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)

Radical C-glycosidation of a 3-methylidene-7-oxabicyclo[2.2.1]heptan-2-one derivative with acetobromomannose gave a alpha-C-mannopyranoside that was converted into alpha-D-ManpCH2(1-->3)-D-GalNAc, a C-disaccharide that inhibits beta-galactosidase from jack bean with IC50 = 9.4 microM and Ki = 7.5 microM (mixed mode of inhibition).
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PMID:Synthesis of alpha-C(1-->3)-mannopyranoside of N-acetylgalactosamine, a new beta-galactosidase inhibitor. 1020 49

A part of human serum immunoglobulin A1(IgA1) was aggregated by treatment with neuraminidase. Aggregated IgA1 was separated from non-aggregated IgA1 by gel permeation chromatography. The prepared asialo-hinge glycopeptide (asialo-HGP) from both IgA1 subfractions was treated with beta-galactosidase to determine the number of beta-linked sugar chains attached on the hinge region. Removal of the galactose residue from asialo-HGP resulted in the HPLC separation of three major peaks. MALDI-TOFMS analysis of the glycopeptides also indicated the presence of three HGP components with three, four and five N-acetylgalactosamine (GalNAc) residues, respectively. Comparison of their relative content among the glycopeptide components showed a higher content of the HGP component with a lower number of GalNAc residues on aggregated IgA1. Thus, asialo-HGP prepared from aggregated IgA1 induced by neuraminidase treatment had an incomplete core structure of O-linked oligosaccharides. Especially, the result suggested that the reduced number of the attached O-linked oligosaccharides on IgA1 take part in phenomena such as self-aggregation of asialo-IgA1.
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PMID:Aggregated human serum immunoglobulin A1 induced by neuraminidase treatment had a lower number of O-linked sugar chains on the hinge portion. 1020 52

Immunoglobulin A1 (IgA1) from normal human serum is known to have O-linked sugar chains, sialylated Galbeta1,3GalNAc, in the hinge portion. In order to reduce the microheterogenity of the sugar chain, the hinge glycopeptide prepared from IgA1 was sequentially treated with neuraminidase and beta-galactosidase. The asialo-, agalacto-hinge glycopeptide (HGP-SG) composed of a 33-mer peptide (HP33) and N-acetylgalactosamine (GalNAc) residues was obtained. The HGP-SG was separated into three major peaks, A, B and C, by high-performance liquid chromatography (HPLC). Each glycopeptide fraction was further separated by capillary electrophoresis (CE). Peaks A, B and C with HPLC abundantly contained HP33 bearing five and six N-acetylgalactosamine residues (HGP33-5,6GN), HGP33-4,5GN and HGP33-3,4GN, respectively. Among these glycopeptide peaks, only the HGP33-5GN peak was partly split into two peaks based on the CE analysis - HGP33-5GN-alpha and -beta. The glycopeptide, HGP25-5GN shortened by the thermolysin digest of HGP33-SG was also well separated into the alpha and beta forms by CE analysis. No differences in their mass and peptide portion were observed between HGP25-5GN-alpha and -beta. Therefore, the obtained result might indicate that HGP25-5GN-alpha was an isomer of HGP25-5GN-beta differing in its stereospecific structure of the peptide portion and/or the attachment site of the GalNAc residue.
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PMID:Mutual separation of hinge-glycopeptide isomers bearing five N-acetylgalactosamine residues from normal human serum immunoglobulin A1 by capillary electrophoresis. 1040 3

