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

Salmonella carrau, which belongs to group H (O:6, 14, 24) of the Kauffmann-White classification system, produced a major (90%) smooth lipopolysaccharide which by SDS-PAGE, glycose analysis, methylation, periodate oxidation, deamination, and 1H- and 13C-n.m.r. studies was shown to have an O-polysaccharide moiety composed of a repeating pentasaccharide having the structure: (formula: see text).
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PMID:Structure of the major lipopolysaccharide antigenic O-chain produced by Salmonella carrau (O:6, 14, 24). 246 81

The gene cluster (rfb region) which determines the synthesis of O101 lipopolysaccharide (LPS) O-antigen was cloned from the Escherichia coli O101:K99:F41 reference strain B41 to give plasmid pPM1301. The smallest subclones represented by pPM1305 and pPM1330 expressed O-antigen in E. coli K-12 similar to (but not identical to) B41, as judged by immunogold electron microscopy and silver staining of LPS separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). At least six proteins were detected by minicell analysis of proteins encoded by pPM1305, which suggests that O-antigen synthesis is genetically complex. Restriction and deletion analysis demonstrated that a minimum of 8.9 kb and a maximum of 11.8 kb are required for O101 O-antigen biosynthesis in E. coli K-12. Examination of LPS banding patterns of other O101 isolates by SDS-PAGE suggested heterogeneity of LPS structure. Southern DNA hybridization analysis using radiolabelled subclones of pPM1305 demonstrated that there was close relationship among the O101 ETEC isolates.
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PMID:Molecular cloning and expression in Escherichia coli K-12 of the O101 rfb region from E. coli B41 (O101:K99/F41) and the genetic relationship to other O101 rfb loci. 247 71

The class-specific antibody response was measured in sequential serum samples from 17 patients after natural bacteremic infection with gram-negative bacilli. There was a five- to sevenfold mean increase over preexisting antibody in levels of IgG (range, less than 1-to 88-fold), IgA (1- to 83-fold), and IgM (less than 1- to 58-fold) antibody to homologous lipopolysaccharide (LPS) in 16 of these patients. In contrast, there was only a two- to threefold mean increase (range, less than 1- to 78-fold) in about half of the patients who had a detectable antibody response to J5 core determinants and in the third who responded to Re core determinants (range, 1- to 20-fold). All but one of the infective strains of bacteria were smooth on analysis with SDS-PAGE and with rough-specific phages. Humans infected with bacteria that had a rough LPS phenotype, however, did elicit antibody similar to that induced in rabbits after immunization with J5 vaccine. Thus, the human antibody response to natural infection with gram-negative bacilli appears to be directed primarily at homologous, strain-specific epitopes, and the response to the epitopes of LPS core antigens is not against widely shared determinants.
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PMID:The human antibody response during natural bacteremic infection with gram-negative bacilli against lipopolysaccharide core determinants. 247 16

Eight strains of Neisseria meningitidis belonging to different serogroups were analysed for their virulence in mice and their release of outer membrane proteins into the medium during growth. All strains released proteins. No detectable lipopolysaccharide was observed. However, SDS-PAGE showed a heterogenicity in the protein number and profile among the different strains of N. meningitidis tested.
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PMID:Neisseria meningitidis: heterogenicity in the outer membrane proteins released into the growth medium. 247 46

Coliphage K30 lysates contain free and phage-associated forms of a bacteriophage-encoded capsule depolymerase (glycanase) enzyme, active against the serotype K30 capsular polysaccharide of Escherichia coli. The free glycanase has been purified to apparent homogeneity. The molecular weight of the enzyme was estimated at 450,000, and when heated in SDS at 100 degrees C, the enzyme dissociated into two subunits of 90,000 and 52,000. The glycanase enzyme was used as a reagent to reversibly degrade the capsular layers on cells of Escherichia coli O9:K30 and Klebsiella O1:K20. This treatment rendered these bacteria sensitive to their respective lipopolysaccharide-specific bacteriophages, coliphage O9-1 and Klebsiella phage O1-3. This novel approach facilitated isolation of lipopolysaccharide O antigen side chain deficient mutants which retained the ability to synthesize the capsule. The response of defined mutants, O+:K-, O-:K+, and O-:K-, to exposure to nonimmune rabbit serum was measured. Results showed that the primary barrier against complement-mediated serum killing in both Escherichia coli O9:K30 and Klebsiella O1:K20 was the O antigen side chains of the lipopolysaccharide molecules. In both strains, the capsule played no role in the determination of serum resistance.
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PMID:Use of a bacteriophage-encoded glycanase enzyme in the generation of lipopolysaccharide O side chain deficient mutants of Escherichia coli O9:K30 and Klebsiella O1:K20: role of O and K antigens in resistance to complement-mediated serum killing. 248 25

