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

Histamine release caused by calcium ionophore A23187 and anti-IgE was examined in leukocyte suspensions from 8 healthy individuals. Staphylococcus aureus, lipopolysaccharide (LPS) from Salmonella typhimurium and influenza A virus were found to enhance the histamine release but did not release histamine per se. The potentiation of mediator release depends on a non-transient signal since the potentiating effect was also obtained by preincubation of the cells with LPS followed by wash-out and stimulation of the cells with anti-IgE. The potentiation was abolished or reduced by galactose, N-acetyl-glucosamine, alpha-methyl-D-glucoside, alpha-methyl-D-mannoside, N-acetylneuraminic acid and lactose, but not by glucose. These findings indicate that the enhancement of mediator release by bacteria, endotoxin, and virus depends on a sugar-mediated reaction.
 ...
PMID:Carbohydrates inhibit the potentiating effect of bacteria, endotoxin and virus on basophil histamine release. 169 60

The purpose of this study was to examine whether Bacteroides (Porphyromonas) gingivalis fimbriae, an important structure involved in attachment of the bacteria to periodontal tissues, activate macrophages and subsequently induce gene expression and production of interleukin-1 (IL-1) in the cells. The fimbriae increased glucose consumption and lysozyme activity in BALB/c macrophages, both criteria of macrophage activation of peritoneal macrophages, in a dose-dependent fashion. A marked increase in the mRNA level of the c-myc gene, an oncogene, in the cells was observed after a 1-h treatment with the fimbriae, and the level decreased rapidly after 3 h. The fimbriae (4 micrograms of protein per ml) markedly induced IL-1 alpha and IL-1 beta gene expression in the cells and IL-1 production. The expression of IL-1 alpha and IL-1 beta genes measured in terms of specific mRNA increased 1 h after the start of treatment and peaked at 6 h. Such increased expression of IL-1 beta was also observed in C3H/HeJ mice, a lipopolysaccharide low-responder strain. The fimbriae stimulated transcriptional activity of IL-1 beta in the cells, but not that of IL-1 alpha. We also observed that fimbriae-induced IL-1 gene expression was not regulated by endogenous prostaglandin triggered by the fimbriae. Therefore, these observations suggest that B. gingivalis fimbriae may be involved in the pathogenesis of adult periodontal disease via triggering of IL-1 production by monocytes/macrophages in periodontal diseases.
 ...
PMID:Bacteroides (Porphyromonas) gingivalis fimbriae activate mouse peritoneal macrophages and induce gene expression and production of interleukin-1. 170 18

O-specific polysaccharide was obtained on mild acid degradation of lipopolysaccharide of Proteus vulgaris 5/43 belonging to OX19 (O-variants). It was found to contain D-glucose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2,6-dideoxy-L-glucose (QuiNAc, N-acetyl-L-quinovosamine) in the ratio of about 1:2:1, the last-named sugar being rather uncommon for bacterial antigens. A computer-assisted 13C-NMR-based analysis, methylation analysis, and selective cleavage with anhydrous hydrogen fluoride and dilute hydrochloric acid were applied for structural elucidation of the polysaccharide and the following structure was established:----2)-beta-D-Glcp-(1----6)-alpha-D-GlcpNAc-(1----3)- alpha-L-QuipNAc-(1----3)-beta-D-GlcpNAc-(1----. Serological studies of the O-antigen and oligosaccharides derived therefrom revealed the importance of the trisaccharide fragment beta-D-Glcp-(1----6)-alpha-D-GlcpNAc-(1----3)-alpha-L- QuipNAc in manifesting the antigenic specificity. Serological cross-reactions were demonstrated between lipopolysaccharides of P. vulgaris 5/43, 8/44, and OX19 strains.
 ...
PMID:Structural and immunochemical studies of O-specific polysaccharide of Proteus vulgaris 5/43 belonging to OX19 group (O-variants). 171 74

Four murine monoclonal antibodies reactive with distinctive regions of the hexose core domain of Salmonella lipopolysaccharide (LPS) were generated and their epitope specificities were delineated. MAST 56 (IgG1) and MAST 50 (IgG3) antibodies elicited by immunizations with Salmonella typhimurium Rb1 and Rb2 mutants, reacted selectively in enzyme immunoassay with the LPS from rough mutants. In contrast, MATy 1 (IgM) and MATy 2 (IgG2b) antibodies raised by an attenuated Salmonella typhi 620 Ty strain were reactive with LPS from both smooth and rough Salmonellae. Immunoblotting analysis showed that MATy 1 distinguished only the bottom bands (naked LPS core) among the heterogeneous LPS populations, whereas MATy 2 gave a ladder pattern (reactive with both naked and O-chain-substituted LPS cores). Differential binding specificities of MATy 1 and MATy 2 antibodies to the naked and capped LPS cores were further analyzed utilizing S. typhimurium polysaccharide fractions with different O-chain:core ratios which were obtained after separation by Sephacryl S-200 chromatography. Steric effects on the antibody reactivity by the bulky O-polysaccharide chain were detected. The use of chemically defined native and synthetic saccharides as inhibitors, in combination with the conformation of the Salmonella core oligosaccharide, permitted the definition of antigenic determinants carried in the core domain recognized by each antibody: (i) the branches I and VIII are essential for MATy 1 recognition, (ii) the backbone III-IV-V for MATy 2, (iii) the backbone II-III-IV-V for MAST 56, and (iv) the backbone plus the branch III-IV-V-VIII for MAST 50. (formula; see text)
 ...
PMID:Epitope mapping of four monoclonal antibodies recognizing the hexose core domain of Salmonella lipopolysaccharide. 172 Jul 77

