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)

The chemical structure of lipid A isolated from Porphyromonas gingivalis lipopolysaccharide was elucidated by compositional analysis, mass spectrometry, and nuclear magnetic resonance spectroscopy. The hydrophilic backbone of free lipid A was found to consisted of beta(1,6)-linked D-glucosamine disaccharide 1-phosphate. (R)-3-Hydroxy-15-methylhexadecanoic acid and (R)-3-hydroxyhexadecanoic acid are attached at positions 2 and 3 of the reducing terminal residue, respectively, and positions 2' and 3' of the nonreducing terminal unit are acylated with (R)-3-O-(hexadecanoyl)-15-methylhexadecanoic acid and (R)-3-hydroxy-13-methyltetradecanoic acid, respectively. The hydroxyl group at position 4' is partially replaced by another phosphate group, and the hydroxyl groups at positions 4 and 6' are unsubstituted. Considerable heterogeneity in the fatty acid chain length and the degree of acylation and phosphorylation was detected by liquid secondary ion-mass spectrometry (LSI-MS). A significant pseudomolecular ion of lipid A at m/z 1,769.6 [M-H]- corresponding to a diphosphorylated GlcN backbone bearing five acyl groups described above was detected in the negative mode of LSI-MS. Predominant ions, however, were observed at m/z 1,434.9 [M-H]- and m/z 1,449.0 [M-H]-, each representing monophosphoryl lipid A lacking (R)-3-hydroxyhexadecanoic and (R)-3-hydroxy-13-methyltetradecanoic acids, respectively. The presence of mono- and diphosphorylated lipid A species was also confirmed by LSI-MS of de-O-acylated lipid A (m/z 955.3 and 1,035.2, respectively).
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PMID:Structural study on the free lipid A isolated from lipopolysaccharide of Porphyromonas gingivalis. 772 2

The production and the effects of tumor necrosis factor alpha (TNF alpha) have been studied in isolated glomeruli and cultured glomerular cells from animal or human origin. Glomeruli from rats injected with E. coli lipopolysaccharide (LPS) and glomeruli exposed to LPS in vitro release TNF alpha into the medium. The glomerular cells responsible for TNF alpha synthesis are mesangial cells. Production of TNF alpha is controlled by other locally produced mediators. Prostaglandin E2 and interleukin-10 are inhibitory. Hydroxyl radicals stimulate the transformation of the transmembrane form of TNF alpha into its soluble form which is secreted into the medium. TNF alpha acts on its producing cells and on the neighbouring cells. It induces contraction of mesangial cells, increases the synthesis of a variety of local mediators including prostaglandins, platelet-activating factor and chemotactic agents, particularly interleukin-8. Synthesis of this cytokine implies activation of tyrosine kinase and of transcription factors, essentially NFkB. Taken together, these results suggest that TNF alpha plays a marked role in the development of glomerular injury and incite us to search for treatments inhibiting its synthesis and its effects.
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PMID:[Production and proinflammatory activity of tumor necrosis factor alpha in the glomerulus]. 778 39

Bacterial lipopolysaccharide (LPS) plays a major role in the development of periapical bone resorption. Although the chemical properties of LPS are altered by treatment with an alkali such as calcium hydroxide, the effects of calcium hydroxide on the biological properties of LPS are not known. The purpose of this study was to investigate whether treatment of LPS with calcium hydroxide alters its biological action as measured by human monocyte secretion of prostaglandin E2. Monocyte cell cultures were stimulated with LPS or calcium hydroxide-treated LPS and culture supernatants were analyzed for prostaglandin E2 content using gas chromatography-mass spectrometry. Prostaglandin E2 was identified in supernatants of LPS-stimulated monocytes but not in those stimulated with calcium hydroxide-treated LPS. It was concluded that the treatment with calcium hydroxide may alter biological properties of bacterial LPS.
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PMID:Alteration of biological properties of bacterial lipopolysaccharide by calcium hydroxide treatment. 799 84

