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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gonorrhea has been known since antiquity. Today, this disease is the most commonly reported infectious disease in the U.S. The natural environment of the etiological agent, Neisseria gonorrhoeae, is man. In this host, the organism usually parasitizes mucosal surfaces populated by columnar epithelial cells. Under certain conditions, the gonococcus may disseminate or spread to adjacent organs. The gonococcus is well adapted to its environment and is a successful parasite. Until recently, gonococci were uniformly sensitive to penicilin. However, a plasmid encoding beta-lactamase has been identified in some isolates. Most strains exhibit specific requirements for various amino acids, vitamins, purines, and pyrimidines. Only glucose, pyruvate, and lactate are utilized as sources of energy. Glucose is dissimilated by a combination of the Entner-Doudoroff and pentose phosphate pathways. A tricarboxylic acid cycle is also present and active under certain conditions. Structurally, the cell envelope of the gonococcus resembles that of a typical Gram-negative bacterium. Gonococci are highly autolytic, especially in older cultures or after depletion of the energy source. Autolysis is not due solely to peptidoglycan hydrolysis, but appears to involve a destabilization of the outer membrane as well. Cell surface components such as pili, lipopolysaccharide, outer membrane proteins, and a capsule are associated with the virulence and pathogenicity of this organism.
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PMID:The biology of the gonococcus. 11 74

Ribonucleic acid was removed from a phenol-water extract of Haemophilus influenzae type a by streptomycin sulfate. This preparation was called purified preparation or PP. It contained neutral sugars (glucose, galactose, mannose, pentose), glucosamine, amino acids, and fatty acids. Heptose and 2-keto-3-deoxyoctonic acid were not present. The biological properties and immunogenicity were compared with the activities of lipopolysaccharide of Escherichia coli or Salmonella typhimurium. Higher doses were necessary to obtain lethality in mice and Sanarelli and Shwartzman reactions with our preparations than were necessary with lipopolysaccharide. The Limulus test and pyrogen assay in rabbits gave the same results with purified preparation and lipopolysaccharide, but pyrogenicity of purified preparation was not destroyed by NaOH treatment. Purified preparation was not as immunogenic at low doeses for rabbits as lipopolysaccharide. The results were different from those obtained with lipopolysaccharide but similar to those known from peptidoglycan studies. The contamination of purified preparation with peptidoglycan was negligible and cannot explain the biological activities of purified preparation. We suggest that the phenol-water extract from H. influenzae is not a classical endotoxin, but rather an endotoxin-like substance.
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PMID:Chemical composition and biological activities of a phenol-water extract from Haemophilus influenzae type a. 31 93

The antiphagocytic antigen (antigen [a]) comprising the microcapsule of a strain of Campylobacter fetus subsp. intestinalis has been purified from culture supernatants by ammonium sulfate fractionation and free-flow electrophoresis. Antigen [a] is a glycoprotein containing about 4% carbohydrate consisting of hexose, pentose, and methylpentose. The composition of the protein was typical of bacterial extramural structural proteins in its low content of basic, aromatic, and sulfur-containing amino acids. The protein had a high content of aspartic acid, threonine, glycine, and alanine. Antigen [a] had an Rf of 0.33 on polyacrylamide gel electrophoresis and a molecular weight calculated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of approximately 98,000. In contrast to its free form in culture supernatants, antigen [a] in vesicles derived from sheared cells appeared to exist in a complex with lipopolysaccharide. This complex could be dissociated by ethylenediaminetetraacetic acid or by ethylenediaminetetraacetic acid plus Triton X-100. A mutant strain that lacked a microcapsule, when incubated with soluble antigen [a] in a calcium medium, became agglutinable by monospecific [a] antiserum and showed an additional structural layer similar in appearance to the microcapsule on its cell wall. Points of similarity are emphasized between antigen [a] of C. fetus and the outer structural protein of the taxonomically related Spirillum serpens.
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PMID:Microcapsule of Campylobacter fetus: chemical and physical characterization. 73 Mar 87

