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

The ability of agarose-linked protamine to bind Salmonella typhimurium lipopolysaccharides was investigated. Radioactively labelled lipopolysaccharides were isolated both from a smooth strain (SH6749, labelled with [14C]galactose) and from a rough strain (SH5014, lipopolysaccharide chemotype Rb2, labelled with [3H]acetate). From 50-micrograms samples of the lipopolysaccharides, protamine-agarose columns bound 99.5-99.9% of the input radioactivity. The binding efficacy was not affected by pH in the range from 3.7 to 10.5. Maximal binding capacity of protamine-agarose for highly soluble (triethylamine form) lipopolysaccharide of SH5014 was estimated to be 13.5 mg/ml packed adsorbent. The bound lipopolysaccharides could be totally released from the columns and recovered by elution with the anionic detergent sodium deoxycholate, or with 0.5 M NaCl in the presence of the uncharged detergent Triton X-100. By analysis in sodium dodecyl sulfate/polyacrylamide gels, the macromolecular quality of the recovered lipopolysaccharide was shown to be identical to that of the original. Protamine-agarose chromatography can thus be applied to purify lipopolysaccharide preparations, and to separate as well as concentrate lipopolysaccharides from dilute solutions without altering their composition. This application was challenged with water as well as insulin solution experimentally contaminated with radiolabelled lipopolysaccharide. While the insulin protein did not bind to the protamine-agarose, the contaminating lipopolysaccharide was effectively trapped.
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PMID:Reversible binding of Salmonella typhimurium lipopolysaccharides by immobilized protamine. 354 25

A procedure was developed for the purification of sheathed flagella from Bdellovibrio bacteriovorus 109J. Preparations of isolated flagella appeared as filaments 28 nm in diameter, did not vary in sheath content by more than 10% from the mean, and contained 50% protein, 38% phospholipid, and 12% lipopolysaccharide (LPS) by weight. The sheath was readily solubilized by Triton X-100, whether or not EDTA was present, and contained all of the LPS and phospholipid and 30 to 40% of the protein of the intact flagella; sedimentable core filament polypeptides accounted for the remainder. Flagellar LPS was significantly enriched in nonadecenoic acid (19:1) and depleted in beta-hydroxymyristic acid relative to outer membrane LPS from intraperiplasmically grown bdellovibrios. These observations suggest that the sheath is a stable domain distinct from the bulk of the outer membrane. The sheath also contained substantially more phospholipid (57%) and less protein (26%) of a more heterogeneous composition than that of previously described outer membranes. This unusual balance of constituents was predicted to result in a fluid membrane compatible with a model for the generation of motility by rotation of the core filament within a highly flexible sheath.
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PMID:Isolation and composition of sheathed flagella from Bdellovibrio bacteriovorus 109J. 403 Jun 91

Purified lipopolysaccharide vesicles dissociate when treated with ethylenediaminetetraacetic acid (EDTA) and then reassemble when dialyzed against Mg(2+). Purified outer, lipopolysaccharide membrane (L membrane) is partially dissociated by treatment with EDTA and fully dissociated upon further treatment with Triton X-100. Both the partially and fully dissociated L membrane can be reassembled by dialysis against Mg(2+). Reassembly of lipopolysaccharide or L membrane in the presence of intact flagella results in specific attachment of flagellar basal bodies to vesicles via the L and sometimes the M ring. Lipopolysaccharide and L membrane appear to be composed of substructures bound together by both Mg(2+) (divalent cation)-mediated and hydrophobic bonds.
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PMID:Dissociation and reassembly of Escherichia coli outer membrane and of lipopolysaccharide, and their reassembly onto flagellar basal bodies. 410 Aug 36

Meningococcal groups B and C have been subdivided into a series of serotypes based upon the antigenic specificity of protein serotype antigens (STA). The purpose of these studies was to obtain the STA by gentle methods and determine its anatomic location in the meningococcal cell. The STA was extracted from group B meningococcal strains by either 0.2 M LiCl or 0.2 M CaCl(2) and isolated from the extracts by gel filtration on Sepharose 6B or by pelleting the STA by centrifugation at 100,000 g. The isolated STA was a lipoprotein-lipopolysaccharide complex with a mol wt of approximately 4 x 10(6) daltons. Antisera prepared against the type 2 STA were bactericidal only for homologous serotype strains. The STA proved to be a constituent of the outer membrane of the cell envelope. This was shown by SDS-polyacrylamide gel electrophoresis (PAGE) of the isolated outer membrane and of the purified STA. The type 2 STA complex contains three principal proteins, one of which is predominant with a mol wt of 41,000 daltons. The type 2 STA was dissociated by Triton X-100 and separated by sucrose gradient isodensity centrifugation into two peaks. The denser peak (rho = 1.26 g/cm(3)) contained the majority of the 41,000 dalton major outer membrane protein as shown by SDS-PAGE. This peak also contained the type 2 antigenic determinant. Thus the major outer membrane protein, extracted as part of a lipoprotein-lipopolysaccharide complex, contains the type 2 STA determinant.
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PMID:An outer membrane protein of Neisseria meningitidis group B responsible for serotype specificity. 413 71

