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

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

Salmonellae are generally resistant to the inhibitory effects of NaNO2. Removal of the lipopolysaccharide of Salmonella typhimurium by ethylenediaminetetraacetic acid pretreatment did not result in subsequent inhibtion of growth by NaNO2, indicating that lipopolysaccharide does not function to exclude NaNO2 from the cell. NaNO2 disappeared from the medium while the cells were growing, but, after stationary phase was reached, no further losses were observed unless the pH was maintained above 7.0. Similar losses were observed in a cell-free system if the redox potential of the medium was between -250 and -175 mV. If the disrupted cell suspension was first heated in a boiling water bath for 15 to 18 min, no NaNO2 loss was observed regardless of the redox potential. S. typhimurium is capable of metabolizing NaNO2, possibly by means of a nitrite-reducing enzyme function which is redox controlled.
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PMID:Redox potential-dependent nitrite metabolism by Salmonella typhimurium. 11 15

Isolation of lipid A by acid hydrolysis of Shigella flexneri lipopolysaccharide resulted in a product that consisted of a heterogeneous mixture of bands when visualized by thin layer chromatography. Differential extraction with ethyl acetate and chloroform, or extraction with EDTA, followed by chloroform-methanol-water (Bligh-Dyer extraction), or a combination of both extraction schemes, resulted in partial purification of immunologically active lipid A. Eight fractions were purified further by preparative thin layer chromatography, and each of the fractions had phosphate, carbohydrate, and esterified fatty acids. Upon incorporation into liposomes, five of the eight purified fractions reacted with anti-lipid A serum, but the three fractions with the most number of esterified fatty acids failed to react with anti-lipid A serum. At least one fraction that originally was unreactive with anti-lipid A serum became reactive as a hapten inhibitor upon removal of esterified fatty acids by alkaline hydrolysis. Alkali-treated fractions from "unreactive" and "reactive" lipid A had similar activities as hapten inhibitors. Our data suggest that lipid A can exist in multiple forms that differ by the number and placement, and possibly by the type, of fatty acids linked to the carbohydrate of lipid A. Highly acylated forms of lipid A do not react with antiserum against the unpurified lipid A mixture, but removal of fatty acids does expose immunoreactive groups.
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PMID:Lipid A from endotoxin: antigenic activities of purified fractions in liposomes. 11 18

Human monocytes, after in vitro activation by mixed lymphocyte culture (MLC) supernatants produce a monokine (MK) that enhances the plaque-forming cell (PFC) response of pokeweed mitogen (PWM)-stimulated human B lymphocytes. Technical conditions and kinetics of MK production were established. Irradiation of monocytes (5000 rads) does not abolish MK production but heat-killed cells are unable to release the factor. Highly T cell-depleted monocyte populations still produced the PFC-enhancing factor. The same MK has an inconsistent enhancing effect on the PFC responses of lipopolysaccharide (LPS) and nocardia water-soluble mitogen (NWSM)-stimulated B cells. Other macrophage activators such as LPS, phytohemagglutinin (PHA), and latex particles failed to induce consistently the liberation of the PFC-enhancing MK. The target cell for the MK activity on PWM-stimulated B cells appears to be the B lymphocyte itself. These studies demonstrate that soluble monocyte products can have substantial modulatory effects on human B cell function.
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PMID:Activation of human B lymphocytes. IX. Modulation of antibody production by products of activated macrophages. 14 73

The present studies demonstrate that xenotropic type C virus is efficiently released in response to lipopolysaccharide by spleen cells of a wide variety of inbred mouse strains. Lipopolysaccharide-mediated virus release primarily involves B lymphocytes and is in part genetically determined. Virus release can also be efficiently stimulated by other naturally occurring B cell mitogens, including Nocardia water soluble mitogen, and PPD. The evidence indicates that these agents act synergistically with halogeneated pyrimidines, but not with each other, to cause virus release. These results indicate that B cell mitogens act to release virus by a mechanism that differs from that of halogenated pyrimidines.
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PMID:Genetic factors infuencing mouse type-C RNA virus induction by naturally occurring B cell mitogens. 19 Mar 19

