Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The serine/threonine O-linked carbohydrates GalNAc alpha and Gal beta 1-3GalNAc alpha, referred to as Tn and T antigens, respectively, appear to be more prevalent in some human carcinomas than in surrounding tissues. Tn/T antigens may represent incomplete synthesis of O-linked oligosaccharides, due to decreased activity of specific glycosyltransferases, or alternatively, increased glycosidases activity in tumors which may expose these internal O-linked oligosaccharide sequences. To explore these possibilities, we measured UDP-Gal:GalNAc alpha-R beta 1-3 galactosyltransferase (beta 3Gal-T) and Gal beta 1-3GalNAc alpha-R beta 1-3 galactosidase in a series of human breast tumors. In addition, glycoproteins extracted from the tumors were separated by SDS-PAGE and stained with the lectins HPA (GalNAc alpha-R reactive) and PNA (Gal beta-3GalNAc alpha-R reactive). The relative levels of HPA- to PNA-reactive glycoproteins in the carcinomas correlated inversely with beta 3Gal-T activities. The results suggest that Tn antigen expression in human breast carcinoma is due in part to low beta 3Gal-T activity, a situation similar to that observed previously in haematopoietic cells of individuals with a condition called Tn syndrome.
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PMID:Tn antigen and UDP-Gal:GalNAc alpha-R beta 1-3Galactosyltransferase expression in human breast carcinoma. 184 11

The tegumental glycocalyx of excysted juvenile (EJ) of Paragonimus ohirai was immunobiochemically characterized using a monoclonal antibody (MS-Mab). HPLC gel filtration showed that the antigens detected by two-site ELISA had a molecular weight of greater than or equal to 2 x 10(6) Da (dextran marker). On reduced SDS-PAGE, the glycocalyx antigen retained in the stacking gel was cleaved into several much smaller antigens after pronase treatment. The antigenic activity of the glycocalyx was stable in two-site ELISA to heat and acid treatments, but sensitive to alkali, periodate, base/borohydride, and pronase treatments. Precipitin formation in immunodouble diffusion between MS-Mab and EJ crude antigen was inhibited only by two monosaccharides: galactose and N-acetylgalactosamine. The purified glycocalyx bound strongly to PNA lectin, fairly well to RCA120 lectin, and slightly to SBA lectin, but not to Con A, WGA, UEA-1, DBA, or LFA lectins. Exo-beta-galactosidase treatment increased SBA binding, whereas it decreased PNA binding. PNA was observed to strongly bind to the body surface of living EJ. The antigenic activity of the glycocalyx was remarkably lost by incubation with exo-beta-galactosidase and O-glycanase. The glycocalyx was reactive with sera of P. ohirai-infected rats, and its reactivity was remarkably reduced by O-glycanase treatment. The ELISA level was higher in sera at an early stage of infection than in a late one. These studies show that the EJ tegumental glycocalyx is antigenic in infection, a marked, high molecular weight glycoprotein containing antigenic O-linked sugars, and that the sugar epitope is at the nonreducing terminal of the O-linked sugars and is composed of galactose and N-acetylgalactosamine.
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PMID:Paragonimus ohirai: immunobiochemical characterization on the tegumental glycocalyx of excysted juvenile recognized by a monoclonal antibody. 190 99

A previously unknown haemagglutinin, named Sambucus nigra agglutinin-III (SNA-III), has been purified from the fruit of the elder (Sambucus nigra). Whereas elder bark agglutinin I (SNA-I) is highly specific for terminal alpha 2,6-linked sialic acid residues, SNA-III displays a high affinity for oligosaccharides containing exposed N-acetylgalactosamine and galactose residues. Different N-terminal sequences and the amino acid composition distinguish the fruit lectin from elder bark agglutinin II (SNA-II), which shows a similar carbohydrate specificity. The 40-fold higher affinity of SNA-III for asialofetuin than for human asialo-alpha 1-acid glycoprotein and human asialotransferrin respectively suggests a preference for O-linked glycans. SNA-III occurs mainly as a monomeric glycoprotein, but tends to form di- and oligo-meric aggregates. This aggregation seems to mediate the multivalent interaction, leading to agglutination. SDS/PAGE revealed two major polypeptides with apparent molecular masses of 32 and 33 kDa respectively. This heterogeneity is probably a result of proteolysis in the C-terminal region. Binding to concanavalin A and susceptibility to peptide: N-glycosidase F indicated the presence of N-glycosidically linked oligosaccharides.
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PMID:Purification and partial characterization of a novel lectin from elder (Sambucus nigra L.) fruit. 191 Mar 34

