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

The lipopolysaccharide of Escherichia coli BB and a number of R-phage selected (e.g. T3, T4) cell-wall-defective mutants were analyzed. From their lipopolysaccharides the respective core oligosaccharides were obtained. Following dephosphorylation, the oligosaccharides were methylated and analyzed by gas chromatography/mass spectrometry. This revealed the sugar sequence in the hexose-heptose region of the core. The linkage of heptose (Hep) to 2-keto-3-deoxyoctonate (KDO) was established as ... Hep 1,5 leads to KDO ... by methylation analysis. The substituted derivative of KDO was identified by gas chromatography and mass spectrometry. The KDO region contains three KDO units. Its structure was elaborated by (a) selective removal and identification of 7-phosphoryl ethanolamine-KDO (KDO-PN), (b) periodate oxidation and thiobarbituric acid reaction in conjunction with mild hydrolysis, (c) a modified methylation analysis. Phosphate substitution of E. coli BB core was studied by beta-elimination and using the information obtained with KDO-PN. The structures of the cell wall lipopolysaccharides from E. coli BB and cell-wall-defective mutants are given.
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PMID:Cell-wall lipopolysaccharide from Escherichia coli B. 110 Mar 90

Four distinct Proteus mirabilis strains were extracted by the phenol/water procedure. After ultracentrifugation of the dialyzed water phase, the pelleted lipopolysaccharide was purified and analyzed. The sugar composition of this lipopolysaccharide fraction I was similar for all four strains, containing only small amounts of strain-specific constituents. A second lipopolysaccharide fraction was isolated from the supernatant above (termed L1 fraction) after removal of nucleic acids. DEAE-cellulose chromatography indicated that this material is not a polysaccharide but rather a water-soluble lipopolysaccharide containing strain-specific constituents such as uronic acids, amino acids, amino sugars, neutral sugars, ethanolamine and phosphate, depending on the strain from which lipopolysaccharide II was isolated.
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PMID:The isolation of two different lipopolysaccharide fractions from various Proteus mirabilis strains. 110 9

A polyol was released from the lipopolysaccharide of Proteus mirabilis, strain D52, during alkaline hydrolysis and its phosphate ester was isolated after acid hydrolysis. This polyol has been identified as ribitol by comparison of the free polyol, its phosphate ester and its anhydro derivative formed after acid treatment with authentic xylitol, D- and L-arabitol, ribitol and their corresponding derivatives on paper and gas-liquid chromatography.
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PMID:Identification of ribitol phosphate as a constituent of the lipopolysaccharide from Proteus mirabilis, Strain D52. 110 10

Isolated walls of Spirillum serpens VHA contained lipid, lipopolysaccharide, and protein in amounts similar to those of other gram-negative organisms. The loosely bound lipids consisted mainly of phosphatidylethanolamine, lyso-phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. Lipopolysaccharide was tightly bound to the wall and could only be removed in a substantial amount after digestion of the wall with Pronase. The lipopolysaccharide contained L-glycero-D-mannoheptose, rhamnose, glucosamine, ethanolamine, and phosphate in common with many of the lipopolysaccharides isolated from the Enterobacteriaceae. However, 2-keto-3-deoxyoctonic acid was not detected. Several unidentified sugars were present. The fatty acid composition resembled that found in lipopolysaccharides isolated from various pseudomonads. Two major regions were identified in the polysaccharide moiety, one apparently corresponding to the core polysaccharide and the other corresponding to the side-chain polysaccharide as in enterobacterial and pseudomonad lipopolysaccharides. The side chains were obtained as low-molecular-weight material and their structure was partially elucidated by the isolation and partial characterization of N-acetylglucosaminyl-(1 leads to 4)-rhamnose.
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PMID:Analysis of the cell wall and lipopolysaccharide of Spirillum serpens. 119 32

