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PubMed1968

Carbohydrate composition of the phenol-soluble lipopolysaccharides of Citrobacter freundii.

Phenol-soluble lipopolysaccharides were obtained from the interphase and phenol phase fractions of 44% aqueous phenol-extracted Citrobacter species. Upon detailed investigation of C. freundii 8090, the two lipopolysaccharide fractions were found to contain different amounts of lipid A, although qualitative composition was similar. Both contained lipid A, 2-keto-deoxyoctonic acid, heptose, phosphate, d-glucose, galactose, rhamnose, 2-acetamido-2 deoxy-d-glucose, 3-acetamido-3,6-dideoxy-d-glucose, O-acetyl, and trace amino acids. Partially purified phenol-phase lipopolysaccharide partitioned into the phenol-soluble phase when refractionated with 44% aqueous phenol, and was further found to be soluble in 88% phenol, 95% ethyl alcohol, and chloroform-methanol (2:1).

Amino Acids↗

PubMed1969

Alteration of physical, chemical, and biological properties of endotoxin by treatment with mild alkali.

Treatment with alkali is one of several methods for removing fatty acids from bacterial endotoxins and, in the process, detoxifying the material. Saponification of fatty acid esters is the major detectable chemical change produced by alkali; however, kinetic studies of mild alkaline hydrolysis of endotoxin failed to correlate rates of detoxification with rates of loss of ketodeoxyoctonates, heptose, O-acetyl groups, or fatty acid esters. The alterations occurring during the critical stages of hydrolysis apparently changed the essential chemical conformation of endotoxic particles before cleavage of a significant amount of material took place. The rates of both saponification and detoxification were markedly increased by carrying out the reaction in media of ethyl alcohol or dimethylsulfoxide instead of water.

Alkalies↗

PubMed1969

Effect of enzymes on the composition and structure of Chromobacterium violaceum cell envelopes.

Cell envelopes of Chromobacterium violaceum were isolated and treated under controlled conditions with trypsin, Pronase, lipase, phospholipase C, lysozyme, and a mixture of enzymes produced by a bacteriolytic Pseudomonas sp. After each enzyme treatment, losses in dry weight, protein, lipid, carbohydrate, 2,6-diaminopimelic acid, and total phosphorus were determined. Electron-microscopic examination of the enzyme-treated envelopes indicated complete or partial loss of envelope rigidity or some envelope fragmentation, or both. Each enzyme hydrolyzed at least one envelope component and liberated several others into the supernatant fluid, where they appeared as nondialyzable particulate components, identified by means of electron microscopy. Unlike the other enzymes, the Pseudomonas sp. enzyme mixture partially liberated all major envelope components except phosphorus, heptose, and 2-keto-3-deoxy octonic acid. In spite of these large losses, the envelopes preserved some features of their integrity and elongated shape.

Bacterial Proteins↗

PubMed1984

Composition of the antigenic material removed from Campylobacter jejuni by heat.

The antigenic material removed form Campylobacter jejuni by the boiling of whole cells in saline was examined biochemically. Analyses showed that the extracted material contained 3 micrograms of protein per ml per mg of wet cells and ca. 2.6 micrograms of carbohydrate per ml per mg of wet cells. Further extraction of the material with chloroform-methanol produced about 0.5 microgram of water-insoluble residue per ml per mg of wet cells, suggesting the presence of lipid as well. Additional analyses revealed the presence of hexose, pentose, heptose, hexosamine, and 2-keto-3-deoxyoctonic acid, and the extract was also positive by the Limulus amoebocyte lysate assay for lipopolysaccharide. An examination by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that at least 10 different protein bands could be detected. One of the major bands corresponded to the major outer membrane protein, as determined by comparison with an outer membrane protein preparation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Another major protein in the heated extract corresponded to a band previously shown to be flagellin. An analysis of the time course of the release of material showed that a significant amount was removed after 3 to 10 min at 100 degrees C, but the release of material seemed to be delayed at lower temperatures. These results show that the treatment of C. jejuni with heat produces a complex mixture of components, including cell wall lipopolysaccharide, the major outer membrane protein, and flagellin. It is likely that some cytoplasmic components are present as well. Blebs of outer membrane have been observed with this organism by electron microscopy. Our results confirm this and suggest that the heating of cells accelerates this blebbing process.

Antigens, Bacterial↗

PubMed1988

Comparative immunochemistry of lipopolysaccharides from typable and polyagglutinable Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis.

