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Lúcia Helena Faccioli - One of the best experts on this subject based on the ideXlab platform.
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A lipidomics approach reveals new insights into Crotalus durissus terrificus and Bothrops moojeni snake venoms
Archives of Toxicology, 2020Co-Authors: Tanize Acunha, Viviani Nardini, Lúcia Helena FaccioliAbstract:Snakebite envenomation causes > 81,000 deaths and incapacities in another 400,000 people worldwide every year. Snake venoms are complex natural secretions comprised of hundreds of different molecules with a wide range of biological functions that after injection cause local and systemic manifestations. Although several studies have investigated snake venoms, the majority have focused on the protein portion (toxins), without significant attention paid to the lipid fraction. Therefore, an untargeted lipidomic approach based on liquid chromatography with high-resolution mass spectrometry (LC-HRMS) was applied to investigate the lipid constituents of venoms of the snake species Crotalus durissus terrificus and Bothrops moojeni . Phosphatidylcholines (PC), Lyso-PCs, phosphatidylethanolamines (PE), Lyso-PE, phosphatidylserine (PS), phosphatidylinositol (PI), ceramides (Cer), and sphingomyelin (SM) species were detected in the analyzed snake venoms. The identified lipids included bioactive compounds such as platelet-activating factor (PAF) precursor, PAF-like molecules, plasmalogens, ceramides, and Sphingomyelins with long fatty acid chain lengths, which may be associated with the systemic responses triggered by C. d. terrificus and B. moojeni envenomation. These responses include platelet aggregation, activation of intercellular adhesion molecule 1 (ICAM1), apoptosis, as well as the production of pro-inflammatory lipid mediators, cytokines, and reactive species. The newly proposed lipidomics strategy provided valuable information regarding the lipid profiles of viperid venoms, which could lead to increased understanding of the complex pathology promoted by snakebite envenomation.
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A lipidomics approach reveals new insights into Crotalus durissus terrificus and Bothrops moojeni snake venoms
Archives of Toxicology, 2020Co-Authors: Tanize Acunha, Viviani Nardini, Lúcia Helena FaccioliAbstract:Snakebite envenomation causes > 81,000 deaths and incapacities in another 400,000 people worldwide every year. Snake venoms are complex natural secretions comprised of hundreds of different molecules with a wide range of biological functions that after injection cause local and systemic manifestations. Although several studies have investigated snake venoms, the majority have focused on the protein portion (toxins), without significant attention paid to the lipid fraction. Therefore, an untargeted lipidomic approach based on liquid chromatography with high-resolution mass spectrometry (LC-HRMS) was applied to investigate the lipid constituents of venoms of the snake species Crotalus durissus terrificus and Bothrops moojeni . Phosphatidylcholines (PC), Lyso-PCs, phosphatidylethanolamines (PE), Lyso-PE, phosphatidylserine (PS), phosphatidylinositol (PI), ceramides (Cer), and sphingomyelin (SM) species were detected in the analyzed snake venoms. The identified lipids included bioactive compounds such as platelet-activating factor (PAF) precursor, PAF-like molecules, plasmalogens, ceramides, and Sphingomyelins with long fatty acid chain lengths, which may be associated with the systemic responses triggered by C. d. terrificus and B. moojeni envenomation. These responses include platelet aggregation, activation of intercellular adhesion molecule 1 (ICAM1), apoptosis, as well as the production of pro-inflammatory lipid mediators, cytokines, and reactive species. The newly proposed lipidomics strategy provided valuable information regarding the lipid profiles of viperid venoms, which could lead to increased understanding of the complex pathology promoted by snakebite envenomation.
Richard M. Epand - One of the best experts on this subject based on the ideXlab platform.
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Non-raft forming sphingomyelin-cholesterol mixtures.
