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1. (CSDB ID: 9235) | report error |
| R-3HOPam-(1-2)-+ | /Variants 0/-+ | | | R-3HOPam-(1-2)-b-D-GlcpN-(1-6)-a-D-GlcpN-(1-P | | P-4)-+ Pam-(1-3)-+ /Variants 0/ is: Pam-(1-3)- OR (exclusively) aiC15-(1-3)- | Show graphically |
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Coxiella burnetii str. Priscilla
(Ancestor NCBI TaxID 777,
species name lookup)
, ICD11: XN0QS ]; infection due to Coxiella burnetii [ICD11: XN0QS ]
savba.sk; kbrandenfz-borstel.deBACKGROUND: Coxiella burnetii is the etiological agent of Q fever found worldwide. The microorganism has like other Gram-negative bacteria a lipopolysaccharide (LPS, endotoxin) in its outer membrane, which is important for the pathogenicity of the bacteria. In order to understand the biological activity of LPS, a detailed physico-chemical analysis of LPS is of utmost importance. RESULTS: The lipid A moiety of LPS is tetraacylated and has longer (C-16) acyl chains than most other lipid A from enterobacterial strains. The two ester-linked 3-OH fatty acids found in the latter are lacking. The acyl chains of the C. burnetii endotoxins exhibit a broad melting range between 5 and 25 degrees C for LPS and 10 and 40 degrees C for lipid A. The lipid A moiety has a cubic inverted aggregate structure, and the inclination angle of the D-glucosamine disaccharide backbone plane of the lipid A part with respect to the membrane normal is around 40 degrees. Furthermore, the endotoxins readily intercalate into phospholipid liposomes mediated by the lipopolysaccharide-binding protein (LBP). The endotoxin-induced tumor necrosis factor alpha (TNF-α) production in human mononuclear cells is one order of magnitude lower than that found for endotoxins from enterobacterial strains, whereas the same activity as in the latter compounds is found in the clotting reaction of the Limulus amebocyte lysate assay. CONCLUSIONS: Despite a considerably different chemical primary structure of the C. burnetii lipid A in comparison with enterobacterial lipid A, the data can be well understood by applying the previously presented conformational concept of endotoxicity, a conical shape of the lipid A moiety of LPS and a sufficiently high inclination of the sugar backbone plane with respect to the membrane plane. Importantly, the role of the acyl chain fluidity in modulating endotoxicity now becomes more evident.
Lipopolysaccharide, X-ray diffraction, lipid A, endotoxin, Coxiella burnetii, lipopolysaccharide-binding, lipopolysaccharide-binding protein, liposome, Molecular Conformation, phospholipid, Matrix-Assisted Laser Desorption-Ionization
Structure type: oligomer|
2. (CSDB ID: 20146) | report error |
| R-3HOMyr-(1-3)-+ | a-L-Rhap-(1-2)-a-L-Rhap-(1-1)-R-3HOMyr | Show graphically |
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Burkholderia plantarii DSM 6535
(previously named: Pseudomonas plantarii DSM 6535)
(Ancestor NCBI TaxID 41899,
species name lookup)
fz-borstel.deHere we report on the purification, structural characterization, and biological activity of a glycolipid, 2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-α(R)-3-hydroxytetradecanoyl-(R)-3-hydroxytetradecanoate (RL-2,2(14)) produced by Burkholderia (Pseudomonas) plantarii. RL-2,2(14) is structurally very similar to a rhamnolipid exotoxin from Pseudomonas aeruginosa and identical to the rhamnolipid of Burkholderia pseudomallei, the causative agent of melioidosis. Interestingly, RL-2,2(14) exhibits strong stimulatory activity on human mononuclear cells to produce tumor necrosis factor alpha, the overproduction of which is known to cause sepsis and the septic shock syndrome. Such a property has not been noted so far for rhamnolipid exotoxins, only for bacterial endotoxins (lipopolysaccharide, LPS). Consequently, we analyzed RL-2,2(14) with respect to its pathophysiological activities as a heat-stable extracellular toxin. Like LPS, the cell-stimulating activity of the rhamnolipid could be inhibited by incubation with polymyxin B. However, immune cell activation by RL-2,2(14) does nor occur via receptors that are involved in LPS (TLR4) or lipopeptide signaling (TLR2). Despite its completely different chemical structure, RL-2,2(14) exhibits a variety of endotoxin-related physicochemical characteristics, such as a cubic-inverted supramolecular structure. These data are in good agreement with our conformational concept of endotoxicity: intercalation of naturally originating virulence factors into the immune cell membrane leads to strong mechanical stress on integral proteins, eventually causing cell activation.
