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

Uridine diphosphate galactose 4-epimerase and phosphomannose isomerase-deficient mutants of Escherichia coli O111:B4 were studied to test the hypothesis that in E. coli a specific relationship exists between O antigenicity, virulence, and capacity to resist phagocytosis. The first mutant, designated J-5, produces a cell wall lipopolysaccharide, the side chains of which do not contain galactose, glucose, N-acetylglucosamine, or colitose. The second mutant produces a cell wall lipopolysaccharide which lacks only colitose. The capacity of these various organisms to kill mice was strikingly different. E. coli O111 was 1000 times as virulent as J-5, and 100 times as virulent as L-2. The capacity of the organisms to kill mice was correlated with their ability to resist phagocytosis and to persist in the peritoneal cavity. The parent strain of O111 resisted phagocytosis by macrophages in vivo and polymorphonuclear leukocytes in vitro. The mutants did not, and the organism most deficient in the saccharide component of its LPS was most susceptible to phagocytosis and least virulent. These results were corroborated by growing the mutants in appropriately supplemented media which permitted the synthesis of complete LPS, reversed the susceptibility to phagocytosis, and restored virulence. Finally, serological reactivity was consistent with previous observations which had demonstrated that the O antigenicity of E. coli is determined by the saccharide composition of its cell wall lipopolysaccharide. Despite the difference in the capacity of the various log-phase organisms to kill mice when injected intraperitoneally, purified lipopolysaccharides extracted from them did not differ significantly in their capacity to kill or produce fever. Thus virulence was shown to be independent of endotoxin activity which in turn seemed to be unrelated to the saccharide composition of the cell wall LPS. Collectively, these data provide at least a partial molecular definition of virulence in E. coli by demonstrating that the presence or absence of specific sugars in its cell wall lipopolysaccharide is a determinant of its antiphagocytic capacity and its virulence.
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PMID:Cell wall composition and virulence in Escherichia coli. 487 25

The adsorption rate constant (ARC) of the Felix O-1 (FO) bacteriophage to sensitive Salmonella strains was used to determine the effect of variations in surface antigens on phage attachment. The N-acetylglucosamine of the common-core polysaccharide of the Salmonella lipopolysaccharide (LPS) was found to be an essential part of the receptor for the FO phage in conformation with earlier reports. It was found that (i) the ARC was low for strains having O side chains containing two or three non core monosaccharides, (ii) the ARC varied when the O side chain contained no, or only one, noncore monosaccharide, (iii) the ARC was high when the O side chain contained only one repeating unit, and (iv) the ARC was high to mutants of chemotype Ra in which the N-acetylglucosamine was the terminal sugar of the LPS. Since a good correlation was found between the ARC of the FO phage and the phage-inactivating capacity of phenol water-extracted LPS, the results suggest that only the structure and composition of the LPS determines the adsorption rate of the FO phage. The phage-inactivating capacity of LPS from the Ra mutants increased in parallel with higher glucosamine contents in the core polysaccharide. In smooth strains having long and numerous O side chains, the access of the FO phage to its receptor is probably blocked by the presence of the side chains, whereas short and numerous side chains or T1 side chains do not interfere with the FO attachment.
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PMID:Influence of O side chains on the attachment of the Felix O-1 bacteriophage to Salmonella bacteria. 489 14

1. The composition of the lipopolysaccharides and the corresponding lipid-free polysaccharides from four R-mutants of Salmonella has been studied. All the lipopolysaccharides, from RI and RII serotypes contained d-glucose, d-galactose, heptose, N-acetylglucosamine and 3-deoxy-2-oxo-octonate. The polysaccharide obtained from the RII lipopolysaccharides also contained all these sugars. The polysaccharides from RI lipopolysaccharides lacked N-acetylglucosamine. 2. From partial hydrolysates of the lipopolysaccharides, a number of oligosaccharides have been isolated and partially characterized. Oligosaccharides containing N-acetylglucosamine or glucosamine were obtained only from RII lipopolysaccharides. Several oligosaccharides composed of glucose and galactose were common to RI and RII preparations. 3. A structural unit, based on the oligosaccharides found, is proposed for the RII lipopolysaccharide. It contains the sequence: alpha-N-acetylglucosaminyl- alpha-glucosyl-alpha-galactosyl-glucosyl.... A second alpha-galactosyl residue is bound to position 6 of the last glucosyl group. The complete unit is believed to to be attached to a polyheptose phosphate backbone in the RII antigen. 4. The RI lipopolysaccharide of Salmonella minnesota contains an analogous structure lacking the terminal N-acetylglucosamine residue. 5. A basal structure common to the lipopolysaccharides of several Salmonella species is proposed.
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PMID:Studies on the structure of lipopolysaccharides of Salmonella minnesota and Salmonella typhimurium R strains. 532 30