Quantification of intracellular and extracellular levels and production rates of reactive oxygen species is crucial to understanding their contribution to tissue pathophysiology. We measured basal rates of oxidant production and the activity of xanthine oxidase, proposed to be a key source of O2- and H2O2, in endothelial cells. Then we examined the influence of tumor necrosis factor-alpha and lipopolysaccharide on endothelial cell oxidant metabolism, in response to the proposal that these inflammatory mediators initiate vascular injury in part by stimulating endothelial xanthine oxidase-mediated production of O2- and H2O2. We determined a basal intracellular H2O2 concentration of 32.8 +/- 10.7 pM in cultured bovine aortic endothelial cells by kinetic analysis of aminotriazole-mediated inactivation of endogenous catalase. Catalase activity was 5.72 +/- 1.61 U/mg cell protein and glutathione peroxidase activity was much lower, 8.13 +/- 3.79 mU/mg protein. Only 0.48 +/- 0.18% of total glucose metabolism occurred via the pentose phosphate pathway. The rate of extracellular H2O2 release was 75 +/- 12 pmol.min-1.mg cell protein-1. Intracellular xanthine dehydrogenase/oxidase activity determined by pterin oxidation was 2.32 +/- 0.75 microU/mg with 47.1 +/- 11.7% in the oxidase form. Intracellular purine levels of 1.19 +/- 1.04 nmol hypoxanthine/mg protein, 0.13 +/- 0.17 nmol xanthine/mg protein, and undetectable uric acid were consistent with a low activity of xanthine dehydrogenase/oxidase. Exposure of endothelial cells to 1000 U/ml tumor necrosis factor (TNF) or 1 microgram/ml lipopolysaccharide (LPS) for 1-12 h did not alter basal endothelial cell oxidant production or xanthine dehydrogenase/oxidase activity. These results do not support a casual role for H2O2 in the direct endothelial toxicity of TNF and LPS.
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PMID:Responses of vascular endothelial oxidant metabolism to lipopolysaccharide and tumor necrosis factor-alpha. 156 24

Gram-negative bacteria express at their surface various amphiphiles among which the lipopolysaccharides (endotoxins, O-antigens) have been studied most intensively. Lipopolysaccharides consist of a heteropolysaccharide portion (O-specific chain and core) which is responsible for the O- (and R-) antigenic properties and a covalently bound lipid component, termed lipid A, which contains the endotoxic principle of lipopolysaccharides. The detailed chemical structure of a large number of O-chains and the general architecture of the core oligosaccharide has been established. Recent analyses of the enterobacterial inner core region indicate the presence of a linear trisaccharide of alpha 2.4-linked 3-deoxy-D-manno-2-octulosonic acid (KDO) residues of which only the reducing group is believed to be located in the main core chain. This KDO residue which provides the link between the polysaccharide and the lipid A component appears to be involved in a recently detected ubiquitous immunodeterminant expressed by lipopolysaccharides of various origin. The chemical structure of enterobacterial lipid A's is now known in some detail. Lipid A of Salmonella, Escherichia coli and Proteus consists of a beta 1.6-linked D-glucosamine disaccharide which carries four (R)-3-hydroxytetradecanoyl groups in positions 2, 3, 2' and 3' and two phosphoryl residues in positions 1 and 4'. Up to three of the hydroxy fatty acids (positions 2, 2' and 3') are, at their 3-hydroxyl groups, acylated by non-hydroxylated acyl residues, and to phosphoryl groups non-acylated, nitrogen-containing residues such as 4-amino-4-deoxy-L-arabinopyranose and phosphorylethanolamine may be bound. The hydroxyl group in position 4 of the glucosamine disaccharide is free and that in position 6' serves as the attachment site for KDO (i.e. the polysaccharide component) in lipopolysaccharide. Based on this structure lipid A analogues have been chemically synthesized and analysed for endotoxic activity in vivo and in vitro. In two test systems (pyrogenicity, local Shwartzman reaction) the synthetic part structures exhibited weak or no endotoxic activity, as did a precursor of lipid A biosynthesis which is structurally identical to one of the analogues. In many other systems, however, including lethal toxicity, B-lymphocyte mitogenicity, macrophage activation, induction of cross tolerance, expression of lipid A antigenicity, the synthetic materials were of comparable activity as bacterial free lipid A. These findings support the structural proposals made for lipid A and they prove the previous hypothesis that the endotoxic principle is embedded in lipid A.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Newer aspects of the chemical structure and biological activity of bacterial endotoxins. 241 65