Gram-negative organisms incorporate hydroxy fatty acids into the lipid A moiety of lipopolysaccharide (LPS), and in the case of some members of the family Enterobacteriaceae, hydroxy fatty acids are incorporated exclusively into lipid A. However, a limited number of Bacteroides species have been shown to incorporate several classes of 3-hydroxy fatty acids, particularly 3-hydroxy iC17:0, into constitutive lipids as well as LPS. The present study examined the distribution of hydroxy fatty acids in two periodontal pathogens, Prevotella intermedia and Porphyromonas gingivalis, by employing a phospholipid extraction procedure (E. G. Bligh and W. J. Dyer, Can. J. Biochem. Physiol. 37:911-917, 1959) which partitioned constitutive lipids into the organic solvent phase and LPS into the aqueous phase. The distribution of hydroxy fatty acids within organic solvent and aqueous extracts of these bacterial species was then compared with the distribution in subgingival plaque samples isolated from either gingivitis or severe periodontitis sites as well as the distribution in gingival tissue samples. The organic solvent and aqueous extracts were hydrolyzed under strong alkaline conditions, and the free fatty acids were treated to form pentafluorobenzyl-ester, trimethylsilyl-ether derivatives. Hydroxy fatty acid levels were quantified by using gas chromatography-negative-ion chemical ionization-mass spectrometry. By using this approach, the mean values of the 3-hydroxy iC17:0 recovered within organic solvent extracts of P. gingivalis strains ranged from 56 to 63% of total 3-hydroxy iC17:0. Substantially less 3-hydroxy iC17:0 (< 5%) was recovered in organic solvent extracts of P. intermedia. By comparison, 75% of the 3-hydroxy iC17:0 in periodontitis subgingival plaque samples was recovered in organic solvent extracts, while only 43% of the 3-hydroxy iC17:0 in gingivitis plaque samples from the same patients was recovered in organic solvent extracts. However, 3-hydroxy iC17:0 was recovered essentially only in organic solvent extracts of both healthy or mildly inflamed and periodontitis gingival tissue samples. The preferential recovery of 3-hydroxy iC17:0 in tissue lipids indicates that gingival tissues do not harbor significant levels of subgingival plaque organisms which contain 3-hydroxy iC17:0. Furthermore, these results indicate that LPS from these organisms is not prevalent in gingival tissues. Finally, these results indicate either selective penetration of certain bacterial lipids into gingival tissues or that 3-hydroxy iC17:0 is metabolically transferred from bacterial lipids into gingival tissue lipids.
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PMID:Distribution of 3-hydroxy iC17:0 in subgingival plaque and gingival tissue samples: relationship to adult periodontitis. 806 90

Apical periodontitis and its concomitant periapical osteolysis is caused by pulpal infection, and bacterial lipopolysaccharide (LPS) is known to play a major role in the bone resorption process. Little is known concerning the effect of root canal intervisit dressings on residual LPS in root canals after bacterial cell lysis. The purpose of this study was to evaluate the effects of calcium hydroxide on bacterial LPS. Free hydroxy fatty acids were quantified in samples of LPS treated with calcium hydroxide. Calcium hydroxide treatment of LPS was shown to release elevated quantities of hydroxy fatty acids. It was concluded that calcium hydroxide hydrolyzed the lipid moiety of bacterial LPS, resulting in the release of free hydroxy fatty acids. This result suggests that calcium hydroxide-mediated degradation of LPS may be an important reason for the beneficial effects obtained with calcium hydroxide use in clinical endodontics.
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PMID:Effect of calcium hydroxide on bacterial lipopolysaccharide. 850 40

In vivo effects of aluminum adjuvant on systemic reaction of bacterial lipopolysaccharide (LPS) in piglets were investigated. Intramuscular injection of 0.1 mg kg-1 of LPS added to aluminum hydroxide gel (LPS(+)AL) mitigated the leukopenia, trembling and serum levels of TNF-alpha and cortisol compared with the injection of LPS suspended in LPS-free saline (LPS(+)SALINE). The serum endotoxin levels were reduced remarkably but relatively long-lasting in the LPS(+)AL. The lethality in mice injected with LPS added to aluminum hydroxide gel was significantly reduced. Likewise, the Limulus activity of a test LPS was reduced by the addition of aluminum hydroxide gel or aluminum chloride.
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PMID:Effects of aluminum adjuvant on systemic reactions of lipopolysaccharides in swine. 858 88

