Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to investigate the effect of tumor necrosis factor alpha (TNF alpha) on hepatocyte necrosis in viral hepatitis, TNF alpha with or without D-galactosamine (D-Gal) was injected into the abdominal cavity of rats. No effect was observed after injection of TNF alpha alone. After injection of TNF alpha with D-Gal, the total bilirubin level in rat blood increased and hepatocyte necrosis appeared (P < 0.05). Moreover, anti-TNF alpha McAb blocked the effect of hepatocyte necrosis produced by D-Gal and lipopolysaccharide (LPS). 130 samples of hepatic tissue were stained with anti-TNF alpha McAb by using ABC immunohistochemistry method. It was found that more severe the hepatocyte necrosis, more the positive cells expressing TNF alpha. There were more TNF alpha positive cells in the tissue of severe hepatitis. These results suggested that TNF alpha is a mediator in hepatocyte necrosis.
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PMID:[The effect of tumor necrosis factor alpha on hepatic necrosis in viral hepatitis]. 927 43

A polysaccharide containing D-Gal, D-GalNAc, 3-(L-2-acetoxypropionamido)-3,6-dideoxy-D-galactose (approximately 80%) and 3-(L-2-hydroxypropionamido)-3,6-dideoxy-D-galactose (approximately 20%) was isolated by mild acid hydrolysis, followed by gel-permeation chromatography, from the phenol-soluble lipopolysaccharide (phenol/water extracted) derived from Acinetobacter strain 94. The polysaccharide, characterised by means of monosaccharide analyses, partial acid hydrolysis, and NMR studies, consisted of a branched tetrasaccharide repeating unit, as depicted below, in which Fucp3Nacyl represents 3-(L-2-hydroxypropionamido)-3,6-dideoxy-D-galactose, in which approximately 80% of the acyl residues are O-acetylated. These Fucp3N derivatives and an O-acetylated acyl group are therefore constituents of bacterial LPS, but to our knowledge are not present in any other natural carbohydrates. [sturcture: see text]
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PMID:Structural studies of the O-antigenic polysaccharide of the lipopolysaccharide from Acinetobacter (DNA group 11) strain 94 containing 3-amino-3,6-dideoxy-D-galactose substituted by the previously unknown amide-linked L-2-acetoxypropionic acid or L-2-hydroxypropionic acid. 928 2

The lipopolysaccharide of Helicobacter mustelae type strain ATCC 43772 was obtained by phenol-water extraction of bacterial cells. Structural investigations were made on the lipid A free saccharide moiety released from the lipopolysaccharide by mild acetic acid hydrolysis. Nuclear magnetic resonance, gas liquid chromatography-mass spectrometry and fast atom bombardment-mass spectrometry were employed in the characterization of products from chemical manipulations. A monoclonal antibody specific for blood group A reacted strongly with lipopolysaccharide of H. mustelae. Chemical and serological data showed that the outer core region of the lipopolysaccharide from H. mustelae ATCC 43772 expresses the monofucosyl A type 1, alpha-D-GalNAc-(1-->3)-[alpha-L-Fuc-(1-->2]-beta-D-Gal-(1-->3)- beta-D-GlcNAc, blood group determinant, a mimic of animal cell surface glycolipids and glycoproteins.
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PMID:The lipopolysaccharide of Helicobacter mustelae type strain ATCC 43772 expresses the monofucosyl A type 1 histo-blood group epitope. 929 27

