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

The cell wall component of Pseudomonas solanacearum that induces disease resistance in tobacco was highly heat stable at neutral or alkaline pH but highly labile at acid pH. Activity was unaffected by nucleases and proteases but destroyed by a mixture of beta-glycosidases. Washing of bacterial cell walls released a lipopolysaccharide (LPS) fraction with high inducer activity. Purified LPS, extracted by a variety of procedures from whole cells, isolated cell walls, and culture filtrates of both smooth and rough forms of P. solanacearum, induced disease resistance in tobacco at concentrations as low as 50 microgram/ml. The LPS from the non-plant pathogens Escherichia coli B, E. coli K, and Serratia marcescens was also active. Cell wall protein, free phospholipid, and nucleic acids were not necessary for activity. Moreover, since LPS from rough forms was active, the O-specific polysaccharide of the LPS was not required for activity. Hydrolysis of the remaining core-lipid A linkage or deacylation of lipid A destroyed inducer activity. When injected into tobacco leaves, purified LPS attached to tobacco mesophyll cell walls and induced ultrastructural changes in the host cell similar to those induced by attachment of whole heat-killed bacteria.
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PMID:Bacterial lipopolysaccharides as inducers of disease resistance in tobacco. 2 13

An alkaline phosphatase mutant of Pseudomonas aeruginosa exhibiting both regulatory and catalytic changes was isolated. Under repression conditions (i.e. high inorganic phosphate (Pi)) the mutant culture produced an alkaline phosphatase (APase) displaying significant activity against both beta-glycerol phosphate (betaGP) and p-nitrophenyl phosphate (pNPP), while the wild type displayed no activity directed towards these substrates under the same conditions. In vivo, the mutant enzyme's ratio of specific activities was 45:1 in favour of betaGP versus pNPP, whereas this ratio was reversed to 1:9 betaGP versus pNPP for the same enzyme isolated from mutant cells. In addition, the kinetic parameters and stability requirements for the mutant-derived enzyme was altered in comparison with those of the wild type. A study of lipopolysaccharide (LPS) preparations from both the mutant and wild type indicated the mutant to be deficient in the core region of its LPS. The authors propose that the modifications in the catalytic activity of the mutant enzyme, demonstrated in vivo, are due to a change in the enzyme's microenvironment.
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PMID:An alkaline phosphatase mutant of Pseudomonas aeruginosa. 1. Effects of regulatory, structural, and environmental shifts on enzyme function. 2 29

Sensitivity to actinomycin D(AD) varies in Pseudomonas fluorescens cells grown in glucose or succinate minimal salts medium. Growth is inhibited in succinate minimal medium by much lower concentrations of AD than in glucose minimal medium. Uptake of selected radioactive metabolites is inhibited by AD in cells incubated for 2 h in succinate medium containing AD but glucose-grown cells were not sensitive. EDTA treatment promotes increased sensitivity to AD in succinate-grown cells but does not alter sensitivity in glucose-grown cells. Succinate-grown cells bound 2-3 times as much 3H-AD as glucose-grown cells. Glucose-grown cells had much higher lipopolysaccharide levels in the envelope than succinate-grown cells. It is proposed that the lipopolysaccharide masks the binding sites and, therefore, is responsible for the difference in binding of AD by the glucose- and succinate-grown cells. The availability of the binding sites is also reflected in the sensitivity of the cells to the antibiotic.
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PMID:Effect of carbon source during growth on sensitivity of Pseudomonas fluorescens to actinomycin D. 4 73

