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

Morphologic study of Bacteroides melaninogenicus subspecies asaccharolyticus by electron microscopy disclosed the presence of a capsule and a cell wall structure otherwise typical of a gram-negative organism. An outer membrane complex was isolated with use of gentle methods. Relative purity of the preparation was confirmed by electron microscopy and by the formation of a single band in a sucrose density gradient. Gel chromatography was used for separation of the major components of the membrane. Antigenicity of the first component, a protein-polysaccharide complex, which cross-reacted with antiserum to another strain of the same subspecies. This component probably represents the capsular antigen and may prove to be the basis for serogrouping. The second membrane fraction differed chemically from the first fraction and represents the lipopolysaccharide component of the outer membrane. Notably, this component lacks 2-keto-3-deoxyoctonate, one of the backbone sugars of aerobic, gram-negative lipopolysaccharides.
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PMID:Purification and immunochemical characterization of the outer membrane complex of Bacteroides melaninogenicus subspecies asaccharolyticus. 1 65

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

The high-molecular fraction of substances of the cell wall of meningococci, groups A and B, isolated in free volume in gel filtration through sepharose 4B and containing both group and intergroup antigens proved to be consisting of 2 subfractions in gel-filtration through Bio-Gel A-150m. Molecular weight of the first was within the range of 100--150 million dalton, and of the second--of 3 to 100 million dalton. In dissociation in sodium deoxycholate the high molecular fraction complex compound of the cell wall of meningococcus strain, group A, isolated from the cerebrospinal fluid of a patient suffering from meningitis broke down into 5 fragments differing in chemical nature and mol wt. There were revealed protein and protein-lipopolysaccharide components with a relatively high mol wt. polypeptide components and low molecular residues of the initial lipopolysaccharide.
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PMID:[Study of molecular heterogeneity and chemical nature of polymeric components of the Meningococcus cell wall]. 9 83

Himalayan rabbits of a closed colony were immunized with injections of heat-killed Salmonella typhi and antiidiotypic antibodies against the induced anti- S. typhi antibodies were produced in rabbits of the same colony as well as in random-bred rabbits. Rabbits of the closed colony showed no proliferative response in a mixed lymphocyte culture of peripheral blood. Antiidiotypic sera from Himalayan rabbits recognized the idiotype in the corresponding immunizing sera alone, while one of sera from random-bred rabbits showed a cross-reaction with 8 out of 10 anti-S. typhi sera of Himalayan rabbits but not with any of 10 anti-S. typhi sera of unrelated random-bred rabbits. The cross-reactivity of the antiserum remained intact after absorption with unrelated immune precipitates. With this antiidiotypic serum the immunizing serum formed a bimodial arc at beta-gamma mobility and all other anti-S. typhi sera containing the cross-reactive idiotype a single arc at beta mobility. Solubilized immune precipitates of cross-reactive idiotype-anti-idiotype reaction could bind radiolabelled lipopolysaccharide (LPS) from S. typhi, but this anti-LPS activity was not revealed in an isoelectric focusing analysis. Gel analysis showed that the cross-reactive idiotype was located mainly in the macroglobulin fractions. The idiotype in the serum of the immunizing rabbits diminished and then was undetectable following the 2nd and the 3rd immunizations. When 3H-TdR uptake was examined in a mixed cell culture of peripheral blood from immunizing and antiidiotypic rabbits, there was a fluctuation in the proliferative response with two peaks occurring at a 4-week interval. An analysis of such a proliferative response was carried out by separating leukocytes and plasma from blood of the immunizing and the antiidiotypic rabbits. Mixed culture of cells alone did not produce a proliferative response, while culture of cells from the immunizing rabbit together with antiidiotypic plasma resulted in a potent reaction, irrespective of the presence of plasma from the immunizing rabbit. Presence of cells from the antiidiotypic rabbit in the culture inhibited this proliferative response. A fluctuation in the proliferative response to antiidiotypic serum was also observed with peripheral blood leukocytes (PBL) from rabbits producing the cross-reactive idiotype, while the antiidiotypic serum did not stimulate cells from rabbits which had been similarly immunized with S. typhi but did not produce the idiotype. PBL from the immunizing rabbit where the idiotype production ceased following the tertiary immunization were found to suppress definitely the proliferative response induced by the cross-reactive idiotype-anti-idiotype reaction. The suppressive activity was lost in PBL from the same rabbit after a cortisone treatment and the following antigenic stimulation of the animal led to reappearance in the serum of the idiotype. These results support the immune regulatory model which involves idiotype-anti-idiotype interactions.
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PMID:Idiotype-related cellular events during the anamnestic immune response to Salmonella typhi in rabbits. 15

