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

A system which allows direct selection for curing of plasmids in Gram-negative bacteria was used to generate derivatives of Rhizobium leguminosarum VF39 cured of each of six plasmids present in this strain. Phenotypes could be correlated with the absence of five of the six plasmids. The smallest plasmid, pRleVF39a, carries genes for the production of a melanin-like pigment as has been previously reported. Plasmid pRleVF39d carries nodulation and nitrogen fixation genes. Curing of the plasmids pRleVF39c and pRleVF39e gave rise to strains which formed Fix- nodules on peas, lentils, and faba beans. The nodules formed by the strains cured of pRleVF39c contained few, if any, bacteria. Analysis of washed cells by SDS-PAGE showed that this strain is defective in lipopolysaccharide (LPS) production; the defect could be complemented by introducing plasmids from several other R. leguminosarum strains, and by the R. leguminosarum biovar phaseoli LPS gene clones pCos126 and pDel27. The nodules formed by the strain cured of pRleVF39e had a reduced symbiotic zone, an enlarged senescence zone, and an abundance of starch granules. This strain grew at a much slower rate than the wild type, was unable to grow on minimal medium, and no longer produced melanin. These defects could be complemented by at least one other Rhizobium plasmid, pRle336e, a plasmid of strain 336 which is distinct from the nodulation plasmid (pRle336c) and the plasmid (pRle336d) which could complement the LPS defect associated with the loss of pRleVF39c. This demonstrates that genes necessary for symbiosis can be carried on at least three different plasmids in R. leguminosarum.
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PMID:Two plasmids other than the nodulation plasmid are necessary for formation of nitrogen-fixing nodules by Rhizobium leguminosarum. 216 88

Outer membrane protein (OMP) and lipopolysaccharide (LPS) phenotypic diversity among 27 oral and extraoral strains of Eikenella corrodens was assessed by SDS-PAGE. Each strain exhibited one to three major protein bands in the 35- to 41.5-kDa range and one or two protein bands of lesser density in the 24.5- to 28-kDa range. Eleven OMP patterns were distinguished among the strains. While oral strains obtained from periodontally healthy and diseased subjects exhibited diverse OMP patterns, five of six strains from extraoral sites of infection expressed an identical OMP pattern. Comparison of the electrophoretic mobilities of LPS from these same strains revealed that E. corrodens LPS consists primarily of low apparent molecular mass forms. Sixteen different LPS phenotypes were differentiated among the strains, with no apparent correlation between LPS phenotype and clinical setting. Strains expressing the same OMP pattern frequently expressed variable LPS phenotypes and vice versa. Analysis of OMP or LPS pattern by SDS-PAGE may be useful in taxonomic and epidemiologic studies of E. corrodens. Additional studies assessing the potential influence of OMP composition on invasiveness of this organism appear warranted.
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PMID:Outer membrane protein and lipopolysaccharide heterogeneity among Eikenella corrodens isolates. 220 40

Tumor necrosis factor (TNF) has been proposed as a primary inflammatory mediator of septic shock. In vitro and in vivo studies indicate that endotoxin- or lipopolysaccharide (LPS)-activated macrophages are a principle source of TNF; however, membrane signal transduction and intracellular pathways by which LPS triggers TNF production in macrophages are unclear. Recent evidence indicates that specific protein phosphorylation via activation of protein kinase C (PKC) is an early, critical step in the signaling of macrophage TNF production by phorbol esters. We hypothesize that PKC activation is also required in LPS-signaled Kupffer cell (KC) TNF production. Murine KCs were obtained by liver perfusion and digestion and then stimulated with LPS (Escherichia coli O111:B4) or LPS in the presence of H-7, a selective PKC inhibitor. Conditioned media was collected at 3 hr for assay of TNF utilizing the L929 cytolysis bioassay standardized to murine-rTNF-alpha. We found that H-7 inhibited significantly LPS signaled TNF release at a concentration of 10 microM, while H-8 (a cyclic nucleotide specific inhibitor) had no effect. The effect of H-7 was dose dependent and present at varying concentrations of LPS. Down regulation of PKC activity by preincubation of KCs with phorbol myristate acetate (PMA, a direct activator of PKC) also resulted in significantly reduced TNF release after LPS stimulation. The inhibitor H-7 (10 microM) also significantly inhibited LPS signaled prostaglandin E2 release in Kupffer cells. Total and specific intracellular protein phosphorylation was determined by trichloroacetic acid precipitation and SDS-polyacrylamide gel electrophoresis after labeling stimulated Kupffer cells with 32Pi. Total protein phosphorylation was not significantly altered by LPS stimulation; however, autoradiograms from PMA- and LPS-stimulated KCs demonstrate enhanced phosphorylation of a 40-kDa protein (2.7 +/- 0.9-fold) and a 33-kDa protein (3.1 +/- 1.0-fold) which were inhibited by H-7. We conclude that activation of PKC and protein phosphorylation are required steps in the signal transduction pathway of LPS-stimulated TNF production in Kupffer cells.
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PMID:Tumor necrosis factor production by Kupffer cells requires protein kinase C activation. 220 49