Lipopolysaccharide, cytokine induction, small-angle X-ray scattering, Fourier-transform infrared spectroscopy, rhamnolipid, Toll-like receptor
Structure type: oligomer|
3. (CSDB ID: 48285) | report error |
| b-D-Glcp2(%)Ac3(%)Ac4(%)Ac6(%)Ac-(1-4)-b-D-Glcp6(%)Ac-(1-?)-LIP | Show graphically |
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Cryptococcus humicola 9-6
(later renamed to: Vanrija humicola 9-6)
(Ancestor NCBI TaxID 5417,
species name lookup)
ibpm.serpukhov.suThe chemical composition of the mycocidal complex (formerly known as microcin) secreted by Cryptococcus humicola was investigated by chemical, mass spectrometric and nuclear magnetic resonance methods. The results indicate that the mycocidal complex is composed of glycolipids with a highly acetylated (up to five acetyl groups) cellobiose backbone [β-D-Glcp-(1'→4)-β-D-Glcp] linked to the ω-hydroxyl group of α,ω-dihydroxy palmitate [16:0-α,ω-di-OH] with an unsubstituted carboxyl group. The acyl chain forming aglycon can be replaced by [18:0-(α,ω-di-OH)], [18:0-(α,ω-1,ω-tri-OH)], and [18:0-(α,ω-2,ω-tri-OH)]. The complex has a comparatively high surface activity; 0.5 mg/ml of it reduced the surface tension of 0.1 M NaHCO(3) from 71 mN/m to 37 mN/m and interfacial tension against n-hexadecane from 39 mN/m to 10 mN/m. The critical micelle concentration of the complex at pH 4.0, determined by the fluorometric method with N-phenyl-1-naphthylamine as fluorescent probe and by the De Nouy ring method, was 20 μM (taking the average molecular mass of the complex to be 750); it did not depend on the presence of 100 mM KCl and was an order of magnitude higher at pH 7.0. By fluorescence resonance energy transfer spectroscopy with N-(7-nitro-2,1,3-benzoxadiazol-4-yl)-phosphatidylethanolamine as energy donor and N-(rhodamine B sulfonyl)-phosphatidylethanolamine as energy acceptor the complex was shown to intercalate into the liposomal lipid matrix. Primary lesions caused by the complex in planar lipid bilayers were revealed as short-living current fluctuations of a broad spectrum of amplitudes. The mycocidal effect of the complex is suggested to be associated with its detergent-like properties
permeability, mass spectrometry, nuclear magnetic resonance spectroscopy, detergent, Cryptococcus, yeast, cellobiose lipid, mycocidal effect, lipid membrane
Structure type: oligomer|
4. (CSDB ID: 48603) | report error |
| b-D-Glcp2(%)Ac3(%)Ac4(%)Ac6(%)Ac-(1-4)-b-D-Glcp6(%)Ac-(1-16)-2,15,16HOPam | Show graphically |
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Cryptococcus humicola 9-6
(later renamed to: Vanrija humicola 9-6)
(Ancestor NCBI TaxID 5417,
species name lookup)
ibpm.serpukhov.suThe chemical composition of the mycocidal complex (formerly known as microcin) secreted by Cryptococcus humicola was investigated by chemical, mass spectrometric and nuclear magnetic resonance methods. The results indicate that the mycocidal complex is composed of glycolipids with a highly acetylated (up to five acetyl groups) cellobiose backbone [beta-D-Glcp-(1'-->4)-beta-D-Glcp] linked to the omega-hydroxyl group of alpha,omega-dihydroxy palmitate [16:0-alpha,omega-di-OH] with an unsubstituted carboxyl group. The acyl chain forming aglycon can be replaced by [18:0-(alpha,omega-di-OH)], [18:0-(alpha,omega-1,omega-tri-OH)], and [18:0-(alpha,omega-2,omega-tri-OH)]. The complex has a comparatively high surface activity; 0.5 mg/ml of it reduced the surface tension of 0.1 M NaHCO(3) from 71 mN/m to 37 mN/m and interfacial tension against n-hexadecane from 39 mN/m to 10 mN/m. The critical micelle concentration of the complex at pH 4.0, determined by the fluorometric method with N-phenyl-1-naphthylamine as fluorescent probe and by the De Nouy ring method, was 2 x 10(-5) M (taking the average molecular mass of the complex to be 750); it did not depend on the presence of 100 mM KCl and was an order of magnitude higher at pH 7.0. By fluorescence resonance energy transfer spectroscopy with N-(7-nitro-2,1,3-benzoxadiazol-4-yl)-phosphatidylethanolamine as energy donor and N-(rhodamine B sulfonyl)-phosphatidylethanolamine as energy acceptor the complex was shown to intercalate into the liposomal lipid matrix. Primary lesions caused by the complex in planar lipid bilayers were revealed as short-living current fluctuations of a broad spectrum of amplitudes. The mycocidal effect of the complex is suggested to be associated with its detergent-like properties.
permeability, mass spectrometry, nuclear magnetic resonance spectroscopy, detergent, Cryptococcus, yeast, cellobiose lipid, mycocidal effect, lipid membrane
Structure type: oligomer ; 653.37 [M-H]-, 821.41 [M-H]-| New query | Export IDs | Home | Help |
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