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

The site specificity of metallic ion binding in Escherichia coli K-12 lipopolysaccharide was assessed by collecting high-resolution phosphorus nuclear magnetic resonance spectra in the presence of manganese, a paramagnetic divalent cation. This technique revealed high-affinity interactions between the cation and all of the lipopolysaccharide phosphoryl groups. To ascertain whether the carboxyl groups of 2-keto-3-deoxyoctonate contributed to the metal cation binding, lipopolysaccharide was chemically modified using a glycine ethyl ester - carbodiimide reaction. Of the three available carboxyl groups, only one was neutralized by the exogenously added ligand; the others appeared to be cross-linked within the molecule. By analogy, only one carboxyl group should be freely available for binding metallic ions, while the others are probably neutralized by the close proximity of endogenous amino substituents. Although high-resolution phosphorus nuclear magnetic resonance showed that an intermolecular conformational change had occurred after the carboxyl groups were neutralized, titration with manganese revealed no differences in the apparent strength of the interactions between the cation and the phosphoryl groups. Together, these data suggest that the high affinity of lipopolysaccharide for divalent metallic ions can be attributed primarily to the phosphoryl substituents and not free carboxyl groups.
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PMID:Site specificity of metallic ion binding in Escherichia coli K-12 lipopolysaccharide. 351 50

The chemical constitutional analysis of the lipopolysaccharide (LPS) isolated from Providencia rettgeri was carried out. Polyacrylamide gel electrophoresis using sodium dodecylsulfate or sodium deoxycholate showed that the lipopolysaccharide mostly consisted of short sugar chains. The lipid A was precipitated out after mild acid hydrolysis of LPS. From the supernatant degraded polysaccharide and unsubstituted core fractions were isolated. Compositional analysis of the core material revealed the presence of galacturonic acid, galactose, glucose, glucosamine, L-glycero-D-manno-heptose, 3-deoxy-D-manno-octulosonic acid, alanine and phosphorus. Methylation analysis of the core material indicated the presence of terminal units of glucose, galacturonic acid and glucosamine. The chemical structure of the lipid A was elucidated. It constitutes a beta-1,6-glucosamine disaccharide substituted on either side by ester and glycosidically-bond phosphate residues. The ester-bound phosphate was found to be substituted by a 4-amino-4-deoxy-L-arabinosyl residue. The amino groups of the backbone disaccharide are N-acylated by 3-O-(14:0)14:0 and 3-O-14:0. Two hydroxyl groups of the disaccharide are esterified by 3-O-(14:0)14:0 and 3-O-14:0. The taxonomical importance of these structural details will be discussed.
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PMID:Lipopolysaccharide of Providencia rettgeri. Chemical studies and taxonomical implications. 352 98

The aqueous layer was isolated from Leptospira interrogans serovar canicola strain Moulton by the hot phenol-water method. After ultracentrifugation, the precipitate was designated as lipopolysaccharide-like substance (LLS) fraction and the chemical composition was compared with that of bacterial LPS. The LLS fraction consists of 35.2% carbohydrate, 3.8% amino sugar, 36.4% lipid, 15.2% protein, and 0.3% phosphorus. Neutral sugars were detected as rhamnose, arabinose, xylose, 4-O-methylmannose, mannose, galactose, and a small amount of erythrose, fucose and glucose by gas-liquid chromatography (GLC), but 2-keto-3-deoxyoctonic acid was not detected in the LLS by thiobarbituric acid test and high voltage paper electrophoresis. Fatty acids detected by GLC were decanoic acid (C10: 0), dodecanoic acid (C12: 0), dodecenoic acid (C12: 1), tridecenoic acid (C13: 1), tetradecanoic acid (C14: 0), hexadecanoic acid (C16: 0), hexadecenoic acid (C16: 1), and octadecenoic acid (C18: 1). With SDS-polyacrylamide gel electrophoresis, bacterial LPS showed many orderly bands, while the banding pattern of the leptospiral LLS was very simple. These findings demonstrate that the physicochemical properties and chemical composition of LLS fraction from Leptospira are different from those of LPS extracted from gram-negative bacteria such as Enterobacteriaceae, and suggesting that Leptospira has no typical LPS.
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PMID:Chemical properties of lipopolysaccharide-like substance (LLS) extracted from Leptospira interrogans serovar canicola strain Moulton. 368 16