In the present study in mice we used the Jerne plaque assay to compare the immunity enhancing potential of different Gram-negative bacteria with special regard to their endotoxin. The results confirm the recent finding that injection of Escherichia coli bacteria of various serotypes may enhance the IgG antibody response to the O antigen of a serologically unrelated E. coli strain injected subsequently, but may suppress the IgM antibody formation. The O antibodies formed were of low avidity but were antigen specific. Smaller amounts of antibodies were formed to a serologically unrelated antigen, E. coli O76, which had not been injected. Of the strains tested as primary stimuli E. coli O4 gave considerably greater enhancement than any other serotype including the homologous E. coli O6, when a short interval between the injections was used. The influence of O4 on the serologically unrelated anti-O6 response was stronger than on the response to the cross-reactive E. coli O18 antigen, suggesting that O antigen cross-reactivity is not the basis for the immunomodulation. Formalin-killed bacteria were more effective in this respect than boiled bacteria or purified lipopolysaccharide and rough mutants (E. coli R1--R4) and E. coli O4 were less effective than many of the other smooth E. coli. These findings suggest that shared determinants in the lipid, basic carbohydrate core or Kunin common antigen portions of the endotoxin do not play the major immunomodulating role in this system. Salmonella reading but not Pseudomonas aeruginosa affected the anti-E. coli O6 response in a similar manner. One explanation for the alterations in the immune response observed implies the presence of an antigen determinant shared by many Enterobacteriaceae in such a position in relation to the O antigen that it can be utilized for cellular co-operative events in the O antibody response. The protein portion of the endotoxin protein--lipid--carbohydrate complex is a possible location.
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PMID:Alteration of the antibody response to Escherichia coli O antigen in mice by prior exposure to various somatic antigens. 5 29

2-Amino-2-deoxygalacturonic acid was identified as a component of the lipopolysaccharide from Pseudomonas aeruginosa N.C.T.C. 8505. The compound probably occurs in the region of polysaccharide responsible for O-antigenic specificity.
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PMID:2-Amino-2-deoxygalacturonic acid in lipopolysaccharides from Pseudomonas aerugimosa. 5 64

A method is described for the preparation of outer and cytoplasmic membranes of Pseudomonas aeruginosa, and the outer membrane proteins characterized. Isolated outer and cytoplasmic membranes differed markedly in the content of 2-keto-3-deoxyoctonate (lipopolysaccharide) and phospholipid as well as in the localization of certain enzymes (NADH oxidase, succinate dehydrogenase, D-lactate dehydrogenase, malate dehydrogenase, and phospholipase), and also in the microscopic morphology. The outer membrane preparation showed activity neutralizing a certain bacteriocin or bacteriophages, whereas the cytoplasmic membrane preparation showed no neutralizing activity. The protein composition of membrane preparations from five different strains of P. aeruginosa [P14, M92 (PAO1), PAC1, P15, and M2008 (PAT)] were determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. More than 50 protein bands were detected in the cytoplasmic membrane preparation. The protein compositions of outer membranes from the five different strains were very similar: at least 6 major bands were found (apparent molecular weights: Band D, 50,000; band E, 45,000; band F, 33,000; bands G and H, 21,000; and band I, 8,000). The protein composition of outer membranes was affected by some physiological growth conditions. Some features of major outer membrane proteins were also studied. Band F showed anomalous migration on SDS polyacrylamide gel electrophoresis depending on the solubilizing conditions or pretreatment with TCA. Band I seemed to be a protein analogous to the lipoprotein which had been found in the outer membrane of Escherichia coli.
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PMID:Separation and characterization of the outer membrane of Pseudomonas aeruginosa. 9 43

The preparation, properties, and immunogenicity of ribosomal vaccines from Pseudomonas aeruginosa are described. These preparations, containing protein and RNA, were tested for immunogenicity by active immunization of mice and subsequent challenge with homologous, live bacteria. The results demonstrated that vaccines prepared from a majority of serotypes used were immunogenic, i.e., afforded 60 to 100% mouse protection against a challenge inoculum containing 8 to 50 50% lethal doses. In some cases vaccine doses as low as 1 microgram of RNA provided 100% mouse protection. Molecular sieve chromatography of a highly immunogenic ribosomal preparation on Sepharose 4B demonstrated the presence of two molecular weight fractions: (i) peak A, an excluded peak (thus having a molecular weight of at least 2 times 10(7)), and (ii) peak B, considerably retarded, with an elution position corresponding to a molecular weight of about 2.2 X 10(6), approximating that of typical 70S ribosomes. Both peaks A and B were immunogenic; however, the immunogenicity of peak A was greater (i.e., a smaller immunizing dose was required) than that of peak B. Peak A was shown to contain components of lipopolysaccharide in addition to protein and RNA (which comprised 80% of the dry weight of peak A). On the other hand, peak B was shown to be free of lipopolysaccharide, and 100% of its dry weight consisted of protein and RNA.
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PMID:Pseudomonas ribosomal vaccines: preparation, properties, and immunogenicity. 10 64

