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)

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

An extract made from the supernatant of Neisseria gonorrhoeae Gc2 strain 1291 degraded the Gc2 polysaccharide antigen. Chemical analysis of this polysaccharide indicated it contains glucose, galactose, glucosamine, galactosamine, glucosamine-6-phosphate, heptose, 2-keto-3-deoxyotonate, and ethanolamine and is the polysaccharide component of gonococcal lipopolysaccharide. Degradation of the polysaccharide by sonic extracts resulted either in complete loss of antigenicity and immunogenicity or in partial degradation to subunits that could inhibit the Gc2-specific hemagglutination inhibition. The factors responsible for degradation were destroyed by heating at 100 degrees C for 5 min or by Pronase digestion, but were unaffected by ribonuclease, deoxyribonuclease, Mg2+, Ca2+, or ethylenediaminetetraacetic acid. The process was pH dependent, with optimal activity occurring at pH 7. Sonic extract supernatants from group B and C meningococcal strains contained degrading properties, whereas similar extracts produced from Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Streptococcus pneumoniae type II failed to degrade the Gc2 polysaccharide.
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PMID:Degradation of the polysaccharide component of gonococcal lipopolysaccharide by gonococcal and meningococcal sonic extracts. 7 94

Antiserum to a purified type R lipopolysaccharide antigen isolated from Neisseria gonorrhoeae was used in a slide agglutination test and compared with conventional carbohydrate utilization and fluorescent antibody tests to confirm the identity of laboratory cultures classified as typical or "atypical" N. gonorrhoeae. Cultures of Corynebacterium vaginalis, N. meningitidis, N. catarrhalis, N. sicca, and N. lactamicus were also tested in the slide agglutination procedure. The addition of both deoxyribonuclease and ribonuclease (1 mg/ml) to the cell suspension medium of phosphate-buffered saline improved the sensitivity and specificity of the agglutination reaction for N. gonorrhoeae. Problems relating to the agglutination test as an aid in identification of N. gonorrhoeae are discussed.
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PMID:Nuclease enhancement of specific cell agglutination in a serodiagnostic test for Neisseria gonorrhoeae. 11 Aug 30

Heat-stable enterotoxin (ST) produced by porcine strains of enterotoxigenic (ENT+) Escherichia coli has been purified to apparent homogeneity by sequential ultrafiltration, acetone fractionation, preparative gel electrophoresis, diethylaminoethyl Bio-Gel A ion-exchange chromatography, and Bio-Gel P-10 gel filtration. The enterotoxin, purified more than 1,500-fold, exhibited a molecular weight of 4,400, as determined by both sodium dodecyl sulfate-gel electrophoresis and gel filtration. A molecular weight of 5,100, representing 47 residues, was calculated from amino acid analysis data. The amino acid content was distinctive, with an unusually high proportion of cystines and few hydrophobic amino acids. A single amino-terminal residue, glycine, was observed. Purified ST was stable to heating (100 degrees C, 30 min) and did not lose biological activity after treatment with Pronase, trypsin, proteinase K, deoxyribonuclease, ribonuclease, and phospholipase C. Periodic acid oxidation and several organic solvents (acetone, phenol, chloroform, and methanol) had no effect on the biological activity of ST. Further, purified ST was stable to acid treatment at pH 1.0 but lost biological activity at pH values greater than 9.0. Neither lipopolysaccharide nor lipid contamination was evident in purified preparations. A characteristic absorption spectrum was observed during the course of the purification, which shifted from a maximum at 260 nm in crude preparations to 270 nm for the purified toxin. Antiserum obtained from rabbits immunized with ST or ST coupled to bovine serum albumin neutralized the action of the enterotoxin in suckling mice; however, passive hemagglutination and hemolysis titer assays suggested that ST is a poor antigen.
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PMID:Purification and chemical characterization of the heat-stable enterotoxin produced by porcine strains of enterotoxigenic Escherichia coli. 34 81

