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

Conjugation of simple ketoses (such as 3-deoxy-D-manno-2-octulosonic acid and N-acetylneuraminic acid) and of various O-specific polysaccharides (from Aeromonas hydrophila and Aeromonas salmonicida) to the bifunctional spacer 1,6-hexanediamine, was achieved by reductive amination. The saccharide--1-(6-amino)-hexane alkyamines obtained were converted into the corresponding isothiocyanate derivatives and coupled to the free epsilon-amino group of lysine residues of the protein carrier bovine serum albumin. In similar manner, the aldehyde group introduced by selective periodate oxidation into the partially O-deacylated lipopolysaccharide of Vibrio anguillarum was conjugated to 1,6-hexanediamine, converted into the corresponding isothiocyanate and covalently attached to bovine serum albumin.
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PMID:Synthesis of glycoconjugates derived from various lipopolysaccharides of the Vibrionaceae family. 292 Jul 31

Extraction of whole promastigotes of Leishmania tropica major and L. donovani with a mixture of hexane and isopropanol (3:2) yielded three fractions containing immunological activity: lipids, where the activity was determined by radioimmunoassay; a lipopolysaccharide-like (LPS-like), water-soluble precipitate, where activity was determined both by radioimmunoassay and double gel diffusion, and the phenol: water extract of the lipid-free promastigotes, where activity was followed by double gel diffusion. The use of a solid state, lipid-based radioimmunoassay for detection of leishmanial antigens provided a sensitive measure of their activity with a considerable degree of species and serotype specificity. We found antibodies to leishmanial lipids in sera from immunized rabbits, convalescent mice, and human patients with confirmed cases of cutaneous leishmaniasis or kala azar. There was very little activity in normal human or animal sera. Analysis by SDS-polyacrylamide gel electrophoresis of fractions from promastigotes surface-labeled with galactose oxidase and sodium borotritiate and preliminary immunochemical characterization of the LPS-like antigen showed that it contained galactose, but otherwise differed immunologically and chemically from excreted factor (EF), the best characterized leishmanial antigen.
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PMID:Lipid and lipopolysaccharide-like antigens of Leishmania promastigotes. 400 12

Macrophage hybridoma clone 5 suppressed B-cell proliferation induced by lipopolysaccharide (LPS). Since paraformaldehyde-fixed macrophages exerted the effect, macrophage-derived mediators were excluded from the inhibition. The inhibitory property of macrophages was present in the membrane fraction and was recovered in the organic phase after extraction using a chloroform/methanol/water system followed by hexane extraction. Therefore, the inhibitory activity found in macrophage clone 5 was concluded to arise from a lipid component. The inhibitory substance was further purified to a homogeneity by LH20 column fractionation using methanol/chloroform as the mobile phase. The purified lipid did not have any effect on the LPS-mediated induction of MHC class II molecules on the B-cell surface. Moreover, the inhibitory property was shown to affect growth of a wide variety of tumor cell lines of human origin. These results suggest that a lipid molecule found on the cell membrane of cloned macrophage hybridoma may participate in the regulation of cell growth through cell contact.
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PMID:Inhibition of cell growth by macrophage membrane lipid molecule. 781 37

Endotoxin or lipopolysaccharide (LPS), a major cell surface component of gram-negative bacteria, which could bind to different cell types when released into the bloodstream, plays a central role in the pathogenesis of septic shock syndromes. We have established a biotinylation procedure for labeling purified LPS molecules from Salmonella minnesota R595 and Escherichia coli J5 bacteria. The biotin group was conjugated to the bacterial LPS either by chemical oxidation of the LPS carbohydrate moiety (inner core region), followed by reduction with biotin-LC-hydrazide (biotinamido hexanoyl hydrazide), or by photoactivatable cross-linking with biotin-LC-ASA [1-(4-azidosalicylamido-)-6(biotinamido)-hexane], which was randomly attached to the carbohydrate and fatty acid (lipid A) groups of the LPS. Both labeled products retained biological activity (or endotoxicity) as evidenced by coagulation of the Limulus amoebocyte lysate. To determine its ability to bind avidin/streptavidin which in turn could be conjugated with enzymatic and fluorescent probes, the biotinylated LPS was used in enzyme immunoassay, Western blot, and flow cytometry. These assays were also used to analyze the binding of LPS ligand to its counterreceptor(s) on whole cell surface, membrane fragments, and in detergent lysates from human endothelial and monocytic cells. The described biotinylated LPS probes can be applied in a wide variety of techniques in receptor biochemistry, immunohistochemistry, and molecular cell biology.
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PMID:Biotinylated lipopolysaccharide binds to endotoxin receptor in endothelial and monocytic cells. 874 78