Lipopolysaccharide (LPS) was extracted and purified from three Pseudomonas aeruginosa strains isolated from the infected lungs of patients with cystic fibrosis. Two of the strains could be typed by O-specific antibody (O:3 and O:9), and the third was polyagglutinable (O:3/9). The separated LPS was characterized by chemical and serological methods. The main neutral sugar constituents (glucose, rhamnose, and heptose) were found in various proportions in the three strains, whereas the amounts of glucosamine, galactosamine, ketodeoxyoctonate, and phosphate were more constant. Ester-bound C12, C16, 3-OH-C10, and 2-OH-C12, together with amide-bound 3-OH-C12, fatty acids were present in equimolar proportions in all three strains. Considerable amounts of LPS were liberated in the culture supernatant of the O:3 bacteria but not in those from the other two strains. This free LPS was shown to be immunologically identical to the cell-bound LPS and the extracted LPS. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, O:3 and O:9 LPS showed a ladder pattern characteristic of smooth LPS, while O:3/9 LPS appeared rough. Rabbit antisera used for O-typing were found by enzyme-linked immunosorbent assay to contain anti-LPS antibodies that reacted strongly with homologous LPS, moderately with O:3/9 LPS, and slightly with heterologous LPS. Immunoblotting showed that common antigenic determinants in the core-lipid A part were involved in the observed cross-reaction. The polyagglutinability of P. aeruginosa may be explained by the antibodies to these common determinants that arose from the partial absence of O polysaccharides.

Antigens, Bacterial↗

PubMed2000

Antigenic diversity of Haemophilus somnus lipooligosaccharide: phase-variable accessibility of the phosphorylcholine epitope.

The lipooligosaccharide (LOS) of Haemophilus somnus undergoes antigenic phase variation, which may facilitate evasion from the bovine host immune response and/or colonization and dissemination. However, LOS antigenic diversity in H. somnus has not been adequately investigated. In this study, monoclonal antibodies (MAbs) specific to various LOS epitopes were used to investigate antigenic variation and stability in LOS from H. somnus strains and phase variants. Clinical isolates of H. somnus exhibited intrastrain, as well as interstrain, antigenic heterogeneity in LOS when probed with MAbs to outer core oligosaccharide epitopes in an enzyme-linked immunosorbent assay (ELISA). However, epitopes reactive with MAbs directed predominately to the inner core heptose region were highly conserved. At least one epitope, which was expressed in few strains, was identified. One LOS component affected by phase variation was identified as phosphorylcholine (PCho), which is linked to the primary glucose residue. Inhibition ELISA, immunoblotting, and electrospray-mass spectrometry were used to confirm that MAb 5F5.9 recognized PCho. LOS reactivity with MAb 5F5.9 was associated with loss of most of the outer core oligosaccharide, indicating that reactivity with PCho was affected by phase variation of the glucose residues in this region. Our results indicate that outer core epitopes of H. somnus LOS exhibit a high degree of random, phase-variable antigenic heterogeneity and that such heterogeneity must be considered in the design of vaccines and diagnostic tests.

Animals↗

PubMed1981

Pseudomonas aeruginosa bacteriophage phi PLS27-lipopolysaccharide interactions.

We investigated the phi PLS27 receptor in Pseudomonas aeruginosa strain PAO lipopolysaccharide (LPS) by analyzing a resistant mutant. This mutant, which was designated AK1282, had the most defective LPS yet reported for a P. aeruginosa rough mutant; this LPS contained only lipid A, 2-keto-3-deoxyoctonate, heptose, and alanine as major components. In addition, this LPS lacked galactosamine, which is present in the inner core of the LPS of other rough mutants. The loss of galactosamine but only a small decrease in the alanine content indicated that the core of strain PAO LPS differed from the core structure which has been suggested for the LPS of other well-characterized P. aeruginosa strains. Our analysis also indicated that galactosamine residues may be crucial for phi PLS27 receptor activity of the LPS. Electrodialysis of LPS and conversion to salt forms (sodium or triethylamine) influenced the phage-inactivating capacity of the LPS, as did the medium in which the inactivation occurred; experiments performed in 1/10-strength broth resulted in much lower PhI50 (concentration of LPS causing a 50% decrease in the titer of phage during 1 h of incubation at 37 degrees C) values than experiments performed in regular-strength broth. Sonication of the LPS also increased the phage-inactivating capacities of the LPS preparations.

Bacteriophages↗

PubMed1975

Isolation and chemical characterization of outer envelope of Leptospira pomona.

