UNIPROT:P43026 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

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

The ligand-binding domain of the chicken type-I interleukin-1 (IL-1) receptor (soluble IL-1R(I); sIL-1R(I)) was cloned into a Pichia pastoris expression system and the resulting sIL-1R(I) binding protein was used to produce antisera in rabbits (anti-IL-1R(I)). Two experiments were conducted to determine the capacity of sIL-1R(I) or anti-IL-1R(I) to block the IL-1 bioactivity (thymocyte co-stimulation) in conditioned media (CM) from HD11 chicken macrophages stimulated with lipopolysaccharide. In the first experiment, pre-incubation of CM with unpurified sIL-1R(I) significantly decreased its thymocyte co-stimulation activity by 57%. Further purification of sIL-1R(I) from other proteins secreted or shed from P. pastoris expression system by size exclusion filtration or ammonium sulfate (60%) precipitation did not influence its capacity to neutralize IL-1 bioactivity. These partially purified sIL-1R(I) preparations significantly decreased thymocyte co-stimulation activity in CM by 70.7 and 77.3%, respectively. In the second experiment, pre-incubation of thymocytes with antisera against the sIL-1R(I) decreased IL-1 activity in CM by 70% relative to control thymocyte cultures that received no antibody and by 59% relative to thymocyte cultures incubated with pre-immune sera. Presumably anti-sIL-1R(I) diminished the IL-1 bioactivity in CM by blocking IL-1 binding to its type-I receptor on thymocytes. Thus, 30% of the IL-1-like activity released by LPS-stimulated HD11 macrophages is probably due to at least one other cytokine. Our data are consistent with the type-I receptor being the primary IL-1 receptor on chicken thymocytes that is capable of providing a signal for proliferation.
...
PMID:Soluble type-I interleukin-1 receptor blocks chicken IL-1 activity. 1124 74

Our objective was to determine whether strains of Pseudomonas aeruginosa can adapt to growth in increasing concentrations of the disinfectant benzalkonium chloride (BKC), and whether co-resistance to clinically relevant antimicrobial agents occurs. Attempts were made to determine what phenotypic alterations accompanied resistance and whether these explained the mechanism of resistance. Strains were serially passaged in increasing concentrations of BKC in static nutrient broth cultures. Serotyping and genotyping were used to determine purity of the cultures. Two strains were examined for cross-resistance to other disinfectants and antibiotics by broth dilution MIC determination. Alterations in outer membrane proteins and lipopolysaccharide (LPS) expressed were examined by SDS-PAGE. Cell surface hydrophobicity and charge, uptake of disinfectant and proportion of specific fatty acid content of outer and cytoplasmic membranes were determined. Two P. aeruginosa strains showed a stable increase in resistance to BKC. Co-resistance to other quaternary ammonium compounds was observed in both strains; chloramphenicol and polymyxin B resistance were observed in one and a reduction in resistance to tobramycin observed in the other. However, no increased resistance to other biocides (chlorhexidine, triclosan, thymol) or antibiotics (ceftazidime, imipenem, ciprofloxacin, tobramycin) was detected. Characteristics accompanying resistance included alterations in outer membrane proteins, uptake of BKC, cell surface charge and hydrophobicity, and fatty acid content of the cytoplasmic membrane, although no evidence was found for alterations in LPS. Each of the two strains had different alterations in phenotype, indicating that such adaptation is unique to each strain of P. aeruginosa and does not result from a single mechanism shared by the whole species.
...
PMID:Pseudomonas aeruginosa cells adapted to benzalkonium chloride show resistance to other membrane-active agents but not to clinically relevant antibiotics. 1190 37

IgY, the egg yolk immunoglobulin, equivalent to the IgG from mammals, has been used in veterinary practice for passive immunisation against bacterial or viral infectious diseases. Enteropathogenic Escherichia coli (EPEC) is the main etiological agent of infantile diarrhoea in Brazil and other developing countries. Our aims were to isolate immunoglobulin IgY from egg yolk laid by EPEC -immunised Leghorn chickens and to study its reactivity to the antigens from this pathogen, including some virulence factors. Leghorn chickens were immunised with a bacterial suspension intramuscularly (three hens) or intravenously (three hens) or with PBS (two hens). Eggs were collected over a period of 17 weeks. IgY isolation procedures were carried out by salt precipitation (ammonium sulphate, in solid form) followed by centrifugations and dialysis. Final preparations were submitted to sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS - PAGE), enzyme-linked immunosorbent assay (ELISA) and immunoblotting. All immunised animals developed good levels of antibodies reactive to whole bacteria or lipopolysaccharide (LPS), in contrast to the control ones. Immunoblottings allowed the recognition of several antigenic fractions of bacterial antigens, some of which had a molecular weight compatible with bacterial virulence factors, confirming the efficacy of the immunisation and the adequacy of the method.
...
PMID:Anti-enteropathogenic Escherichia coli immunoglobulin Y isolated from eggs laid by immunised Leghorn chickens. 1207 19