A method is developed to obtain lectin from jack fruit (Artocarpus integrifolia) seeds using an affinity chromatography on a sorbent prepared from the egg white. The minimum agglutination concentration of human erythrocytes is 80 ng/ml, the molecular weight of the preparation is about 39 kDa, it contains 1.8% of neutral hexoses and 3.1% of hexosamines. PAAG electrophoresis in the alkali system has revealed several molecular forms of lectin isolated by preparative electrophoresis, their properties are investigated. SDS-PAAG electrophoresis has revealed several types of polypeptide chains among which two chains (12 and 14 kDa) are predominant. Lectin possesses affinity to galactosides (not to free galactose) and N-acetylgalactosamine and interacts with O-glycans with high affinity. The preparation has mitogenic activity in optimal concentration 50 micrograms/ml.
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PMID:[Production of lectin from jack fruit (Artocarpus integrifolia) seeds and its interaction with carbohydrates and glycoproteins]. 192 89

Natural human interferon alpha 2 (IFN-alpha 2) was isolated from a preparation of partially purified human leucocyte IFN by monoclonal-antibody immunoaffinity chromatography. The purified protein had a specific activity of 1.5 x 10(8) i.u./mg; it was estimated to constitute 10-20% of the total antiviral activity of leucocyte IFN. N-Terminal amino-acid-sequence analysis identified the subspecies IFN-alpha 2b and/or IFN-alpha 2c, whereas IFN-alpha 2a was not detectable. The structure of natural IFN-alpha 2 was found to differ from that of its recombinant (Escherichia coli-derived) equivalent. First, reverse-phase h.p.l.c. showed that natural IFN-alpha 2 was significantly more hydrophilic then expected. Secondly, the apparent molecular mass of the natural protein determined by SDS/PAGE was higher than that of recombinant IFN-alpha 2; incubation under mild alkaline conditions known to eliminate O-linked carbohydrates resulted in a reduction of the apparent molecular mass to that of the recombinant protein. On sequence analysis of proteolytic peptides, Thr-106 was found to be modified. These results suggested that Thr-106 of natural IFN-alpha 2 carries O-linked carbohydrates. Reverse-phase h.p.l.c. as well as SDS/PAGE of natural IFN-alpha 2 showed that glycosylation is heterogeneous. For characterization of the carbohydrate moieties, the protein was treated with neuraminidase and/or O-glycanase and analysed by gel electrophoresis; in addition, glycopeptides obtained by proteinase digestion and separated by h.p.l.c. were characterized by sequence analysis and m.s. Further information on the composition of the glycans was obtained by monosaccharide analysis. The results indicate that natural IFN-alpha 2 contains the disaccharide galactosyl-N-acetylgalactosamine (Gal-GalNAc) linked to Thr-106. In part of the molecules, this core carbohydrate carries (alpha-)N-acetylneuraminic acid, whereas a disaccharide, probably N-acetyl-lactosamine, is bound to Gal-GalNAc in another proportion of the protein. Further glycosylation isomers are present in small amounts. As IFN-alpha 2 is the only IFN-alpha species with a threonine residue at position 106, it may represent the only O-glycosylated human IFN-alpha protein.
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PMID:Natural human interferon-alpha 2 is O-glycosylated. 204 76