Several fractions were extracted from the cell envelope (CE) of Neisseria meningitidis group B and characterized with regard to their morphology, antigenicity, protein composition, and toxicity. Whole bacterial cells were suspended in a medium of low ionic strength and disrupted in a French pressure cell. The crude CE thus obtained were separated into cell membrane (CM) enriched and cell wall (CW) enriched fractions on sucrose density gradients. In addition, CM and CW fractions were separated from CE on the basis of differential solubility in the nonionic detergent, Triton X-100. The Triton-insoluble fraction, containing primarily CW components, was further treated with a mixture of Triton and ethylenediaminetetraacetic acid, which was shown to remove additional protein and most of the lipopolysaccharide. Electron microscope examination of the various fractions revealed typical unit membrane structures in the case of CM, or large, open segments in the case of CW. The Triton-insoluble and especially the Triton-ethylenediaminetetraacetic acid-insoluble fractions consisted of small vesicular structures. All fractions, except the Triton-soluble fraction, when assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were shown to contain one major protein component accounting for more than 50% of the total. Sera from rabbits immunized with the various fractions formed precipitin lines in immunodiffusion tests against the homologous and some of the heterologous fractions. High-titer bactericidal antibodies were also demonstrated in these sera when tested against the homologous strains. Toxicity studies in rats sensitized with lead acetate indicate that the level of contamination of Triton-insoluble/Triton-ethylenediaminetetraacetic acid-insoluble fractions with lipopolysaccharide was significantly smaller than that of the other fractions.
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PMID:Protein fraction with immunogenic potential and low toxicity isolated from the cell wall of Neisseria meningitidis group B. 421 75

Extraction of a partially purified preparation of cell walls from Escherichia coli with the nonionic detergent Triton X-100 removed all cytoplasmic membrane contamination but did not affect the normal morphology of the cell wall. This Triton-treated preparation, termed the "Triton-insoluble cell wall," contained all of the protein of the cell wall but only about half of the lipopolysaccharide and one-third of the phospholipid of the cell wall. This Triton-insoluble cell wall preparation was used as a starting material in an investigation of several further treatments. Reextraction of the Triton-insoluble cell wall with either Triton X-100 or ethylenediaminetetraacetic acid (EDTA) caused no further solubilization of protein. However, when the Triton-insoluble cell wall was extracted with a combination of Triton X-100 and EDTA, about half of the protein and all of the remaining lipopolysaccharide and phospholipid were solubilized. The material which remained insoluble after this combined Triton and EDTA extraction still retained some of the morphological features of the intact cell wall. Treatment of the Triton-insoluble cell wall with lysozyme resulted in a destruction of the peptidoglycan layer as seen in the electron microscope and in a release of diaminopimelic acid from the cell wall but did not solubilize any cell wall protein. Extraction of this lysozyme-treated preparation with a combination of Triton X-100 and EDTA again solubilized about half of the cell wall protein but resulted in a drastic change in the morphology of the Triton-EDTA-insoluble material. After this treatment, the insoluble material formed lamellar structures. These results are interpreted in terms of the types of noncovalent bonds involved in maintaining the organized structure of the cell wall and suggest that the main forces involved are hydrophobic protein-protein interactions between the cell wall proteins and to a lesser degree a stabilization of protein-protein and protein-lipopolysaccharide interactions by divalent cations. A model for the structure of the E. coli cell wall is presented.
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PMID:Effect of ethylenediaminetetraacetic acid, Triton X-100, and lysozyme on the morphology and chemical composition of isolate cell walls of Escherichia coli. 500 Dec 5

Pseudomonas aeruginosa H181 and H185 are resistant to initial exposure to polymyxin B and continue to grow in its presence. Growth of the strains in the presence of 50 U of polymyxin B per ml was characterized by a doubling time of 120 min, whereas the doubling time in the absence of polymyxin was 60 min. Growth for two generations in the presence of polymyxin caused a 23 to 31% increase in lipopolysaccharide content. In addition, a marked increase in susceptibility to the detergents sodium deoxycholate, Triton X-100, and sodium dodecyl sulfate was observed. The resistant mutants had a small but significant reduction in their levels of dodecanoic acid as compared with the parent strain; however, this was the only consistent alteration observed in levels of fatty acids or readily extractable lipids. Polymyxin was fluorescently labeled by coupling to 1-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride). Growth of strains H181 and H185 in the presence of dansylated polymyxin resulted in a stable association between the fluorescent antibiotic and the outer membrane. We postulate that these alterations are part of an adaptive response by the strains to the presence of polymyxin in the growth medium and reflect a resistance mechanism distinct from the mechanism affording polymyxin B resistance when these strains are initially exposed to the antibiotic.
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PMID:Evidence for two distinct mechanisms of resistance to polymyxin B in Pseudomonas aeruginosa. 609 68