Cells of Leptospira interrogans serotype pomona harvested from a chemically defined medium were resuspended in 0.01 M phosphate buffer of pH 7.3. Electron microscopy showed that 90 min of exposure effectively ruptured the outer envelope, freeing it from the cells as small flakes. Both zonal centrifugation in sucrose gradients and centrifugation in isopycnic KBr and CsCl gradients could be used to separate the outer envelope from the axial filaments and protoplasmic cylinders. The latter method resulting in higher yields of purified envelope with the particular protocols used. Thin sections of isolated outer envelope showed the same trilaminar structure seen in sections of intact cells. The outer layers were 1.5 nm thick and appeared as single layers of electron-dense particles. The central electron-transparent layer was 2.0-2.5 nm thick and appeared structureless. The gross chemical composition of the purified outer envelope was 47% protein, 27% carbohydrate, and 23% lipid. Colorimetric carbohydrate determinations revealed hexose, pentose, and 6-deoxyhexose; hexosamine was identified during amino acid analysis. Muramic acid, heptose, and 2-keto-3-deoxyoctonate were not detected. Thin-layer chromatography revealed only polar lipids, about 98% phosphatidylethanolamine and 2% lysophosphatidylethanolamine. Fatty acids identified by gas-liquid chromatography were octadecanoic, octadecenoic, hexadecanoic, and hexadecenoic. Amino acid analysis revealed 17 amino acids, histidine and glutamic acid being most abundant. The outer envelope was interpreted to be comparable with the outer double-track layer found in the cell covering of gram-negative eubacteria.

Amino Acids↗

PubMed1983

Morphological and physiological characteristics and lipopolysaccharide composition of N2-fixing (C2H2-reducing) root-associated Pseudomonas sp.

A dinitrogen-fixing Pseudomonas sp. was isolated from the roots of the grass Deschampsia caespitosa. The motile organism, which had 4 to 10 polar flagella, was gram negative, obligately aerobic, oxidase positive, arginine dihydrolase positive, and fluorescent. To verify API20B, API20E, and Oxi-Ferm identifications, as well as results from standard microbiological tests and electron microscopic examinations, which all indicated the organism to be a Pseudomonas, we analyzed its lipopolysaccharide. The lipopolysaccharide contained neutral sugars, phosphorus, heptose, hexosamine, 2-keto-3-deoxyoctonate, and fatty acids, which were dodecanoic, 3-hydroxydecanoic, 2-hydroxydodecanoic, and 3-hydroxydodecanoic acids. Both the qualitative and quantitative compositions resembled known data of the genus Pseudomonas. Dinitrogen fixation, determined as C2H2 reduction in semisolid medium, was supported by several carbon sources including malate and glucose. The N2 fixation activity was decreased if the oxygen concentration of the gas phase was lowered to one-tenth of atmospheric concentration. The highest specific nitrogenase activity recorded was 954 nmol C2H4/mg bacterial protein per hour, which is about 30% of that noted for Azospirillum lipoferum used as reference.

Acetylene↗

PubMed1984

P1 bacteriophage and tellurite sensitivity in Klebsiella pneumoniae and Escherichia coli.

Klebsiella pneumoniae and Escherichia coli respond inversely toward P1 bacteriophage or TeO3(-2). Klebsiella pneumoniae is resistant to both antagonists and E. coli is sensitive. However, P1 cmts lysogens (P1 cmts resistant) of K. pneumoniae became sensitive to tellurite and when cured from P1 cmts regained resistance. Escherichia coli spontaneous mutants selected for resistance to either P1 or TeO3(-2) were collaterally resistant to the other. As well, TeO3(-3) enhanced the adsorption of P1 vir to both E. coli and K. pneumoniae. Several outer membrane proteins were enhanced in the K. pneumoniae lysogens and were reduced in E. coli lysogens; one of which was the same molecular weight (77 000) in both bacteria. When partially purified it enhanced the plaque efficiency of P1 vir. Lipopolysaccharide (LPS) from E. coli C600 inactivated P1 vir, but neither the P1 lysogens nor LPS derived from the lysogens inactivated P1 vir. Escherichia coli P1 lysogens produced only heptose-deficient LPS. It is suggested that both LPS and outer membrane protein(s) comprise the P1 receptor. TeO3(-2) may interact with one or both components.

Adsorption↗

PubMed1984

Lipopolysaccharide composition of three strains of Haemophilus influenzae.

The lipopolysaccharides of three strains of Haemophilus influenzae with varying beta-lactam susceptibility were examined. All three strains contained galactose, glucose, galactosamine, glucosamine, heptose, phosphate, and a trace of mannose. None contained fucose, rhamnose, or mannosamine. Levels of 2-keto-3-deoxy-octulosonic acid were consistently detected in all three strains at levels similar to that of Salmonella typhimurium LT2, but only following hydrolysis with 4 N hydrochloric acid.

