Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The structure of the lipopolysaccharide from Escherichia coli K12, strain CR34 has been investigated. The lipopolysaccharide contains D-galactose, D-glucose, D-glucosamine, L-glycero D-mannoheptose, 2-keto-3-deoxyoctonate and lipid A. The core region does not contain D-glucosamine but contains galactose, glucose, and heptose in the molar ratios 1:3:6. Methylations were performed on the lipopolysaccharide and on the degraded polysaccharide obtained after acetic acid hydrolysis of the lipopolysaccharide. It was found that galactose is in terminal position partly in the form of galactopyranose, partly in the form of galactofuranose. A part of the heptose was found as unsubstituted heptofuranose. A mole of glucose was 1 leads to 2 linked and another mole of glucose was 1 leads to 6 linked. Periodate oxidation of the lipopolysaccharide followed by borohydride reduction eliminates galactose and only a part of glucose and of heptose. A mole of heptose gave mannose and thus it is unsubstituted in C6 and C7. One mole of glucose and one mole of heptose were not degraded by periodate oxidation.
 ...
PMID:[Study of the lipopolysaccharide from Escherichia coli K12 CR34]. 77 Jan 68

Escherichia coli O14 is one of the few strains of Enterobacteriaceae which in the rabbit engender antibodies in high titers against the common enterobacterial antigen (CA). It is a rough strain that does not possess a specific side chain in its lipopolysaccharide structure (rfa+rfb-). An rfa mutant (rfa-rfb-) was isolated from this parental strain. Chemical analysis revealed the absence of one glucose and of one galactose molecule in the core polysaccharide of the mutant. The incomplete synthesis of the core was accompanied by loss of immunogenicity of CA. In the mutant, in contrast to the wild type, CA was not bound to the core; hence, the core lipopolysaccharide might exert immunosuppressive activity on CA. A protein fraction of normal rabbit serum was shown to destroy the erythrocyte-coating capacity of CA. This fraction also displayed immunosuppressive activity on free CA but not on CA bound to the core polysaccharide.
 ...
PMID:Role of the rfa locus in the immunogenicity of common enterobacterial antigen. 77 Mar 25

A mutant of Escherichia coli that lacks uridine 5'-diphosphate galactose-4-epimerase makes lipopolysaccharide with less carbohydrate than the parent, unless galactose is present during growth. Carbohydrate is dense, and the outer membrane, which contains lipopolysaccharide, was found to be denser when isolated from cells grown with galactose then when galactose was omitted. Cells given galactose after growth in its absence rapidly formed dense regions within the outer membrane that disappeared when galactose was removed. These results indicate that lipopolysaccharide enters the outer membrane nonrandomly at a minimum of 10 to 22 discrete "insertion points." Isopycnic centrifugation provides a method for isolating these regions.
 ...
PMID:Mode of insertion of lipopolysaccharide into the outer membrane of escherichia coli. 77 Apr 32

The lipopolysaccharide from Escherichia coli O9:K30- was isolated in about 2% yield with aqueous 45% phenol at 65 degrees C, followed by ultracentrifugation. The polysaccharide moiety was obtained by graded hydrolysis and gel permeation chromatography. It consisted of a mannan which carried on its reducing end the core oligosaccharide of the R1 type. The mannan contained 1 leads to 2 and 1 leads to 3 linkages in a ratio of 3:2, as determined by methylation analysis and mass spectrometry. On periodate oxidation, 58% of the mannose residues were destroyed. Degradation of oligosaccharide mixtures with alpha-mannosidase from jack bean meal, as well as a specific rotation of [alpha]25D = +89 degrees indicated that all mannosyl linkages have the alpha-configuration. Smith degradation resulted in the liberation of mannosyl (1 leads to 3)-mannose (bound to glyceraldehyde), as established by methylation analysis. From these results we conclude that the O9 polysaccharide of E. coli has a pentasaccharide repeating unit of alpha-mannosyl(1 leads to 3)-alpha-mannosyl-(1 leads to 2)-alpha-mannosyl-(1 leads to 2)-alpha-mannosyl-(1 leads to 2)-mannose, which are joined in the polysaccharide through alpha-(1 leads to 3)-mannosyl linkages.
 ...
PMID:The O9 antigen of Escherichia coli. Structure of the polysaccharide chain. 78 26

The F6R rough mutants isolated from Shigella flexneri F6S, serotype 5b, and the FH rough mutants, derived from other serotypes of S. flexneri, were chemotyped according to the chemical analysis of their lipopolysaccharides. Further, the following stages of lipopolysaccharide core biosynthesis in S. flexneri have been established: --(KDO)3--heptose--heptose--glucose--galactose; the last three stages are: either --glucose--glucosamine--glucose, or --glucosamine--glucose--glucose. The results of the chemical study of the R lipopolysaccharides are compatible with the assumption of the existence of a similar core in all considered S. flexneri serotypes.
 ...
PMID:[Chemotypes of "Shigella flexneri" R mutants and related phage receptors. I. -- Chemical study of the lipopolysaccharides (author's transl)]. 79 13

Extraction of mycelium or walls of Micropolyspora faeni with cold or hot aqueous phenol yielded a lipopolysaccharide consisting of lipid A, phosphate, galactose, arabinose, glucose, glucosamine, and a dideoxy sugar. Extraction with trichloroacetic acid (TCA) yielded an incomplete molecule lacking lipid A. Part of an O-chain was secreted into the culture medium. Phenol and TCA extracts gave three lines of precipitation with human serum from cases of farmer's lung disease, and one of these was given by the culture medium polysaccharide. Serologically-reactive sugars were arabinose, galactose and glucose. The lipopolysaccharide fixed on to red cells which agglutinated in the presence of specific antibody and lysed on the addition of complement. The lipopolysaccharide appeared to elicit mainly IgM antibodies in animals, but IgM and IgG antibodies in humans.
 ...
PMID:Isolation of lipopolysaccharide from the walls of Micropolyspora faeni: chemical composition and serological reactivity. 80 48