A simple extraction procedure was used for preparing cell surface proteins (CSPs) from Shigella dysenteriae type 1. The preparations obtained using either buffer or water extractions were free from lipopolysaccharide (LPS), as well as cytoplasmic and periplasmic proteins. By SDS-PAGE, about 25 polypeptides were detected, and Western-blot analysis recognised 15 polypeptide antigens. When analysed by crossed immunoelectrophoresis, using anti-Shigella dysenteriae type 1 rabbit sera, 18 antigenic bands were identified. Proteins obtained by this method were found to be highly immunogenic in rabbits. The cell-surface proteins were compared to outer membrane proteins (OMPs) obtained from the S. dysenteriae type 1 strain by a standard procedure involving lysozyme-EDTA extraction, sucrose density centrifugation, and detergent treatment. They were found to contain periplasmic, cytoplasmic, and lipopolysaccharide contaminants. Thus, the procedure described here offers a quick and simple alternative for obtaining relatively pure cell surface proteins from Shigella dysenteriae type 1. This method will be useful when immunogenically active proteins free from other cellular components are required for studies.
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PMID:Cell surface proteins from Shigella dysenteriae type 1. 220 98

A monoclonal antibody, prepared against whole cells of Clostridium tyrobutyricum, recognized a surface antigen extracted by heat treatment or by hot phenol-water treatment. This antigen, after analysis by polyacrylamide gel electrophoresis and immunoblotting, has been shown to present a regularly-spaced ladder pattern similar to those shown by the lipopolysaccharide of many gram-negative bacteria. The proteinase K has been shown to have no effect on the recognition of this epitope by the monoclonal antibody. On the contrary, the inhibition of the antigen reactivity to the monoclonal antibody after a mild periodate oxidation suggests the involvement of a carbohydrate moiety in the epitope. Moreover, the SDS-PAGE analysis of phenol-water extracts has shown an additional compound, detected by silver staining but not recognized by the monoclonal antibody.
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PMID:Demonstration of a surface antigen of Clostridium tyrobutyricum by use of immunoblotting with a monoclonal antibody. 232 79

The immunophysical characteristics of 29 Serratia marcescens strains isolated from hospitalized patients in three different cities were studied. Their outer membrane antigens were compared by solid-phase radioimmunoassay inhibition, and their proteinase K-treated, whole-cell lysates were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analysis. The strains had a limited number of unique outer membrane lipopolysaccharide (LPS) and capsular polysaccharide (K) antigens. By solid-phase radioimmunoassay inhibition, these strains could be divided into four distinct LPS and five K antigenic groups. By SDS-PAGE, the LPS groups could be further divided into three distinct SDS-PAGE core polysaccharide profiles and five distinct O-side-chain polysaccharide profiles. Immunoblot analysis with rabbit antiserum confirmed the limited heterogeneity of these isolates. Of the strains tested, no PAGE profile was unique to blood or nonblood isolates or to organisms collected from a given hospital. Variability of O and core PAGE profiles was not a function of organism growth cycle. Five representative Serratia strains were tested by SDS-PAGE and immunoblot analysis and in a bactericidal assay with normal human serum. We found that (i) the normal human serum had antibodies to the LPS of each of the strains, (ii) the anti-LPS antibody measured by immunoblot did not correlate with the level of bactericidal activity in the normal human serum, (iii) three of four sepsis isolates were serum sensitive, (iv) two Serratia strains serum sensitive in log-phase growth became serum resistant in late stationary-phase growth and under limiting nutrient conditions, and (v) no LPS PAGE profile distinguished serum-sensitive from serum-resistant strains.
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PMID:Immunophysical characterization of human isolates of Serratia marcescens. 240 11

