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)

Purified disaccharide peptide monomers obtained from Neisseria gonorrhoeae by enzymatic digestion of gonococcal peptidoglycan damaged the mucosa of human fallopian tubes in organ culture. Two peptidoglycan fragments were tested: a nonreducing, anhydromuramyl-containing monomer (the principal fragment shed by growing gonococci) and the analogous reducing, muramidase-derived monomer. The damage produced by either of these peptidoglycan monomers resulted in sloughing of ciliated cells from the mucosa and resembled the damage observed in active gonococcal infection and that produced by filter-sterilized toxic supernatant fluids from gonococcal-infected organ cultures. The minimal toxic dose of peptidoglycan monomers was 0.75 micrograms/ml. Neither lipopolysaccharide, sodium dodecyl sulfate, nor Triton X-100, possible contaminants from the monomer-purification procedures, was present in sufficient quantity to account for the damage. Both of the gonococcal peptidoglycan monomers may be present in vivo and thus may play a role in the pathogenesis of gonococcal infection.
 ...
PMID:Ability of monomeric peptidoglycan fragments from Neisseria gonorrhoeae to damage human fallopian-tube mucosa. 642 21

The lamB protein, the receptor for phage lambda, was purified from the outer membrane of Escherichia coli K-12 by extraction with Triton X-100 and EDTA, chromatography on DEAE-Sephacel in Triton X-100, exchange of Triton for cholate by gel filtration, and chromatography on Sephacryl S-200 in cholate, NaCl, and EDTA. The purified protein appeared to exist as several oligomeric species. In an equilibrium retention assay with reconstituted vesicles containing phospholipids and lipopolysaccharide, the lamB protein conferred permeability for disaccharides. In a liposome swelling assay designed to measure rates of diffusion, the lamB protein conferred permeability to phospholipid liposomes for a variety of substrates. The rates obtained indicate the permeation facilitated by the lamB protein is specific, discriminating among substrates by both size and configuration. For example, maltose diffused into liposomes 40 times faster than sucrose, about 8 times faster than cellobiose, and about 12 times faster than maltoheptaose. The results suggest that the lamB protein forms a transmembrane channel containing a site (or sites) that loosely interacts with the solutes.
 ...
PMID:Specificity of diffusion channels produced by lambda phage receptor protein of Escherichia coli. 644 20

Major antigens in Neisseria gonorrhoeae were identified by surface labelling the organisms with 125I and electrophoresing extracts in polyacrylamide with sodium dodecyl sulphate. Horizontal slices of the gels were cut out and tested in individual wells against patients' sera using ELISA. Serum from local gonococcal infections reacted with Protein II and, probably, lipopolysaccharide, but not with Protein I in deoxycholate (DOC) extracts and gave no reaction with Triton X-100 extracts. Serum from disseminated gonococcal infections reacted with Protein I in the DOC extract and with pili and a number of undefined possibly cytoplasmic membrane antigens in the Triton X-100 extract. The significance of the results and the potential of the method are discussed.
 ...
PMID:Analysis of antibodies in local and disseminated Neisseria gonorrhoeae infections by means of gel electrophoresis-derived ELISA. 681 21

Cell envelopes prepared from smooth and rough strains of Brucella were characterized on the basis of lipopolysaccharide and protein content. The action of three kinds of detergents on Brucella cell envelopes and Escherichia coli control cell envelopes was examined on the basis of the proteins and lipopolysaccharides that were extracted. As compared with those of E. coli, Brucella cell envelopes were resistant to nonionic detergents. Zwittergents 312 and 316 were most effective in extracting E. coli cell envelopes, and Zwittergent 316 was most effective in extracting Brucella cell envelopes. Sarkosyl extracted proteins but extracted only trace amounts of lipopolysaccharides from cell envelopes of both bacteria. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the Sarkosyl-resistant proteins revealed a composition similar to that of the proteins exposed on the surfaces of viable cells, as determined by the lactoperoxidase-125I radioiodination method. EDTA, with either Tris-HCl or Tris-HCl-Triton X-100, did not have detectable effects on Brucella cell envelopes. Ultracentrifugation of purified lipopolysaccharides in detergents and EDTA demonstrate that, in contrast to that of E. coli, Brucella lipopolysaccharide was not stabilized by divalent cations. Sarkosyl was ineffective in dispersing lipopolysaccharides, whereas the action of Zwittergents was related to the length of their alkyl chains.
 ...
PMID:Effects of nonionic, ionic, and dipolar ionic detergents and EDTA on the Brucella cell envelope. 681 15