Electron micrographs of lipopolysaccharide (LPS) from Serratia marcescens which have been extracted with phenol/water, suspended in dist. water and subsequently negatively stained reveale round to ovoid particles besides singular ribbon-like structures. These structures are interpreted as collapsed LPS-strands of the outer membrane (OM). Fine structure investigations were carried out on strand-like structures which had been obtained by light alcalization of the particle suspension. Partial denaturation of LPS in ethylene-diaminotetracetic acid with polymyxin B (PB) gave rise to broad bends with periodic 180 degrees-torsions, indicating a helical structure. Chemically fixed LPS in phosphate buffer which were only partial transformed into LPS-strands, additionally revealed that a given LPS-strand consists of two electron-microscopic identical sub-strands which form a double helix. After short times of exposure to PB, negatively stained cells of Serratia marcescens show strand-like cell wall components on the cell surface consisting of longitudinal fibrils. In a further stage of denaturation, the strand-like structures form "projections" of the OM or are completely loosened. Based on a helical arrangement in the negative staining preparations as well as in the thin sections, they are identified as LPS-strands. Presumably, the LPS in the OM exists as contiguous strains. The development of the "double track"-aspect of the LPS in thin sections may be explained as a result of the projections of the helical longitudinal fibrils into the image plane.
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PMID:[Ultrastructural study of lipopolysaccharide and of polymyxin B-induced changes of the outer membrane of Serratia marcescens (author's transl)]. 20 Nov 29

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

The inclusion of vitamin C in the drinking water of BALB/c mice was without effect on the humoral antibody response to sheep red blood cells and bacterial lipopolysaccharide. However, there was a significantly increased cell-mediated immune response as determined by increased T-lymphocyte responses to concanavalin A. This might suggest a mechanism, along with interferon enhancement, for the possible protection by vitamin C against some viral infections.
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PMID:Vitamin C and the immune response. 30 Jun 89

The B-cell mitogens lipopolysaccharide (LPS), Nocardia water-soluble mitogen (NWSM), and dextran sulfate (DxS) react with different subpopulations of B lymphocytes. Selective in vitro killing of cells responding to either LPS or NWSM has little effect on the in vitro response to the other mitogen, although the response to DxS is reduced in both cases. If, after selective in vitro killing, cells are injected into irradiated mice for 2-3 wk before measuring their in vitro mitogen responses, the same specificity pattern is seen. Thus, one is dealing with different B-cell subpopulations rather than different stages of maturation of a single population. Treatment with various alloantisera and complement before measuring the mitogen response to LPS and NWSM shows that (a) whereas all LPS response cells carry surface Ig, a subpopulation of NWSM responsive cells does not; (b) both LPS- and NWSM-responsive cells carry I-A antigens but might not I-E or I-J antigens; (c) all LPS-responsive cells carry I-C antigens, whereas approximately 25% of NWSM responsive cells do not: (d) there is a subpopulation of NWSM-responsive cells carrying neither surface Ig nor I-C antigens and resistant to anti-theta treatment.
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PMID:Mitogenic analysis of murine B-cell heterogeneity. 30 86

Lipopolysaccharide from strains of Haemophilus influenzae was extracted and isolated by the hot phenol-water procedure. The preparations were relatively insoluble in water but could be solubilized with surface-active agents. The preparations contained carbohydrate (30%), fatty acid (29%), and phosphate (4.7%); protein content was less than 1%. Thin-layer chromatography, gas-liquid chromatography, and colorimetric assays detected glucose, galactose, glucosamine, heptose, and a 2-keto-3-deoxy-octonate-like molecule (less than 1%). Neither methylpentose nor dideoxyhexose was detected. The lipid portion was composed of fatty acids common to lipopolysaccharide of Salmonella. The preparations provoked positive dermal Shwartzman reactions and biphasic febrile responses in rabbits, responses typical of endotoxic activity. The 50% lethal dose for mice was decreased from 16.5 microgram/g to 0.015 microgram/g by concomitant administration of actinomycin D. The preparations were shown to be polyclonal activators of bone marrow-derived (B) cells. Limulus lysate gelation was seen with 8.0 ng of lipopolysaccharide. Preliminary hemagglutination data suggested at least three different antigenic factors associated with the lipopolysaccharide of H. influenzae type b. The H. influenzae lipopolysaccharide appeared biologically similar to that of enterobacteria but chemically different.
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PMID:Characterization of lipopolysaccharide of Haemophilus influenzae. 31 Aug 55


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