Salmonella transductants and recombinants differing the O-antigenic side chain of their lipopolysaccharide are taken up at different rates by the murine macrophage-like cell line J774. Bacteria containing abequose, mannose, rhamnose, and galactose in O-antigenic side chain were taken up at the slowest rate; the one containing tyvelose instead of abequose was taken up at an intermediate rate; and the one containing mannose, N-acetylglucosamine, and glucose, instead of the above sequence, was taken up at the highest rate. These rates correlate well with the known virulence of these strains; the most virulent is the one taken up slowest, the one taken up at an intermediate rate is less virulent, and the one taken up fastest is the least virulent. The differences in ingestion rates reflect differences in affinity of the bacteria for the macrophages and not in the rate of ingestion once interaction has occurred, suggesting a receptor-mediated process. The majority of uptake is probably dependent on complement, as shown by the requirement for a serum component(s) destroyed by heating at 56 degrees C or by incubation with zymosan. Specific antibody is not required. We therefore postulate that relative virulence in vivo may reflect the relative ability of the polysaccharide of bacterial lipopolysaccharide to activate complement, thus determining the susceptibility of the bacteria to ingestion via the complement receptor of phagocytic cells.
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PMID:Phagocytosis of bacteria by macrophages: changing the carbohydrate of lipopolysaccharide alters interaction with complement and macrophages. 612 Jan 95

A hybridoma produced by the polyethylene glycol fusion of the NS-1 variant of the P3x63Ag8 BALB/c plasmacytoma to splenocytes harvested from a BALB/c mouse immunized with whole gonococci was found to be producing antibody to a common region on gonococcal lipopolysaccharide (LPS). Enzyme-linked immunosorbent assay inhibition systems were established by utilizing this antibody, designated 3F11, and 100% inhibition occurred with both LPS and the LPS-LPS and LPS-derived polysaccharides partially inhibited the enzyme-linked immunosorbent assay, whereas similar preparations isolated from Escherichia coli O:111, the J-5 mutant of this strain, and Salmonella minnesota Re595 failed to inhibit the assay. Studies utilizing whole gonococcal strains 4505 and the isogenic variant 4505r, which lacks both the LPS serotype and common determinants as inhibitors, demonstrated that the determinant recognized by the 3F11 antibody was present on the surface of 4505 and absent on 4505r. Inhibition studies were performed with beta-glucose, beta-galactose, D-glucosamine, D-galactosamine, heptose, 2-keto-3-deoxyoctanoate, N-acetylglucosamine, N-acetylgalactosamine, alpha-lactose, and beta-lactose. Complete inhibition of the enzyme-linked immunosorbent assay occurred with D-galactosamine, and partial inhibition was achieved with both alpha-lactose and beta-lactose. Based on these observations, the 3F11 antibody recognizes a site common to gonococcal LPS which is partially shared by meningococcal LPS. The chemical structure of the determinant appears to be a D-galactosamine-O-D-galactopyranosyl-(1-4)-D-glucopyranose. Additional specificity may be conferred by the steric relationship of the determinant on the intact LPS.
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PMID:Monoclonal antibody analysis of lipopolysaccharide from Neisseria gonorrhoeae and Neisseria meningitidis. 617 50

The repeating pentasaccharide of O-antigen from Escherichia coli O111 contains galactose, glucose, N-acetylglucosamine, and colitose, the latter representing the major antigenic determinant. Phenol extraction of this strain was previously shown to release two fractions (I and II) containing O-antigen carbohydrate, and both fractions were believed to be lipopolysaccharide. We have now characterized fractions I and II and conclude that only fraction II represents lipopolysaccharide. Fraction II contains phosphate, 2-keto-3-deoxyoctonate, beta-hydroxymyristic acid, and potent endotoxin activity, whereas fraction I was deficient in all of these properties of the lipid A and core oligosaccharide regions of lipopolysaccharide. Fractions I and II each represented 50% of the total cellular O-antigen, and both were present on the cell surface. Both fractions were metabolically stable, and no precursor-product relationship existed between them. Fraction II had a number-average molecular weight of 15,800, corresponding to an average of 12 O-antigen repeats per molecule. In contrast, fraction I had a number-average molecular weight of 354,000, corresponding to an average of 404 O-antigen repeats per molecule. Before heat treatment, cells of E. coli O111 are poorly agglutinated by O-serum; although this indicates the presence of a capsule, the corresponding K-antigen was never detected. We conclude that fraction I, when present on the cell surface, inhibits agglutination of unheated cultures of E. coli O111 by O-serum because: (i) a variant strain which lacks fraction I was agglutinated by O-serum without prior heating; (ii) erythrocytes coated with purified fraction I behaved like bacteria containing fraction I in showing inhibition of O-serum agglutination; and (iii) heat treatment released fraction I and rendered bacterial cells agglutinable in O-serum.
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PMID:A surface polysaccharide of Escherichia coli O111 contains O-antigen and inhibits agglutination of cells by O-antiserum. 617 23