We previously found that one of the pharmacological effects of N-tert-butyl-alpha-phenylnitrone (PBN) is the release of nitric oxide (NO) under oxidative conditions. However, to confirm this hypothesis in vivo, NO released from PBN must be distinguished from NO produced in biological systems, and therefore we undertook the synthesis of PBN using labeled 15N to identify its corresponding 15NO in vivo. The properties were examined with an ESR spectrometer. To synthesize 15N-PBN, the starting material, ammonium-15N chloride, was converted to 2-amino-15N-2-methylpropane, oxidized to 2-methyl-2-nitropropane-15N, and finally reacted with benzaldehyde to give 15N-PBN. The final product was purified by repeated sublimation. With ferrous sulfate-methyl glucamine dithiocarbamate complex, Fe (MGD)2, as a trapping agent to measure the NO levels of 15N-PBN or 14N-PBN in vitro, the peak intensity of 15NO[Fe(MGD)2] was over 50% stronger than that of 14NO[Fe(MGD)2], and that 15NO and 14NO had the corresponding two-and three line hyperfine structures due to their nuclear spin quantum numbers. Subsequently, the ESR spectrum of 15NO derived from 15N-PBN was significantly different than that of lipopolysaccharide (LPS)-induced NO, which was derived from biological cells, and therefore we have demonstrated the possibility to distinguish 15NO from PBN and 14NO generated from cells. These results suggested that 15N-PBN is a useful molecule, not only as a spin-trapping agent, but also as an NO donor to explore the pharmacological mechanisms of PBN in vivo.
...
PMID:ESR characterization of a novel spin-trapping agent, 15N-labeled N-tert-butyl-alpha-phenylnitrone, as a nitric oxide donor. 1245 Jan 31

Lipid A is the lipophilic moiety of lipopolysaccharides (LPSs), the major components of the external membrane of almost all gram-negative bacteria. It is responsible for the toxicity of LPS and has a heterogeneous structure composed of a bis-phosphorylated glucosamine disaccharide backbone that is acylated at the positions 2, 3 of the GlcN I (proximal) and GlcN II (distal) residue with O- and N-linked 3-hydroxy fatty acids (primary substitution). These fatty acids are further acylated by means of their 3-hydroxy groups (secondary substitution). The toxicity of Lipid A is dependent on its primary structure; the number, the length, and the distribution of the fatty acids on the disaccharide backbone strongly influence the endotoxic activity. In this paper a general and easy methodology to obtain secondary fatty acid distribution, which is one of the most difficult issues in the structural determination of Lipid A, is proposed. The method combines ammonium hydroxide hydrolysis and matrix assisted laser desorption ionization (MALDI)-mass spectrometry analysis and has been successfully proven with five different Lipid A species. The procedure exploits the lower stability under mild alkaline conditions of acyl and acyloxyacyl esters with respect to that of the acyl and acyloxyacyl amides. The partially degraded Lipid A species obtained are analyzed by MALDI-MS. The generality of this approach was tested on five Lipid As, namely those arising from Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas reactans, and Burkholderia caryophylli.
...
PMID:Ammonium hydroxide hydrolysis: a valuable support in the MALDI-TOF mass spectrometry analysis of Lipid A fatty acid distribution. 1245 82

CD14 is a protein that mediates lipopolysaccharide (LPS)-induced biological responses such as activation of a transcriptional factor, nuclear factor (NF)-kappaB. It exists as a soluble form (sCD14) in serum and mediates LPS responses of epithelial and endothelial cells as well as a membrane-bound form (mCD14) on monocytes and macrophages. To obtain sCD14 in large quantity for its structural and functional characterization, we expressed the full-length form of human recombinant sCD14 (rsCD14) in a methylotrophic yeast, Pichia pastoris. The recombinant protein was expressed as a major protein in the culture supernatant and purified by ammonium sulfate precipitation, followed by three steps of ion exchange chromatographies. Finally, 1.6 mg of the protein was obtained in high purity from 2L of the supernatant and its identity to sCD14 was confirmed by NH(2)-terminal amino acid sequence analysis. The purified protein was found to have N-linked sugars by an analysis of enzymatic deglycosylation. A native PAGE analysis revealed that the protein was able to form complexes with LPS. In addition, the rsCD14 protein could mediate the LPS-mediated activation of NF-kappaB in human embryonic kidney 293 cells transfected with Toll-like receptor 4 and MD-2, indicating that the purified protein is biologically active. Thus, the rsCD14 protein expressed in P. pastoris and highly purified in a large amount is useful for its structural and functional studies.
...
PMID:Purification and characterization of human soluble CD14 expressed in Pichia pastoris. 1269 96