Opsonizing and agglutinating activities of plasma from the freshwater clam, Corbicula fluminea, were found to be inhibited by the sugars, 2-deoxy-D-glucose (deoxy-Glu) and N-acetyl-D-galactosamine (GalNAc). The plasma opsonin/agglutinin was subsequently isolated by a two-step separation procedure. Aldehyde-fixed rabbit erythrocytes (RRBC) were used as a solid-phase plasma opsonin affinity absorbant, and deoxyGlu and GalNAc were used in the eluting buffer to desorb several RRBC-binding plasma proteins. The second step involved the further separation of sugar-eluted proteins by Sephacryl S-200 gel filtration. A plasma protein with an apparent molecular weight of 40 kd on SDS-PAGE under nonreducing conditions was found to possess both agglutinating and opsonizing activities. It was further shown to be composed of two identical 20 kd subunits associated through disulfide linkage(s). Although this protein shares some structural similarity with other bivalve opsonins, differences in native molecular size or subunit structure, agglutinating properties and/or sugar binding specificity support the current hypothesis that naturally occurring plasma opsonins of molluscs represent a heterogeneous group of proteins unified primarily through their lectin-like characteristic of binding specific carbohydrate determinants.
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PMID:Immunorecognition in the freshwater bivalve, Corbicula fluminea. II. Isolation and characterization of a plasma opsonin with hemagglutinating activity. 208 70

An alpha-3-N-acetylgalactosaminyltransferase that transfers N-acetylgalactosamine from UDP-N-acetylgalactosamine to H-active structures to form A determinants was purified to homogeneity from human gut mucosal tissue of blood-group-A subjects. The mucosa was homogenized, then treated with Triton X-100, and the solubilized enzyme was purified by affinity chromatography on UDP-hexanolamine-agarose and octyl-Sepharose CL-4B. Enzyme activity was recovered in 44% yield with a specific activity of approx. 7 mumol/min per mg. The only effective acceptor substrates for the transferase were those containing a subterminal beta-galactosyl residue substituted at the O-2 position with L-fucose. The purified enzyme had a weak capacity to transfer D-galactose from UDP-D-galactose to similar acceptors to make blood-group-B determinants. H.p.l.c. and SDS/PAGE analysis indicated an Mr of 40,000 for the purified enzyme. For the first time a partial amino acid sequence Xaa-Ser-Leu-Pro-Arg-Met-Val-Tyr-Pro-Gln-Ile-Ser?-Val-Leu was obtained for the N-terminal region of the soluble alpha-3-N-acetylgalactosaminyltransferase.
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PMID:Purification, properties and partial amino acid sequence of the blood-group-A-gene-associated alpha-3-N-acetylgalactosaminyltransferase from human gut mucosal tissue. 212 Nov 35

Previously, on the basis of lectin binding and glycosidase digestion assays, we have suggested that N-acetyl-D-glucosamine residues (GlcNAc) are major structural components of both trophozoites and in vivo cysts of the intestinal parasite Giardia lamblia. In this report we confirm that GlcNAc is present both in trophozoites and in vitro cysts as assessed by lectin binding and glycosidase digestion assays, galactosyltransferase labeling, immunochemical analysis using antibodies specific for GlcNAc and its beta 1-4 oligomers, and by gas chromatography/mass spectrometry (GC/MS). The results show that wheatgerm agglutinin (WGA) binds specifically to intact trophozoites and in vitro cysts as well as to SDS-PAGE separated proteins. WGA binding to the separated proteins was markedly reduced after their digestion with N-acetyl-beta-D-glucosaminidase, supporting the conclusion that WGA is reacting with terminal beta-linked GlcNAc residues. Labeling of trophozoites and cysts by 3H-exogalactosylation with galactosyltransferase further confirmed the presence of terminal GlcNAc in both surface and intracellular glycoproteins. The presence of GlcNAc is also supported by microfluorometric analysis using antibodies to (GlcNAc)1, (GlcNAc)2, and (GlcNAc)3, which revealed a sugar-inhibitable binding of the antibody to live trophozoites. Finally, the presence of GlcNAc in both cysts and trophozoites was unequivocally confirmed by GC/MS analysis of detergent-extracted membranes and of glycoproteins isolated by affinity chromatography on WGA-agarose. GC/MS analysis also revealed mannose (Man), N-acetyl-D-galactosamine (GalNAc), fucose (Fuc), galactose (Gal), glucose (Glc) and N-acetylneuraminic acid (NANA) to be present in cysts. All these sugars were also present in trophozoites, except for GalNAc. The glycoproteins isolated by WGA affinity chromatography were 5- to 40-fold enriched in GlcNAc, further supporting the conclusion that WGA reacts with GlcNAc in Giardia. In summary, the data presented here provide biological and chemical evidence for GlcNAc in both cysts and trophozoites of G. lamblia and are consistent with previously published results from this and other laboratories.
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PMID:N-acetyl-D-glucosamine is present in cysts and trophozoites of Giardia lamblia and serves as receptor for wheatgerm agglutinin. 212 47