Chemically and serologically identical O-specific fractions were isolated from two different lipopolysaccharide (LPS) preparations of Proteus mirabilis O27. The release of a labile constituent in mild hydrolysis deprived those fractions of their serological activity. The compound was identified as N-acetyl-D-glucosamine and its terminal position in the molecule was established by methylation analysis. The non-carbohydrate constituent of the specific fractions: lysine and alanine are linked via their amino group. Terminal residues of N-acetylglucosamine, have to be considered as immunodeterminants of Proteus mirabilis O27. The role of other carbohydrate and non-carbohydrate constituents for the serological specificity of P. mirabilis O27 is discussed.
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PMID:Immunochemical studies on the O-specific side chains of the heterogeneous lipopolysaccharide from Proteus mirabilis O27. 618 57

Pyocins from Pseudomonas aeruginosa were used to select several lipopolysaccharide (LPS) mutants of Neisseria gonorrhoeae strain FA19. Three classes of LPS mutans were found in the initial group selected for study. The LPS of one class lacked galactose. That of a second group lacked the typical heptose found in the parental LPS, was reduced in glucose, galactose, and N-acetylglucosamine content, appeared to contain a new unidentified sugar component, and consisted of two species of LPS separable on sodium dodecyl sulfate-polyacrylamide gels. The LPS of a third strain lacked the heptose, glucose, galactose, and N-acetylglucosamine found in the oligosaccharide portion of parental FA19 LPS. The minimal inhibitory concentration for polymyxin B of the mutant strains was 3 to 4 times that of the parental strain. The strains lacking only galactose were as resistant as the parent to the bactericidal action of normal human serum, but cells of the other two classes were quickly killed by serum. Gonococcal LPS thus appears to be important in determining phenotypic properties of the cells.
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PMID:Pyocin-resistant lipopolysaccharide mutans of Neisseria gonorrhoeae: alterations in sensitivity to normal human serum and polymyxin B. 628 51

The O-specific polysaccharide of the 0114 antigen (lipopolysaccharide) of Escherichia coli 0114 and oligosaccharides obtained from it by Smith degradation and hydrogen fluoride solvolysis were analyzed, using proton and 13C nuclear magnetic resonance spectroscopy and methylation. The results indicated that the 0114 polysaccharide has the tetrasaccharide repeating unit alpha-N-acetylglucosamine(1 leads to 4) beta-3,6-dideoxy-3-(N-acetyl-L-seryl)aminoglucose(1 leads to 3) beta-ribofuranose(1 leads to 4)galactose. In the polysaccharide the repeating units are joined through beta 1 leads to 3-galactosyl linkages. This structure is compared with that of the serologically cross-reacting Shigella boydii 08 antigen and the serological similarity is discussed.
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PMID:Cell-wall lipopolysaccharide of Escherichia coli 0114:H2. Structure of the polysaccharide chain. 630 15

Salmonellae with differences only in the O-antigenic polysaccharide of their lipopolysaccharide were previously shown to differentially activate complement via the alternative pathway, causing them to be ingested at different rates by the mouse macrophage-like cell line J774. We now show that this mechanism could explain the different virulence of these strains in vivo. Mouse peritoneal macrophages (thioglycolate induced) ingest these salmonellae at rates that are inversely proportional to the known virulence of the organisms and virtually identical to the rates observed with J774. As with J774, complement is required for this differential uptake, since serum was required and heating (56 degrees C for 30 min) or zymosan treatment of the serum destroyed activity. The known receptor for nonreducing terminal mannose-, fucose-, N-acetylglucosamine, and glucose-containing glyco-proteins did not participate, since uptake was not inhibited by high concentrations of mannan. When clearance of bacteria from the bloodstream of mice was measured, the least virulent organism was cleared very much faster than the most virulent organism, in confirmation of earlier data. When complement in the mice was destroyed by pretreatment with cobra venom factor, the clearance of the least virulent strain was greatly reduced, whereas the very slow clearance of the most virulent strain was unaffected. These data strongly support the hypothesis that when bacteria have polysaccharide in lipopolysaccharide that activates complement efficiently, the bacteria will be phagocytosed, whereas if the polysaccharide activates complement poorly, the bacteria escape ingestion and may cause disease.
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PMID:Complement activation by polysaccharide of lipopolysaccharide: an important virulence determinant of salmonellae. 634 90


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