Chemistry and physics of lipids, 2004Co-Authors: Richard M. EpandAbstract:Sphingomyelin from biological membranes forms segregated domains with cholesterol in fluid bilayers. However, a synthetic form of sphingomyelin with an oleoyl chain linked to sphingosine is not incorporated into cholesterol-rich domains. We have studied the properties of mixtures of oleoyl-sphingomyelin and cholesterol as well as mixtures of oleoyl-sphingomyelin with 1-stearoyl-2-oleoyl-phosphatidylcholine by DSC and NMR. Cholesterol has a high miscibility with oleoyl-sphingomyelin and it does not separate in crystalline form until the mol fraction of cholesterol reaches a value above 0.6. A large fraction of the cholesterol crystals that are formed are in the monohydrate form. Furthermore, these crystals rehydrate relatively rapidly compared with pure cholesterol crystals in the absence of phospholipid. The environment of the carbonyl group of the phospholipid indicates that it is similar to other forms of sphingomyelin with saturated acyl chains. Also similar to other forms of sphingomyelin, the quaternary ammonium group of oleoyl-sphingomyelin is more rigid than that of phosphatidylcholines, as indicated by the strong resonance observed with cross-polarization/magic angle spinning. Additionally, oleoyl-sphingomyelin produces a larger alteration than egg sphingomyelin of the phase transition of 1-stearoyl-2-oleoyl-phosphatidylcholine. These studies indicate that oleoyl-sphingomyelin, unlike saturated forms of sphingomyelin, does not form segregated domains with cholesterol because of its greater miscibility with phosphatidylcholine.
Tanize Acunha - One of the best experts on this subject based on the ideXlab platform.
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A lipidomics approach reveals new insights into Crotalus durissus terrificus and Bothrops moojeni snake venoms
Archives of Toxicology, 2020Co-Authors: Tanize Acunha, Viviani Nardini, Lúcia Helena FaccioliAbstract:Snakebite envenomation causes > 81,000 deaths and incapacities in another 400,000 people worldwide every year. Snake venoms are complex natural secretions comprised of hundreds of different molecules with a wide range of biological functions that after injection cause local and systemic manifestations. Although several studies have investigated snake venoms, the majority have focused on the protein portion (toxins), without significant attention paid to the lipid fraction. Therefore, an untargeted lipidomic approach based on liquid chromatography with high-resolution mass spectrometry (LC-HRMS) was applied to investigate the lipid constituents of venoms of the snake species Crotalus durissus terrificus and Bothrops moojeni . Phosphatidylcholines (PC), Lyso-PCs, phosphatidylethanolamines (PE), Lyso-PE, phosphatidylserine (PS), phosphatidylinositol (PI), ceramides (Cer), and sphingomyelin (SM) species were detected in the analyzed snake venoms. The identified lipids included bioactive compounds such as platelet-activating factor (PAF) precursor, PAF-like molecules, plasmalogens, ceramides, and Sphingomyelins with long fatty acid chain lengths, which may be associated with the systemic responses triggered by C. d. terrificus and B. moojeni envenomation. These responses include platelet aggregation, activation of intercellular adhesion molecule 1 (ICAM1), apoptosis, as well as the production of pro-inflammatory lipid mediators, cytokines, and reactive species. The newly proposed lipidomics strategy provided valuable information regarding the lipid profiles of viperid venoms, which could lead to increased understanding of the complex pathology promoted by snakebite envenomation.
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A lipidomics approach reveals new insights into Crotalus durissus terrificus and Bothrops moojeni snake venoms
Archives of Toxicology, 2020Co-Authors: Tanize Acunha, Viviani Nardini, Lúcia Helena FaccioliAbstract:Snakebite envenomation causes > 81,000 deaths and incapacities in another 400,000 people worldwide every year. Snake venoms are complex natural secretions comprised of hundreds of different molecules with a wide range of biological functions that after injection cause local and systemic manifestations. Although several studies have investigated snake venoms, the majority have focused on the protein portion (toxins), without significant attention paid to the lipid fraction. Therefore, an untargeted lipidomic approach based on liquid chromatography with high-resolution mass spectrometry (LC-HRMS) was applied to investigate the lipid constituents of venoms of the snake species Crotalus durissus terrificus and Bothrops moojeni . Phosphatidylcholines (PC), Lyso-PCs, phosphatidylethanolamines (PE), Lyso-PE, phosphatidylserine (PS), phosphatidylinositol (PI), ceramides (Cer), and sphingomyelin (SM) species were detected in the analyzed snake venoms. The identified lipids included bioactive compounds such as platelet-activating factor (PAF) precursor, PAF-like molecules, plasmalogens, ceramides, and Sphingomyelins with long fatty acid chain lengths, which may be associated with the systemic responses triggered by C. d. terrificus and B. moojeni envenomation. These responses include platelet aggregation, activation of intercellular adhesion molecule 1 (ICAM1), apoptosis, as well as the production of pro-inflammatory lipid mediators, cytokines, and reactive species. The newly proposed lipidomics strategy provided valuable information regarding the lipid profiles of viperid venoms, which could lead to increased understanding of the complex pathology promoted by snakebite envenomation.