Cultures of eight non-pathogenic species of Neisseria grown in simple defined media released lipopolysaccharide (free lipopolysaccharide) by a process distinct from cellular autolysis. Analyses of the pure cellular and free lipopolysaccharides obtained from six species of Neisseria revealed that they were remarkably similar and were devoid of detectable O-antigen side chains. Three distinct types of core-oligosaccharides were demonstrated. Type I core-oligosaccharide was a branched structure of alpha-D-glucopyranosyl units (7 mol) terminated by a reducing end group of 3-deoxy-D-manno-octulosonic acid. Type II core-oligosaccharide contained D-glucose, 2-deoxy-2-amino-D-glucose, L-rhamnose, L-glycero-D-manno-heptose, 3-deoxy-D-manno-octulosonic acid, phosphate, and ethanolamine in a molar ratio of 3:2:1:1:1:1:1. Type III coreoligosaccharide was composed of D-glucose, L-glycero-D-manno-heptose, 3-deoxy-D-manno-octulosonic acid, and phosphate in a molar ratio of 3:3:1:1. Lipopolysaccharides of N. caviae and N. sicca contained type I core-oligosaccharides exclusively, while those of N. flava and N. perflava contained only type II core-oligosaccharide. Cellular lipopolysaccharide from N. cinerea contained core-oligosaccharides of types I and II in a ratio of 27:73, while the analogous preparation from N. flavescens contained core-oligosaccharide types II and III in a ratio of 21:4. Free lipopolysaccharides from these two organisms contained only one type of coreoligosaccharide. Lipid A components of all the lipopolysaccharide preparations were very similar being composed of about 25% by weight of dodecanoic acid, 3-hydroxy-dodecanoic acid, and 3-hydroxy-tetradecanoic acid.
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PMID:Cellular and free lipopolysaccharides of some species of Neisseria. 122 Aug 63

The Lipid A from the lipopolysaccharide of Pseudomonas aeruginosa was examined by high-field nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). The backbone structure and the position of phosphate substituents were unambiguously established by one- and two-dimensional 1H, 13C, and 31P NMR techniques on a de-O-acylated Lipid A sample. The Lipid A has a beta-(1,6)-glucosamine disaccharide structure which is substituted by phosphomonoesters through glycosidic bonds at C-1 and at C-4'. The configuration of the glycosidically linked phosphate at position C-1 was identified as alpha which is the same as that of Enterobacterial Lipid A. Chemical analysis revealed that the Lipid A contained 2-hydroxydodecanoic, 3-hydroxydodecanoic, dodecanoic, 3-hydroxydecanoic, and hexadecanoic acids in the approximate molar ratios 2.2:2.0:0.2:0.8:0.4. From 1H NMR and fast atom bombardment (FAB) mass spectrometry on the de-O-acylated Lipid A, it was established that both glucosamine residues were N-acylated by 3-hydroxydodecanoic acid. The identity and positions of the ester bound fatty acids in the intact Lipid A were investigated by negative ion FAB-MS. In addition to the hexaacyl and pentaacyl Lipid A species, a tetraacyl species was identified. Heterogeneity due to hydroxylated and nonhydroxylated dodecanoic acid esters could be uniquely localized to the nonreducing beta-glucosamine residue from the fragmentation pattern observed in the negative ion FAB-MS. The complete structure of the Lipid A from P. aeruginosa will be useful in understanding the determinants responsible for the endotoxin activity of this molecule.
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PMID:Characterization of lipid A from Pseudomonas aeruginosa O-antigenic B band lipopolysaccharide by 1D and 2D NMR and mass spectral analysis. 128 66

Endotoxin (lipopolysaccharide [LPS])-induced cytokine release has been implicated in the pathogenesis of sepsis. Sublethal doses of LPS induce tolerance to a septic insult. This study evaluated pretreatment with interleukin 1 (IL-1) against an LPS challenge and examined its relationship to endotoxin tolerance. C3H/HeN mice (N = 100) were injected intraperitoneally with phosphate-buffered saline (control group), IL-1 (200 micrograms/kg), or LPS (1 mg/kg) for 3 days. On day 5, peritoneal macrophages were harvested and assayed for antimicrobial activity (superoxide anion production and Candida albicans phagocytosis). Serum cytokine levels and survival after an LPS challenge on day 5 were also assessed. Pretreatment with IL-1 or LPS significantly increased superoxide anion production, C albicans phagocytosis, and survival compared with pretreatment with phosphate-buffered solution. Interleukin 6 levels significantly decreased in the IL-1 and LPS groups. Peak levels of tumor necrosis factor significantly decreased only in the LPS group. Thus, pretreatment with IL-1 or low doses of LPS may exert protective effects by decreasing levels of interleukin 6 while increasing antimicrobial activity. Mice pretreated with IL-1 were protected from endotoxin despite elevated peak levels of tumor necrosis factor, suggesting a different mechanism for endotoxin tolerance than for tolerance to tumor necrosis factor.
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PMID:Interleukin 1 and its relationship to endotoxin tolerance. 131 50