Carbohydrates↗

PubMed1988

Chemical characterization of lipopolysaccharide from Edwardsiella ictaluri, a fish pathogen.

The chemical components of lipopolysaccharide (LPS) from the fish pathogen Edwardsiella ictaluri (Ed. ictaluri) were analyzed by SDS-PAGE, gas chromatography, and spectrophotometry, and compared with those of Salmonella typhimurium and Escherichia coli 0111:B4. Only four to five low molecular weight species of LPS from Ed. ictaluri were detected by silver staining after separation by polyacrylamide gel electrophoresis. The low molecular weight species, as well as a low sugar content, indicate that the LPS from Ed. ictaluri was of the rough type, compared with that of S. typhimurium and E. coli which were both of the smooth type LPS. Quantitatively, mannose was not a major sugar component in Ed. ictaluri, unlike S. typhimurium. Palmitic, palmitoleic, and cis-9,10-methylene-hexadecanoic acids were predominant fatty acids among the total cellular lipids of Ed. ictaluri. C14 fatty acids comprised 78% of the total in the LPS of this bacterium, with beta-hydroxy-myristate representing 55%. The results of this study suggest that the lipid A segment of the LPS molecule of Ed. ictaluri is similar to S. typhimurium and E. coli, at least with respect to fatty acid content; however, the core polysaccharide of E. ictaluri differs in that it has twice the heptose content.

Carbohydrates↗

PubMed1994

Lipopolysaccharides of Legionella erythra and Legionella oakridgensis.

The chemical composition of lipopolysaccharides from Legionella erythra and Legionella oakridgensis was analysed. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed both lipopolysaccharides to have a smooth-type character. The polysaccharide part of both lipopolysaccharides contained D-mannose, D-glucose, D-glycero-D-mannoheptose, L-glycero-D-manno-heptose, 2-keto-3-deoxyoctonic acid, L-fucosamine, D-glucosamine, and glucosamine phosphate. In addition, L-rhamnose, glycerol phosphate, and glucose phosphate were identified in the polysaccharide part of L. erythra lipopolysaccharide. The main sugar identified in the lipid A part of both lipopolysaccharides, 2,3-diamino-2,3-dideoxy-D-glucose, was found to be substituted with a complex fatty acid composition including at least 16 different amide-linked 3-hydroxy fatty acids. Both lipopolysaccharides contained nonhydroxy fatty acids and the uncommon 27-oxo-octacosanoic acid, 29-oxotriacontanoic acid, and 27-hydroxyoctacosanoic acid. The lipopolysaccharide of L. oakridgensis also contained 29-hydroxytriacontanoic acid. The dioic long-chain acids heptacosane-1,27-dioic acid and nonacosane-1,29-dioic acid were only present in the lipopolysaccharide of L. erythra.

Carbohydrates↗

PubMed1996

Physicochemical properties of PM-factor, a surface-active agent produced by Pseudomonas marginalis.

An extracellular surface-active agent, PM-factor, was obtained by high-speed centrifugation from the culture broth of Pseudomonas marginalis PD-14B. PM-factor exhibited emulsifying activity on a broad spectrum of hydrocarbon liquids, including aromatics, aliphatics, crude oil, and creosote. The factor appeared as ball-shaped particles of varying diameter when examined by electron microscopy (0.16-1.4 microns). Gel filtration chromatography demonstrated a high molecular mass of the factor (> 10(6) Da). The ultraviolet absorption spectrum manifested a peak in the region 200 nm rather in the region 260-280 nm. Amino acid analysis showed a very low amount of aromatic amino acids residues in the protein moiety of PM-factor. The presence of 3-deoxy-D-mannooctulosonic acid, heptose, hexosamine, phosphorus, and 3-hydroxy fatty acid indicated that PM-factor contained lipopolysaccharide. The emulsifying activity of PM-factor was inhibited strongly by mercuric chloride and moderately by EDTA. Polymyxin B, Ca2+, and Mg2+ markedly stimulated the factors emulsifying activity. Roles of the bioemulsifier in the functioning of P. marginalis as a plant pathogen and in bioremediation are discussed.

Bacterial Outer Membrane Proteins↗

PubMed1975

The lipopolysaccharides of Neisseria gonorrhoeae colony types 1 and 4.