In the present work, the combination of chemical and enzymatic methods to obtain neoglycoproteins is described. Three bovine serum albumin (BSA)-conjugates, BSA-[GalNAc alpha-], BSA-[Gal(beta 1-3)GalNAc(alpha-], and BSA-[Neu5Ac(alpha 2-3)Gal(beta 1-3)GalNAc(alpha-], were prepared. alpha GalNAc derivatives were galactosylated employing crude beta-galactosidase from bovine testes. The use of oversaturated donor solutions (pNP beta Gal) enhanced the yields up to 60%. This method was verified using divalent structures as acceptors, that rendered di- and tri-galactosylated products. Further treatment of the disaccharides with CMP-Neu5Ac and alpha 2-3 sialyltransferase from pork liver led to formation of trisaccharides. Finally, mono-, di-, and trisaccharides were coupled to BSA employing a thiolic group introduced into the protein for Michael addition to a maleinimide group in the spacer-arm of the saccharide components. The results were monitored by HPLC and MALDI-TOF.
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PMID:Chemoenzymatic synthesis of spacer-linked oligosaccharides for the preparation of neoglycoproteins. 1046 14

The radical C-glycosidation of (-)-(1S,4R,5R, 6R)-6-endo-chloro-3-methylidene-5-exo-(phenylseleno)-7-ox abi cyclo[2. 2.1]heptan-2-one ((-)-4) with 2,3,4, 6-tetra-O-acetyl-alpha-D-mannopyranosyl bromide gave (+)-(1S,3R,4R, 5R,6R)-6-endo-chloro-5-exo-(phenylseleno)-3-endo-(1',3',4', 5'-tetra-O-acetyl-2', 6'-anhydro-7'-deoxy-D-glycero-D-manno-heptitol-7'-C-yl)-7-oxabi cyc lo[ 2.2.1]hept-2-one ((+)-5) that was converted into (+)-(1R,2S,5R, 6R)-5-acetamido-3-chloro-2-hydroxy-6-(1',3',4',5'-tetra-O-acetyl)-2', 6'-anhydro-7'-deoxy-D-glycero-D-manno-heptitol-7'-C-yl)cyclohex -3-en- 1-yl acetate ((+)-10) and into (+)-(1R,2S,5R, 6S)-5-bromo-3-chloro-2-hydroxy-6-(1',3',4',5'-tetra-O-acetyl-2', 6'-anhydro-7'-deoxy-D-glycero-D-manno-heptitol-7'-C-yl)cyclohex -3-en- 1-yl acetate ((+)-19). Ozonolysis of (+)-10 and further transformations provided 2-acetamido-2,3-dideoxy-3-C-(2', 6'-anhydro-7'-deoxy-D-glycero-D-manno-heptitol-7'-C-yl)-D-galac tos e (alpha-C(1-->3)-D-mannopyranoside of N-acetylgalactosamine (alpha-D-Manp-(1-->3)CH(2)-D-GalNAc): 1). Displacement of the bromide (+)-19 with NaN(3) in DMF provided the corresponding azide ((-)-20) following a S(N)2 mechanism. Ozonolysis of (-)-20 and further transformations led to 2-acetamido-2,3-dideoxy-3-C-(2', 6'-anhydro-7'-deoxy-D-glycero-D-manno-heptitol-7'-C-yl)-D-talose (alpha-C(1-->3)-D-mannopyranoside of N-acetyl D-talosamine (alpha-D-Manp-(1-->3)CH(2)-D-TalNAc): 2). The neutral C-disaccharide 1 inhibits several glycosidases (e.g., beta-galactosidase from jack bean with K(i) = 7.5 microM, alpha-L-fucosidase from human placenta with K(i) = 28 microM, beta-glucosidase from Caldocellum saccharolyticum with K(i) = 18 microM) and human alpha-1, 3-fucosyltransferase VI (Fuc-TVI) with K(i) = 120 microM whereas it 2-epimer 2 does not. Double reciprocal analysis showed that the inhibition of Fuc-TVI by 1 displays a mixed pattern with respect to both the donor sugar GDP-fucose and the acceptor LacNAc with K(i) of 123 and 128 microM, respectively.
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PMID:The C-disaccharide alpha-C(1-->3)-mannopyranoside of N-acetylgalactosamine is an inhibitor of glycohydrolases and of human alpha-1,3-fucosyltransferase VI. Its epimer alpha-(1-->3)-mannopyranoside of N-acetyltalosamine is not. 1089 Nov 23