The rfb genes of Vibrio cholerae O1 (Ogawa serotype) were subcloned into a derivative of pBR322. This plasmid was transformed into several Escherichia coli K-12 mutant strains which produce an incomplete lipopolysaccharide (LPS)-core-oligosaccharide region. The data indicate that the V. cholerae O-antigen is assembled onto the E. coli LPS and that at least two glucoses are needed in the core in order to achieve a high level of production. These data are consistent with the reported presence of glucose in the V. cholerae LPS-core-oligosaccharide region.
 ...
PMID:Effect of lipopolysaccharide core synthesis mutations on the production of Vibrio cholerae O-antigen in Escherichia coli K-12. 172 66

The rfa locus of Escherichia coli K-12 includes a block of about 10 closely spaced genes transcribed in the same direction which are involved in synthesis and modification of the hexose region of the lipopolysaccharide core. We have sequenced the first three genes in this block. The function of the first of these genes is unknown, but we have designated it rfaQ on the basis of its location and similarity to other rfa genes. Complementation of Salmonella typhimurium rfa mutants with E. coli rfa restriction fragments indicated that the second and third genes in the block were rfaG and rfaP. The deduced sizes of the RfaQ, RfaG, and RfaP proteins are 36,298, 42,284, and 30,872 Da, respectively, and the proteins are basic and lack extensive hydrophobic domains. RfaQ shares regions of homology with proteins RfaC and RfaF, which are involved in synthesis of the heptose region of the core. Proteins RfaB, RfaG, and RfaK share a region of homology, which suggests that they belong to a second family of Rfa proteins which are thought to be hexose transferases.
 ...
PMID:Identification and sequences of the lipopolysaccharide core biosynthetic genes rfaQ, rfaP, and rfaG of Escherichia coli K-12. 173 25

1. Cells from the bone marrow and cells from the thymus of the rat were incubated in the presence of glucose and glutamine and phytohaemagglutinin, concanavalin-A or lipopolysaccharide. Cells were harvested at times up to 4 hr, extracted and maximum activities of hexokinase, lactate dehydrogenase, citrate synthase or glutaminase measured. 2. In bone marrow cells, there were little changes in enzyme activities except for an increase in the activity of citrate synthase which was prevented by concanavalin-A. This mitogen also caused a decrease in the activity of hexokinase. 3. In contrast, in thymocytes, the activities of hexokinase and glutaminase were decreased in the control condition but addition of lipopolysaccharide, a B-cell mitogen prevented these decreases in activity and concanavalin-A maintained the activity of glutaminase. Concanavalin-A caused a decrease in hexokinase activity but a marked increase in that of glutaminase. 4. It is suggested that changes in the maximum activities of hexokinase and glutaminase over this 4 hr period may represent the effect of removal of thymus-produced growth factors, whose effects can be replaced, at least in part, by two mitogens.
 ...
PMID:Effect of B- and T-cell mitogens on the maximum activities of hexokinase, lactate dehydrogenase, citrate synthase and glutaminase in bone marrow cells and thymocytes of the rat during four hours of culture. 177 87

The disaccharide L-glycero-D-manno-heptosyl-D-glucose was isolated from the lipopolysaccharide (LPS) of Escherichia coli K-12 strain W3100 after partial hydrolysis with acid, and the structure was determined by methylation analysis, n.m.r. spectroscopy, and comparison with a synthetic standard. In addition, the oligosaccharides L,D-Hep-D-Glc-D-Glc and L,D-Hep-D-Glc-D-Glc-D-Glc were isolated, and their structures were established by g.l.c.-m.s. and methylation analysis. The results indicated that L-glycero-D-manno-heptose, a characteristic constituent of the inner core region, may also occur in the outer core region which, in E. coli, is generally composed of hexoses. A revised structure of the carbohydrate backbone of the hexose/heptose region of the LPS is given.
 ...
PMID:Structural analysis of the heptose/hexose region of the lipopolysaccharide from Escherichia coli K-12 strain W3100. 179 30

