Thermotropic phase behavior of milk sphingomyelin and role of cholesterol in the formation of the liquid ordered phase examined using SR-XRD and DSC
| Autor: | Christelle Lopez, Javier Pérez, Ken Cheng |
|---|---|
| Přispěvatelé: | Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Synchrotron SOLEIL (SOLEIL), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Liquid ordered phase Lipid Bilayers diffraction 01 natural sciences Biochemistry chemistry.chemical_compound [SDV.IDA]Life Sciences [q-bio]/Food engineering Lamellar structure membrane membrane des globules gras milk Molecular Structure xrd Temperature food and beverages cholestérol Sphingomyelins Membrane Cholesterol X-ray crystallography Thermodynamics lipids (amino acids peptides and proteins) Sphingomyelin x ray phospholipide rayon x Surface Properties Phospholipid Thermotropic crystal Phase Transition 03 medical and health sciences Structure-Activity Relationship Differential scanning calorimetry Animals diffraction x Molecular Biology phospholipid 030102 biochemistry & molecular biology 010401 analytical chemistry Organic Chemistry Cell Membrane Cell Biology lait 0104 chemical sciences sphingolipide Crystallography chemistry sphingolipid [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition |
| Zdroj: | Chemistry and Physics of Lipids Chemistry and Physics of Lipids, Elsevier, 2018, 215, pp.46-55. ⟨10.1016/j.chemphyslip.2018.07.008⟩ |
| ISSN: | 0009-3084 |
| DOI: | 10.1016/j.chemphyslip.2018.07.008⟩ |
| Popis: | Sphingomyelin (SM) and cholesterol are major lipid components of biological membranes involved in the formation of ordered domains. In this study, we investigated the biophysical properties of milk-SM bilayers and determined the effect of cholesterol. The thermotropic phase behaviours of milk-SM and milk-SM/cholesterol mixtures were characterized using differential scanning calorimetry (DSC) and high flux synchrotron radiation X-ray diffraction (SR-XRD). The melting phase transition temperature determined for fully hydrated milk-SM bilayers was Tm = 34.3 ± 0.1 °C. The thermotropic phase behavior of milk-SM is complex, reflecting the mixture of different molecular species. Structural reorganisations successively occurring on heating of fully hydrated milk-SM bilayers were interpreted as follows: i) melting of C16:0-SM, ii) conversion of long and saturated SM species from fully interdigitated (Lβ1) to mixed interdigitated (Lβ2) lamellar structures evidencing gel phase polymorphism and then iii) transition to the fluid liquid-crystal Lα phase. We demonstrated that cholesterol modulates the physical properties of milk-SM bilayers and that building up of the lamellar liquid-ordered Lo phase is completed for 33 mol% of cholesterol. The ordering effect of cholesterol on milk-SM bilayers and the temperature-independent behavior of the Lo phase formed by milk-SM/cholesterol complexes were characterized. The findings of this work will contribute in a better understanding of the biological functions exerted by the milk-SM as a function of its phase state and interactions with cholesterol (e.g. hypocholesterolemic effect). |
| Databáze: | OpenAIRE |
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