The lipopolysaccharide (LPS) of Chlamydia psittaci was extracted from yolk sac-grown elementary bodies, purified, and characterized chemically, immunochemically, and biologically. The LPS contained D-galactosamine, D-glucosamine, phosphorus, long-chain fatty acids, and 3-deoxy-D-manno-2-octulosonic acid in the molar ratio of approximately 1:2:2:6:5. The antigenic properties of the isolated LPS were compared with those of the LPS from Chlamydia trachomatis and Salmonella minnesota Re by the passive hemolysis and passive hemolysis inhibition tests, absorption, hydrolysis kinetics, and Western blot analysis with rabbit polyclonal antisera against chlamydiae and with a mouse monoclonal antibody recognizing a genus-specific epitope of chlamydial LPS. Two antigenic determinants were identified, one of which was chlamydia specific and the other of which was cross-reactive with Re LPS. Both determinants were destroyed during acid hydrolysis, whereby a third antigen specificity was exposed which was indistinguishable from the lipid A antigenicity. In rabbit polyclonal antisera prepared against Formalin-killed elementary bodies or detergent-solubilized membranes, two antibody specificities were differentiated. One of these was chlamydia specific, and the other was cross-reactive with Re LPS. The LPS of C. psittaci was inactive within typical endotoxin parameters (lethal toxicity, pyrogenicity, local Shwartzman reactivity); it was, however, active in some in vitro assays, such as those testing for mouse B-cell mitogenicity and the induction of prostaglandin E2 in mouse peritoneal macrophages.
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PMID:Chemical, biological, and immunochemical properties of the Chlamydia psittaci lipopolysaccharide. 377 Sep 53

The separation and properties of a new immuno-potentiator, Benincasa cerifera mitogen (BCM) fraction, were investigated. BCM fraction was separated from hot water extract of the seed of Benincasa cerifera Savi (Tohgashi) by gel filtration using Sepharose 4B. BCM fraction is a heteropolymer consisting of uronic acid, neutral sugars, protein, and phosphorus. The proliferation and differentiation of murine B cells were markedly stimulated by BCM fraction. The in vitro development of peritoneal macrophages into antitumor macrophages was also activated by the addition of BCM fraction to cultures. BCM fraction augmented the IgM and IgG antibody responses against sheep erythrocytes (SRBC) and the induction of delayed-type footpad reaction against SRBC. The antitumor activity of BCM fraction was observed in terms of prolongation of the survival period of mice bearing Meth A fibrosarcoma. After hydrolysis with 1% acetic acid at 100 degrees C for 4 h, marked mitogenic activity was found in a precipitate composed of 29% neutral sugars, 50% uronic acid, 1% protein, and 0.1% phosphorus. The precipitate did not contain detectable amino sugar. The possibility that the biological activities of BCM fraction may be due to contamination by bacterial lipopolysaccharide was ruled out on the basis of the results of chemical analysis and of marked mitogenicity noted in C3H/HeJ spleen cell cultures.
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PMID:Immunopotentiator separated from hot water extract of the seed of Benincasa cerifera Savi (Tohgashi). 387 10

Lipoteichoic acids (LTAs) were chromatographically purified from crude phenol-water extract of whole cells of some streptococcal species, which included Streptococcus pyogenes Sv, Streptococcus mutans 6715, and Streptococcus sanguis ATCC 10556. Among these, special attention was paid to S. pyogenes LTA for analyses of chemical composition and biological activities. All LTA preparations contained equimolar amounts of glycerol and phosphorus. Chemical analyses showed that S. pyogenes LTA contained glycerophosphate, alanine, glucose, and fatty acids (as palmitic acid) at molar ratio of 1 : 0.1 : 0.1 : 0.25. The crude phenol-water extract and isolated LTA from S. pyogenes Sv were found to be mitogenic for spleen cells of BALB/c and BALB/c (nu/nu) mice, but not for thymus cells of BALB/c mice. The mitogenicity of deacylated LTA (dLTA) was significantly lower than that of LTA. It was also found that various LTA preparations possessed polyclonal B cell activation ability and adjuvant activity both in vivo and in vitro, as demonstrated by using hemolytic plaque assay. LTA, but not dLTA, induced macrophage activation which resulted in tumor cytotoxicity in mice. Limulus lysate activity of S. pyogenes LTA was approximately 1,000 fold lower than that of Escherichia coli lipopolysaccharide. These results indicate that streptococcal LTA possesses various immunobiological activities that modulate lymphoreticular system in vivo and in vitro.
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PMID:Chemical properties and immunobiological activities of streptococcal lipoteichoic acids. 389 80

Studies of the lipopolysaccharide of Pseudomonas alcaligenes strain BR 1/2 were extended to the polysaccharide moiety. The crude polysaccharide, obtained by mild acid hydrolysis of the lipopolysaccharide, was fractionated by gel filtration. The major fraction was the phosphorylated polysaccharide, for which the approximate proportions of residues were; glucose (2), rhamnose (0.7), heptose (2-3), galactosamine (1), alanine (1), 3-deoxy-2-octulonic acid (1), phosphorus (5-6). The heptose was l-glycero-d-manno-heptose. The minor fractions from gel filtration contained free 3-deoxy-2-octulonic acid, P(i) and PP(i). The purified polysaccharide was studied by periodate oxidation, methylation analysis, partial hydrolysis, and dephosphorylation. All the rhamnose and part of the glucose and heptose occur as non-reducing terminal residues. Other glucose residues are 3-substituted, and most heptose residues are esterified with condensed phosphate residues, possibly in the C-4 position. Free heptose and a heptosylglucose were isolated from a partial hydrolysate of the polysaccharide. The location of galactosamine in the polysaccharide was not established, but either the C-3 or C-4 position appears to be substituted and a linkage to alanine was indicated. In its composition, the polysaccharide from Ps. alcaligenes resembles core polysaccharides from other pseudomonads: no possible side-chain polysaccharide was detected.
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PMID:Studies of the polysaccharide fraction from the lipopolysaccharide of Pseudomonas alcaligenes. 436 26