The determinant(s) of gonococcal resistance to killing by human phagocytes has been extracted from outer membrane vesicles (OMV) of a phagocyte-resistant strain, BS4 (agar), with sodium cholate (1%, w/v). The extracts, like the OMV, nullified the effect of antiserum raised against whole BS4 (agar) to promote intracellular killing of the latter by human peripheral blood phagocytes. Fractionation of the extract on Sephadex G75 produced an active fraction with much less protein and lipopolysaccharide (LPS) than in the original extract. Furthermore, crude LPS prepared from the resistant gonococci was inactive. These results imply that the factor(s) promoting intracellular resistance is a protein. SDS-PAGE of the active fraction suggested that the factor was not a principal outer membrane protein nor one of three proteins previously thought to be associated with resistance. In contrast to a similar preparation from a phagocyte-susceptible strain, BSSH, the active fraction from BS4 (agar) showed faintly staining proteins in the regions of 20 and 60 kDal. When eluted from the gels, the former but not the latter neutralized the above effect of antisera, thus associating the 20 kDal protein(s) with resistance to intracellular killing.
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PMID:Association of resistance of Neisseria gonorrhoeae to killing by human phagocytes with outer-membrane proteins of about 20 kilodaltons. 241 May 44

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to analyze the lipopolysaccharides isolated from strains of Aeromonas hydrophila which exhibit virulence for fish and which autoaggregate during growth in static broth culture. The lipopolysaccharides contained O-polysaccharide chains of homogeneous chain length. Two of the strains produced a surface protein array, and immunofluorescence and phage-binding studies revealed that a number of these O-polysaccharide chains of homogeneous length traversed the protein array and were exposed on the cell surface. Immunochemical analyses by immunoblotting, enzyme-linked immunosorbent assay, immunofluorescence, and immunoprecipitation with both polyclonal and monoclonal antibodies revealed the presence of three epitopes on the polysaccharide moiety of this homogenous-chain-length lipopolysaccharide morphotype. One epitope was species serogroup specific and reactive by immunoblotting. This epitope was not present on the heterogeneous-chain-length O polysaccharides of nonautoaggregating strains of A. hydrophila examined. The second epitope was conformation dependent and cross-reactive with an epitope on the homogenous-chain-length O polysaccharides of Aeromonas salmonicida lipopolysaccharide. The third epitope was recognized by a monoclonal antibody and appeared to involve that region of the A. hydrophila and A. salmonicida lipopolysaccharide molecules which contained the O-polysaccharide-core oligosaccharide glycosidic linkage.
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PMID:Electrophoretic and immunochemical analyses of the lipopolysaccharides from various strains of Aeromonas hydrophila. 241 8

Serologically polyagglutinating (PA) and non-typable (NT) strains of Pseudomonas aeruginosa are frequently isolated from cystic fibrosis (CF) patients, but are uncommon in other patients. From serologically typical parent strains, we isolated two variants (one PA, the other NT) which differed from the parent in bacteriophage susceptibility or in sensitivity to the bactericidal action of normal human serum. The PA and NT variants (strains 7/1 and 18S respectively) reacted with antiserum to the parent strains 7 and 18R but did not absorb homologous specific O antibody from antiserum to the parent strains. In contrast the parent strains absorbed anti-PA and anti-NT antibodies from antisera to the variant strains. The yield of lipopolysaccharide (LPS) from acetone-dried cells of the parent strain 7 was similar to that of the PA derivative; but the NT strain 18S yielded only half the LPS of its parent strain. LPS of the variant 7/1 gave a banding profile by SDS-PAGE similar to that of the parent LPS 7, but lacked high-molecular-weight components. LPS of the variant 18S appeared to be grossly different in profile from LPS 18R. Of 533 isolates of P. aeruginosa that were tested with O antisera and with antisera to the two variants, 15% were O-typable and 22% were O-non-typable; 26% reacted with anti-PA serum alone, 10% with anti-NT serum alone, and 27% were agglutinated by both sera. There was a statistically significant correlation between serum sensitivity of CF isolates and their reaction with the PA or NT antisera.
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PMID:Polyagglutinating and non-typable strains of Pseudomonas aeruginosa in cystic fibrosis. 241 63

A simple physical-chemical method for estimating the lipopolysaccharide (LPS, i.e. endotoxin) content of meningococcal polysaccharide vaccines is described. The low molecular weight LPS was first separated from the high molecular weight polysaccharide by SDS-polyacrylamide gel electrophoresis. The LPS was then selectively visualized by a highly sensitive silver stain which can detect 5 ng of meningococcal LPS. The method can detect concentrations of LPS in meningococcal polysaccharides as low as 0.01%, and was used to measure semiquantitatively the LPS in bulk powders of meningococcal polysaccharides and in vaccines in final containers. The LPS in the bulk powders and in the vaccines was also assayed by the gelation of Limulus polyphemus ameobocyte lysate and the results of the two methods were in agreement.
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PMID:The analysis of lipopolysaccharide (endotoxin) in meningococcal polysaccharide vaccines by silver staining following SDS-polyacrylamide gel electrophoresis. 242 Aug 3


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