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

Whole cells of Pseudomonas aeruginosa possess rhodanese activity. The enzyme can be released by rapidly resuspending the cells in cold Tris--HCl buffer. Approximately 95% of the rhodanese activity is released by cold shock. Release of the enzyme can be inhibited either by preincubating the cells with Mg2+ or by incorporating Mg2+ into the shocking buffer. The effect of Mg2+ can be reversed by washing the cells twice with buffer prior to cold shock. While rhodanese can be released from P. aeruginosa by cold shock, lactic dehydrogenase, a cytoplasmic enzyme, remains within the cell. Diazo-7-amino-1,3-napthalenedisulfonic acid, a compound which does not penetrate the cytoplasmic membrane, completely inactivated rhodanese and alkaline phosphatase, a periplasmic enzyme, whereas lactic dehydrogenase retained its full activity. These data suggest that rhodanese in P. aeruginosa, like alkaline phosphatase, is located distal to the cytoplasmic membrane in the periplasmic space. Electron micrographs also show that portions of the lipopolysaccharide outer membrane are shed from the cell during cold shock, while cells preincubated with Mg2+ did not release segments of their outer membrane.
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PMID:Release of rhodanese from Pseudomonas aeruginosa by cold shock and its localization within the cell. 11 Apr 32

The bacterial component responsible for the induction of transient cold agglutinin syndrome in rabbits after intravenous injection of heat-killed Listeria monocytogenes type 4B has been purified and biologically and chemically characterized. A purified immunoglobulin M cold agglutinin was prepared from high-titer sera resulting from the immunization of rabbits with heat-killed L. monocytogenes type 4B and was subsequently used to monitor the purification of the bacterial component responsible for its induction. The bacterial component was isolated from a hot phenol-water extract of lyophilized L. monocytogenes type 4B by multiple molecular sieve chromatography. Upon chemical analysis the purified material was found to be strikingly similar in chemical composition to gram-negative lipopolysaccharide endotoxins. The material contained 15% total fatty acid (of which 50% was beta-hydroxymyristic acid), 40 to 45% neutral sugar (glucose, galactose, and rhamnose), 11.5% amino sugar, 12% uronic acid, 2.5% 2-keto-3-deoxyoctonic acid, 2% heptose, 0.87% phosphorus, and 1.6% amino acid, thereby accounting for 85 to 90% of the weight of the component. Electron micrographs of the purified material were similar to those of lipopolysaccharide preparations from gram-negative organisms. The purified material exist in aqueous solutions as large aggregates, but can be dissociated into a single smaller subunit (3.1S) by dialysis against sodium dodecyl sulfate buffer. The listerial component was toxic and pyrogenic to rabbits, producing symptoms typical of gram-negative endotoxins. Activity in the limulus lysate gelation assay and in the carbocyanine dye assay provides a further link of this material with classical gram-negative endotoxins.
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PMID:Isolation, characterization, and biological properties of an endotoxin-like material from the gram-positive organism Listeria monocytogenes. 11 Jun 84

R-plasmid RP1 was transferred to Pseudomonas aeruginosa cells, as indicated by their resistance to carbenicillin, ampicillin, cephaloridine, kanamycin, and tetracycline, and by the presence of a periplasmic beta-lactamase. The wild-type cells (RP1-) were lysed by ethylenediaminetetraacetic acid but not by ethylene-glycol-bis(2-aminoethyl ether)-N,N-tetraacetic acid, whereas cells carrying the plasmid (RP1+) were resistant to both these chelating agents. RP1+ and RP1- strains were both sensitive to the lytic action of polymyxin B and the lethal action of cold shock, but the effect was less marked in the RP1+ cultures. A proportion of the RP1+ cells surviving cold shock lost resistance to carbenicillin, tetracycline, and kanamycin. The chemical composition of whole cells and cell walls of RP1+ differed from that RP1- in the content of cation, phospholipid, and markers for lipopolysaccharide and peptidoglycan. Differences in cell wall composition, response to ethylenediaminetetraacetic acid and polymyxin B, and the effects of cold shock are all compatible with the hypothesis that RP1 confers changes in the cell envelope, probably in the outer membrane, of P. aeruginosa.
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PMID:Influence of R-plasmid RP1 of Pseudomonas aeruginosa on cell wall composition, drug resistance, and sensitivity to cold shock. 12 23