Effective immunization against infection with Pseudomonas aeruginosa is difficult to evaluate because agglutinin levels decline rapidly. Because fractionation of hyperimmune sera often yields more specific antibody than can be accounted for by direct agglutination tests, an immunoglobulin-specific assay based on antiglobulin augmentation was used to characterize antibody responses of C3H/HeJ mice vaccinated with P. aeruginosa type 2 lipopolysaccharide. Nonagglutinating antibodies, initially detected at 2 weeks post-primary vaccination, were predominantly immunoglobulin G after 5 weeks, and they remained elevated at levels usually 32-fold higher than the direct titer throughout the 4-month study period. The sequential production of immunoglobulin M, then immunoglobulin G, followed that found in orthodox immunological responses. Sera that contained nonagglutinating antibodies but not direct agglutinins (14 to 16 weeks) enhanced phagocytosis of P. aeruginosa type 2 by macrophages from unimmunized mice and passively immunized mice against lethal challenge doses; bactericidal activity of these sera was not demonstrated in the presence or absence of complement. When challenged with 1, 10, and 100 50% lethal doses at 16 weeks, survival rates of actively immunized mice were significantly higher than those of unvaccinated mice (P < 0.001). Thus, at a time when no direct agglutinins were detectable, the augmented system detected nonagglutinating antibodies that could confer protracted resistance in vaccinated mice to pseudomonas infection.
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PMID:Role of nonagglutinating antibody in the protracted immunity of vaccinated mice to Pseudomonas aeruginosa infection. 10 67

A method for separating the outer and inner membranes of Pseudomonas aeruginosa PAO1 in the absence of added ethylenediaminetetraacetic acid was devised. The method yields two outer membrane fractions which show the same protein pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but differ substantially in their relative contents of phospholipids. One of these outer membrane fractions and the inner membrane fraction are less than 4% cross-contaminated, as judged by the content of typical inner and outer membrane markers. The outer membrane contains four major protein bands with apparent molecular weights of 37,000, 35,000, 21,000 and 17,000. Vesicles reconstituted from lipopolysaccharide and phospholipids were impermeable to all saccharides included in the vesicles during vesicle formation. When the vesicles contained outer membrane proteins, they fully retained only those saccharides of greater than 9,000 molecular weight, suggesting that the exclusion limit of the outer membrane of P. aeruginosa for saccharides is substantially larger than the figure (500 to 600 daltons) obtained for certain enteric bacteria. The advantages and potential disadvantages of having an outer membrane with a higher exclusion limit for hydrophilic substances are discussed.
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PMID:Outer membranes of gram-negative bacteria. XIX. Isolation from Pseudomonas aeruginosa PAO1 and use in reconstitution and definition of the permeability barrier. 10 18

A procedure is described for isolating a high-molecular-weight polysaccharide (PS) from the slime of Pseudomonas aeruginosa immunotype 1. The resultant material, obtained from the void volume of a Sephadex G-100 column, was composed of carbohydrate and water. No lipopolysaccharide (LPS), 2-keto-3-deoxyoctonoate, heptose, phosphate, or protein was detectable, and nucleic acid contamination was generally below 1%. The carbohydrate composition of the PS was glucose, rhamnose, galactose, arabinose, and mannose. PS had a molecular weight of between 100,000 and 350,000 and did not disaggregate when chromatographed in the presence of sodium deoxycholate. An antigen immunologically indistinguishable from PS could be obtained from LPS by either acetic acid hydrolysis and column chromatography or by allowing solutions of LPS to stand at room temperature for 3 days. Some of this LPS-associated polysaccharide eluted as the void volume of a G-100 column but differed from PS by its lack of galactose and arabinose. LPS also contained an immunodeterminant not shared with PS that was detected by its stability to dilute alkali treatment (0.1 N NaOH, 37 degrees C, 2 h). PS was destroyed by alkali treatment. PS appeared to represent a form of LPS polysaccharide side chain that contains galactose and arabinose and is of a high molecular weight.
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PMID:Isolation and characterization of a high-molecular-weight polysaccharide from the slime of Pseudomonas aeruginosa. 10 40


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