Four monoclonal antibodies were raised against the lipopolysaccharide of Rhizobium leguminosarum bv. phaseoli CFN42 grown in tryptone and yeast extract. Two of these antibodies reacted relatively weakly with the lipopolysaccharide of bacteroids of this strain isolated from bean nodules. Growth ex planta of strain CFN42 at low pH, high temperature, low phosphate, or low oxygen concentration also eliminated binding of one or both of these antibodies. Lipopolysaccharide mobility on gel electrophoresis and reaction with other monoclonal antibodies and polyclonal antiserum indicated that the antigenic changes detected by these two antibodies did not represent major changes in lipopolysaccharide structure. The antigenic changes at low pH were dependent on growth of the bacteria but were independent of nitrogen and carbon sources and the rich or minimal quality of the medium. The Sym plasmid of this strain was not required for the changes induced ex planta. Analysis of bacterial mutants inferred to have truncated O-polysaccharides indicated that part, but not all, of the lipopolysaccharide O-polysaccharide portion was required for binding of these two antibodies. In addition, this analysis suggested that O-polysaccharide structures more distal to lipid A than the epitopes themselves were required for the modifications at low pH that prevented antibody binding. Two mutants were antigenically abnormal, even though they had abundant lipopolysaccharides of apparently normal size. One of these two mutants was constitutively unreactive toward three of the antibodies but indistinguishable from the wild type in symbiotic behavior. The other, whose bacteroids retained an epitope normally greatly diminished in bacteroids, was somewhat impaired in nodulation frequency and nodule development.
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PMID:Rhizobium leguminosarum CFN42 lipopolysaccharide antigenic changes induced by environmental conditions. 131 98

After conventional hydrolysis of lipopolysaccharides (LPSs), Kdo was not detectable by the periodate-thiobarbituric acid test in those of any member of Vibrionaceae except the gems Plesiomonas, but phosphorylated Kdo was demonstrated after strong-acid hydrolysis. Dephosphorylation, periodate oxidation, and methylation analysis of LPS preparations from 7 strains selected from all genera of Vibrionaceae, except Plesiomonas, showed that the inner-core region (unlike that in enteric Gram-negative bacteria) contains only one molecule of Kdo 4-phosphate 5-substituted with heptose, a constituent of the distal part of the core region, as in enteric bacteria. The undetectability of Kdo in LPS after conventional hydrolysis and the occurrence of phosphorylated Kdo in strong-acid hydrolysates and of Kdo 4-phosphate in the inner-core region are taxonomic characteristics of the family Vibrionaceae.
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PMID:Taxonomic implication of the apparent undetectability of 3-deoxy-D-manno-2-octulosonate (Kdo) in lipopolysaccharides of the representatives of the family Vibrionaceae and the occurrence of Kdo 4-phosphate in their inner-core regions. 139 28

The combined effects of the synthetic glucosaminylmuramyl dipeptide (GMDP) on the antitumor activity of chemically synthesized lipid A analogs, compound A-103 (glucosamine-4-phosphate with (R)-3-tetradecanoyloxytetradecanoyl group at the C-2 and C-3 positions), Escherichia coli-type lipid A (506), Salmonella typhimurium LT-2 lipopolysaccharide (LPS) against Meth A fibrosarcoma in mice were examined. Meth A fibrosarcoma cells (5 x 10(5) were inoculated intradermally into BALB/c mice on day 0, and compound A-103 and/or GMDP was administered intravenously (i.v.) on days 7 and 9. Two i.v. injections of A-103 (50 micrograms) alone or GMDP (10 micrograms) alone induced 42.8 or 51.8% inhibition of the rate of tumor growth, however, A-103 (100 micrograms) with GMDP (10 micrograms) exhibited a high 68.7% inhibition rate 19 days after tumor inoculation. The inhibition of the tumor growth rate by the combination A-103 (100 micrograms) or 506 (50 micrograms) with GMDP (10 micrograms) was stronger than that of A-103 or 506 with MDP (10 micrograms). The combination of LPS (1 or 10 micrograms) with GMDP (10 micrograms) exhibited a higher inhibition rate than that of LPS with MDP, and three or four tumor-free mice out of five mice were observed, suggesting that the combined effect of GMDP is more potent than that of MDP. With the addition of GMDP, A-103 did not enhance the production of tumor necrosis factor (TNF) on the basis of L929 cell lysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Combined effects of synthetic lipid A analogs or bacterial lipopolysaccharide with glucosaminylmuramyl dipeptide on antitumor activity against Meth A fibrosarcoma in mice. 146 73


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