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)

We used Salmonella enteritidis serotype dublin strain SL1438, a nonreverting, aromatic-dependent, histidine-requiring mutant, as a recipient for a recombinant plasmid coding for production of the nontoxic B subunit of the heat-labile Escherichia coli enterotoxin. The S. enteritidis derivative EL23 produced heat-labile enterotoxin subunit B that was indistinguishable from heat-labile enterotoxin subunit B produced by strains of E. coli or Salmonella typhi harboring the same plasmid. Mice immunized orally with strain EL23 developed progressively increasing mucosal and serum antibody responses to both heat-labile enterotoxin subunit B and to the lipopolysaccharide of the vaccine strain. The mucosal antibody response was shown to be immunoglobulin A specific and to be capable of neutralizing the biological activities of both E. coli heat-labile enterotoxin and cholera enterotoxin in vitro.
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PMID:Oral immunization of mice with attenuated Salmonella enteritidis containing a recombinant plasmid which codes for production of the B subunit of heat-labile Escherichia coli enterotoxin. 352 89

Escherichia coli lipopolysaccharide (LPS) induced a strong secretion of corticosterone in C3H/HeN mice with a concomitant increase in the splenic histidine decarboxylase activity. Treatment of the mice with alpha-fluoromethyl histidine, a suicide substrate for the enzyme, markedly attenuated both the secretion and the increase. In C3H/HeJ mice, LPS provoked little corticosterone release and induction of the enzyme. However, these mice responded to tetradecanoyl phorbol acetate with a large increase in both this secretion and enzyme activity. Injection of LPS produced a comparable increase in the serum histamine and corticosterone level and activity of histidine decarboxylase in various tissues of genetically mast-cell-deficient W/WV mice and in closely related +/+ mice. These results suggest that secretion of corticosterone caused by LPS is mediated by histamine produced through induction of histidine decarboxylase in non-mast cells.
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PMID:Possible role of endogenous histamine in mediation of LPS-induced secretion of corticosterone in mice. 375 16

Strain TA102 of S. typhimurium is a new histidine-requiring mutant, particularly suited to the detection of oxidative mutagens acting at A.T base pairs. 10 oxidizing chemicals, previously tested in strain TA102, were used to evaluate the mutagenic sensitivity of the L-arabinose forward mutation assay of S. typhimurium with respect to those types of mutagens. The mutagenicity of each compound was determined by liquid test, measuring both the frequency of mutants among the survivors and the absolute number of mutants growing in selective plates with traces of D-glucose. Strain BA13 with a wild-type lipopolysaccharide barrier was used as compared to the deep rough derivative strain BA9. The chemicals studied were: bleomycin, t-butyl hydroperoxide, chromium trioxide, cumene hydroperoxide, formaldehyde, glyoxal, glutaraldehyde, hydrogen peroxide, paraquat, and phenylhydrazine. Additionally, ultrasonic oscillation was used as a presumable non-mutagenic lethal control treatment. The L-arabinose forward mutation assay detected the mutagenic activity of all the chemicals under study with a high degree of sensitivity, including paraquat which is unable to revert strain TA102. Positive responses were obtained at doses equivalent to or 10 times lower than the doses detected by strain TA102. The results support the idea that the L-arabinose forward mutation assay could replace the set of specific tester strains used by the histidine reverse mutation assay in general screening for genetic toxins.
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PMID:Oxidative mutagens specific for A-T base pairs induce forward mutations to L-arabinose resistance in Salmonella typhimurium. 389 49

Exposure of limulus hemocytes to bacterial endotoxins (lipopolysaccharide, LPS) results in the activation of the intracellular clotting system, consisting of several protein components. During the separation of these components, a potent anticoagulant, named anti-LPS factor, which inhibits the endotoxin-mediated activation of the coagulation cascade, was found in hemocytes from both Tachypleus tridentatus and Limulus polyphemus (Tanaka, S., et al. (1982) Biochem. Biophys. Res. Commun. 105, 717-723). The principle isolated from the Tachypleus hemocyte lysate by column chromatographies on dextran sulfate-Sepharose CL-6B and Sephadex G-50 under sterile conditions was a simple basic protein with an apparent molecular weight of 15,000. It consisted of a single chain polypeptide containing a total of 128 amino acids. The COOH-terminal end was presumed to be histidine, but no NH2-terminal end reactive to phenylisothiocyanate was detected. The isolated anti-LPS factor specifically inhibited the endotoxin-mediated activation of factor C, which has recently been identified as an LPS-sensitive serine protease zymogen in the hemocytes. This inhibition appeared to be due to the binding of anti-LPS factor with LPS. Moreover, anti-LPS factor had an antibacterial effect on the growth of Gram-negative bacteria (Salmonella minnesota R595 and 1114W) but not on that of Gram-positive bacteria (Staphylococcus aureus 209P). These biological activities of the isolated anti-LPS factor suggest an important role in cellular defence of limulus against microbial invasion.
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PMID:Isolation and biological activities of limulus anticoagulant (anti-LPS factor) which interacts with lipopolysaccharide (LPS). 403 Jul 41