1. The effects of indomethacin were investigated on haemodynamics, haematological and blood glucose values, and the release of tumour necrosis factor (TNF), platelet activating factor (PAF) and eicosanoids in anaesthetized pigs receiving 5 micrograms kg-1 E. coli lipopolysaccharide (LPS) over 60 min into the superior mesenteric artery. The animals were observed for an additional period of 2 h after the termination of LPS infusion. 2. Eight of the 17 animals infused with LPS and not treated with indomethacin died within 30 min after the beginning of LPS infusion (non-survivors), while the other 9 survived the experimental period of 3 h though in a state of shock (survivors). 3. No alterations were observed in plasma concentrations of PAF and eicosanoids (thromboxane B2 (TXB2), 6-keto prostaglandin F1 alpha (6-keto PGF1 alpha) and leukotriene B4 (LTB4] in non-survivors. However, a marked increase was detected in TNF release. A significant, though transient, increase in concentrations of PAF, TNF and eicosanoids occurred in the survivors. The peak in the concentrations of PAF and TXB2 preceded the maximum in TNF values in survivors. 4. Another group of 7 LPS-infused pigs was treated with indomethacin (2 mg kg-1, i.v. bolus 60 min before the start of LPS infusion, followed by a continuous infusion of 3 mg kg-1 h-1). This treatment prevented death and shock despite the high concentrations of circulating TNF and PAF. Concentrations of cyclo-oxygenase enzyme products were reduced, whereas LTB4 release was not affected. The effect of indomethacin on haemodynamic changes occurred earlier than on cyclo-oxygenase products.5. In another group of 6 pigs indomethacin (2mg kg- 1, i.v.) was given 20-25 min after the start of LPS infusion at which time mean arterial blood pressure (MABP) had decreased below 40mmHg indicating imminent death. This indomethacin treatment immediately reversed the hypotension, restored the organ perfusion, delayed the haemoconcentration and thrombocytopenia and prevented death. However, TNF and PAF concentrations remained elevated. Concentrations of cyclo-oxygenase products studied were reduced by the end of the observation period, whereas LTB4 production was unaffected.6. The decrease in MABP induced by exogenous PAF was temporarily prevented by indomethacin.7. These data indicate that the beneficial effect of indomethacin in LPS-induced septic shock is related to cyclo-oxygenase inhibition as well as to a direct vasoconstrictor property of the drug.
 ...
PMID:Sequential release of tumour necrosis factor, platelet activating factor and eicosanoids during endotoxin shock in anaesthetized pigs: protective effects of indomethacin. 179 28

The T-even type Escherichia coli phage Ox2 recognizes the outer membrane protein OmpA as a receptor. This recognition is accomplished by the 266 residue protein 38, which is located at the free ends of the virion's long tail fibers. Host-range mutants had been isolated in three consecutive steps: Ox2----Ox2h5----Ox2h10----Ox2h12, with Ox2h12 recognizing the outer membrane protein OmpC efficiently and having lost some affinity for OmpA. Protein 38 consists, in comparison with these proteins of other phages, of two constant and one contiguous array of four hypervariable regions; the alterations leading to Ox2h12 were all found within the latter area. Starting with Ox2h12, further host-range mutants could be isolated on strains resistant to the respective phage: Ox2h12----h12h1----h12h1.1----h12h1.11----h12 h1.111. It was found that Ox2h12h1.1 (and a derivative of Ox2h10, h10h4) probably uses, instead of OmpA or OmpC, yet another outer membrane protein, designated OmpX. Ox2h12h1.11 was obtained on a strain lacking OmpA, -C and -X. This phage could not grow on a mutant of E. coli B, possessing a lipopolysaccharide (LPS) with a defective core oligosaccharide; Ox2h12h1.111 was obtained from this strain. It turned out that the latter two mutants used LPS as a receptor, most likely via its glucose residues. Selection for resistance to them in E. coli B (ompA+, ompC-, ompX-) yielded exclusively LPS mutants, and in another strain, possessing OmpA, C and X, the majority of resistant mutants were of this type. Isolated LPS inactivated the mutant phages very well and was inactive towards Ox2h12. By recombining the genes of mutant phages into the genome of parental phages it could be shown that the phenotypes were associated with gene 38. All mutant alterations (mostly single amino acid substitutions) were found within the hypervariable regions of protein 38. In particular, a substitution leading to Ox2h12h1.11 (Arg170----Ser) had occurred at the same site that led to Ox2h10 (His170----Arg), which binds to OmpC in addition to OmpA. It is concluded that not only can protein 38 gain the ability to switch from a protein to a carbohydrate as a receptor but can do so using the same domain of the polypeptide.
 ...
PMID:Single mutations in a gene for a tail fiber component of an Escherichia coli phage can cause an extension from a protein to a carbohydrate as a receptor. 182 15


<< Previous 1 2 3 4 5 6 7 8 9 10