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)

In vitro treatment of A/J mouse bone marrow with anti-Thy 1.2 serum and guinea pig complement (GPC) eliminated its ability to induce graft-vs-host (GVH) mortality in lethally irradiated C57BL/6J x A/F1 (BAF1) mice. The anti-Thy 1.2 and GPC treatment of A/J marrow significantly reduced spleen cell activation by phytohemagglutinin (PHA) but not lipopolysaccharide (LPS) stimulation in A/J mice assayed 6 weeks after lethal irradiation and reconstitution with the treated marrow. However, the anti-Thy 1.2 treatment of A/J bone marrow did not impair the ability of the lethally irradiated, reconstituted, syngeneic mice to reject C57BL/6J skin grafts. We conclude that lymphocytes in bone marrow which are susceptible to inactivation by anti-Thy 1.2 mediate allograft reactions and/or that radioresistant cells which persist in the recipient initiate rejection of allogeneic skin grafts.
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PMID:Effects of restoring lethally irradiated mice with anti-Thy 1.2-treated bone marrow: graft-vs-host, host-vs-graft, and mitogen reactivity. 2 64

An alkaline phosphatase mutant of Pseudomonas aeruginosa exhibiting both regulatory and catalytic changes was isolated. Under repression conditions (i.e. high inorganic phosphate (Pi)) the mutant culture produced an alkaline phosphatase (APase) displaying significant activity against both beta-glycerol phosphate (betaGP) and p-nitrophenyl phosphate (pNPP), while the wild type displayed no activity directed towards these substrates under the same conditions. In vivo, the mutant enzyme's ratio of specific activities was 45:1 in favour of betaGP versus pNPP, whereas this ratio was reversed to 1:9 betaGP versus pNPP for the same enzyme isolated from mutant cells. In addition, the kinetic parameters and stability requirements for the mutant-derived enzyme was altered in comparison with those of the wild type. A study of lipopolysaccharide (LPS) preparations from both the mutant and wild type indicated the mutant to be deficient in the core region of its LPS. The authors propose that the modifications in the catalytic activity of the mutant enzyme, demonstrated in vivo, are due to a change in the enzyme's microenvironment.
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PMID:An alkaline phosphatase mutant of Pseudomonas aeruginosa. 1. Effects of regulatory, structural, and environmental shifts on enzyme function. 2 29

Spleen and lymph node cells from DBA/2 (H-2d) donor mice treated with multiple injections of bacterial lipopolysaccharide (LPS) were tested in vivo for reactivity against normal tissues of host AKR (H-2k) mice against an AKR long-passage, acute lymphoblastic leukemia (BW5147). LPS treatment of donor mice resulted in a reduction in graft-versus-host (GVH) reactivity without loss of graft-versus-leukemia (GVL) reactivity. Immunocompetent cells from LPS treated DBA/2 donors were effective when used for adoptive immunotherapy (in combination with chemoradiotherapy) of BW5147 leukemia. GVH associated mortality decreased as the dose of spleen cells from LPS treated histoincompatible donors was increased as much as four times the number necessary to eliminate leukemia. The mechanism by which LPS reduced GVH reactivity without eliminating GVL reactivity is unclear; however, it does not appear to be the result of a dilution in the number of GVH reactive cells by nonlymphoid elements in the donor spleen nor of the adjuvant effects of LPS on resistance to bacterial infections.
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PMID:Graft versus leukemia. VIII. Selective reduction in antihost reactivity without loss of antileukemic reactivity by treatment of donor mice with lipopolysaccharide. 2 84

Thiobacillus ferrooxidans is an acidophilic organism important to metal leaching of low-grade ores. The aforementioned importance is related to the ability of the bacterium to oxidize reduced iron and sulfur, principally found in nature as pyrite (FeS2). The present study dealt with sulfide oxidation at low pH values and the involvement of the cell envelope in the process of the inorganic oxidations. Sulfide oxidation was noted in spheroplasts of T. ferrooxidans prepared by enzymatic and chemical treatments and partially purified by differential centrifugation. No enzyme activities were noted in membrane fractions containing enrichments of lipopolysaccharide symbolic of outer membrane material or in membrane vesicles containing (or associated with) higher levels of proteins. Results to date indicate that in an acid milieu the envelope structure containing both the outer membrane and the intact inner cytoplasmic membrane is required for sulfide oxidation.
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PMID:Sulfide oxidation by spheroplasts of Thiobacillus ferrooxidans. 2 80

Purified lipopolysaccharide-protein complex (LPS-PC) extracted by trichloroacetic acid from phase I Coxiella burnetii organisms induced in mice and rabbits fair levels of antibodies directed to antigen 1 and antigen 2, as detected by complement-fixation (CF), microagglutination (MA), opsonization-phagocytosis (OP) and serum protection (SP) tests. In guinea pigs only very low levels of MA antibodies against antigen 2 were demonstrated. In rabbit serum, MA antibodies directed to antigen 2 were found exclusively in the IgM fraction after the primary immunizing dose; the second dose was followed by gradual shift of MA antibodies to the IgG class. Two immunizing doses of the LPS-PC were more effective when testing antibody response in mice or protection of mice and guinea pigs against phase I virulent challenge.
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PMID:Immunological properties of the lipopolysaccharide-protein complex of Coxiella burnetii. 2 70