A crude polysaccharide fraction (DAP-1) was prepared from roots of Dipsacus asperoides by hot water extraction and EtOH precipitation, and tested for anti-complementary activity, mitogenic activity of lymphocytes, and effects on acid phosphatase and phagocytic activities of macrophages. DAP-1 showed not only anti-complementary activity but also a stimulating effect on the mitogenic activity of lymphocytes. DAP-1 also significantly suppressed the phagocytic activity of macrophages. Although DAP-1 directly stimulated the mitogenecity of lymphocytes, it had no effect on lipopolysaccharide- or concanavalin A-induced mitogenic activity of lymphocytes. Periodate oxidation and pronase digestion suggested that the polysaccharide moiety in DAP-1 contributed to the expression of its anti-complementary and mitogenic activities and that the protein moiety in DAP-1 was responsible for its effect on phagocytosis. DAP-1 gave three polysaccharide fractions (DAP-2, 3, and 4) by fractionation using cetyltrimethylammonium bromide. All the fractions had potent anti-complementary activity, but showed different stimulating or suppressive effects on the proliferation of lymphocytes, phagocytosis, or acid phosphatase activity. Three potent anti-complementary polysaccharides (DAP-4I-1a, DAP-4I-1b, and DAP-4IIa-1) were purified from DAP-4 by anion-exchange chromatography, gel filtration, and HPLC. DAP-4I-1a, I-1b, and IIa-1 consisted of Ara, Rha, Xyl, Gal, Glc and GlcA in a molar ratio of 1.0:0.7:1.0:18.6:22.2:nil; 1.0:0.1:0.3:19.3:26.8:nil; and 3.7:trace:0.6:26.3:5.5:1.0; respectively. Among the polysaccharides, only DAP-4IIa-1 reacted with beta-glucosyl-Yariv antigen. Methylation analysis indicated that DAP-4I-1a mainly comprised 4-linked Gal and 3-, 4-, and 6-linked Glc, whereas DAP-4IIa-1 consisted mainly of terminal Araf, 3-linked Glc, and 3,6-branched Gal.
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PMID:Fractionation and chemical properties of immunomodulating polysaccharides from roots of Dipsacus asperoides. 934 40

A polymeric fraction (the O-antigenic side-chain) has been isolated from the lipopolysaccharide of Burkholderia gladioli pv. gladioli strain NCPPB 1891 after mild acid hydrolysis. The components of the polymer and their molar proportions were L-Rha (1), D-Gal (1), D-Man (1), and O-acetyl (1). By means of chemical degradations and NMR studies, the repeating unit of the polymer was shown to be a linear trisaccharide of the structure shown. [formula: see text]
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PMID:Structural studies of the O-specific side-chain of lipopolysaccharide from Burkholderia gladioli pv. gladioli strain NCPPB 1891. 935 38

The O-antigen chain from the lipopolysaccharide of Helicobacter pylori strain UA861 was determined to be composed of an elongated type 2 N -acetyllactosamine backbone, -[-->3)-beta-D-Gal-(1-->4)-beta-D-GlcNAc-(1-]n-->, with approximately half of the GlcNAc units carrying a terminal alpha-d-Glc residue at the O -6 position. The O-chain of H.pylori UA861 was terminated by a N -acetyllactosamine [beta-D-Gal-(1-->4)-beta-D-GlcNAc] (LacNAc) epitope and did not express terminal Lewis X or Lewis Y blood-group determinants as previously found in other H.pylori strains. The absence of terminal Lewis X and Lewis Y blood-group epitopes and the replacement of Fuc by Glc as a side chain in the O-chain of H.pylori UA861 represents yet another type of lipopolysaccharide structure from H.pylori species. These structural differences in H.pylori lipopolysaccharide molecules carry implications with regard to possible different pathogenic events between strains and respective hosts.
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PMID:Glucosylated N-acetyllactosamine O-antigen chain in the lipopolysaccharide from Helicobacter pylori strain UA861. 945 Oct 19

Gal alpha 1,3Gal carbohydrate residues are present in the glycoproteins and glycolipids of lower mammals, and appear to be involved in the binding specificity of several membrane receptors. We report here that endothelial cells stimulated with lipopolysaccharide or inflammatory cytokines modulate their expression of UPD-Gal: beta-D-Gal alpha 1,3-galactosyltransferase (alpha 1,3GT), the Golgi enzyme that attaches a galactose in alpha 1,3 configuration to an N-acetyllactosamine acceptor. Upon activation, the steady state level of mRNA is transiently increased, the modifications being paralleled by a transcriptional regulation of the gene. Cell-associated enzyme activity, on the other hand, falls rapidly after activation, before being up- and downregulated with kinetics that parallel those of the mRNA, and after 3 days reaches a level representing 40-60% of the activity in cells before activation. Overall Gal alpha 1,3Gal expression at the cell surface follows enzyme activity, except that it is insensitive to the rapid and transient reduction of activity occurring shortly after activation. This reduced alpha 1,3GT activity in stimulated EC is correlated with lower stability of the protein, and with a switch in the expression of the isoform pattern, isoform 1 being predominant in resting cells whereas after activation it is isoform 2 that predominates. The two isoforms, however, appear to have similar intrinsic stability, so that the reduced stability of the enzyme in activated EC probably results from an induced proteolytic degradation pathway.
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PMID:Transcriptional and posttranscriptional regulation of alpha 1,3-galactosyltransferase in activated endothelial cells results in decreased expression of Gal alpha 1,3Gal. 959 46