The cell envelope of Neisseria gonorrhoeae, colony type 4, was studied. Outer membrane was isolated by lysozyme and ethylenediaminetetraacetic acid treatment of plasmolyzed cells according to Wolf-Watz et al. (1973). The degree of purity of the membrane preparations was checked by electron microscopy. The membrane fraction obtained had a density of 1.25 g/cm(3), was rich in phospholipase A and lysophospholipase, and contained only 10% of the total membrane activity of succinate dehydrogenase and d-lactate dehydrogenase. The outer membrane protein profile after sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed at least six major proteins. The predominating protein showed a molecular weight of 35,000. The lipopolysaccharide component was characterized by gas chromatography. The carbohydrates found were galactose, glucose, and glucosamine. d-Glycero-l-manno-heptose was present in very low amounts. Lipid A contained lauric acid, stearic acid, and beta-hydroxy-myristic acid. About 20% of the fatty acids in the outer membrane was derived from lipid A. The phospholipids were characterized as phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. There was no evidence for a lipoprotein anchored to the peptidoglycan. The peptidoglycan of N. gonorrhoeae was of the chemotype I. The cell envelope of N. gonorrhoeae was found to be highly permeable to gentian violet. Cell envelopes of one penicillin-resistant and two penicillin-sensitive strains were compared. Only moderate differences in fatty acid composition were found.
 ...
PMID:Cell envelope of Neisseria gonorrhoeae: outer membrane and peptidoglycan composition of penicillin-sensitive and-resistant strains. 80 26

Exopolysaccharides were prepared from cultures of four Myxococcus strains grown on solid and in liquid media, and also from the fruiting bodies. Lipopolysaccharides could be extracted with aqueous phenol from the vegetative bacteria, but were absent from microcysts. Mannose and D-glucose were present in all the exopolysaccharides and three of the lipopolysaccharides examined. Other monosaccharides identified in the exopolysaccharides were D-galactose, N-acetylglucosamine and N-acetylgalactosamine. The composition of the lipopolysaccharides was more complex than that of the exopolysaccharides and, in addition to the neutral hexoses and amino sugars, rhamnose was identified in two preparations and ribose in another. No lipopolysaccharide preparations contained O-methyl xylose or heptose. The polysaccharides secreted by the bacillary forms grown on solid or in liquid media closely resembled the polysaccharides isolated from the fruiting bodies, in which they provided a matrix surrounding the microcysts. Each pair of polysaccharides contained the same monosaccharides, although in slightly different proportions. Differences were found in preparations from different strains. These results suggest that in the development cycle of the genus Myxococcus, considerable use is made of pre-existing enzyme systems to synthesize the precursors necessary for polysaccharide synthesis. Any specific difference between the polysaccharide produced by the bacilli and that surrounding the microcysts may lie in the fine structure, rather than in the individual components.
 ...
PMID:Comparison of polysaccharides produced by Myxococcus strains. 80 82

From Escherichia coli 0124 two lipopolysaccharide preparations were obtained with phenol/water extraction and cetavlon precipitation. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and chemical analysis showed that the two preparations from E. coli 0124 and the corresponding preparations from Shigella dysenteriae type 3 reacted alike. The O-specific polysaccharide moiety was characterized with proton magnetic resonance spectroscopy, optical rotation and paper electrophoresis. The constituents were determined by gas chromatography and ion-exchange chromatography. The polysaccharide contained glucose (Glc), galactose (Gal), galactosamine (GalN) and 4-O-(1'-carboxyethyl)-D-glucopyranose (glucolactilic acid, GlcLA) in the molar ratios of 1:2:1:1. Glucolactilic acid, which has a structure similar to muramic acid, was first found in Sh. dysenteriae. The polysaccharide from E. coli 0124 and oligosaccharides obtained from it by partial acid hydrolysis were subjected to methylation analysis using the method of combined gas chromatography--mass spectrometry. The results indicated that the pentasaccharide repeating unit of the polysaccharide is (see article). In the polysaccharide the repeating units are joined through galactofuranosidic linkages. This structure is identical with that of the somatic polysaccharide of Sh. dysenterae type 3.
 ...
PMID:Cell-wall lipopolysaccharide of the 'Shigella-like' Escherichia coli 0124. Structure of the polysaccharide chain. 81 66

The formation of the components of the cell envelope of Acinetobacter sp. 199A was investigated by measuring the incorporation of [3H]leucine into protein, [14C]galactose into lipopolysaccharide, 32P into phospholipid, and [3H]diaminopimelic acid into peptidoglycan. Whereas the lipopolysaccharide and intrinsic protein of the outer membrane were stable, some of the regularly arranged surface protein, the alpha-protein, was lost into the growth medium. Only newly synthesized alpha-protein was lost. The peptidoglycan of the murein layer was also labile. Selective inhibition of the formation of individual components of the cell envelope with penicillin, chloramphenicol, and bacitracin showed that incorporation of protein into the outer membrane required the simultaneous formation of complete lipopolysaccharide. The converse was not true: protein synthesis was not required for lipopolysaccharide incorporation. Formation of the outer membrane and the murein layer proceeded independently.
 ...
PMID:Synthesis and turnover of the regularly arranged surface protein of Acinetobacter sp. relative to the other components of the cell envelope. 93 51


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>