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)

To study the involvement of acyl carrier protein (ACP) in the metabolism of exogenous fatty acids in Vibrio harveyi, cultures were incubated in minimal medium with [9,10-3H]myristic acid, and labeled proteins were analyzed by gel electrophoresis. Labeled acyl-ACP was positively identified by immunoprecipitation with anti-V. harveyi ACP serum and comigration with acyl-ACP standards and [3H]beta-alanine-labeled bands on both sodium dodecyl sulfate- and urea-polyacrylamide gels. Surprisingly, most of the acyl-ACP label corresponded to fatty acid chain lengths of less than 14 carbons: C14, C12, C10, and C8 represented 33, 40, 14, and 8% of total [3H]14:0-derived acyl-ACPs, respectively, in a dark mutant (M17) of V. harveyi which lacks myristoyl-ACP esterase activity; however, labeled 14:0-ACP was absent in the wild-type strain. 14:0- and 12:0-ACP were also the predominant species labeled in complex medium. In contrast, short-chain acyl-ACPs (< or = C6) were the major labeled derivatives when V. harveyi was incubated with [3H]acetate, indicating that acyl-ACP labeling with [3H]14:0 in vivo is not due to the total degradation of [3H]14:0 to [3H]acetyl coenzyme A followed by resynthesis. Cerulenin increased the mass of medium- to long-chain acyl-ACPs (> or = C8) labeled with [3H]beta-alanine fivefold, while total incorporation of [3H]14:0 was not affected, although a shift to shorter chain lengths was noted. Additional bands which comigrated with acyl-ACP on sodium dodecyl sulfate gels were identified as lipopolysaccharide by acid hydrolysis and thin-layer chromatography. The levels of incorporation of [3H] 14:0 into acyl-ACP and lipopolysaccharide were 2 and 15%, respectively, of that into phospholipid by 10 min. Our results indicate that in contrast to the situation in Escherichia coli, exogenous fatty acids can be activated to acyl-ACP intermediates after partial degradation in V. harveyi and can effectively label products (i.e., lipid A) that require ACP as an acyl donor.
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PMID:Exogenous myristic acid can be partially degraded prior to activation to form acyl-acyl carrier protein intermediates and lipid A in Vibrio harveyi. 828 14

Xanthomonas hortorum pv. vitians is a Gram-negative bacterium that acts as the causative agent of bacterial leaf spot and headrot in lettuce. The lipopolysaccharide (LPS) of this bacterium is suspected to be an important molecule for adhesion to the plants. We have isolated the LPS, prepared the lipid A and the polysaccharide moieties thereof, and characterised all preparations by compositional analysis. Main sugar components are rhamnose and 3-acetamido-3,6-dideoxy-galactose which presumably furnish the O-specific polysaccharide. Other sugars are mannose, glucose, 6-deoxygalactose (fucose), and galacturonic acid, which should be core region constituents, and glucosamine, which builds up the carbohydrate backbone of lipid A. The LPS contains several phosphate groups, most of which are present in the core region. The main fatty acids in the lipid A are C10:0, 3-OH-C10:0 and 3-OH-C12:0. The latter is the only amide-linked fatty acid. Two fatty acids present in small amounts were identified, C8:0 and C11:0.
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PMID:Isolation and characterisation of the lipopolysaccharide from Xanthomonas hortorum pv. vitians. 1056 88