Epidemiologists have observed a positive association between human morbidity and mortality and the atmospheric concentrations of fine particulate matter (PM), but the mechanisms underlying the toxic effects of PM have not been elucidated. Various components of ambient PM have been implicated in toxicity (including ultrafine particles, transition metals, organics and oxidants). Our research focused on hydrogen peroxide (H2O2). We speculated that fine PM transports H2O2 into the lower lung, leading to tissue injury and to accumulation and activation of macrophages in these regions. The macrophages release cytotoxic mediators and proinflammatory cytokines that contribute to the pathogenesis of tissue injury. To test this hypothesis, we conducted studies to determine (1) whether tissue injury induced by aerosols is mediated by cytotoxic H2O2 carried into the lower lung by fine particles and (2) whether exposure of rats to fine PM leads to accumulation of activated macrophages in the lung. For our studies, systems were designed to generate model atmospheric fine PM and atmospheric peroxides consisting of an ammonium sulfate [(NH4)2SO4] aerosol (mass median diameter, 0.46 +/- 0.14 microm) and H2O2. We also constructed a 6-port nose-only exposure chamber. Female Sprague Dawley rats were exposed for 2 hours to aerosols consisting of (NH4)2SO4 (430 microg/m3), (NH4)2SO4 + 10, 20 or 100 ppb H2O2, vapor-phase H2O2 (10, 20 or 100 ppb), or particle-free air. Studies using oxygen-18 (18O)-labeled H2O2 were conducted to validate the transport of H2O2 into the lower lung with (NH4)2SO4. Rats were killed immediately (0 hours) or 24 hours after exposure. Compared with control animals, inhalation of (NH4)2SO4 and H2O2, alone or in combination, had no major effect on cell number or viability, protein content, or lactate dehydrogenase (LDH) levels in bronchoalveolar lavage (BAL) fluid collected either immediately or 24 hours after exposure. However, electron microscopy revealed that a larger number of neutrophils in pulmonary capillaries adhered to the vascular endothelium, especially in lungs of rats exposed to (NH4)2SO4 + H2O2. Inhalation of (NH4)2SO4 + H2O2 was also found to be associated with altered macrophage functional activity. Thus, exposing rats to (NH4)2SO4 + 20 ppb H2O2 or 20 ppb H2O2 alone caused a level of tumor necrosis factor alpha (TNF-alpha) production by lung macrophages that was higher than in controls. This higher level was observed immediately after exposure and persisted for at least 24 hours. Greater TNF-alpha production was also detected 24 hours after exposure to (NH4)2SO4 + 10 ppb H2O2. Immediately after rats inhaled (NH4)2SO4 + 10 ppb H2O2 or 20 ppb H2O2 alone, we also observed a transiently higher production of superoxide anion (O2-) by alveolar macrophages. Macrophages isolated 24 hours after exposure to 20 ppb H2O2 also produced larger quantities of superoxide anion. In contrast, immediately after exposure, macrophages from rats exposed to (NH4)2SO4 + 10 ppb H2O2 or to 20 ppb H2O2 alone generated less nitric oxide (NO). Reduced nitric oxide production was also observed 24 hours after exposure to (NH4)2SO4 + 10 ppb H2O2 or to 10 or 20 ppb H2O2 alone. Reduced nitric oxide production may have been due to superoxide anion-driven formation of peroxynitrite (ONOO-) anions. In this regard, nitrotyrosine, an in vivo marker of peroxynitrite, was detected in lung tissue immediately after rats were exposed to (NH4)2SO4 + H2O2 or to H2O2 alone (10 or 20 ppb). We also found that alveolar macrophages from rats exposed to (NH4)2SO4 + H2O2 showed a greater expression of the antioxidant enzyme heme oxygenase-1 (HO-1) when stimulated with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Similar results were observed after exposure of rats to an organic peroxide aerosol (cumene hydroperoxide). Taken together, the results of our studies demonstrate that biological effects of inhaled H2O2 are augmented by fine PM. Moreover, tissue injury induced by (NH4)2SO4 + H2O2 may be related to altered production of cytotoxic mediators by alveolar macrophages. Determining the relevance of these toxicologic results to human health will be important in future studies for evaluating the risk of exposure.
...
PMID:Peroxides and macrophages in the toxicity of fine particulate matter in rats. 1503 94

