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)

Covalent modification of proteins via phosphorylation is a well-documented mechanism whereby intracellular events are controlled by external stimuli. Treatment of thioglycollate-elicited, C57Bl/6 murine peritoneal macrophages with nanogram quantities of bacterial lipopolysaccharide (LPS) consistently results in altered 32Pi labeling of a specific set of proteins (e.g., proteins of 67, 37, 33, and 28 kD), as measured by autoradiography after SDS-polyacrylamide gel electrophoresis. Induction of this pattern of phosphorylation is duplicated by the lipid A moiety of LPS. The LPS-stimulated changes in phosphate labeling are both dose- and time-dependent. Of various pharmacologic agents tested, the phosphorylation pattern induced in macrophages by the tumor promoter phorbol myristic acetate shows similarity to the pattern induced by LPS. Analysis of pp 28 and pp 37 from both LPS- and PMA-treated macrophages by limited proteolysis demonstrates that these phosphoproteins are structurally related and that the sites of phosphorylation are similar for both treatment conditions. Macrophages from the genetically LPS-unresponsive C3H/HeJ strain show no alteration in their pattern of phosphorylation after treatment with LPS. Control macrophages, from C3H/HeN mice, respond to LPS in a fashion identical to that seen in C57Bl/6 macrophages. Pretreatment of macrophages with IFN-gamma potentiates the effect of LPS (i.e., yields a level of altered phosphate labeling greater than that observed with LPS or PMA alone). Together, the data indicate that LPS causes altered phosphate labeling of a defined set of proteins, and that the circumstances of this response are consistent with a possible role in coupling LPS-initiated signals to the induction of functional competence in macrophages.
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PMID:LPS induces altered phosphate labeling of proteins in murine peritoneal macrophages. 308 77

On SDS-PAGE, solubilized and proteinase K treated preparations of Neisseria gonorrhoeae strain BS4 (agar) showed differences in silver stained lipopolysaccharide (LPS) patterns, before and after induction to resistance to serum killing by incubation for 3 h at 37 degrees C with low Mr fractions from lysates of guinea pig red blood cells. Preparations from the original serum susceptible gonococci and LPS purified from such bacteria showed two components, but the preparations from the serum resistant gonococci were deficient in the higher Mr component. Furthermore, on immunoblotting with fresh human serum (FHS), the two LPS components of the susceptible gonococci reacted strongly with IgM. With preparations from the serum resistant gonococci there was no reaction in the area corresponding to the higher Mr component and a weaker reaction with the component of low Mr. Purified LPS from the susceptible gonococci neutralized the bactericidal activity of FHS against N. gonorrhoeae strain BS4 (agar) probably by reacting with the relevant antibody, since heated FHS was no longer bactericidal when mixed with a source of complement (human placental serum) after prior reaction with the LPS. These neutralization tests coupled with the results of immunoblotting strongly suggest that increased serum resistance is due to the lack of the high Mr LPS moiety.
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PMID:Lipopolysaccharide alteration is associated with induced resistance of Neisseria gonorrhoeae to killing by human serum. 309 92

The secretion of immunoglobulin (Ig) from cultured mononuclear cells by lipopolysaccharide (LPS) stimulation is inhibited by monoclonal nonspecific suppressor factor (MNSF), a lymphokine produced by murine T cell hybridoma. In an attempt to develop a murine monoclonal antibody (MAb) with specific reactivity against MNSF, a cell fusion technique that incorporated immune murine splenocytes and HAT-sensitive murine myeloma cells was used. Cross-reactivity experiments confirmed that the MAb (MO6) does not bind to unrelated proteins such as bovine serum albumin, mouse IgG, and murine interferon-gamma (IFN-gamma). There are no effects when anti-IFN-gamma antibodies are used with MNSF. As far as biological activity is concerned, MO6 inhibits in vitro the activity of MNSF in terms of the Ig secretion from cultured lymphocytes. By using MO6, affinity chromatography and immunoblotting were performed. The MNSF on the SDS-PAGE showed a band with m.w. of approximately 70,000, indicating the formation of an aggregate in saline; but after treatment with 0.4 M pyridine-acetic acid buffer, separate bands of 24,000 and 16,000 daltons were evident. Therefore MO6 recognizes 70,000 and both 24,000 and 16,000 daltons. Thus we confirmed by using this MAb and affinity chromatography, the existence of human counterpart, human nonspecific suppressor factor (hNSF), in supernatant from concanavalin A-stimulated T cells. When hNSF was fractionated by high pressure liquid chromatography (HPLC), the activity was found in a region corresponding to 70,000 daltons. However, when fractionated in pyridine-acetic acid buffer, hNSF activity was distributed in a slightly wider range of 15,000 to 30,000 daltons. Physicochemical analysis showed that the purified hNSF is resistant to either heating at 56 degrees C or to 2-mercaptoethanol treatment; however, it is labile to acidification at pH 2.0 and is also sensitive to protease treatment, the characteristics of which were similar to those of murine MNSF. Thus MO6 was confirmed to be a pertinent tool for isolation of hNSF, as well as for murine MNSF.
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PMID:Characterization of monoclonal nonspecific suppressor factor (MNSF) with the use of a monoclonal antibody. 310