A sialyl T-antigen-linked tetrapeptide was prepared by the combined method of chemical synthesis and enzymatic synthesis. The GalNAc-linked peptide was first obtained by using a commercial peptide synthesizer, and then a galactose residue was attached with beta-(1-->3)-linkage by transglycosylating with a recombinant beta-galactosidase from Bacillus circulans. The sialic acid residue was then combined by alpha-(2-->3)-linkage with sialytransferase from rat liver.
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PMID:Efficient synthesis of a sialyl T-antigen-linked glycopeptide by the chemoenzymatic method. 1099 67

Adhesion of human colon carcinoma variant cell lines expressing different levels of the cell surface sialyl Lewis X (sLeX) antigen to frozen sections of mouse liver was examined. KM12-HX cells that bound the monoclonal antibody (mAb) FH6 (anti-sLeX) and thus expressed a high level of sLeX demonstrated a greater degree of adhesion to liver sections than their low-binding counterparts, KM12-LX cells. The adhesion of KM12-HX cells to liver sections was partially blocked by mAb FH6, but not by another anti-sLeX mAb, KM93. The adhesion was Ca2+ dependent but was not inhibited by anti-E-selectin. Endo-beta-galactosidase treatment significantly reduced adhesion and resulted in the loss of cell surface binding sites for mAb FH6. O-linked oligosaccharides from KM12-HX cells incubated in the presence of p-nitrophenyl-N-acetylgalactosaminide were fractionated by a combination of gel filtration, anion exchange chromatography, and normal phase high-performance liquid chromatography. The structure of a mAb FH6-reactive and endo-beta-galactosidase-sensitive glycan was estimated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry in a post source decay mode and by glycosidase digestions to be NeuAc alpha2-3Gal beta1-4GlcNAc beta1-3Gal beta1-4Glc-NAc beta1-3Gal beta1-4(+/-Fuc alpha1-3)GlcNAc beta1-6(NeuAc alpha2-3Gal beta1-3)GalNAc-pNP. Mild detergent lysates of mouse liver surface-labeled with sulfo-NHS biotin were incubated with glutaraldehyde-fixed monolayers of KM12-HX cells, and bound components were isolated after EDTA treatment. A Mr 49,000 component that bound only to KM12-HX cells and not to KM12-LX cells was identified.
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PMID:Involvement of cell surface glycans in adhesion of human colon carcinoma cells to liver tissue in a frozen section assay: role of endo-beta-galactosidase-sensitive structures. 1101 56

We attempted to determine whether beta1,3-galactosyltransferase beta3Gal-T5 is involved in the biosynthesis of a specific subset of type 1 chain carbohydrates and expressed in a cancer-associated manner. We transfected Chinese hamster ovary (CHO) cells expressing Fuc-TIII with beta3Gal-T cDNAs and studied the relevant glycoconjugates formed. beta3Gal-T5 directs synthesis of Lewis type 1 antigens in CHO cells more efficiently than beta3Gal-T1, whereas beta3Gal-T2, -T3, and -T4 are almost unable to direct synthesis. In the clone expressing Fuc-TIII and beta3Gal-T5 (CHO-FT-T5), sialyl-Lewis a synthesis is strongly inhibited by swainsonine but not by benzyl-alpha-GalNAc, and sialyl-Lewis x is absent, although it is detected in the clones expressing Fuc-TIII and beta3Gal-T1 (CHO-FT-T1) or Fuc-TIII and beta3Gal-T2 (CHO-FT-T2). Endo-beta-galactosidase treatment of N- glycans prepared from clone CHO-FT-T5 releases (+/-NeuAcalpha2-->3)Galbeta1-->3[Fucalpha1-->4]GlcNAcbeta1-->3Gal but not GlcNAcbeta1-->3Gal or type 2 chain oligosaccharides, which are found in CHO-FT-T1 cells. This result indicates that beta3Gal-T5 expression prevents poly-N-acetyllactosamine and sialyl-Lewis x synthesis on N-glycans. Kinetic studies confirm that beta3Gal-T5 prefers acceptors having the GlcNAcbeta1-->3Gal end, including lactotriosylceramide. Competitive reverse transcriptase mediated-polymerase chain reaction shows that the beta3Gal-T5 transcript is expressed in normal colon mucosa but not or poorly in adenocarcinomas. Moreover, recombinant carcinoembryonic antigen purified from a CHO clone expressing Fuc-TIII and beta3Gal-T5 reacts with anti-sialyl-Lewis a and carries type 1 chains on oligosaccharides released by endo-beta-galactosidase. We conclude that beta3Gal-T5 down-regulation plays a relevant role in determining the cancer-associated glycosylation pattern of N-glycans.
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PMID:beta 1,3-Galactosyltransferase beta 3Gal-T5 acts on the GlcNAcbeta 1-->3Galbeta 1-->4GlcNAcbeta 1-->R sugar chains of carcinoembryonic antigen and other N-linked glycoproteins and is down-regulated in colon adenocarcinomas. 1105 88