Chemical composition of the lipopolysaccharides obtained from the strain Rhodomicrobium vannielii (ZoBell) grown in photo- and chemoheterotrophic conditions was compared. No significant differences in the constitution of both lipopolysaccharides were revealed, except for the presence of an additional 2-0-methyl-pentose and palmitic acid in the LPS isolated from the chemotrophically grown bacteria. The degraded polysaccharides from both lipopolysaccharide preparations, when fractionated in column chromatography, revealed the occurrence of two fractions only: the first one containing all the sugars present in the respective lipopolysaccharide and the second composed of KDO. Glucan was shown to be produced by the investigated strain in phototrophic conditions only.
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PMID:Comparison of lipopolysaccharides of Rhodomicrobium vannielii grown in photo- and chemotropic conditions. 241 83

Previous work from this laboratory has demonstrated the persistence of Bacteroides intermedius in the livers of mice receiving an intraperitoneal inoculum of B. intermedius and Fusobacterium necrophorum. This study was undertaken to determine whether F. necrophorum enhanced the in vitro growth of B. intermedius. Tryptose phosphate broth did not support the growth of B. intermedius alone, but the bacterium did survive in a tryptose phosphate broth culture of F. necrophorum. B. intermedius cultured in F. necrophorum-conditioned tryptose phosphate broth grew impressively, reaching maximal absorbance at 24 h after inoculation. The growth of B. intermedius in F. necrophorum-conditioned tryptose phosphate broth was proportional to the amount of conditioned medium present. The B. intermedius growth-stimulating factor was detectable in conditioned medium 8 h after inoculation with F. necrophorum and could be detected throughout the 96-h incubation period. Growth-factor-active fractions eluted from a Sephadex G-100 column did not absorb at 280 nm and were retained on the column until 4 column volumes were eluted. The growth factor was nondialyzable and stable to boiling, lyophilization, extraction with hot aqueous phenol, and trypsin digestion. The factor was inactivated by exposure to pH 2.0 in the pepsin digestion protocol. Significant amounts of hexose, methyl pentose, and 2-keto-3-deoxyoctonate were detected in pooled growth-factor-active fractions eluted from the Sephadex column. This pool was also active in the Limulus lysate endotoxin assay. These results suggest that the B. intermedius growth-stimulating factor produced by F. necrophorum is a lipopolysaccharide.
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PMID:Enhancement of Bacteroides intermedius growth by Fusobacterium necrophorum. 370 Jun 5

Mild acid hydrolysis with 1% acetic acid (100 degrees C, 15-60 min) of lipopolysaccharide (LPS) isolated from Coxiella burnetii phase I cells leads to a drastic decrease in its serological reactivity as shown by the passive hemolysis test. This decrease in reactivity occurs parallel or even prior to the cleavage of LPS into free lipid A and the polysaccharide moiety. During this mild hydrolysis two unusual sugars (X and Y) are released from the LPS, which were obtained in pure state by thin-layer chromatography. Analysis of their alditol acetate derivatives by gas chromatography/mass spectrometry revealed that sugar X is a 6-deoxy-3-C-methyl-hexose and sugar Y a 3-C-(hydroxymethyl)-pentose. Using a range of authentic standards and different thin-layer and gas chromatographic conditions, X could be recognized as 6-deoxy-3-C-methyl-gulose (virenose), very probably as the L form of this sugar (L-virenose). Y has been identified as 3-C-(hydroxymethyl)-lyxose (dihydrohydroxystreptose) by comparing it with newly synthesized 3-C-(hydroxymethyl)-pentoses (Dahlman, O., Garegg, P. J., Mayer, H., Schramek, S., unpublished results). Both branched sugars are (at least partially) in terminal positions since methylation analysis of LPS afforded (mainly) their permethylated derivatives. This analysis further showed virenose to be linked in C. burnetii phase I LPS as pyranose and dihydro-hydroxystreptose as furanose. The terminal linkage and the chemical nature of X and Y are in accordance with the observed acid-lability of the serological determinants.
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PMID:3-C-branched aldoses in lipopolysaccharide of phase I Coxiella burnetii and their role as immunodominant factors. 399 91