The endotoxic activity of Fusobacterium necrophorum bov 5 was investigated. The supernatant (S) fluid and cell wall (CW) preparation, obtained after differential centrifugation of the ruptured cell mass, were lethal for mice. The toxicity of the S fluid was stable during prolonged storage, treatment with formalin, and heating for 15 minutes at 80, 100, and 121 C, but was destroyed by alkaline hydrolysis with 0.25 N NaOH. The toxic factor was found in a high molecular weight (MW) fraction after gel filtration. The properties exhibited by the toxic S fluid resembled those of endotoxic lipopolysaccharide (LPS). Extracted and partially purified LPS (endotoxin) from F necrophorum bov 5 demonstrated a mouse median lethal dose (mouse LD50) of 16.8 mg/kg of body weight. The toxic LPS material, a high molecular weight moiety as estimated by gel filtration, was resistant to ribonuclease (RNase), deoxyribonuclease (DNase), and pronase treatment. A positive Shwartzman reaction (median skin lesion dose (SLD50) equal to 3.32 mug/kg of body weight) and biphasic fever response (minimal dose required to produce a fever index of 40 sq cm which falls on the linear portion of dose-response curve (FL40) equal to 0.41 mug/kg of body weight) further indicated the toxin was endotoxin in nature. The LPS from F necrophorum bov 5 was less toxic than Salmonella typhimurium LPS; but had considerable toxicity for experimental animals. The toxic activity of the partially purified F necrophorum bov 5 endotoxin was separated into 2 fraction regions by diethylaminoethyl (DEAE)-cellulose chromatography. The data provide evidence for the production of a potent endotoxin, possibly composed of more than one toxic component, which may be released upon cell disruption.
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PMID:Endotoxin from Fusobacterium necrophorum of bovine hepatic abscess origin. 114 41

The nucleic acid fraction from cells of 6 species of bacterium and 2 kinds of vertebrate, calf and salmon, was extracted and purified by the same procedures as described previously. When the spleen cells from BALB/c mice were incubated with the nucleic acid fraction from either of the bacteria, natural killer (NK) activity of the cells was remarkably elevated and the cells produced factors to activate macrophages and to inhibit viral growth. It was shown that the factor to activate macrophages was interferon (IFN)-gamma and that to inhibit viral growth was IFN-alpha/beta. On the other hand, the nucleic acid fraction from either of the vertebrate cells did not show such activities. Pretreatment of the bacterial nucleic acid fraction with DNase, but not with RNase, abrogated completely the biological activities. The activities of the bacterial nucleic acid were not influenced by the presence of polymyxin B, an inhibitor of lipopolysaccharide (LPS), and the spleen cells from not only BALB/c mice but also LPS-insensitive C3H/HeJ mice were activated, indicating that the activities of the fraction were not ascribed to LPS contaminated possibly into the fraction, but to DNA itself. Intralesional injection with the bacterial DNA fraction caused regression of mouse IMC tumors, but the injection with the vertebrate DNA fraction did not. These findings prompted us to examine the biological activities of DNA samples from a variety of animals and plants, which were provided from other laboratories or purchased from manufacturers. All of the DNA samples from cells of 5 kinds of bacterium, 2 of virus and 4 of invertebrate augmented NK activity and induced IFN, more or less, in mouse spleen calls, while the DNA from 10 kinds of vertebrate, including 3 of fish and 5 of mammal, showed no such activities. The DNA from 2 species of plants, were also inactive. Possible mechanisms to explain the different biological activities of DNA from different cell sources were discussed based on our previous finding that the particular palindromic sequences with a G-C motif(s) are required for induction of IFNs and activation of NK cells with synthetic 30-mer oligonucleotides.
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PMID:DNA from bacteria, but not from vertebrates, induces interferons, activates natural killer cells and inhibits tumor growth. 128 Dec 60

Serum levels of IgM, IgG and IgG-antibody subclasses directed against cell envelopes, lipopolysaccharides and cytoplasmic fractions from Capnocytophaga sputigena, C. gingivalis and C. ochracea were examined in age-, race- and sex-matched periodontally healthy (n = 25) subjects and subjects with adult periodontitis (n = 25). The envelopes and cytoplasmic fractions were obtained by ballistic disintegration of the cells and ultracentrifugation. Cell envelopes were treated with DNase, RNase and lysozyme. Lipopolysaccharides were obtained by hot phenol-water extraction and treated with DNase and RNase. The relative levels of the antibodies in response to the cell fractions were measured by the streptavidinbiotin micro enzyme-linked immunosorbent assay. Both groups showed IgM and IgG antibodies to each fraction of the three Capnocytophaga species, but the frequency of positive IgG subclass responses varied. The IgG4 responses were lower than the other subclasses. There were no significant differences between the IgM antibody levels of the two groups. However, the adult periodontitis group had significantly lower IgG antibody titres to the cell envelopes and cytoplasmic fractions of C. gingivalis and C. ochracea, and lipopolysaccharide of C. gingivalis. These results were reflected in the depressed levels of IgG1 and/or IgG2 to these cellular fractions from the same bacterial species. The adult periodontitis group also showed a lower level of IgG1 to the cytoplasmic fractions of C. sputigena without any depression in the total IgG antibody level. There were no significant differences between the groups in IgG3 and IgG4 antibody levels to any of the cellular fractions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Serum antibody responses in human periodontitis to cellular components of Capnocytophaga. 141 21