This study demonstrates for the first time that respiratory epithelial cells are able to produce the acute phase protein lipopolysaccharide (LPS)-binding protein (LBP), which is known to play a central role in the defense to bacterial endotoxins (or LPS). Indications for local presence of LBP in human lung was obtained via reverse transcriptase/polymerase chain reaction that showed LBP messenger RNA (mRNA) expression. Therefore, LBP production by the human lung epithelial cell line A549, a human adenocarcinoma with features of type II pneumocytes, was studied. These cells produced LBP in response to interleukin (IL)-1beta, IL-6, and tumor necrosis factor- alpha, a response that was strongly enhanced by dexamethasone. In addition, LBP mRNA was detected in A549 cells, in increasing amounts as a result of stimulation. The pattern of cytokine-induced LBP production in A549 cells was similar to the pattern in the human liver epithelial cell line HuH-7. Moreover, the molecular weight of A549-derived LBP was approximately 60 kD, which is similar to HuH-7-derived LBP. Biologic activity of LBP produced by A549 cells was evaluated on the basis of its ability to interact with LPS. Further indications that type II alveolar epithelial cells are able to produce LBP were obtained from the observations that the murine lung type II epithelial cell line C10 produced murine LBP, and that isolated human primary type II pneumocytes expressed LBP mRNA, which was enhanced after stimulation of cells. The local production of this endotoxin binding protein by lung epithelial cells might contribute to a highly specific response at the site of exposure to bacteria and bacterial endotoxins.
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PMID:Production of the acute-phase protein lipopolysaccharide-binding protein by respiratory type II epithelial cells: implications for local defense to bacterial endotoxins. 1091 79

Transcript expression of 24 chemokines (CKs) was examined throughout 8 days in mouse lungs with type-1 (Th1) or type-2 (Th2) cytokine-mediated granulomas induced by bead-immobilized mycobacterial purified protein derivative or Schistosoma mansoni egg antigens. Where possible, CK protein levels were also measured. In addition, we examined effects of in vivo cytokine depletions. Findings were as follows: 1) bead challenge induced increases in 18 of 24 CK transcripts with type-1 and type-2 responses displaying different patterns. CKs fell into four categories: a) type-1-dominant (gamma-interferon-inducible protein (IP-10), monokine induced by INF-gamma (MIG), macrophage inflammatory protein-2 (MIP-2), lipopolysaccharide-induced chemokine (LIX), rodent growth-related oncogene homologue (KP), macrophage inflammatory protein-1alpha (MIP-1alpha) and -1beta (MIP-1beta), lymphotactin), b) type-2-dominant (eotaxin, monocyte chemotactic protein-2 (MCP-2) and -3 (MCP-3), liver and activation-regulated chemokine (LARC), T cell activation protein-3 (TCA-3), c) type-1 and type-2 co-dominant (MCP-1, MCP-5, monocyte-derived chemokine (MDC), thymus and activation-related chemokine (TARC), C10), and d) constitutive (lungkine, secondary lymphoid-tissue chemokine (SLC), EBI1-ligand chemokine (ELC), fractalkine, macrophage inflammatory protein-1gamma (MIP1-gamma), and stromal cell derived factor-1alpha (SDF1-alpha). 2) CKs displayed characteristic temporal patterns. CXC (IP-10, MIG, MIP-2, LIX, KC) and certain CC (MCP-1, MCP-5, MIP-1alpha, MIP-1beta) CKs were produced maximally within 1 to 2 days. Others (MCP-2, MCP-3, eotaxin, lymphotactin, LARC, TCA-3) displayed peak expression later. 3) Interferon-gamma neutralization profoundly abrogated MIG, but had little effect on other CKs. Tumor necrosis factor-alpha neutralization caused up to 50% reduction in a range of CKs. These findings indicate that type-1 and type-2 granulomas display characteristic CK profiles with coordinated expression that is under cytokine-mediated regulation.
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PMID:Chemokine expression dynamics in mycobacterial (type-1) and schistosomal (type-2) antigen-elicited pulmonary granuloma formation. 1129 May 68

Gas chromatography-mass spectrometry (GC-MS) using a quadrupole instrument and GC-tandem MS (GC-MS-MS) using an ion trap instrument were applied to determine 3-hydroxy fatty acids (3-OH FAs) with 10-18 carbon chain lengths, specific components of the endotoxin (lipopolysaccharide, LPS) of Gram-negative bacteria, in 30 house dust samples. The two methods provided similar detection sensitivity for methyl ester/trimethylsilyl derivatives of the 3-OH FAs and allowed these acids to be distinguished from co-eluting 2-OH FA derivatives. The correlation coefficients between endotoxin activity (Limulus test) and the combined amounts of 3-OH C10, 3-OH C12, and 3-OH C14 were 0.60 and 0.61 when using GC-MS and GC-MS-MS, respectively. The superior selectivity of GC-MS-MS was illustrated in analyses of sub-milligram amounts of dust, where the chromatograms achieved by GC-MS were difficult to interpret due to a high background and several closely eluting compounds. GC-MS-MS is therefore preferable to GC-MS for determining 3-OH FAs in minute (sub-milligram) amounts of dust.
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PMID:Use of quadrupole GC-MS and ion trap GC-MS-MS for determining 3-hydroxy fatty acids in settled house dust: relation to endotoxin activity. 1152 95