Claude Wolf - One of the best experts on this subject based on the ideXlab platform.
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Thermotropic and structural evaluation of the interaction of natural Sphingomyelins with cholesterol.
Biochimica et Biophysica Acta, 2009Co-Authors: Peter J Quinn, Claude WolfAbstract:Abstract The structural transitions in aqueous dispersions of egg-sphingomyelin and bovine brain-sphingomyelin and sphingomyelin co-dispersed with different proportions of cholesterol were compared during temperature scans between 20° and 50 °C using small-angle and wide-angle X-ray scattering techniques. The Bragg reflections observed in the small-angle scattering region from pure phospholipids and codispersions of sphingomyelin:cholesterol in molar ratios 80:20 and 50:50 could all be deconvolved using peak fitting methods into two coexisting lamellar structures. Electron density profiles through the unit cell normal to the bilayer plane were calculated to derive bilayer and water layer thicknesses of coexisting structures at 20° and 50 °C. Codispersions of sphingomyelin:cholesterol in a molar ratio 60:40 consisted of an apparently homogeneous bilayer structure designated as liquid-ordered phase. Curve fitting analysis of the wide-angle scattering bands were applied to correlate changes in packing arrangements of hydrocarbon in the hydrophobic domain of the bilayer with changes in enthalpy recorded by differential scanning calorimetry. At 20 °C the wide-angle scattering bands of both pure Sphingomyelins and codispersions of sphingomyelin and cholesterol could be deconvolved into two symmetric components. A sharp component located at a d-spacing of 0.42 nm was assigned to a gel phase in which the hydrocarbon chains are oriented perpendicular to the bilayer plane. A broader symmetric band centered at d-spacings in the region of 0.44 nm was assigned as disordered hydrocarbon in dispersions of pure sphingomyelin and as liquid-ordered phase in codispersions of sphingomyelin and cholesterol. It is concluded from the peak fitting analysis that cholesterol is excluded from gel phases of egg and brain Sphingomyelins at 20 °C. The gel phases coexist with liquid-ordered phase comprised of egg-sphingomyelin and 27 mol% cholesterol and brain-sphingomyelin and 33 mol% cholesterol, respectively. Correlation of the disappearance of gel phase during heating scans and the enthalpy change recorded by calorimetry in codispersions of sphingomyelin and cholesterol leads to the conclusion that a major contribution to the broadened phase transition endotherm originates from dilution of the cholesterol-rich liquid-ordered phase by mobilization of sphingomyelin from the melting gel phase.
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hydrocarbon chains dominate coupling and phase coexistence in bilayers of natural phosphatidylcholines and Sphingomyelins
Biochimica et Biophysica Acta, 2009Co-Authors: Peter J Quinn, Claude WolfAbstract:The structure and thermotropic phase behaviour of aqueous dispersions of egg phosphatidylcholine, egg sphingomyelin, bovine brain sphingomyelin and binary mixtures of phosphatidylcholine and Sphingomyelins have been examined by synchrotron X-ray diffraction methods. Small-angle lamellar Bragg peaks and wide-angle X-ray scattering bands have been subjected to peak fitting procedures to identify coexisting gel and fluid as well as fluid–fluid bilayer structures. Molecular species of egg phosphatidylcholine exhibit fluid–fluid immiscibility throughout heating scans from 20 ° to 50 °C. Egg and brain Sphingomyelins exhibit gel–fluid bilayer coexistence at temperatures below the main phase transition temperature and fluid–fluid phase coexistence at higher temperatures. Binary mixtures of equimolar proportions of egg phosphatidylcholine and either of the Sphingomyelins show gel–fluid phase coexistence at temperatures below the gel phase transition temperature of the respective sphingomyelin. Binary mixtures containing egg sphingomyelin show fluid–fluid immiscibility at all temperatures of the heating scans whereas the fluid phase of mixtures comprising brain sphingomyelin are apparently miscible at all temperatures. An analysis of binary mixtures containing egg sphingomyelin and egg phosphatidylcholine in molar ratios 50:50, 67:33 and 83:17 at 50 °C to identify the composition of the lamellar phases indicated that the two phospholipids are immiscible in bilayers in the fluid phase. The results are discussed in terms of the role of intermolecular hydrogen bonds and hydrocarbon chain composition of Sphingomyelins in maintaining coupling across fluid bilayers.