A comparative study on the endotoxic effects of lipopolysaccharide (LPS) from Veillonella parvula ATCC 10790 and from Bacteroides intermedius BMH was performed using an in vivo approach in the C57BL/6 mouse. Phenol-water extracted LPS of such anaerobes was purified by ultracentrifugation and DNase/RNase digestion, and characterized by a metachromatic assay for endotoxins and by electrophoresis on SDS-polyacrylamide gel and silver staining. Mouse LD50 for V. parvula LPS was 1.479 mg and for B. intermedius greater than 3.160 mg. Sublethal amounts of the LPS from anaerobes as well as from facultative aerobes decreased daily water intake and body weight in the mouse. Endotoxin from Salmonella typhimurium SL1102, Escherichia coli 0128:B12 and V. parvula had a strong effect on water intake and body weight, whereas Bacteroides intermedius LPS activity was very weak. The results of the present report suggest that V. parvula LPS has a toxic in vivo activity on mouse, which is comparable to LPS from classic enteric organisms and stronger than B. intermedius LPS.
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PMID:Biological effects of Veillonella parvula and Bacteroides intermedius lipopolysaccharides. 177 87

The effect of mouse testicular extract (TE) on lymphocyte activation was investigated. TE, in the dose range 75-600 micrograms ml-1, suppressed significantly the blastogenic response of splenocytes to concanavalin A (Con-A), pokeweed mitogen (PWM), phytohaemagglutinin (PHA) and lipopolysaccharide (LPS). TE also suppressed the blastogenic response of B-cells to LPS and of T-cells to PHA in a dose-dependent manner as well as suppressing the mixed lymphocyte reaction (MLR). Pretreatment of splenocytes with TE did not however, completely suppress their blastogenic response to Con-A, when the treated cells were washed prior to culturing. Furthermore, TE did not inhibit the on-going blastogenesis of splenocytes that had been activated already with Con-A for 48 h. Splenocytes obtained from TE-treated mice remained capable of responding to Con-A stimulation, whereas they did not respond to listerial antigens when mice were immunized with Listeria monocytogenes together with TE. The effects of TE were enhanced significantly by heating to 100 degrees C, but were resistant to pronase, RNase and DNase. These results suggest that TE affects non-specifically the stage of lymphocyte sensitization to antigens or mitogens.
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PMID:Suppressive effect of a mouse testicular extract on lymphocyte activation. 190 36

Initiation of the immunoglobulin heavy chain switch DNA rearrangement event is thought to involve conversion of the target switch region DNA to an accessible state. Accessibility is likely to be mediated by the binding of regulatory proteins to sequences in or near switch regions. A DNase hypersensitivity assay was used to recognize possible regions of protein binding in the gamma 1 switch region of the B cell hybridoma 470.25. A strong DNase hypersensitive site was identified 5' of the tandemly repeated S gamma 1 sequences. Data from other laboratories suggest that this hypersensitive site is associated with switch recombination to gamma 1. However, the 470.25 cell does hypersensitive sites within the repetitive portion of the gamma 1 switch region was also identified. A gel retardation assay for protein--DNA interaction revealed a sequence present in several copies in the gamma 1 switch region that specifically binds nuclear proteins. This binding sequence, SG1BS, contains the octanucleotide sequence ATGCAAAA, a 7/8 match to the transcriptional enhancer octamer motif found in immunoglobulin promoters and the heavy chain enhancer. Binding competition studies of SG1BS demonstrate that both the octamer and flanking sequences are critical for binding. By size- and tissue-distribution, the factors that bind SG1BS are not distinguishable from the previously identified octamer-binding factors OTF-1 and OTF-2. The ability of proteins to bind the S gamma 1 octamer motif is increased 2.3-fold upon IL-4 induction of lipopolysaccharide-stimulated B cells.
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PMID:Nuclear protein binding to octamer motifs in the immunoglobulin gamma 1 switch region. 202 12


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