Addition of cations (20 to 50 mM for Mg(2+) or Ca(2+) or 100 to 500 mM for Na(+)) to N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid buffer during preparation of membranes from smooth and rough strains of Salmonella typhimurium LT2, Salmonella minnesota, and Escherichia coli O8 had two effects on the composition of the membranes isolated. First, in rough strains of chemotypes Ra to Re the "total membranes" (pellets from high-speed centrifugation) were deficient in the proteins of the outer membrane. The missing proteins were found to have been sedimented in a prior low-speed centrifugation in a fraction we call "cation-aggregated membranes." Since these membranes were enriched for lipopolysaccharide and for outer membrane proteins, deficient in succinic dehydrogenase, and contained primarily the dense peak after sucrose gradient centrifugation, it appears to be relatively pure outer membrane. About 10% of the membrane protein of smooth strains and up to 50% that of rough strains were cation-aggregated membranes, appearing to contain most of the outer membrane of rough strains. Thus, cation aggregation may be a useful means of preparation of outer membrane samples. The second effect was that with cation addition, several high-molecular-weight proteins not seen when membranes were prepared without cation addition were found in the total membranes of both smooth and rough strains after high-speed centrifugation. These proteins were bound by cations to the inner membranes, since they were soluble in Triton X-100 and separated into the less dense peak upon sucrose gradient centrifugation. They originated from the cytoplasm or the periplasm, since they corresponded to soluble proteins found in the supernatant after high-speed centrifugation and were depleted from this supernatant when preparation was done in the presence of cations.
 ...
PMID:Interactions of cations with membrane fractions of smooth and rough strains of Salmonella typhimurium and other Gram-negative bacteria. 701 32

Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.
 ...
PMID:Enzyme immunoassay with enhanced specificity for detection of antibodies to Chlamydia trachomatis. 752 55

Endotoxin (lipopolysaccharide, LPS) is commonly found as a contaminant in plasmid DNA preparations. We demonstrate here that the quantities of LPS typically contaminating DNA preparations can generate a toxicity to primary cells (primary human skin fibroblasts, primary human melanoma cells) in the presence of entry-competent adenovirus particles. Toxicity can be observed with as little as 100 ng/ml free LPS or 100 pg/ml LPS when the LPS is assembled into polylysine/adenovirus complexes. Simple and effective methods of removing the contaminating LPS using either a polymyxin B resin or Triton X-114 extraction are described. Treatment of DNA samples to remove LPS eliminates the toxicity to primary cells.
 ...
PMID:Lipopolysaccharide is a frequent contaminant of plasmid DNA preparations and can be toxic to primary human cells in the presence of adenovirus. 758 87

The potentiality of the Triton X-114 phase separation technique for the removal of lipopolysaccharide (LPS, endotoxin) from Klebsiella sp. I-714 exopolysaccharide (EPS) has been investigated. Classical purification and chemical detoxification methods were evaluated for their effectiveness in removing residual LPS, while preserving structural and functional integrity of EPS. Ultracentrifugation, Detoxi-Gel, and ion-exchange chromatography did not remove endotoxin, except gel filtration chromatography performed at 60 degrees C in sodium deoxycholate buffer. In this case, the bioactivity of the purified EPS fraction was significantly lowered, as was seen after alkaline hydrolysis treatment. Moreover, the acetic acid detoxification procedure hydrolyzed EPS. As an alternative, phase partitioning of EPS in Triton X-114 at low temperature provided a fast, mild, and efficient method for the removal of LPS as shown by a 100-fold reduction in Limulus amebocyte lysate (LAL) activity and only a 2-fold reduction in bioactivity. Gel filtration chromatography performed at 4 degrees C with Triton X-114 buffer and phase partitioning with the more hydrophilic Triton X-100 nonionic detergent at 75 degrees C led to a similar decrease in LAL activity. This novel application of Triton X-114 partitioning is a nondegradative alternative to the chemical detoxification of gram-negative bacterial EPS for vaccine production. Purification of endotoxin-contaminated polysaccharides prior to screening for biological activity should also benefit from this technique. The extraction scheme using Triton X-114 can be easily used in large-scale purification processes.
 ...
PMID:A nondegradative route for the removal of endotoxin from exopolysaccharides. 776 98

The production of functional porins involves multiple steps including: export of precursor polypeptides from the cytoplasm, assembly of monomers into trimers, and stabilization of trimers by association with lipopolysaccharide. In this report, a late export/assembly intermediate of the maltoporin (LamB) is found in the inner membrane of Escherichia coli using cell fractionation studies. This processed intermediate is transiently associated with a unique Triton X-100-insoluble subfraction of the inner membrane. The kinetics of appearance and solubility characteristics of this intermediate correspond to those of the metastable trimer form of LamB, suggesting that the export and assembly pathways overlap in the inner membrane prior to final localization in the bulk outer membrane.
 ...
PMID:Export and trimerization pathways of maltoporin overlap in the inner membrane of Escherichia coli. 817 45

The assembly of the in vitro synthesized outer membrane protein PhoE into purified outer membranes was investigated. The assembly appeared to be strongly stimulated by the presence of low amounts of Triton X-100 (optimal 0.08%, w/v). The role of Triton X-100 in the in vitro system was further examined. Pretreating outer membranes with Triton X-100 did not make the membranes competent for correct assembly, indicating that the detergent did not act on the membrane but at the protein level. PhoE became assembly-incompetent with a half-life of approximately 12 min and 90 s at 37 degrees C in the absence and presence, respectively, of 0.08% Triton X-100. Apparently, Triton X-100 induces an assembly-competent state in the PhoE protein with a very short half-life. Furthermore, the efficiency of correct assembly of PhoE was greatly reduced when outer membranes of deep rough lipopolysaccharide mutants were used, indicating an important role of lipopolysaccharides in the assembly of the porin.
 ...
PMID:In vitro insertion and assembly of outer membrane protein PhoE of Escherichia coli K-12 into the outer membrane. Role of Triton X-100. 866 43


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