A growing body of evidence suggests that mammalian ovulation bears similarities to local inflammatory reactions. Monocytes/macrophages, eosinophils, and neutrophils are known to infiltrate the area surrounding the dominant follicle before ovulation. Candidate local chemoattractants may include a family of small cytokines, also known as chemokines. In the present study, quantitative RT-PCR was used to initially identify and quantify the chemokines expressed in the preovulatory rat ovary. The chemokines monocyte chemotatic protein 1 (MCP-1), MCP-3, macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, MIP-1gamma, regulated upon activation normal T cell expressed and secreted, eotaxin, interferon-inducible protein of 10 kDa, growth-regulated oncogene, lymphotactin, and fractalkine were all expressed in the PMSG-primed rat ovary 6 h post human CG. C10, T cell activation gene 3, exodus, exodus-2, cytokine-induced neutrophil chemoattractant-2, MIP-2, and lipopolysaccharide-induced C-X-C were not expressed in the PMSG-primed rat ovary 6 h post human CG. The cyclic variation of the ovary-positive chemokines was also evaluated throughout the course of a superovulated ovarian cycle. Significant preovulatory up-regulation relative to the untreated control state was documented for MCP-1 (18-fold), MCP-3 (12-fold), and growth-regulated oncogene (25-fold). In contrast, the preovulatory ovarian expression of eotaxin, fractalkine and regulated upon activation normal T cell expressed and secreted was not increased. These observations suggest that intraovarian chemokines may be responsible for the cyclic intraovarian residence of representatives of the white blood cell series.
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PMID:Expression, hormonal regulation, and cyclic variation of chemokines in the rat ovary: key determinants of the intraovarian residence of representatives of the white blood cell series. 1186 98

The chemical structure of lipid A from the lipopolysaccharide of the mushroom-associated bacterium Pseudomonas reactans, a pathogen of cultivated mushroom, was elucidated by compositional analysis and spectroscopic methods (MALDI-TOF and two-dimensional NMR). The sugar backbone was composed of the beta-(1'-->6)-linked d-glucosamine disaccharide 1-phosphate. The lipid A fraction showed remarkable heterogeneity with respect to the fatty acid and phosphate composition. The major species are hexacylated and pentacylated lipid A, bearing the (R)-3-hydroxydodecanoic acid [C12:0 (3OH)] in amide linkage and a (R)-3-hydroxydecanoic [C10:0 (3OH)] in ester linkage while the secondary fatty acids are present as C12:0 and/or C12:0 (2-OH). A nonstoichiometric phosphate substitution at position C-4' of the distal 2-deoxy-2-amino-glucose was detected. Interestingly, the pentacyl lipid A is lacking a primary fatty acid, namely the C10:0 (3-OH) at position C-3'. The potential biological meaning of this peculiar lipid A is also discussed.
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PMID:Structural determination of lipid A of the lipopolysaccharide from Pseudomonas reactans. A pathogen of cultivated mushrooms. 1202 88