The chemical structure of lipid A of lipopolysaccharide isolated from Comamonas testosteroni was determined by quantitative analysis, methylation analysis, mass spectrometry and NMR spectroscopy. The lipid A backbone was found to consist of 6-O-(2-deoxy-2-amino-beta-D-glucopyranosyl)-2-deoxy-2-amino-alpha-D-g luc ose which was phosphorylated in positions 1 and 4'. Hydroxyl groups at positions 4 and 6' were unsubstituted, and position 6' of the non-reducing terminal residue was identified as the attachment site of the polysaccharide part. Liquid secondary-ion/mass spectrometry revealed a pseudomolecular ion at m/z 1572 [M-H]- as a major diphosphoryl lipid component carrying six acyl groups. Fatty acid distribution analysis and electrospray ionization/mass spectrometry of the lipid A showed that positions 2,2',3, and 3' of the sugar backbone were N-acylated or O-acylated by (R)-3-hydroxydecanoic acid, and that the hydroxyl groups of the amide-linked residues attached to positions 2 and 2' were further O-acylated by tetradecanoic and dodecanoic acids, respectively.
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PMID:Chemical structure of lipid A isolated from Comamonas testosteroni lipopolysaccharide. 864 87

Stimulatory effects of aluminium hydroxide, lipopolysaccharide (LPS), muramyldipeptide (MDP), and empty liposomes on the antigenicity of inactivated bovine herpesvirus 1 were tested in mice. Compared with the standard effect of aluminium hydroxide, stronger antibody responses were observed in mice treated with empty liposomes or LPS alone, or a combination thereof. The strongest antibody response was recorded in mice treated with a combination of inactivated BHV-1, MDP and empty liposomes.
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PMID:Enhancement of antibody response to bovine herpesvirus 1 with non-specific immunostimulants. 869 67

Immunoglobulin heavy chain (IgH) class switch recombination and regulation of IgH expression levels are processes suggested to be controlled by the IgH 3' enhancer. Here we demonstrate that CD40 or IgM receptor stimulation of primary B cells results in transactivation of this enhancer. 4-Hydroxy-3-nitrophenylacetyl (NIP)-BSA induction of a K46 B cell line expressing a chimeric NIP-specific CD40 single chain receptor results in a ligand receptor-dependent response of a 3' enhancer ETS/AP-1 minimal promoter construct. Gel retardation analysis and genomic footprinting experiments reveal that CD40 or IgM induction recruits NFAB (nuclear factors of activated B cells) to the ETS/AP-1 motif. While IgM signalling recruits c-Fos, JunB and Elf-1 (NFAB-I), only JunB and Elf-1 were observed following CD40 signalling (NFAB-II). CD40 signalling, however, induces a Fos family-related partner for JunB, which may account for the transcriptional activity observed by NFAB-II in K46 cells. We propose a model whereby CD40 and IgM receptor-mediated signalling converge in the process of 3' enhancer activation in B lymphocytes. Our data provide a putative molecular explanation as to why CD40L-deficient mice, and possibly patients with hyper-IgM syndrome, are unable to undergo T cell-dependent class switch recombination but respond properly upon lipopolysaccharide-induced switch recombination.
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PMID:A T cell controlled molecular pathway regulating the IgH locus: CD40-mediated activation of the IgH 3' enhancer. 897 95

The adjuvant properties of several immunostimulant molecules on the murine antibody response to Bothrops asper snake venom were evaluated. Mice receiving venom together with either sodium alginate, calcium alginate, aluminum hydroxide, muramyl dipeptide, killed Brucella abortus or B. abortus smooth lipopolysaccharide developed a similar antibody response. Despite the fact that in some cases animals injected with venom and Salmonella montevideo lipopolysaccharide developed a significantly higher antibody titer when compared to other experimental groups, no statistically significant differences were observed in most of the comparisons.
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PMID:Effect of adjuvants on the antibody response of mice to Bothrops asper (Terciopelo) snake venom. 918 Nov 6


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