The lipopolysaccharides (LPS) of strains of Neisseria gonorrhoeae grown in type 1 (T1) and 4 (T4) colony forms have been isolated. LPS from T4 colony type cells on mild hydrolysis gave a lipid A and a core oligosaccharide composed of 2-amino-2-deoxy-D-glucose, D-glucose, D-galactose, L-glycero-D-manno-heptose and 3-deoxy-D-manno-octuosonic acid that appeared to be common to all the strains examined. LPS from T1 colony type cells on mild hydrolysis gave a lipid A and high molecular weight O polysacc,arides which showed considerable differences in glycose composition for each strain examined. In those strains examined, T4 cells appear to produce a common "R" type LPS whereas T1 cells produce an "S" type LPS with structurally different O polysaccharide structures which probably account for serologically differentiated strains of N. gonorrhoeae.

Amino Sugars↗

PubMed1980

The R-type lipopolysaccharides of Neisseria meningitidis.

The lipopolysaccharides of all the different serogroups of Neisseria meningitidis are of the "R" type despite the morphologically smooth appearance and the demonstrated virulence of the organisms from which they were derived. This was confirmed when each of the lipopolysaccharides was found to be devoid of detectable O-antigen side chains, giving only a low "molecular" weight core oligosaccharide when subjected to mild acid hydrolysis. The cores were modified by dephosphorylation and subjected to sugar and methylation analysis by gas-liquid chromatography. Although all the different cores contained identical components (glucose, galactose, glucosamine, heptose, and 2-keto-3-deoxyoctonate) they could be separated into three distinct categories according to their galactose:glucose ratios. These categories are typified by the cores obtained from groups A, C, and 29-e which have galactose:glucose ratios of 1:2, 2:2, and 2:1, respectively. The modified cores were methylated and analyzed by gas chromatography--mass spectrometry and on the basis of differences in the derived methylated sugars the cores could again be divided into the same three categories as above. This structural diversity also results in some serological specificity as demonstrated by the complete serogroup specificity of the group A lipopolysaccharide.

Antigens, Bacterial↗

PubMed1977

Structural features of Salmonella typhimurium lipopolysaccharide required for activation of tissue factor in human mononuclear cells.

Activation of mononuclear cell tissue factor was examined utilizing lipopolysaccharides obtained from wild-type and both Rc and Re mutants of Salmonella typhimurium. Wild-type (smooth) lipopolysaccharide, galactose-deficient (Rc) lipopolysaccharide, heptose-deficient (Re) lipopolysaccharide, and lipid A preparations were all active in their ability to generate tissue factor activity in human mononuclear cells grown in tissue culture. Polymyxin B has been reported to prevent some of the lethal effects of endotoxin in vivo, and the drug reportedly binds to the 2-keto-3-deoxyoctulosonate-lipid A region of the lipopolysaccharide molecule. Polymyxin B was effective in inhibiting the tissue factor generating activity of wild-type lipopolysaccharide, Re lipopolysaccharide, and lipid A in a dose-dependent fashion. Treatment of lipid A preparations with mild alkali abolished the ability of these preparations to activate tissue factor in cells. Analogous to many of the other biologic properties of lipopolysaccharide, tissue factor activation in human mononuclear cells appears to depend upon the integrity of the lipid A portion of the molecule.

Cells, Cultured↗

PubMed1977

Characterization of gonococcal antigens responsible for induction of bactericidal antibody in disseminated infection.

The role of gonococcal antigens in serum bactericidal activity was determined for an isolate of Neisseria gonorrhoeae from a patient with disseminated gonococcal infection (DGI). Gonococcal outer membranes were purified by differential ultracentrifugation of sheared organisms treated with EDTA. The membranes were solubilized in an endotoxin-disaggregating buffer, and the proteins were separated from the endotoxin by molecular sieve chromatography. Chemical characterization of the endotoxin from the DGI strain revealed the presence of heptose (7.8% of carbohydrate composition) and 2-keto-3-deoxyoctonate (6.1%, wt/wt) in concentrations similar to rough endotoxins of gram-negative enteric bacteria. Dermal Schwartzman reactions were positive for this endotoxin (4 mug) and the corresponding outer membrane (139 mug), but negative for the protein fraction (>500 mug). The patient's whole serum or the IgG fraction, each with complement, reduced the number of the infecting organisms by greater than 1 log(10) in a bactericidal assay. Outer membrane and its protein and endotoxin fractions (0.8-500 mug) from the DGI strain were separately preincubated with the patient's convalescent serum and specific inhibition of bactericidal activity occurred with the endotoxin fraction (25 mug) and the outer membrane (100 mug); the protein (500 mug) exhibited no inhibition. Similar results were obtained by inhibiting the bactericidal activity of rabbit antiserum, prepared by intravenous inoculation of an isolate from a patient with pelvic inflammatory disease, with antigen purified from that strain. That this was specific immune inhibition and not anticomplementary activity was shown by the failure of these antigens to inhibit other complement-dependent bactericidal systems.

Adult↗