Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Because of increased interest in surface carbohydrates of Rhizobium in relation to host specificity, phenol-water extractions were carried out of whole cells of Rhizobium strains of the species R. leguminosarum, R. phaseoli, R. trifolii and R. meliloti. Fractionation of the crude extracts with cetavlon afforded polysaccharide mixtures, which were essentially free of RNA and acidic exopolysaccharide (EPS). They could be separated into a high molecular weight heteropolysaccharide fraction of lipopolysaccharide (LPS) nature and a low molecular weight glucan fraction. Glucan turned out to be the principal polysaccharide component of the cells (up to 10% of the dry cell weight), when cultivated in carbohydrate-rich media, and to be present as firmly attached capsular material. Glucan (mol wt 3000) structure was elucidated by methylation and periodate oxidation techniques. Methylation yielded 3, 4, 6-tri-O-methyl-D-glucose, characterized by GLC-MS, as the only product of hydrolysis of the fully methylated glucan. The glucan consumed 1 mole of periodate per mole anhydroglucose unit and gave sophorose on partial hydrolysis. From these data a linear beta-1,2-linked glucan structure was deduced. The occurrence of beta-1,2-glucan and the implications for the specific binding properties of Rhizobium cells are discussed.
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PMID:Surface carbohydrates of Rhizobium. I. Beta-1, 2-glucans. 58 86

Paramylon, a beta-(1-->3)-D-glucan, isolated from Euglena gracilis, was tested for its adjuvant activity on the antibody response to sheep red blood cell (SRBC) in mice. Paramylon markedly enhanced anti-SRBC plaque-forming cell production at a dose of 10 mg/kg. It was also found that in vitro addition of lipopolysaccharide in culture to macrophages from paramylon-treated mice produced a large amount of interleukin 1 (IL-1) and there was a significant level of interleukin 6 (IL-6) induced transiently in the blood of these mice. As IL-1 and IL-6 play crucial roles in the immune response to T cell-dependent antigens like SRBC, the immunopotentiating effect of paramylon might be expressed through the action of these cytokines.
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PMID:Cytokine-related immunopotentiating activities of paramylon, a beta-(1-->3)-D-glucan from Euglena gracilis. 128 96

The Drosophila melanogaster cell line mbn-2 was explored as a model system to study insect immune responses in vitro. This cell line is of blood cell origin, derived from larval hemocytes of the mutant lethal (2) malignant blood neoplasm (1(2)mbn). The mbn-2 cells respond to microbial substances by the activation of cecropin genes, coding for bactericidal peptides. The response is stronger than that previously described for SL2 cells, and four other tested Drosophila cell lines were totally unresponsive. Bacterial lipopolysaccharide, algal laminarin (a beta-1,3-glucan), and bacterial flagellin were strong inducers, bacterial peptidoglycan fragments gave a weaker response, whereas a formyl-methionine-containing peptide had no effect. Experiments with different drugs indicate that the response may be mediated by a G protein, but not by protein kinase C or eicosanoids, and that it requires a protein factor with a high rate of turnover.
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PMID:In vitro induction of cecropin genes--an immune response in a Drosophila blood cell line. 144 51

Respirable cotton dust, implicated in the pathogenesis of byssinosis, contains a number of bioactive compounds. These include lipopolysaccharide (LPS), tannins, bacterial peptides, byssinosin, iacinilene C, and 1,3-beta-D-glucan. The exact aetiological agent of byssinosis in such dust has not been definitively identified nor has its mechanism of action on lower lung surfaces been determined. In the present study 1,3-beta-D-glucan, Enterobacter agglomerans LPS, and ovine pulmonary surfactant were mixed in varying combinations. After incubation, their characteristics were determined by sucrose density centrifugation, TLC, and carbohydrate analysis. Precipitates were found in mixtures containing surfactant-glucan and surfactant-glucan-LPS, but not in surfactant-LPS. Precipitates were not seen in the surfactant, LPS, and glucan controls. The formation of a precipitate did not increase the density of the surfactant glucan mixture when compared by density gradient centrifugation with the surfactant control. The interaction between surfactant and glucan was analysed by molecular modelling. The energy of a surfactant-glucan complex (60.07 kcal/mol) was calculated to be much lower than the sum of glucan (47.09 kcal/mol) and surfactant (30.98 kcal/mol) when added separately. The results indicate that 1,3-beta-D-glucan does interact with surfactant and this complex may play a part in the pathogenesis of byssinosis by altering lung physiology maintained by pulmonary surfactant.
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PMID:Agglutination of lung surfactant with glucan. 146 75

Four patients with ovarian cancer received 20 mg of sizofiran, a beta-1,3-glucan (molecular weight: 450,000), intramuscularly one day before and 4, 7, 11, 14, 18 and 21 days after second look laparotomy and recombinant interferon-gamma (rIFN-gamma) intraperitoneally on the day of second look laparotomy and 4, 7, 11, 14, 18 and 21 days thereafter. The peritoneal cavity was washed with physiological saline and peritoneal macrophages (M phi) were isolated. The number of M phi increased 30-1600 times during the treatment period. The concentrations of interleukin-1, interferon-gamma, tumor necrosis factor and prostaglandin E2 were also found increased in the supernatant fluid of M phi cultured for 24 hours with 10 micrograms/ml of lipopolysaccharide. The present study demonstrated that the activation of peritoneal M phi could be maintained and its number was increased by repeated dosing of sizofiran and rIFN-gamma in combination every three or four days in patients with ovarian cancer. Peritoneal M phi thus activated may exert an antitumor effect on ovarian cancer.
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PMID:Maintenance of the activation of peritoneal macrophages in patients with ovarian cancer by sizofiran and recombinant interferon-gamma. 152 54