The lipopolysaccharides LPS I and LPS II, isolated from the hypovirulent EV40 strain of Yersinia pestis, are composed only of type R lipopolysaccharides. This type consists of two forms a and b, depending on their solubility pattern in a solvent mixture containing varying proportions of chloroform, methanol, hexane, and hydrochloric acid. LPS I consists of one subtype, RIb, while LPS II consists of two subtypes, RIIa and RIIb. Analysis by gel electrophoresis shows that the mass of these lipopolysaccharide forms are in the vicinity of 2000-3000 Da. The RIb and RIIb subtypes, which are found in the majority of lipopolysaccharide I and II fractions, are composed of ketoses and amines that are similar to those occurring in LPS I and LPS II. In contrast, the two subtypes RIIa and RIIb are different both in terms of the composition of lipid A and the extent of its substitution. Certain fractions of RIIa contain only lipid A and 3-deoxy-D-manno-octulosonic acid (KDO), while other fractions of RIIb possess a lipid A, which is not substituted by arabinose. The whole set of these R-type lipopolysaccharide forms are excellent models for the study of the role of the primary structure of the polysaccharide region, and for the effect of lipid A substitution on the biological activity of bacterial lipopolysaccharides.
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PMID:[Isolation and chemical characterization of type R lipopolysaccharides of a hypovirulent strain of Yersinia pestis]. 974 73

A lipid fraction obtained by activity-guided fractionation from the hexane extract of Sideritis javalambrensis was evaluated for anti-inflammatory activity. This fraction significantly inhibited paw oedema induced by carrageenan as well as ear oedema induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in mice after oral or topical administration, respectively. Quantitation of the specific marker myeloperoxidase (MPO) demonstrated that its topical anti-inflammatory activity was associated with reduction in cell infiltration into inflamed tissues. The lipid fraction significantly decreased leukocyte granular enzyme release (beta-glucuronidase), but failed to inhibit superoxide generation. Histamine release from mast cells was also suppressed in a concentration-dependent manner. In addition, non-toxic concentrations of this fraction reduced nitric oxide (NO) generation in lipopolysaccharide (LPS)-treated J774 macrophages. Taken together, these results suggest that the lipid fraction exerts in vivo anti-inflammatory activity with the partial contribution of inhibitory actions on some inflammatory responses.
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PMID:Anti-Inflammatory properties of a lipid fraction obtained from Sideritis javalambrensis. 1104 Dec 50

Inducible cyclooxygenase (COX-2) has been implicated in the processes of inflammation and carcinogenesis. Thus, the potential COX-2 inhibitors have been considered as anti-inflammatory or cancer chemopreventive agents. In this study, the methanolic extract of the cortex of Eugenia caryophyllata Thunberg (Myrtaceae) was found to potently inhibit the prostaglandin E(2) production in lipopolysaccharide (LPS)-activated mouse macrophage RAW264.7 cells (98.3% inhibition at the test concentration of 10 microg/ml). Further, hexane-soluble layer was the most active partition compared to ethyl acetate, n-butanol, and water-soluble parts. By bioassay-guided fractionation of hexane-soluble partition, eugenol was isolated and exhibited a significant inhibition of PGE(2) production (IC(50) = 0.37 microM). In addition, eugenol suppressed the cyclooxygenase-2 (COX-2) gene expression in LPS-stimulated mouse macrophage cells. On the line of COX-2 playing an important role in colon carcinogenesis further study was designed to investigate the effect of eugenol on the growth and COX-2 expression in HT-29 human colon cancer cells. Eugenol inhibited the proliferation of HT-29 cells and the mRNA expression of COX-2, but not COX-1. This result suggests that eugenol might be a plausible lead candidate for further developing the COX-2 inhibitor as an anti-inflammatory or cancer chemopreventive agent.
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PMID:Eugenol suppresses cyclooxygenase-2 expression in lipopolysaccharide-stimulated mouse macrophage RAW264.7 cells. 1275 41