The oligosaccharide side chains of a human anti-lipopolysaccharide IgM produced by a human-human-mouse heterohybridoma were analyzed at each of its five conserved N-glycosylation sites. This antibody also has a potential sixth N-glycosylation site in the variable region of its heavy chain which is not glycosylated. The oligosaccharides were released by digestion with various endo- and exoglycosidases and analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and fluorophore-assisted carbohydrate electrophoresis. The antibody has various complex- and hybrid-type oligosaccharide structures at Asn 171, various sialylated complex-type oligosaccharides at Asn 332 and 395, and high-mannose-type oligosaccharides at Asn 402 and 563. Of note is the presence in this human IgM of oligosaccharides containing N-glycolylneuraminic acid and N-acetylneuraminic acid in the ratio of 98:2 as determined using anion-exchange chromatography. Furthermore, we observed oligosaccharide structures containing Gal alpha (1,3)Gal that have not been reported as components of human glycoproteins.
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PMID:Structural characterization of the oligosaccharides of a human monoclonal anti-lipopolysaccharide immunoglobulin M. 959 48

The recent cloning of the lipooligosaccharide (LOS) a-2,3-sialyltransferase from Neisseria meningitidis immunotype L3 permitted us to examine other immunotypes for this structural gene. We identified the gene and measured the enzyme activity in the L1 immunotype strain which had previously been reported to lack sialic acid in its LOS because it contains a terminal alpha-linked galactose which was thought not to be an acceptor for the sialyltransferase. This finding prompted us to re-examine the structure of the LOS from the L1 immunotype, which revealed the presence of sialic acid on the terminal alpha-linked galactose. Oligosaccharides derived from the LOS were shown to be sialylated by composition and methylation analysis, mass spectrometry and nuclear magnetic resonance. The detailed structural analysis showed the sialic acid to occur only at 06 of the terminal a-D-galactopyranose residue of the alpha-D-Gal-1,4-beta-D-Gal-1,4-beta-D-glc trisaccharide (Pk epitope) chain of the LOS, in the alpha-D configuration. These data are the first report of a alpha-2,6-linked sialic acid in a bacterial LOS or lipopolysaccharide, and also the first report of a sialylated Pk epitope.
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PMID:Structure of an alpha-2,6-sialylated lipooligosaccharide from Neisseria meningitidis immunotype L1. 968 75

The lipopolysaccharide (LPS) core of the Gram-negative bacterium Rhizobium leguminosarum is more amenable to enzymatic study than that of Escherichia coli because much of it is synthesized from readily available sugar nucleotides. The inner portion of the R. leguminosarum core contains mannose, galactose, and three 3-deoxy-D-manno-octulosonate (Kdo) residues, arranged in the order: lipid A-(Kdo)2-Man-Gal-Kdo-[O antigen]. A mannosyltransferase that uses GDP-mannose and the conserved precursor Kdo2-[4'-32P]lipid IVA (Kadrmas, J. L., Brozek, K. A., and Raetz, C. R. H. (1996) J. Biol. Chem. 271, 32119-32125) is proposed to represent a key early enzyme in R. leguminosarum core assembly. Conditions for demonstrating efficient galactosyl- and distal Kdo-transferase activities are now described using a coupled assay system that starts with GDP-mannose and Kdo2-[4'-32P]lipid IVA. As predicted, mannose incorporation precedes galactose addition, which in turn precedes distal Kdo transfer. LPS core mutants with Tn5 insertions in the genes encoding the putative galactosyltransferase (lpcA) and the distal Kdo-transferase (lpcB) are shown to be defective in the corresponding in vitro glycosylation of Kdo2-[4'-32P]lipid IVA. We have also discovered the new gene (lpcC) that encodes the mannosyltransferase. The gene is separated by several kilobase pairs from the lpcAB cluster. All three glycosyltransferases are carried on cosmid pIJ1848, which contains at least 20 kilobase pairs of R. leguminosarum DNA. Transfer of pIJ1848 into R. meliloti 1021 results in heterologous expression of all three enzymes, which are not normally present in strain 1021. Expression of the lpc genes individually behind the T7 promoter results in the production of each R. leguminosarum glycosyltransferase in E. coli membranes in a catalytically active form, demonstrating that lpcA, lpcB, and lpcC are structural genes.
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PMID:Cloning and overexpression of glycosyltransferases that generate the lipopolysaccharide core of Rhizobium leguminosarum. 975 77


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