A major problem in the development of vaccines against Gram-negative bacteria is the endotoxic -activity of lipopolysaccharide (LPS), which is determined by its lipid A moiety. Nevertheless, LPS would be an interesting vaccine component because of its immune-stimulating properties. In the present study, we have changed the fatty acid composition of Neisseria meningitidis LPS by replacing the lpxA gene of strain H44/76 with the Escherichia coli or Pseudomonas aeruginosa homologue. The majority of the O-linked 3-OH C12 in N. meningitidis lipid A was replaced by 3-OH C14 (strain HA01E) and 3-OH C10 (strain HA25P) respectively. Both strains, but most notably strain HA01E, had reduced amounts of LPS compared with the wild-type strain. In addition, growth was severely impaired for HA01E. The major outer membrane proteins were expressed normally. Outer membrane complexes of both strains normalized on their LPS content showed a 10-fold reduction in their ability to induce tumour necrosis factor (TNF)-alpha. Immunogenicity studies in BALB/c mice revealed that the adjuvant activity of the LPS was not affected. Thus, the replacement of the O-linked fatty acids in meningococcal lipid A results in immunogenic outer membranes with reduced endotoxic activity, more suitable for use in outer membrane vesicle vaccines.
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PMID:Expression of foreign LpxA acyltransferases in Neisseria meningitidis results in modified lipid A with reduced toxicity and retained adjuvant activity. 1239 Mar 52

Lipid A is the bioactive centre of lipopolysaccharide (LPS), and its properties exhibit various endotoxic and biological effects toward host cells. We examined whether Toll-like receptors (TLRs) are mediated by the signals from various synthetic acylated derivatives of d-glucosamine monophosphate. All test synthetic monosaccharide lipid A analogues similar to acylated beta-(1-6)-d-glucosamine disaccharide bisphosphates, such as Escherichia coli-type lipid A (compound 506) and its precursor (compound 406), clearly induced nuclear factor (NF)-kappaB activation in Ba/F3 cells expressing murine TLR4 and its accessory protein MD-2 (Ba/mTLR4/mMD-2), but no induction was found in those expressing murine TLR2 (Ba/mTLR2). Compound 411, the non-reducing sugar moiety of compound 506, exhibited interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha)-producing activities in human peripheral blood mononuclear cells (PBMC), whereas compound 401, the reducing moiety of compounds 506 and 406, and Gifu lipid A-46 (GLA-46), the non-reducing moiety of compound 406, induced no production of IL-8 and TNF-alpha, which was similar to the findings for compound 406. Among the synthetic triacylated monosaccharide lipid A analogues, some compounds with three tetradecanoyl (C14) groups or that included a dodecanoyl (C12) group were more active toward murine and human cells than were other analogues with a decanoyl (C10) or hexadecanoyl (C16) group. Furthermore, IL-8 production in PBMC stimulated with the active monosaccharide lipid A analogues as well as compound 506 was clearly inhibited by the monoclonal antibody to human TLR4. These findings suggest that monosaccharide lipid A analogues similar to disaccharide lipid As are capable of activating both murine and human cells through TLR4.
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PMID:Cell activation by monosaccharide lipid A analogues utilizing Toll-like receptor 4. 1294 Nov 42

Important pathogens in the genus Yersinia include the plague bacillus Yersinia pestis and two enteropathogenic species, Yersinia pseudotuberculosis and Yersinia enterocolitica. A shift in growth temperature induced changes in the number and type of acyl groups on the lipid A of all three species. After growth at 37 degrees C, Y. pestis lipopolysaccharide (LPS) contained the tetra-acylated lipid IV(A) and smaller amounts of lipid IV(A) modified with C10 or C12 acyl groups, Y. pseudotuberculosis contained the same forms as part of a more heterogeneous population in which lipid IV(A) modified with C16:0 predominated, and Y. enterocolitica produced a unique tetra-acylated lipid A. When grown at 21 degrees C, however, the three yersiniae synthesized LPS containing predominantly hexa-acylated lipid A. This more complex lipid A stimulated human monocytes to secrete tumour necrosis factor-alpha, whereas the lipid A synthesized by the three species at 37 degrees C did not. The Y. pestis phoP gene was required for aminoarabinose modification of lipid A, but not for the temperature-dependent acylation changes. The results suggest that the production of a less immunostimulatory form of LPS upon entry into the mammalian host is a conserved pathogenesis mechanism in the genus Yersinia, and that species-specific lipid A forms may be important for life cycle and pathogenicity differences.
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PMID:Variation in lipid A structure in the pathogenic yersiniae. 1516 39


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