The extract of Barbados cherry (acerola fruit), a fruit of Malpighia emarginata DC., has been reported to display diverse biological activities such as prevention of age-related diseases. We investigated here the possible effect of Barbados cherry extract on nitric oxide (NO) production by activated macrophages. Barbados cherry was roughly separated into 4 or 5 fractions by two different methods, using various organic solvents such as hexane, acetone, methanol (70% and 100%) and water, and assayed for its ability to inhibit NO production by lipopolysaccharide (LPS)-stimulated mouse macrophage-like Raw 264.7 cells. Among these fractions, AcOEt extracts (AE0) in Method I and acetone extract (A0) in Method II showed the highest inhibitory activity of NO production (SI > 20 and SI = 31, respectively). When these fractions were subjected to silica gel column chromatography, higher inhibitory activity for NO production was concentrated in AcOEt (AE6) (SI = 64) and benzene-AcOEt (1:4) (A10) fractions (SI > 59). Western blot analysis demonstrated that AE6 and A10 fractions reduced the intracellular concentration of inducible NO synthase (iNOS) by approximately one-third. ESR spectroscopy showed that these fractions scavenged various radical species such as superoxide anion (O2-) and NO radicals. These data suggest that the inhibitory effect on NO production by Barbados cherry extracts is partly due to the inhibition of iNOS expression, and scavenging of O2- and NO radicals.
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PMID:Inhibition of LPS-stimulated NO production in mouse macrophage-like cells by Barbados cherry, a fruit of Malpighia emarginata DC. 1292 58

Gavin, John J. (Rutgers, The State University, New Brunswick, N.J.), and Wayne W. Umbreit. Effect of biotin on fatty acid distribution in Escherichia coli. J. Bacteriol. 89:437-443. 1965.-Biotin deficiency causes changes in the composition and distribution of the fatty acids in cell wall-cell membrane fractions of Escherichia coli T 94A. Most notable among the fatty acid changes are decreased amounts of unsaturated fatty acids, the presence of unsaponifiable lipid material, and the lack of a lipopolysaccharide fraction in the cell wall-cell membrane. Also, though the hexane-extractable material from the lipoprotein fraction of biotin-adequate cells will transfer glucose from water to hexane, the same material from biotin-deficient cells will not.
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PMID:EFFECT OF BIOTIN ON FATTY ACID DISTRIBUTION IN ESCHERICHIA COLI. 1425 12

Activity-guided fractionation of the n-hexane and CHCl3-soluble fractions of Sindora sumatrana using a bioassay based on the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production by inducible nitric oxide synthase (iNOS) in murine macrophage RAW 264.7 cells led to the isolation of the known compound, (+)-7beta-acetoxy-15,16-epoxy-3,13(16),14-clerodatriene-18-oic acid (2) as an active constituent. In addition, a new trans-clerodane diterpenoid, (+)-2-oxokolavenic acid (1), together with six known compounds, (+)-3,13-clerodadiene-16,15-olide-18-oic acid (3), (+)-7beta-acetoxy-3,13-clerodadiene-16,15-olide-18-oic acid (4), (+)-7beta-acetoxy-16-hydroxy-3,13-clerodadiene-16,15-olide-18-oic acid (5), beta-caryophyllene oxide (6), clovane-2beta,9beta-diol (7), and caryolane-1,9beta-diol (8) were isolated and found to be inactive. The structure of compound 1 was determined using physical and spectroscopic methods such as 1D and 2D-NMR experiments. The known compounds 2-8 were identified by the spectroscopic data and by comparison with the published values. Of eight isolates (1-8), only compound 2 exhibited an iNOS inhibitory activity with IC50 value of 51.6 microM.
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PMID:Di- and sesqui-terpenoids isolated from the pods of Sindora sumatrana and their potential to inhibit lipopolysaccharide-induced nitric oxide production. 1508 33


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