The specificity of binding of stimulator-derived H-2 antigens by mixed lymphocyte culture (MLC)-activated T blasts was investigated under conditions of antigen excess. We have shown that the detectable proportion of alloantigen-binding blasts from primary MLC is a function of antigen concentration, and can represent up to more than 90 percent of total blasts, when the antigen is presented in the appropriate form (on mitomycin-treated viable stimulator cells, or membrane vesicles prepared from lipopolysaccharide blasts), and at nonlimiting concentration. Thus stimulator alloantigen-binding directly parallels the proliferative response and is not restricted to a subpopulation of T blasts. However, the marked dependence of the binding on antigen concentration indicates that cells with a wide range of receptor affinities for the stimulating determinants are involved. In view of this possibility, the specificity of binding by these cells was studied. We have demonstrated that stimulator K, I, and D region products are bound by nonoverlapping subpopulations of blasts, the sum of which may represent 93 percent of total blasts. Thus, specific distinction by these cells between different H-2 region products is not affected by the putative heterogeneity in terms of receptor affinities. However, specificity with respect to unrelated H-2 haplotypes is strictly dependent on antigen concentration. A preferential binding of stimulator membrane vesicles occurs at limiting concentrations; whereas the majority of blasts bind stimulator and third- party vesicles equally well at high vesicle concentrations. The binding of both vesicle types is specific in that it can be inhibited with the relevant anti-H-2 sera. Furthermore, stimulator and third-party vesicles seem to compete for binding sites on the same cells, as shown by cold antigen inhibition. From these results, we propose that there is an imperfect distinction between stimulator and third-party H-2 antigens by the majority of primary MLC blasts. In contrast, highly selected long-term MLC blasts do not bind third-party H-2 antigens at any concentration, and seem to have high affinity for the stimulating antigens. We conclude that large numbers of clones with low-affinity (cross- reactive) receptors are generated in primary MLC, most of which become eliminated during long-term selection. This implies that the frequency of cells strictly specific for nonshared stimulating determinants must be minute.
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PMID:The receptor specificity of alloreactive T cells. Distinction between stimulator K, I, and D region products and degeneracy of third-party H-2 recognition by low-affinity T cells. 15 39

This is the first report describing in vivo biologic activities elicited by a non-toxic, polysaccharide-rich, water soluble fraction obtained by partial acidic hydrolysis from endotoxic lipopolysaccharide. The two activities present in this preparation were a) mouse bone marrow cell colony formation stimulation (CSF) and b) protection of mice against lethal irradiation. With polysaccharide-deficient rough mutants of salmonella minnesota, the CSF-inducing activity could be restricted to the "core" region of the LPS structure. Sixty-minute hydrolysis with 1 N HCl at 100 degrees C or 0.1 M sodium metaperiodate oxidation at cold room temperature completely abolished CSF-inducing activity of the preparation, whereas it showed considerable resistance to mild alkaline hydrolysis. These findings indicate that the active component in this preparation is carbohydrate in nature. Lipid preparations from smooth LPS or from Re rough mutants are either much less active or completely inactive in the above two assays. The fully active polysaccharide rich preparation was found to be inert in seven other characteristic endotoxicity parameters.
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PMID:Relation of structure to function in bacterial endotoxins. VIII. Biological activities in a polysaccharide-rich fraction. 23 55

V. cholerae El Tor Ogawa strain O17SR grown on trypticase soy agar were extracted with 0.05 M cyclohexylamino propane sulfonic acid (CAPS) pH 9.5 at 37 degrees C for 1 hour. The bacteria were then removed by centrifugation and millipore filtration. The filtered fluid, after being dialysed against many changes of cold distilled water, was concentrated and passed through Sephadex G200 column. Three protein profiles were eluted out with 0.05 M Tris buffer pH 8.6. The haemagglutinin and the bacterial lipopolysaccharide (LPS) were confined to the first profile. They were subsequently separated by agarose gel electrophoresis. The haemagglutinin was found to be more anodic than the LPS. After homogenization of the gel strips containing the haemagglutinin followed by centrifugation at 9,000 g pure haemagglutinin was obtained in the supernatant. Rabbit aniserum against pure haemagglutinin contained protective antibodies against V. cholerae infection in the baby mouse model. Specific antibodies prepared from this antiserum was as protective as the antibodies directed against whole V. cholerae and heat stable somatic antigens of V. cholerae upon the same weight unit.
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PMID:The study of intestinal immunity against V. cholerae: purification of V. cholerae El Tor haemagglutinin and the protective role of its antibody in experimental cholera. 48 20

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.
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PMID:Isolation of lipopolysaccharide from the walls of Micropolyspora faeni: chemical composition and serological reactivity. 80 48