Modulation of protein expression during interferon-gamma (IFN-gamma)-lipopolysaccharide (LPS)-mediated macrophage tumoricidal activation has been examined by metabolic radiolabeling of various murine peritoneal macrophage populations with [35S]methionine followed by SDS-PAGE analysis. Although both IFN-gamma and LPS are capable of stimulating the expression of several proteins when used independently, combined treatment induced the enhanced or de novo expression of a 120,000 dalton polypeptide. The expression of this protein was synergistically regulated by both IFN-gamma and LPS in a manner strongly reminiscent of the functional synergism that these two agents exhibit with respect to induction of tumoricidal activity. p120 expression could be seen first at approximately 3 hr after the addition of both agents, reached optimal expression by 6 hr, and maintained elevated synthesis for up to 24 hr. This time course corresponds closely to that seen for the acquisition of tumoricidal competence. Macrophages elicited in the primed state of activity in vivo with methyl vinyl ether co-polymer II (MVE-II) did not express p120, but could be induced to do so when treated with low doses of LPS. Under similar conditions, MVE-II-elicited cells also acquire tumoricidal activity. Macrophages obtained from mice chronically infected with bacillus Calmette-Guerin constitutively expressed both p120 and cytolytic activity. If such macrophages were cultured for 24 hr, the expression of both events decayed and was lost, but could be restored by treatment with low doses of LPS. Thus the data support a strong correlation between the expression by macrophages of a novel 120,000 dalton protein and the expression of tumor cytotoxicity.
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PMID:Expression of a 120,000 dalton protein during tumoricidal activation in murine peritoneal macrophages. 310 74

Two mutations associated with antibiotic supersusceptibility in Pseudomonas aeruginosa strain Z61 were transferred separately into strain PAO222, using R68.45-mediated conjugation and phage F116L transduction. One mutation (absA) was 40% contransducible with pro-82 at 26 min on the P. aeruginosa chromosome and was associated with increased susceptibility to beta-lactams, gentamicin and hydrophobic agents. Strains carrying the absA mutation also displayed enhanced uptake of a hydrophobic fluorescent probe, 1-N-phenylnaphthylamine, and were found, by SDS-PAGE, to be altered in the pattern of lipopolysaccharide O-antigen distribution. The other mutation (absB), associated with increased susceptibility to beta-lactams and gentamicin but not to hydrophobic agents, was cotransducible with met-28 and proC at 20 min on the chromosome. The absB mutation caused a structurally undefined alteration in the physical interaction of EDTA and gentamicin with the outer membrane.
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PMID:Mapping and characterization of two mutations to antibiotic supersusceptibility in Pseudomonas aeruginosa. 313 Apr 61

The percentage of beta-lactamase producing Haemophilus influenzae strains from patients with meningitis in The Netherlands increased from 0% in 1975/1976 to 4.6% in 1985/1986 (n = 1559). Twenty-three isolates resistant to ampicillin, penicillin, chloramphenicol, rifampicin and/or tetracycline were subtyped to determine if one resistant strain was spreading. (Sub)typing was performed by capsular typing, analysis of the major outer membrane protein patterns on sodium dodecylsulfate gels (SDS-PAGE subtypes), lipopolysaccharide serotyping and biotyping. The (sub)types of the resistant strains were similar to those of sensitive strains, thus indicating that antibiotic resistant strains develop at random.
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PMID:Comparison of antibiotic resistant and sensitive strains of Haemophilus influenzae type b in The Netherlands by outer-membrane protein subtyping. 313 38

Intercellular adhesion molecule-1 (ICAM-1) on the surface of cultured umbilical vein and saphenous vein endothelial cells was upregulated between 2.5- and 40-fold by rIL-1, rTNF, LPS and rIFN gamma corresponding to up to 5 X 10(6) sites/cell. Endothelial cell ICAM-1 was a single band of 90 kD in SDS-PAGE. Purified endothelial cell ICAM-1 reconstituted into liposomes and bound to plastic was an excellent substrate for both JY B lymphoblastoid cell and T lymphoblast adhesion. Adhesion to endothelial cell ICAM-1 in planar membranes was blocked completely by monoclonal antibodies to lymphocyte function associated antigen-1 (LFA-1) or ICAM-1. Adhesion to artificial membranes was most sensitive to ICAM-1 density within the physiological range found on resting and stimulated endothelial cells. Adhesion of JY B lymphoblastoid cells, normal and genetically LFA-1 deficient T lymphoblasts and resting peripheral blood lymphocytes to endothelial cell monolayers was also assayed. In summary, LFA-1 dependent (60-90% of total adhesion) and LFA-1-independent basal adhesion was observed and the use of both adhesion pathways by different interacting cell pairs was increased by monokine or lipopolysaccharide stimulation of endothelial cells. The LFA-1-dependent adhesion could be further subdivided into an LFA-1/ICAM-1-dependent component which was increased by cytokines and a basal LFA-1-dependent, ICAM-1-independent component which did not appear to be affected by cytokines. We conclude that ICAM-1 is a regulated ligand for lymphocyte-endothelial cell adhesion, but at least two other major adhesion pathways exist.
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PMID:Lymphocyte function-associated antigen-1 (LFA-1) interaction with intercellular adhesion molecule-1 (ICAM-1) is one of at least three mechanisms for lymphocyte adhesion to cultured endothelial cells. 313 64