Pseudomonas aeruginosa PAO1 was grown in vivo in chambers implanted into the peritoneums of mice and rats. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracts of bacterial cells taken from the chambers and washed to remove loosely bound host proteins revealed the presence of the major outer membrane proteins D2, E, F, G, and H2. Western immunoblotting with specific antisera confirmed the presence of porin protein F and lipoprotein H2. However, there was no apparent induction of the phosphate starvation-inducible porin P or the divalent cation starvation-inducible protein H1. Small amounts of proteins with molecular weights similar to those of the iron-regulated outer membrane proteins were found in cells grown in vivo; however, their presence could not be confirmed immunologically. The presence of pili and flagella on the cells grown in vivo was demonstrated by electron microscopy and Western immunoblotting. A consistent alteration in the lipopolysaccharide banding pattern was observed after growth in vivo. Compared with cells of strain PAO1 grown in vitro, cells grown in vivo appeared to lack a series of high-molecular-weight O-antigen-containing lipopolysaccharide bands and gained a new series of lower-molecular-weight lipopolysaccharide bands. This alteration in the lipopolysaccharide after growth in vivo did not affect the O-antigen serotype or the resistance of the bacteria to serum.
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PMID:Surface characteristics of Pseudomonas aeruginosa grown in a chamber implant model in mice and rats. 249 57

We show here that purified lipoarabinomannan (LAM) from Mycobacterium tuberculosis can cause the release of tumour necrosis factor (TNF) in vitro from human blood monocytes and activated mouse peritoneal macrophages, and the production of TNF in vivo in mice pretreated with Propionibacterium acnes, with a potency comparable to that of lipopolysaccharide (LPS) from Gram negative bacteria. Like LPS, LAM binds to polymyxin B. We confirmed that its activity was distinct from any contaminating LPS and was associated with the antigenic activity by affinity chromatography, using a monoclonal antibody specific for LAM. Treatment with dilute alkali greatly diminished the TNF-inducing activity, suggesting that omicron-acyl groups may be involved. When LAM was fractionated by electrophoresis on SDS-Page and blotted on nitrocellulose, most TNF-inducing capacity coincided with the bulk of the LAM, as estimated by molecular weight and antigenic activity. This modification of the Western blotting technique may be generally useful for the study of macrophage-triggering molecules. The ability of LAM to cause the release of TNF may be responsible for some of the characteristics of tuberculosis, such as fever, weight loss, raised acute phase reactants and necrosis that can be mediated by this cytokine.
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PMID:Lipoarabinomannan from Mycobacterium tuberculosis induces the production of tumour necrosis factor from human and murine macrophages. 250 77

Changes in lipopolysaccharide (LPS) which occur when serum susceptible gonococci are converted to resistance by incubation with cytidine 5'-monophospho-N-acetyl neuraminic acid (CMP-NANA) have been investigated. Transfer of radioactivity to bacterial LPS from CMP-NANA labelled with 14C in the NANA moiety was detected by fluorography following lysis, proteinase K digestion and SDS-PAGE. Incorporation of radioactivity was inhibited by cytidine 5'-monophosphate (CMP). Both the radioactivity of the LPS and the resistance of gonococci to fresh human serum were largely lost after incubation with neuraminidase. No evidence was obtained to suggest that CMP-NANA is an inducer of new protein synthesis as well as a substrate for the sialylation of LPS. Little radioactivity was incorporated into components other than LPS. Sialylated, serum resistant gonococci were less able than serum susceptible gonococci to absorb the bactericidal activity of fresh human serum. Hence, we conclude that serum resistance conferred on gonococci by CMP-NANA is due to transfer of sialyl groups to surface LPS sites and this inhibits their reaction with bactericidal antibody in human serum.
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PMID:Sialylation of lipopolysaccharide and loss of absorption of bactericidal antibody during conversion of gonococci to serum resistance by cytidine 5'-monophospho-N-acetyl neuraminic acid. 250 53

Ice nucleation activity and the iceC gene product were quantified in different subcellular fractions of the Pseudomonas syringae source strain and in Escherichia coli containing the cloned iceC gene to determine the activity of this protein in different subcellular locations. Ice nuclei were nearly completely retained during isolation of cell envelopes but exhibited a decrease in the temperature at which they were expressed. Ice nucleation activity was found in Triton X-100 insoluble membrane fragments as well as in slowly sedimenting and high-density membrane fragments. Nearly all ice nucleation activity was associated with the outer membrane because the partitioning of 3-ketodeoxyoctonate (a lipopolysaccharide component) and ice nuclei in cell fractions were similar to and opposite that of NADH oxidase (a cytoplasmic membrane component). The iceC gene product had an apparent mass of 150,000 Da based on migration in SDS-polyacrylamide gels. This protein was not found in soluble cell components. Nearly all of the iceC gene product, which occurred in low abundance, was associated with the outer membrane of both P. syringae and E. coli. Therefore, the iceC gene product is located at and is maximally active in or on the outer membrane of cells of the source strain and heterologous strains.
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PMID:Localization of ice nucleation activity and the iceC gene product in Pseudomonas syringae and Escherichia coli. 252 Aug 25

A method for identification of the components of immune complexes would increase our understanding of the pathogenesis of chronic diseases such as Pseudomonas aeruginosa lung infection in cystic fibrosis. Capillary tube, gel diffusion and turbidimetric methods of determining immune complex formation were investigated with antigens from P. aeruginosa and the homologous rabbit antisera. Visible complexes were formed in the first two methods with flagella antigens. Purified lipopolysaccharide from P. aeruginosa would not form visible precipitates and a rapid and economical turbidimetric method was developed with 96-well microtiter plates. Larger quantities of immune complexes were formed in vitro with antigen/antibody ratios determined by the above methods. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting (Western blotting) were evaluated and found to be useful in determining the antigen and antibody components of these immune complexes.
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PMID:Determination of the components of immune complexes made in vitro with antigens derived from Pseudomonas aeruginosa. 256 92


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