In Venezuela, 1,012 cattle sera were screened for their ability to precipitate Brucella melitensis 16M smooth-lipopolysaccharide (S-LPS), B melitensis B115 polysaccharide B (poly B), B abortus 1119-3 O-polysaccharide (PS), or B abortus 1119-3 cyclic 1,2 linked beta-D-glucan (beta-glucan) in an agar-gel immunodiffusion assay. These sera were previously classified as being Brucella abortus-infected, S-19-vaccinated, or negative after an assessment of historical records and results of 5 standard serologic tests. Most of the sera (85%) from infected cattle precipitated S-LPS, poly B, and PS. Serologic results for poly B and PS were identical. On the other hand, 13% of the sera from vaccinated cattle precipitated S-LPS, but none of these sera precipitated poly B or PS. It was concluded that purified PS can alternate with poly B as an antigen to differentiate sera of B abortus-infected from B abortus S-19-vaccinated cattle. None of these sera precipitated beta-glucan.
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PMID:Evaluation of polysaccharide, lipopolysaccharide, and beta-glucan antigens in gel immunodiffusion tests for brucellosis in cattle. 159 66

The effect of orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of a fungus, Sclerotinia sclerotiorum IFO 9395, on the function of Peyer's patch (PP) cells was investigated in comparison with that on spleen cells in mice. Oral administration of SSG enhanced the proliferative response of PP cells to a T-cell mitogen, concanavalin A (Con A), and a B-cell mitogen, lipopolysaccharide (LPS), although the response of spleen cells was not affected. Peyer's patch cells taken from mice which had received oral administration of SSG two days before, showed enhanced plaque-forming cell (PFC) response to sheep red blood cells (SRBC) after antigen (SRBC) stimulation for 5 days in vitro. These results suggest that oral administration of SSG can modulate the mucosal immune response.
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PMID:Oral administration of SSG, a beta-glucan obtained from Sclerotinia sclerotiorum, affects the function of Peyer's patch cells. 182 93

Hemocytes of the solitary ascidian, Halocynthia roretzi, released a succinyl-Leu-Leu-Val-Tyr-4-methylcoumaryl-7-amide hydrolyzing enzyme in response to lipopolysaccharide treatment. The response was dependent on the temperature for incubating hemocytes. The protease release reaction was not triggered by beta 1-3 glucan. The protease released showed strict substrate specificity and its activity was inhibited by EDTA and o-phenanthroline, but not by phosphoramidon, diisopropylfluorophosphate, N-ethylmaleimide, or p-chloromercuribenzoic acid. Thus, the enzyme was characterized as a phosphoramidon-insensitive metallo-protease. Calcium ionophore, phorbol myristate acetate, concanavalin A, and thrombin also induced the release of the same protease from H. roretzi hemocytes.
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PMID:Lipopolysaccharide induces release of a metallo-protease from hemocytes of the ascidian, Halocynthia roretzi. 205 Feb 43

The effect of orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on the function of peritoneal macrophages in CDF1 mice was examined. Oral administration of SSG (20, 40, 80 or 160 mg/kg, daily for 10 consecutive days) enhanced the acid phosphatase activity of peritoneal macrophages. The greatest enhancing effect was observed at 80 mg/kg of SSG. Relatively long periods of administration (more than 10 consecutive days) were needed to induce significant enhancing effects. Phagocytic activity, candidacidal activity, hydrogen peroxide (H2O2) production and interleukin-1 (IL-1) production of peritoneal macrophages were also enhanced after the administration of SSG by the oral route (80 or 160 mg/kg). However, the durations of the activated state after completion of administration differed depending on the activity. Enhanced activity of lysosomal enzyme (acid phosphatase) was also shown in peritoneal macrophages taken from C3H/HeJ mice, which is a nonresponder strain to bacterial lipopolysaccharide (LPS). These results demonstrate that SSG given by the oral route can activate peritoneal macrophages in mice.
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PMID:Effect of orally administered beta-glucan on macrophage function in mice. 227 30

The synthesis of periplasmic beta(1-2)glucan is required for crown gall tumor formation by Agrobacterium tumefaciens and for effective nodulation of alfalfa by Rhizobium meliloti. The exoC (pscA) gene is required for this synthesis by both bacteria as well as for the synthesis of capsular polysaccharide and normal lipopolysaccharide. We tested the possibility that the pleiotropic ExoC phenotype is due to a defect in the synthesis of an intermediate common to several polysaccharide biosynthetic pathways. Cytoplasmic extracts from wild-type A. tumefaciens and from exoC mutants of A. tumefaciens containing a cloned wild-type exoC gene synthesized in vitro UDP-glucose from glucose, glucose 1-phosphate, and glucose 6-phosphate. Extracts from exoC mutants synthesized UDP-glucose from glucose 1-phosphate but not from glucose or glucose 6-phosphate. Membranes from exoC mutant cells synthesized beta(1-2)glucan in vitro when exogenous UDP-glucose was added and contained the 235-kilodalton protein, which has been shown to carry out this synthesis in wild-type cells. We conclude that the inability of exoC mutants to synthesize beta(1-2)glucan is due to a deficiency in the activity of the enzyme phosphoglucomutase (EC 2.7.5.1), which in wild-type bacteria converts glucose 6-phosphate to glucose 1-phosphate, an intermediate in the synthesis of UDP-glucose. This interpretation can account for all of the deficiencies in polysaccharide synthesis which have been observed in these mutants.
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PMID:Biochemical characterization of avirulent exoC mutants of Agrobacterium tumefaciens. 230 61


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