Clostridium septicum is responsible for several diseases in humans and animals. The bacterium is capable of a simple kind of multicellular behavior known as swarming. In this investigation, environmental and physiologic factors affecting growth and swarm cell formation in C. septicum were studied over a range of dilution rates (D = 0.02 to 0.65 h(-1)) in glucose-limited, glucose-excess, and mucin-limited chemostats. Cellular differentiation was observed at low specific growth rates, irrespective of the carbon and energy source, showing that swarming occurred in response to nutrient depletion. Differential expression of virulence determinants was detected in swarm cells. Hemolysin was secreted by short motile rods but not swarm cells, whereas in cultures grown with glucose, only swarm cells formed DNase, hyaluronidase, and neuraminidase. However, neuraminidase and, to a lesser degree, hyaluronidase were induced in short motile rods in mucin-limited cultures. Both swarm cells and short rods were cytotoxic to Vero cells. Mucin was chemotaxic to C. septicum, and large amounts of mucin-degrading enzymes (beta-galactosidase, N-acetyl beta-glucosaminidase, glycosulfatase, and neuraminidase) were produced. Synthesis of these enzymes was catabolite regulated. In chemostat experiments, glycosulfatase secretion occurred only in swarm cells at low dilution rates in mucin-limited cultures. Determinations of oligosaccharide utilization demonstrated that N-acetylglucosamine, galactose, and N-acetylgalactosamine were the main carbon sources for C. septicum in mucin. Neuraminic acid was not assimilated, showing that neuraminidase does not have a direct nutritional function in this pathogen.
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PMID:Toxin synthesis and mucin breakdown are related to swarming phenomenon in Clostridium septicum. 1116 9

Thomsen-Friedenreich antigen (T antigen) disaccharide, beta-D-galactose-(1-->3)-alpha-N-acetyl-D-galactosamine (beta-D-Gal-(1-->3)-alpha-D-GalNAc), containing glycolipid mimicry was synthesized using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase from Bacillus sp. This enzyme could transfer the disaccharide from a p-nitrophenyl substrate to water-soluble 1-alkanols and other alcohols at a transfer ratio of 70% or more. Although the transfer ratios were lower for water-insoluble than water-soluble alcohols, they were shown to increase by adding sodium cholate to the reaction mixtures. The enzyme also transferred the disaccharide directly from asialofetuin to 1-alkanols. The anomeric bond between the disaccharide and 1-alkanols of the transglycosylation product is in the alpha configuration as determined by sequential digestion of jack bean beta-galactosidase and Acremonium alpha-N-acetylgalactosaminidase. Since the transglycosylation product, beta-D-Gal-(1-->3)-alpha-D-GalNAc-(1-->O)-hexyl, efficiently inhibits the binding of anti-T antigen monoclonal antibody to asialofetuin, it has potential as an agent for blocking T antigen-mediated cancer metastasis.
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PMID:Enzymatic syntheses of T antigen-containing glycolipid mimicry using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase. 1126


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