1. Qualitative and quantitative analytical results for the lipopolysaccharide from acetone-dried cells of Pseudomonas aeruginosa (N.C.T.C. 1999) are presented and possible contamination of the material with nucleic acid was further examined. 2. Additional sugars detected (only in large-scale hydrolysates) were mannose and arabinose; traces of spermidine and putrescine were also found. 3. The heptose component is l-glycero-d-mannoheptose. 4. The thiobarbituric acid-positive component is a 3-deoxy-2-octulonic acid, of which only 35-40% links lipid A to the polysaccharide. This linkage is not broken by hydrolysis with acetic acid up to 0.08m. 5. Liberation of lipid A required hydrolysis with 0.1m-hydrochloric acid, which substantially degraded the polysaccharide moiety. 6. Fractions obtained from the degraded polysaccharide by high-voltage electrophoresis were examined; in these, the alanine/galactosamine molar ratio is approx. 1. 7. Hydrazinolysis of whole lipopolysaccharide showed that at least 40% of the alanine is in amide linkage, possibly with galactosamine. 8. Lipid A, solubilized by alkaline methanolysis was fractionated; most of the phosphorus of the higher-molecular-weight fractions was released as P(i) by a phosphomonoesterase. 9. Hydrazinolysis of lipid A destroyed approx. 80% of the glucosamine, and glycosidically linked glucosamine oligosaccharides could not be isolated.
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PMID:Further studies of the chemical composition of the lipopolysaccharide of Pseudomonas aeruginosa. 462 91

Isolated cell envelopes of Pseudomonas aeruginosa were treated with N,N'-dimethylformamide (DMF) or with ethylenediaminetetraacetate (EDTA). DMF solubilized 73% of the dry weight of the cell envelope, 76% of the protein, 78% of the carbohydrate, and 76% of the phosphorus. Electron microscopy showed that DMF caused extensive alterations in the appearance of the cell envelope with blebs and bleblike vesicles predominating. After incubation with EDTA, the cell envelopes appeared to have lost material, but still retained the cell-like morphology. Analysis of DMF-solubilized proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed 16 protein bands. There were three major proteins that predominated, however, with molecular masses of 43,000 (protein A), 16,500 (protein B), and 72,000 daltons (protein C). Evidence is presented that protein A and protein B are glycoproteins. Gel electrophoresis of EDTA-solubilized material revealed that a number of proteins were released from the cell envelope. However, electrophoresis of an isolated protein-lipopolysaccharide complex released by EDTA showed that protein A and protein B were the major protein components of this complex. These data suggest that protein A and protein B are components of the outer cell wall membrane of P. aeruginosa. There is suggestive evidence that these proteins may play a role in maintaining the structural integrity of the cell envelope. Whether these proteins also have enzymatic activity could not be discerned from the present study, although it is possible that they may be associated with the terminal stages of lipopolysaccharide synthesis.
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PMID:Proteins released from cell envelopes of Pseudomonas aeruginosa on exposure to ethylenediaminetetraacetate: comparison with dimethylformamide-extractable proteins. 463 46

The endotoxin of a heptoseless mutant of Salmonella minnesota R595 was extracted with phenol-water. Most of this material was found distributed in the insoluble fraction of the extract. The results showed that the R595 endotoxin behaved as a lipid rather than as a lipopolysaccharide (LPS). The preparation, although it does not contain O-specific polysaccharides, does contain 2-keto-3-deoxyoctonic acid (KDO), hexosamine, and several other unidentified compounds. Therefore, the term "glycolipid" is used in this paper instead of lipopolysaccharide. The crude glycolipid fraction, which was soluble in a mixture of chloroform-methanol (8:2), was purified by a procedure including fractionation with organic solvents and by different-column chromatographic methods. Although a chromatographic fraction of the glycolipid showed homogeneity in most systems investigated, the presence of contaminants could not be excluded. Chemical analysis of the glycolipids showed the absence of hexoses and heptoses. Constituents which were found were hexosamine, KDO, fatty acids, and phosphorus, which showed a relatively simple chemical composition. Partial acidic hydrolysis of the glycolipid yielded hexosamine-phosphates, as described in "Lipid A" fractions of smooth LPS preparations. Thin-layer chromatography of the partially hydrolyzed glycolipid showed a pattern similar to "Lipid A" fractions of other strains. The biological activity of the glycolipid was at the same level as that of other gram-negative endotoxins. Pyrogenicity, Shwartzman reactivity, and chick embryo ld(50) values were as high or higher than those of purified Serratia marcescens endotoxin preparations, but mouse ld(50) measurements gave significantly lower results.
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PMID:Endotoxic glycolipid from a heptoseless mutant of Salmonella minnesota. 496 63


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