Sialoglycoprotein (SGP) having relatively high molecular weight was purified from human submandibular sublingual saliva by anion exchange chromatography on Q-Sepharose Fast Flow followed by gel filtration on Superose 6 prep grade. The molecular weight of SGP was estimated to be about 440,000 and the isoelectric points obtained by IEF-PAGE, ranged from 5.2 to 5.8. The purified SGP contained high compositions of glutamic acid, proline, glycine and aspartic acid which were calculated as about 57% of the total amino acids, and about 15% of sugars such as N-acetylneuraminic acid, galactose, fucose, mannose, N-acetylgalactosamine and N-acetylglucosamine. A panel of 23 murine monoclonal antibodies (MAbs; 8 IgG1, 15 IgM) directed against SGP was prepared. Although three protein components were detected by SDS PAGE, SGP specific MAb reacted intensely with a 60 kilodalton of protein component. Bacteroides gingivalis 381 showed high binding ability to SGP, but this interaction was inhibited by SGP specific MAb. To detect SGP in the pellicle formed on fragments of human dental enamel, SGP specific MAb were used. During the first hour of formation, rapid increase of SGP detected was observed, and it remained relatively unchanged between 1 and 24 h after beginning of pellicle formation. This work has suggested that SGP purified from submandibular-sublingual saliva is a main component of salivary pellicle on tooth surface and plays an important role in the interaction with oral bacteria including Bacteroides gingivalis.
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PMID:[Preparation and application of monoclonal antibodies against sialoglycoprotein purified from human submandibular-sublingual saliva]. 213 77

1. Perchloric acid-soluble glycoprotein fraction (PASF) extracted from human liver metastases (LM) of sigmoid colon carcinoma was chromatographed on a DEAE-cellulose column. The main fraction (DEAE-nonadsorbed fraction) passed through the column was then subjected to Sephacryl S-200 superfine gel filtration and separated into 12 fractions. 2. Among 12 fractions, only both Fractions 3 and 4 were demonstrated to be chemically and immunologically homogeneous glycoproteins, respectively, by a combination of chemical composition analysis, SDS-PAGE and EITB assay using antisera against the DEAE-nonadsorbed fractions of PASFs from human LMs, normal liver (NL) and normal sigmoid colon (NSC). Each of Fractions 3 and 4 reacted with anti-LM serum to give one immuno complex on a nitrocellulose sheet in EITB assay, but did not react with anti-NL and -NSC sera. 3. Apparent molecular weights of 80,900 and 62,100, respectively, were found for Fractions 3 and 4. Both the fractions, respectively, had abnormal sugar compositions. Fraction 3 contained sialic acid, fucose, galactose, N-acetylglucosamine and N-acetylgalactosamine, but lacked glucose and mannose, and Fraction 4 contained sialic acid, fucose, galactose and N-acetylglucosamine, but lacked glucose, mannose and N-acetylgalactosamine, as sugar components.
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PMID:Isolation and partial characterization of two glycoproteins from human liver metastases of sigmoid colon carcinoma. 216 27


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