The copper-albumin chelate (Cu2+-Alb), at concentrations less than 100 micrograms/ml, has potent noncytolytic antiproliferative activity for murine splenocytes stimulated by phytohemagglutinin-M, lipopolysaccharide (Escherichia coli 055:B5), or allogeneic cells and for phytohemagglutinin-M-stimulated human leukocytes. Inhibitory effects on the incorporation of [3H]leucine into trichloroacetic acid-precipitable protein is observed only at concentrations of Cu2+-Alb above 1 mg/ml. Only albumins with a histidine residue at position number 3 (rabbit, human, bovine) which bind one copper molecule at a high affinity site are capable of eliciting Cu2+-dependent suppression. Canine albumin, which has a tyrosine residue at position 3 and does not bind Cu2+, is nonsuppressive . Copper-albumin is suppressive in both the G1 and S phases of the cell cycle, thus clearly differentiating its suppressive activity from that of normal human plasma. It is not clear, however, if the Cu2+-Alb chelate is the active suppressive species or whether albumin is more efficient than other Cu2+ chelates in donating Cu2+ to another suppressive molecule. The biological significance of Cu2+-Alb-induced suppression is unknown. Although several possibilities are discussed, the potential to generate "artifactual" suppression by the formation of Cu2+-Alb chelates as a result of protein isolation procedures using Cu2+-contaminated reagents is considered to be an important potential problem.
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PMID:Suppression of lymphocyte proliferation by copper-albumin chelates. 623 4

Hemagglutinin (HAin) of Fusobacterium necrophorum was separated from the bacterial cells by trypsinization-sonication, and purified by the gel filtration on Sephadex G-100 column. The final product obtained from gel filtration gave one precipitin line in the immunodiffusion gel and produced a single band in polyacrylamide gel electrophoresis. The molecular weight of the HAin was estimated to be about 19000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It was heat labile and comparatively rich in alanine, glutamine and histidine. Electron microscopy observation revealed that the HAin was a filamentous rod with 0.5-1.0 nm width or frequently showed a cluster form. The hemagglutinability was inhibited by addition of albumins but not by sugars and lipopolysaccharide. Anti HAin rabbit serum inhibited hemagglutination.
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PMID:Purification and partial characterization of Fusobacterium necrophorum hemagglutinin. 644 9

Pseudomonas aeruginosa infection plays a primary pathogenetic role in the chronic respiratory tract disease of cystic fibrosis (CF) patients. Despite pronounced humoral immune responses, reflected by high levels of antibodies against Pseudomonas in serum and in sputum, the antibodies do not eliminate this bacterium. In the present study we have used affinity chromatography with a lipopolysaccharide substituted immunoadsorbent gel to isolate high titers (meanCF = 1:256) of immunotype specific Pseudomonas IgG antibodies from the sera of nine CF subjects, and have evaluated the functional ability of these antibodies to promote phagocytosis and intracellular killing of P. aeruginosa in an in vitro human alveolar macrophage culture system. The phagocytic and intracellular bactericidal kinetics revealed that CF IgG antibodies function in an inhibitory fashion. Both the rate of phagocytosis (rateCF = 204 cpm/unit time) and absolute bacterial uptakes maximal at 120 min (uptakeCF = 18 x 10(3) 14C cpm) were inhibited compared with appropriate positive controls (hyperimmune serum, HIS; [rateHIS = 399; uptakeHIS = 29 x 10(3), P less than 0.005]). The ability of such CF-derived opsonins to potentiate macrophage intracellular bactericidal processes was mildly impaired (bacterial survivalCF = 15 x 10(3) colony forming units (CFU)/min, survivalHIS = 9 x 10(3)). Further characterization of this defect, assessed with functional studies of the Fab and Fc portions of the immunoglobulin molecule, revealed an impairment in the attachment of these specific antibodies to the alveolar macrophage membrane Fc gamma receptors. Preliminary studies of the physical-chemical properties of these immunoglobulins were normal. The expression of this inhibitory activity in vivo may facilitate Pseudomonas colonization and the subsequent established infections in the respiratory tracts of CF subjects.
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PMID:Cystic fibrosis pseudomonas opsonins. Inhibitory nature in an in vitro phagocytic assay. 679 32