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blood Sphingomyelins from two european countries
Biochimica et Biophysica Acta, 1995Co-Authors: Haralambos Katsikas, Claude WolfAbstract:The objectives of this study were to isolate and analyse human blood Sphingomyelins from two European populations which have significant differences in both the composition of dietary fat source and the rate of mortality from coronary heart disease. Blood samples have been taken from healthy adult volunteers from a Greek (Thessaloniki) and a French (Paris) region. The sphingomyelin fraction from red blood cells and plasma, separately, have been isolated by thin-layer chromatography and analysed by mass spectrometry after soft chemical ionisation with gas ammonia. The conditions used gave spectra with three discrete areas which correspond to ions coming from sphingoid bases, fatty acids and ceramides. Eight sphingoid bases have been detected in both red blood cells and plasma. Sphingosine was the major contributor. The rest of the sphingoid bases have 16 to 19 carbon atoms and 0 to 2 double bonds. Fourteen fatty acids, the same for red blood cells and plasma, have been detected with 16 to 26 carbon atoms and 0 to 2 double bonds. Palmitic acid was the most abundant fatty acid. Thirty eight ceramides have been detected in red blood cells and forty in plasma. Thirty six ceramides were common in red blood cells and plasma. Statistically significant differences (P < 0.01) have been detected between the two populations for some sphingoid bases, fatty acids and ceramides. Differences have also been found between the two populations in the degree of saturation of these sphingomyelin parts. These differences are attributed to (a) high monounsaturated fat, olive oil, consumption by Greeks and (b) other environmental and genetic factors. It is suggested that the detected differences between the two populations contribute to the different coronary heart disease rates observed among Greeks and French.
Rhoderick E. Brown - One of the best experts on this subject based on the ideXlab platform.
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Sterol Structure and Sphingomyelin Acyl Chain Length Modulate Lateral Packing Elasticity and Detergent Solubility in Model Membranes
Biophysical Journal, 2003Co-Authors: Xin-min Li, Maureen M. Momsen, Howard L. Brockman, Rhoderick E. BrownAbstract:Membrane microdomains, such as caveolae and rafts, are enriched in cholesterol and sphingomyelin, display liquid-ordered phase properties, and putatively function as protein organizing platforms. The goal of this investigation was to identify sterol and sphingomyelin structural features that modulate surface compression and solubilization by detergent because liquid-ordered phase displays low lateral elasticity and resists solubilization by Triton X-100. Compared to cholesterol, sterol structural changes involved either altering the polar headgroup (e.g., 6-ketocholestanol) or eliminating the isooctyl hydrocarbon tail (e.g., 5-androsten-3β-ol). Synthetic changes to sphingomyelin resulted in homogeneous acyl chains of differing length but of biological relevance. Using a Langmuir surface balance, surface compressional moduli were assessed at various surface pressures including those (π ≥ 30 mN/m) that mimic biomembrane conditions. Sphingomyelin-sterol mixtures generally were less elastic in a lateral sense than chain-matched phosphatidylcholine-sterol mixtures at equivalent high sterol mole fractions. Increasing content of 6-ketocholestanol or 5-androsten-3β-ol in sphingomyelin decreased lateral elasticity but much less effectively than cholesterol. Our results indicate that cholesterol is ideally structured for maximally reducing the lateral elasticity of membrane sphingolipids, for enabling resistance to Triton X-100 solubilization, and for interacting with Sphingomyelins that contain saturated acyl chains similar in length to their sphingoid bases.
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cholesterol decreases the interfacial elasticity and detergent solubility of Sphingomyelins
Biochemistry, 2001Co-Authors: Maureen M. Momsen, Howard L. Brockman, Janice M Smaby, Rhoderick E. BrownAbstract:The interfacial interactions of cholesterol with Sphingomyelins (SMs) containing various homogeneous acyl chains have been investigated by Langmuir film balance approaches. Low in-plane elasticity among the packed lipids was identified as an important physical feature of the cholesterol−sphingomyelin liquid-ordered phase that correlates with detergent resistance, a characteristic property of sphingolipid−sterol rafts. Changes in the in-plane elastic packing, produced by cholesterol, were quantitatively assessed by the surface compressional moduli (Cs-1) of the monolayer isotherms. Of special interest were Cs-1 values determined at high surface pressures (>30 mN/m) that mimic the biomembrane situation. To identify structural features that uniquely affect the in-plane elasticity of the sphingomyelin−cholesterol lateral interaction, comparisons were made with phosphatidylcholine (PC)−cholesterol mixtures. Cholesterol markedly decreased the in-plane elasticity of either SM or PC regardless of whether they wer...