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

Fusobacterium nucleatum Fev1 lipopolysaccharide was split by hydrolysis with 1% acetic acid into acid-soluble polysaccharide and lipid A. Gel filtration of the polysaccharide on Bio-Gel P-60 gave a high-molecular-weight fraction eluted with the void volume, and a fraction eluted at 2.4 x Vo. The high-molecular-weight fraction contained L-glycero-D-manno-heptose in relatively large amounts, glucose, glucosamine, an unknown amino compound and small amounts of (or no) D-glycero-D-manno-heptose. Phosphorus and 3-deoxy-D-manno-octulosonic acid were not detected. The other fraction contained L- and D-glycero-D-manno-heptose, glucose, glucosamine, 3-deoxy-d-manno-octulosonic acid and phosphorus. Further fractionation experiments and serological investigations indicated that the high-molecular-weight fraction carried the O-antigenic side chains, whereas the material eluted from Bio-Gel P-60 at 2.4 x Vo represented the core oligosaccharide.
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PMID:Immunochemical studies of partially hydrolyzed lipopolysaccharide from Fusobacterium nucleatum Fev1. 43 47

The lipopolysaccharide (LPS) content of peritoneal fluids of BALB/c mice given mineral oil injections and of normal mice was measured. Peritoneal fluids were passed through DEAE-Bio-Gel columns to remove an inhibitor to the Limulus amebocyte lysate reaction and then were assayed for LPS by a spectrophotometric Limulus amebocyte lysate test. A highly significant difference between control animals and animals given mineral oil injections was found. A clear correlation between LPS concentration and time after first oil injection was shown. P-200 gel chromatography and heat stability of the active material were consistent with the behavior of LPS. The possible role of LPS in the pathogenesis of plasma cell tumor is discussed.
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PMID:Role of lipopolysaccharide in the production of plasma cell tumors in mice given mineral oil injections. 62 74

Lipopolysaccharides have been extracted from Escherichia coli O111:B4 by phenol extraction and by a new method employing aqueous butanol. Both methods yield very similar lipopolysaccharide preparations. Gel filtration chromatography of either preparation yields two physically and chemically distinct lipopolysaccharide fractions. One fraction contains lipopolysaccharide molecules with long antigenic side chains. It acts like a highly asymmetric unit with an apparent weight of 1.5 times 10-6 and is not dissociated by detergents or deacylation. The second fraction has a short antigenic side chain and can be dissociated by sodium dodecyl sulfate and Triton X-100 into units of approximately 90,000. Some properties of the lipopolysaccharide fractions vary with the method of extraction.
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PMID:Fractions of lipopolysaccharide from Escherichia coli O111:B4 prepared by two extraction procedures. 80 83

An N-acetyl-D-glucosamine-specific cell associated hemagglutinin (HA) was isolated and purified from a strain of Vibrio cholerae 01 by chitin affinity chromatography followed by separation on Bio Gel P-150. A single stained protein band of 47 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was observed with the purified HA. HA-antisera produced a single precipitin band against the purified HA in an immunodiffusion test without exhibiting any reactivity towards purified lipopolysaccharide (LPS). Purified HA, used as solid-phase antigen in an enzyme-linked immunosorbent assay (ELISA), reacted strongly with HA-antisera but cross-reacted negligibly with antisera raised against purified LPS. Hemagglutinating activity of the purified HA was highly sensitive to N-acetyl-D-glucosamine. The immunogold-labelling method using HA-antisera confirmed the location of the HA on the surface of the bacterial cells. The HA-antisera reacted with a protein component of the homologous outer membrane preparation. A significant inhibition was observed in the adhesive capability of the V. cholerae 01 strain to isolated rabbit intestinal epithelial cells (RIEC) in vitro when the later were pre-treated with the purified HA.
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PMID:N-acetyl-D-glucosamine-specific lectin purified from Vibrio cholerae 01. 145 12

We describe the development and application of a radioimmunoassay to detect circulating interleukin (IL)-1 beta concentrations in the rat. No IL-1 immunoreactivity above the detection limit of the assay (100 pg/ml) could be detected in plasma of control rats. In contrast, immunoreactive IL-1 was detected after intravenous administration of rat recombinant IL-1 beta (rrIL-1 beta) or bacterial lipopolysaccharide (LPS) to rats. The effect of LPS on plasma immunoreactive IL-1 concentrations was time and dose dependent. The immunoreactive IL-1 response to LPS was prevented by in vivo macrophage depletion induced by liposome-directed macrophage suicide technique. Gel filtration of plasma from LPS-treated rats revealed the presence of a high and a smaller molecular form of immunoreactive IL-1. The small molecular immunoreactive IL-1 peak coeluted with rrIL-1 beta and probably represents the 17-kDa form of IL-1 beta. In conclusion, our data support the hypothesis that IL-1 secreted by macrophages can act as a humoral signal molecule to induce the immunological, metabolic, and neuroendocrine changes in response to bacterial LPS.
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PMID:Development and application of a radioimmunoassay to detect interleukin-1 in rat peripheral circulation. 147 82


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