Pyocin typing of 82 Pseudomonas aeruginosa strains, collected from different Iranian clinical sources, revealed that one isolate, P. aeruginosa 42A, produced pyocin S2, a protease-sensitive bacteriocin. Pyocin S2 production was induced by mitomycin C (2 micro g/mL) in the pyocin S2 producer P. aeruginosa 42A. Pyocin S2 was purified using ion exchange chromatography with CM-Sepharose CL-6B and sodium phosphate buffer (pH 8) from an 80% ammonium sulfate precipitate of whole-cell lysates. Pyocin activity of the fractions was detected using the Govan spot testing method. The purity of the active fraction was confirmed by SDS-PAGE, where a single band with a molecular mass of 74 kDa was detected. Cytotoxic effects of purified pyocin S2 and partially purified pyocin from P. aeruginosa 42A on the human tumor cell lines HepG2 and Im9 and the normal human cell line HFFF (Human Foetal Foreskin Fibroblast) were studied by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The results demonstrated that partially purified pyocin and pyocin S2 exhibited substantial inhibitory effects on the growth of the tumor cell lines HepG2 and Im9, while no inhibitory effects were observed on the normal cell line HFFF. Pure lipopolysaccharide was used as a control and was found to have no inhibitory effect on any of the cell lines tested.
...
PMID:Cytotoxic effects of pyocin S2 produced by Pseudomonas aeruginosa on the growth of three human cell lines. 1521 46

Association of various autoimmune and infectious diseases with genetic variation in the solute carrier family 11 member 1 (SLC11A1) gene, formerly known as the natural resistance-associated macrophage protein 1 (NRAMP1) gene, is in accordance with its role in iron metabolism and immune function. In this investigation, in vitro studies were performed to determine whether allelic variants in the promoter region of the gene are affected by iron loading, thereby leading to differential expression of SLC11A1. Constructs containing five different SLC11A1 5'-(GT)n polymorphic alleles identified in the South African population (alleles 2, 3, 5, 8, and 9) and a C to T point mutation at nucleotide position -237, both in the absence and presence of allele 3, were cloned into the pGL2-Basic luciferase-reporter vector and transfected into U937 and THP-1 cells. Addition of exogenous stimuli, including interferon-gamma, bacterial lipopolysaccharide, and ferric ammonium citrate, demonstrated significant differences in the ability of these alleles to regulate gene expression. Striking differences were obtained upon iron loading, with allele 3 showing opposite effects in the presence or absence of promoter polymorphism -237C-->T. Our findings provide direct evidence that this promoter polymorphism is functional and support the hypothesis that iron dysregulation mediated by allelic effects of SLC11A1 underlies disease susceptibility linked to infectious and autoimmune conditions.
...
PMID:Expression of the SLC11A1 (NRAMP1) 5'-(GT)n repeat: opposite effect in the presence of -237C-->T. 1522 10

A capillary electrophoresis-electrospray-mass spectrometry technique for the characterization of lipopolysaccharides (LPSs) was developed, permitting the separation of trace-level O-deacylated LPS isoforms for subsequent structural characterization using tandem mass spectrometry (MS/MS). The separation buffer and electrospray interface were optimized first using O-deacylated LPS samples from large-scale preparations. It was found that with microelectrospray or sheath-solution interface, we could separate LPS in anionic forms and detect them using either negative or positive ion mode MS. For negative ion detection mode MS, 30 mM morpholine with addition of 5% v/v methanol was employed as separation buffer. When positive ion detection mode MS was required, 10 mM ammonium acetate with addition of 5% methanol was used as separation buffer. The structural assignments obtained from MS/MS and capillary zone electrophoresis-electrospray-MS (CZE-ESMS) analyses enabled the identification of isomeric glycoforms. Application of this technique to the analysis of LPS from the galE mutants of Neisseria meningitidis strain BZ157 B5+ revealed the presence of isomeric glycoforms, in which the location of a functional group phosphoethanolamine was found to be in either inner core or lipid A-OH regions. The described technique was also applied to the analysis of LPS samples from the galE mutant of N. meningitidis strains F1576 A4+ and A4-. The occurrence of isomeric LPS glycoforms differing by the location or presence of neutral sugar residues, such as hexoses, can also be characterized using MS/MS.
...
PMID:Application of capillary electrophoresis- electrospray-mass spectrometry to the separation and characterization of isomeric lipopolysaccharides of Neisseria meningitidis. 1523 2

<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>