Mergenhagen, Stephan E. (National Institutes of Health, Bethesda, Md.). Polysaccharide-lipid complexes from Veillonella parvula. J. Bacteriol. 90:1730-1734. 1965.-A strain of Veillonella parvula (V2) elaborates an extracellular slime when grown in a nutrient medium containing only dialyzable components. Deproteinization with chloroform-butanol of ethyl alcohol-precipitated material from the supernatant culture fluid leads to the isolation of a water-soluble lipopolysaccharide (LPS1). Another component (LPS2), showing similarity in biological and immunological properties to the endotoxic antigen (LPC) isolated from whole cells, was extracted with phenol from the insoluble emulsion remaining after chloroform-butanol extraction of slime. Analysis of polysaccharides by thin-layer chromatography demonstrated the presence of glucose and galactose in LPS1 and glucose, glucosamine, galactosamine, and a methyl pentose in LPC. LPS1 failed to give a positive epinephrine skin test after intravenous injection in rabbits and failed to kill pertussis-sensitized mice, whereas LPS2 and LPC were active in both of these bioassays. Both lipopolysaccharides (LPS1 and LPC) exhibited type-specific haptenic activity in hemagglutination tests with numerous anti-Veillonella rabbit sera. LPS1 was found in these tests to be unrelated to a heterologous strain of Veillonella possessing a related somatic antigen. These experiments reveal the presence of two chemically and immunologically distinguishable polysaccharide-lipid complexes in this strain of V. parvula.
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PMID:Polysaccharide-lipid complexes from Veillonella parvula. 585 93

The composition of lipopolysaccharides derived from various Salmonella T forms was studied. All T1-form lipopolysaccharides examined contained 14 to 22% each of both d-galactose and pentose in addition to 4 to 9% each of ketodeoxyoctonic acid, heptose, d-glucosamine, and d-glucose. The pentose was identified as d-ribose. The T2-form lipopolysaccharide examined did not contain a significant amount of pentose, nor more than the usual amounts of d-galactose. Periodate oxidation of T1 (lipo) polysaccharides followed by NaBH(4) reduction revealed that ribose was almost quantitatively protected, galactose was destroyed, and threitol and mannose were newly formed. The latter two products probably originated from 4-linked galactose and heptose, respectively. Ribose and galactose were found in specific precipitates of T1 lipopolysaccharide with anti-T1 antiserum but were not found in specific precipitates of alkali-treated T1 lipopolysaccharide and of Freeman degraded polysaccharide with anti-T1 serum Ribose and galactose are present in these degraded preparations in the form of nondialyzable polymers. The T1-form mutant lipopolysaccharides lacked the O-specific sugars constituting the side-chains in the wild-type antigens. They did not produce the soluble O-specific haptenic polysaccharide known to be accumulated in RI strains. With these properties, T1 lipopolysaccharides resemble RII lipopolysaccharides. Like RII degraded polysaccharides, T1-degraded polysaccharides also contained glucosamine. Furthermore, strong cross-reactions were found to exist between T1 and RII lipopolysaccharides in both hemagglutination inhibition assays and in precipitation tests. It is proposed that T1 lipopolysaccharides represent RII lipopolysaccharides to which polymers consisting of ribose and galactose are attached.
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PMID:Lipopolysaccharides of Salmonella T mutants. 605 95


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