The chemical composition of the outer membrane fractions (OMFs) of Eikenella corrodens strains 23834 and 470 as well as the strain 23834 lipopolysaccharide (LPS) was determined. The OMFs were obtained by Triton X-100 treatment of the heavier membrane fraction from sucrose density centrifugation of the total membrane fraction. The resulting OMFs of strains 23834 and 470, free of cytoplasmic membrane components, were found to contain 69.6 and 75.0% (wt/wt) protein, 4.8 and 9.2% lipid, 4.6 and 4.7% carbohydrate, and 2.0 and 4.6% muramic acid, respectively. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis both OMFs contained one major peptide determined to be 33,500 daltons for the strain 23834 OMF, and 37,500 daltons for the strain 470 OMF. Analysis of the OMF fatty acids revealed hexadecanoic, hexadecenoic, octadecenoic, and lesser amounts of octadecanoic acids. Transmission electron microscopic examination of the OMFs revealed typical large sheets of membrane. Structures (10 nm in diameter) resembling pores were also evident. The E. corrodens LPS was found to be composed of 34.5% (wt/wt) carbohydrate and 25.0% lipid A. Only minute amounts of 2-keto-3-deoxyoctonate and heptose could be detected. Fatty acid analysis revealed primarily octadecanoic and hexadecanoic acids, with lesser amounts of octadecenoic acid. No hydroxy fatty acids were detected. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed the E. corrodens LPS to resemble other smooth-type LPSs. Transmission electron microscopic examination revealed a vesicle-like morphology. The E. corrodens LPS appears not to be a "classical," i.e., enteric, type of LPS.
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PMID:Isolation and characterization of the outer membrane and lipopolysaccharide from Eikenella corrodens. 636 Aug 92

Monoclonal antibodies (MoAbs) to the lipopolysaccharide (LPS) of Bacteroides fragilis were produced by immunizing mice before hybridization with bacterial outer membranes solubilized with Triton X-100. Nineteen stabile clones were established. They all produced antibodies that reacted more strongly with purified B. fragilis LPS than with crude sonicated antigen in an enzyme immunoassay. Four MoAbs were studied by immunoblotting and enzyme immunoassay inhibition. Immunoblotting confirmed that the target of the MoAbs was LPS. Marked and homogeneous staining occurred in the immunoblotting with both purified LPS and outer membranes in the molecular weight range of 8,000 to 27,000. In enzyme immunoassay inhibition, MoAbs reacted positively with 93 to 96% of B. fragilis strains, including prototype strains ATCC 23745 and NCTC 9343. Within the B. fragilis group, the MoAbs reacted positively with two of five B. ovatus strains and two to six of nine B. thetaiotaomicron strains. No marked cross-reactivity with other bacteria was observed. These results confirm earlier findings that the B. fragilis LPS contains an immunodominant antigenic determinant common to almost all B. fragilis isolates.
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PMID:Monoclonal antibodies to Bacteroides fragilis lipopolysaccharide. 638 67

Polypeptide and polysaccharide outer membrane components of Brucella abortus 99 (S) were investigated by analysis of cell-wall fractions by sodium dodecyl-sulfate polyacrylamide gel electrophoresis and staining with coomassie blue and periodic acid silver stain. Crude cell-walls were deprived by Triton X-100 treatment of most cytoplasmic material as seen by electron microscopy and cytochrome determination (cell-walls). They were submitted to hot SDS to obtain intentionally after centrifugation, peptidoglycan in the insoluble fraction: SDS-I fractions or peptidoglycan sacculi, and outer membrane components in the SDS soluble fraction as for Enterobacteriaceae. The SDS-soluble fraction contained two major components: a high molecular weight broad band of smooth lipopolysaccharide (S-LPS) and a 43k polypeptide band. The SDS-I fractions were treated by lysozyme to solubilize peptidoglycan before analysis. They contained two major polypeptide groups 36-37-38k, 25-26-27k, a minor one at 31k and variable amounts of high molecular weight S-LPS. The polypeptide and polysaccharide patterns of the entire outer membrane obtained from lysozyme hydrolysed cell-walls are the sum of both SDS soluble and insoluble fraction patterns. These results mean that 25-27k and 36-38k bands are strongly bound to peptidoglycan, probably covalently. The 25-26-27k bands heavily stained for polysaccharides would be glycopolypeptides. In addition, the polysaccharide patterns of S-LPS fraction appears as a high molecular weight broad band, contrary to the multiple regularly spaced bands of high molecular weight E. coli S-LPS. The B. abortus outer membrane is composed of four major components: LPS, 43k and 36-37-38k polypeptides and 25-26-27k glycopeptides.
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PMID:Evidence of three major polypeptide species and two major polysaccharide species in the Brucella outer membrane. 641 68


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