Serum-susceptible (SS) Neisseria gonorrhoeae were induced to resistance (SR) to complement-mediated killing by fresh human serum (FHS) by a small-Mr factor(s) from guinea-pig blood in 3 h at 37 degrees C, but not in the presence of bacteriostatic concentrations of chloramphenicol or neomycin, indicating that proteins mediated the acquisition of resistance. SDS-PAGE protein profiles of lysates of equal numbers of gonococci showed only two qualitative differences between SR and SS organisms, both in minor components (a protein A of about 205 kDa in the former and not the latter and vice versa for a protein B of about 16 kDa). Many proteins, however, including the three principal outer-membrane proteins, were present in larger amounts in SR gonococci. The lack of major changes in proteins when resistance is acquired was confirmed by immunoblotting the two protein profiles with the IgG of hyper-immune rabbit anti-SR and anti-SS sera, of rabbit anti-SR serum after absorption by SS organisms and of FHS used alone and after absorption with SS organisms. The IgM of FHS, which is responsible for most of the bactericidal activity, showed only faint reactions with a few proteins common to both SS and SR gonococci and no reactions when the FHS was absorbed with SS gonococci. This is in contrast to the strong and different reactions given with lipopolysaccharide (LPS) components of SS and SR organisms, which, prepared from the former organisms, neutralize the bactericidal activity of FHS. Hence, the relatively small protein changes accompanying induction are less likely to be directly responsible for serum resistance than the more profound LPS changes.
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PMID:Protein changes associated with induced resistance of Neisseria gonorrhoeae to killing by human serum are relatively minor. 313 26

Recently evidence has been obtained that a minute amount of cytidine 5'-monophospho-N-acetyl neuraminic acid (CMP-NANA) or a closely related compound is the low Mr factor in human red blood cells which induces Neisseria gonorrhoeae (BS4(agar] to resistance to killing by fresh human serum. Induction of gonococci to resistance by both CMP-NANA and semi-purified low Mr factor from red blood cells was accompanied by a 35-55% reduction of silver staining of lipopolysaccharide separated in SDS-PAGE gels of proteinase K digests. These alterations in lipopolysaccharide are probably responsible for conferring serum resistance. However, lipopolysaccharide-containing digests from resistant as well as from susceptible gonococci neutralised serum bactericidal activity. These observations may have wider implications since CMP-NANA is a sialylating agent wide-spread in mammalian tissues and LPS is ubiquitous amongst Gram-negative pathogens.
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PMID:Cytidine 5'-monophospho-N-acetyl neuraminic acid and a low molecular weight factor from human blood cells induce lipopolysaccharide alteration in gonococci when conferring resistance to killing by human serum. 314 16

The chemical components of lipopolysaccharide (LPS) from the fish pathogen Edwardsiella ictaluri (Ed. ictaluri) were analyzed by SDS-PAGE, gas chromatography, and spectrophotometry, and compared with those of Salmonella typhimurium and Escherichia coli 0111:B4. Only four to five low molecular weight species of LPS from Ed. ictaluri were detected by silver staining after separation by polyacrylamide gel electrophoresis. The low molecular weight species, as well as a low sugar content, indicate that the LPS from Ed. ictaluri was of the rough type, compared with that of S. typhimurium and E. coli which were both of the smooth type LPS. Quantitatively, mannose was not a major sugar component in Ed. ictaluri, unlike S. typhimurium. Palmitic, palmitoleic, and cis-9,10-methylene-hexadecanoic acids were predominant fatty acids among the total cellular lipids of Ed. ictaluri. C14 fatty acids comprised 78% of the total in the LPS of this bacterium, with beta-hydroxy-myristate representing 55%. The results of this study suggest that the lipid A segment of the LPS molecule of Ed. ictaluri is similar to S. typhimurium and E. coli, at least with respect to fatty acid content; however, the core polysaccharide of E. ictaluri differs in that it has twice the heptose content.
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PMID:Chemical characterization of lipopolysaccharide from Edwardsiella ictaluri, a fish pathogen. 320 99


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