Currently practiced methods for the detection of gram negative bacteriuria require culturing and overnight incubation. Such an approach to bacteriuria detection is unacceptable for any screening program which requires rapid presumptive evidence of infection. In this study, the lipopolysaccharide-dependent formation of a unique dye absorption spectra of the cationic carbocyanine dye, 1-ethyl-2-[3-(1-ethylnaphtho[1,2d]-thiazolin-2-ylidene)-2-methylpropenyl] naphtho[1,2d]-thiazolium bromide, was used to detect bacteriuria caused by gram negative organisms in a hospitalized population. In an evaluation of 168 first morning and randomly collected suspected bacteriuric urines, the dye test detected 66% of the loop plate positive urines with false positive and false negative values of 28% and 34%, respectively. However, 37% of the false positive results occurred in urines containing less than 10(5) gram negative bacteria/ml and an additional 24% of the false positives were seen for patients currently receiving antibiotic treatment. Urine specimens were also evaluated using the limulus lysate assay for lipopolysaccharide.
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PMID:Detection of lipopolysaccharide in suspected bacteriuric urine using a carbocyanine dye. 2 63

Endotoxin has been shown to induce amyloidosis in mice and to result in the appearance in serum of large amounts of amyloidrelated protein (SAA). After injection of 300 mug lipopolysaccharide Escherichia coli, SAA behaves as an acute phase reactant with levels reaching a peak of >600 mug/ml at 18-22 h and returning to base line (<50 mug/ml) by 48 h in each of four strains tested; only the endotoxin-resistant C3H/HeJ strain showed a smaller response. Lesser, though significant, elevations were also found after subcutaneous injection of 25 mg of casein, bovine serum albumin, ovalbumin, or monomeric immunoglobulin G, whereas pyrogen-free human serum albumin/U. S. Pharmacopeia failed to raise SAA levels. SAA generation may thus be a result of endotoxin contamination of these protein preparations. Also present in equivalent amounts in acidified serum from endotoxin-treated mice, but barely detectable in control sera, was a 3,000-dalton molecule whose amino acid sequence is identical to the amino terminal 24 residues of mouse albumin. The appearance of SAA and the amino terminal albumin fragment after endotoxin were unaffected by pretreatment with cobra venom factor, and equivalent levels were found in C5-deficient mice. Pretreatment with pepstatin in vivo, or before acidification in vitro, prevented the appearance of the albumin fragment but had no effect on the appearance of SAA, whereas leupeptin and antipain did not affect the appearance of either SAA or the albumin fragment. These studies suggest that the generation of SAA after endotoxin administration does not involve complement activation or intravascular proteolytic activity, whereas the liberation of a specific peptic-like cleavage product of albumin appears to be the consequence of an acid protease.
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PMID:Some effects of the administration of endotoxin in mice. Specific cleavage of serum albumin by an acid protease and the generation of amyloid serum component. 3 28

Mice with graft versus host reaction (GVHR) show a decreased production of serum interferon and that produced by the bone marrow and spleen cells and blood leukocytes in vitro upon inoculation with Newcastle disease virus. Interferon induction with lipopolysaccharide of Flexner bacteria resulted in activation of production of serum interferon and that induced in spleen cell and blood leukocyte suspensions. Serum interferon production after administration of poly(I) . poly(C) was similar in mice with GVHR and controls.
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PMID:[Comparative study of interferon production in mice with the graft versus host reaction]. 3 29

Comparison of some properties of phase I and phase II Coxiella burnetii cells suggests the presence of lipopolysaccharide (LPS) also in the surface structures of phase II cells. Polysaccharide chains were released from them by mild acid hydrolysis and corpuscular residues resulting from such hydrolysis elicited in rabbits anti-lipid A-antibodies. Toxicity for adrenalectomized and actinomycin D-sensitized mice was demonstrated with phase I cells, but not with much higher concentrations of phase II cells. By contrast, the extent of protection against formation of ascitic tumour in mice with comparable concentrations of phase I and phase II cells was similar.
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PMID:Attempts at demonstration of lipopolysaccharide in phase II Coxiella burnetii. 3 51

Heat-labile enterotoxin (LT) produced by a human strain of enterotoxigenic Escherichia coli (286C(2)) was purified to homogeneity from pH extracts of fermentor-grown cells by ultrafiltration, (NH(4))(2)SO(4) fractionation, hydrophobic chromatography on norleucine-Sepharose 4B, hydroxylapatite chromatography, and Bio-Gel P-150 filtration. Purified LT preparations exhibited biological activity comparable to that of cholera toxin in four bioassays specific for the two enterotoxins (Y-1 adrenal tumor cells, Chinese hamster ovary cells, pigeon erythrocyte lysates, and skin permeability test). The overall yield of LT protein was 20%, which represented a 500-fold purification over pH extracts. A native molecular weight of 73,000 was determined by gel electrophoresis. The toxin dissociated upon treatment with sodium dodecyl sulfate, pH 7.0, into two components with molecular weights of 44,000 and 30,000. Purified LT preparations were remarkably stable over a wide range of storage conditions, temperatures, and pH's. The biological activity was increased by incubation with trypsin and completely destroyed by pronase and proteinase K, whereas deoxyribonuclease I, ribonuclease, and phospholipase D had no effect. The amino acid composition of purified LT was quite different from that of cholera toxin. Neither carbohydrate nor lipopolysaccharide was present in purified preparations. The purification scheme appeared applicable to LT produced by other human and porcine enterotoxigenic strains, but reflected the amount of LT produced by each strain. These data show that LT and cholera toxin share many common chemical and physical properties, but must be purified by different techniques.
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PMID:Purification and chemical characterization of the heat-labile enterotoxin produced by enterotoxigenic Escherichia coli. 3 93


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