The analysis of the components of a bacterium may be envisaged from the biological aspect (fractionation), the ultrastructural aspect (staining of the structures examined electron-microscopically), and the biological aspect (measure of an activity). In this report we attempt to examine the components of brucella from all three aspects simultaneously. The brucella envelopes have the same ultrastructure as that of gramnegative bacteria: outer membrane, thick stratum or peptidoglycane, periplasmic space, cytoplasmic membrane. The outer membrane of brucella in phase S contains many types of polysaccharides: (1) the lipopolysaccharide (LPS) (S) and polysaccharide B are solubilized by the phenol-uater and ether-water methods, by trichloracetic acid (TCA), by heated sodium dodecyl-sulfate (SDS). The exact localization of polysaccharide B is not known; by the phenol-water extraction method, the LPS (S) in its toxic form (endotoxin) passes in solution into the phenol phase, unlike the endotoxin of enterobacteria, which passes into the aqueous phase. In addition to its toxicity, this LPS (S) is responsible for reactions of immediate hypersensitivity as well as serological reactions towards the standard antigen. It presents A + M antigenic sites; (2) one or more of the polysaccharides remains unsolubilized by the ether-water method, but solubilized by heated SDS; (3) a polysaccharide is linked to peptidoglycane. The structure of the outer membrane of the brucella in phase R is analogous to that of LPS, carrying antigen R, characteristic of these strains. This antigen may be utilized for the serological diagnosis of infections due to brucella R (B. ovis) or vaccinations by a vaccine in phase R. The peptidoglycane fraction extracted by the heated SDS has a more complex structure than that of E. coli: it consists of a supplementary outer layer containing amino acids and polysaccharides. This fraction has a vaccinal activity. A soluble protein fraction, without organized structure, no doubt of cytoplasmic origin, may be extracted by a cold saline solution. This fraction, known as "brucelline", reveals delayed hypersensitivity when injected intradermally. The biological activity of the other structures (periplasm, cytoplasmic membrane, ribosomes...) is not known. Biological activities have been attributed to fractions, but since these are badly defined from the structural point of view it is difficult to determine the connection between activities and structures.
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PMID:[Structure and constituents of Brucella. Characterization and biological properties of the fractions]. 126 52

The effect of LPSw (a lipopolysaccharide from wheat flour) on the bone resorption of 18-d chick embryonic calvaria was examined in an organ culture following the method of Raisz. Bone was prelabeled in culture medium containing 45Ca and chased in a cold medium. On addition of test samples, labeled calcium was released indicating the grade of bone resorption. LPSw (10-100 ng/ml) stimulated bone resorption, showing an effect comparable to parathyroid hormone (PTH) (1 U/ml). PTH at 1 U/ml decreased the total amount of calcium and phosphorus, while LPSw did not. LPSw is thus assumed to stimulate bone resorption more actively than PTH.
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PMID:Homeostasis as regulated by activated macrophage. VIII. LPSw (a lipopolysaccharide from wheat flour) can regulate bone resorption of chick embryo. 139 47

Mice stressed daily by brief cold water immersions for 1, 8 or 14 days showed changes in immune system function which were dependent on the number of mice per cage, frequency of stress exposures and total number of stress exposures. Changed percentages of spleen B and CD4, but not of CD8 cells were determined when the mice were stressed either once or twice daily. With CD4 cells, increased percentages were seen after stress once daily but a decreased percentage was seen after stress twice daily. Furthermore, the Concanavalin A-stimulated spleen cell mitogenesis was decreased after 1 day of stress in mice stressed once daily as opposed to after 8 and 14 days of stress in mice stressed twice daily. After 14 days of stress, the lipopolysaccharide stimulated mitogenesis was increased if the mice were stressed once daily but decreased if the mice were stressed twice daily. With two mice per cage, we observed a decreased spleen cell mitogenesis after 14 days of stress. With four mice per cage, the spleen cell mitogenesis was decreased after 8 and 14 days of stress. If spleen cell populations from mice stressed twice daily for 8 days were depleted of macrophages and CD4 or CD8 cells, the effect of stress on the mitogenesis was removed from the CD8 cells. Spleen cells of mice stressed for 14 days showed a decreased mitogenesis when depleted of adherent cells and reconstituted with adherent cells from control mice. Furthermore, the adherent cells from these mice had decreased ability to support mitogenesis of adherent cell-depleted spleen cells from control mice as well as a decreased IL-1 production.
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PMID:The effect of various contexts of stress on the mouse spleen lymphocytes and macrophage co-stimulatory activity. 190 2


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