphingolipids were isolated from the malignant cells of several patients with different types of acute leukemia. Analyses were performed by high performance liquid chromatography combined with enzymatic hydrolysis of glycosphingolipids using glycosidases (Escherichia freundii endo-beta-galactosidase, jack bean beta-galactosidase, and beef kidney beta-hexosaminidase). We found that acute leukemia cells contain very little or none of the more complex neutral glycosphingolipids that are found in normal leukocytes or chronic leukemia cells. Lymphoblasts, in particular, are rich in neutral glycosphingolipids with only 1 or 2 carbohydrate units. The most significant finding of our study was that, in contrast to normal leukocytes and chronic leukemia cells which have a single predominant tetraosylceramide species, acute leukemia cells (9 out of 10 patients analyzed) were found to have significant amounts of both globo (GalNAc beta 1 leads to 3Gal alpha 1 leads to 4Gal beta 1 leads to 4Glc beta 1 leads to 1ceramide) and neolactotetraosylceramide (Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1ceramide). These results indicate that the composition of neutral glycosphingolipids in acute leukemia cells differs significantly from that found in normal or chronic leukemia cells.
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PMID:Neutral glycosphingolipids of human acute leukemias. 695 4

We previously demonstrated that P-selectin binds with high affinity to a trace, homodimeric glycoprotein ligand on human myeloid cells. The ligand carries the sialyl Lewis x (sLe(x)) epitope, a limited number of N-linked glycans, and clustered, sialylated O-linked glycans. In this study we demonstrate that the polypeptide component of this ligand is identical to that of P-selectin glycoprotein ligand-1 (PSGL-1), a molecule recently identified by expression cloning from a human myeloid cell cDNA library. We have examined the effects of glycosidases on purified, radioiodinated PSGL-1 from human neutrophils to further characterize the structure and function of the attached oligosaccharides. We found that PSGL-1 had poly-N-acetyllactosamine, only some of which could be removed with endo-beta-galactosidase. The majority of the Le(x) and sLe(x) structures were on endo-beta-galactosidase-sensitive chains. Peptide:N-glycosidase F (PNGaseF) treatment removed at least two of the three possible N-linked oligosaccharides from PSGL-1. Expression of Le(x) and sLe(x) was not detectably altered by PNGaseF digestion, indicating that these structures were primarily on O-linked poly-N-acetyllactosamine. Endo-beta-galactosidase-treated PSGL-1 retained the ability to bind to P-selectin, suggesting that some of the oligosaccharides recognized by P-selectin were either on enzyme-resistant poly-N-acetyllactosamine or on chains which lack poly-N-acetyllactosamine. PNGaseF treatment did not affect the ability of PSGL-1 to bind to P-selectin, demonstrating that the oligosaccharides required for P-selectin recognition are O-linked. PSGL-1 also bound to E-selectin, but with at least 50-fold lower affinity than to P-selectin. These data suggest that PSGL-1 from human neutrophils displays complex, sialylated, and fucosylated O-linked poly-N-acetyllactosamine that promote high affinity binding to P-selectin, but not to E-selectin.
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PMID:The P-selectin glycoprotein ligand from human neutrophils displays sialylated, fucosylated, O-linked poly-N-acetyllactosamine. 752 78


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