Outer membrane proteins were derived from one rough and four smooth strains of Brucella abortus by sequential extraction of physically disrupted cells with N-lauroylsarcosinate and dipolar ionic detergent. Extraction of outer membrane proteins was ineffective, however, without predigestion with lysozyme. Three groups of proteins were present and could be separated in their native state by sequential anion-exchange chromatography and gel filtration. Membrane proteins contained substantial quantities of tightly adherent lipopolysaccharide which could be reduced but not eliminated by extraction of cells with trichloroacetic acid before disruption. Group 2 proteins, apparently trimers in their native state, gave rise to 43,000- and 41,000-molecular-weight bands after complete denaturation in sodium dodecyl sulfate. They were antigenically identical among all the strains, showed close resemblance in amino acid composition to each other and a general similarity to OmpF of Escherichia coli, and are proposed to be the porins of B. abortus. Group 3 proteins occurred as 30,000-molecular-weight bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, although additional bands were frequently observed in this region. In none of the strains did group 3 proteins manifest heat-modifiable characteristics. Proteins of different strains bore a high degree of similarity to each other in amino acid composition, except in methionine, isoleucine, tyrosine, and histidine. Differences occurred consistently in amino acid composition between group 2 and 3 proteins, and some of these correspond to differences between OmpF and OmpA. Group 2 and 3 proteins were antigenically distinct from each other, but the principal group 3 antigens were shared among all the strains. Despite the lack of heat modifiability, perhaps influenced by adherent lipopolysaccharide, group 3 proteins are proposed as counterparts to OmpA. Most of the group 1 proteins, minor components, were physically associated with those of group 3 unless in sodium dodecyl sulfate. Group 1 proteins produced a major band at 94,000 and exhibited heat modifiability. No evidence was found of a low-molecular-weight lipoprotein in the outer membrane of B. abortus, but this is not taken to exclude its occurrence.
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PMID:Outer membrane proteins of Brucella abortus: isolation and characterization. 680 64

The effects of L-histidinol, a structural analog of the essential amino acid L-histidine, on the proliferative responses and anticancer drug vulnerability of cultured spleen cells from male C57BL/6J mice exposed to optimal mitogenic doses of concanavalin A (Con A) or E. coli lipopolysaccharide (LPS) were investigated. By means of tritiated thymidine ([3H]dThd) incorporation into acid-insoluble material as the criterion for proliferation. L-histidinol was shown to provide a dose-dependent inhibition of mitogenic responses elicited by Con A and LPS. Total (apparent) inhibition was provided by 1-mM concentrations of the analog and, at this concentration, [3H]dThd incorporation was totally reversible even after 72 hours of sustained exposure. Simultaneous addition of L-histidinol and either of the mitogens provide a Go-like arrest for 24 hours. Thereafter, the cells appeared to begin slow cell cycle transit but did not traverse the G1/S boundary within 96 hours of incubation. These responses of cultured murine lymphocytes to L-histidinol provided dramatic and extended protection from the cell cycle phase-specific drug cytosine arabinoside and dramatic but transient protection from the cell cycle-specific drug 5-fluorouracil. In principle, these findings extend the L-histidinol anticancer drug approach for improving the therapeutic index of antineoplastic agents, not only to both cycle- and phase-specific drugs, but also to primary cells of myeloid origin.
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PMID:L-histidinol protection against cytotoxic action of cytosine arabinoside and 5-fluorouracil in cultured mouse spleen cells. 695 Jan 59

The injection of Escherichia coli lipopolysaccharide (LPS) into mice produced simultaneous induction of histidine and ornithine decarboxylases in the liver, lung, spleen and kidney. The time courses of the changes in activities of the two enzymes were similar in all the tissues. After the injection, both activities increased within 1.5 hr, peaked at 4.5 hr and returned to the basal levels within 15 hr. The induction of these enzymes was very sensitive to this agent, i.e. as little as 1 microgram/kg of the E. coli lipopolysaccharide produced significant increases in these enzyme activities. An increase in the product amines, histamine and putrescine, followed the rise of enzyme activities. The levels of histamine changed more rapidly than those of putrescine. In spite of the increase in putrescine, there was no increase in spermidine and spermine. In the brain and thymus the LPS induced ornithine decarboxylase, but not histidine decarboxylase. In the blood, the histamine level increased without an increase in the activity of histidine decarboxylase. These results are discussed in relation to the actions of lipopolysaccharide. A simple method for the simultaneous assay of the activities of histidine and ornithine decarboxylases without using radioisotope substrates was used in this study.
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PMID:Simultaneous induction of histidine and ornithine decarboxylases and changes in their product amines following the injection of Escherichia coli lipopolysaccharide into mice. 704 56


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