title: Probing the Role of Ceramide Headgroup Polarity in Short-Chain Model Skin Barrier Lipid Mixtures by ²H Solid-State NMR Spectroscopy.
abstract: The thermoptropic phase behaviors of two stratum corneum model lipid mixtures composed of equimolar contributions of either Cer[NS18] or Cer[NP18] with stearic acid and cholesterol were compared. Each component of the mixture was specifically deuterated such that the temperature-dependent (2)H NMR spectra allowed disentanglement of the complicated phase polymorphism of these lipid mixtures. While Cer[NS] is based on the sphingosine backbone, Cer[NP] features a phytosphingosine, which introduces an additional hydroxyl group into the headgroup of the ceramide and abolishes the double bond. From the NMR spectra, the individual contributions of all lipids to the respective phases could be determined. The comparison of the two lipid mixtures reveals that Cer[NP] containing mixtures have a tendency to form more fluid phases. It is concluded that the additional hydroxyl group of the phytosphingosine-containing ceramide Cer[NP18] in mixture with chain-matched stearic acid and cholesterol creates a packing defect that destabilizes the orthorhombic phase state of canonical SC mixtures. This steric clash favors the gel phase and promotes formation of fluid phases of Cer[NP] containing lipid mixtures at lower temperature compared to those containing Cer[NS18].
authors.affiliation: Institute of Medical Physics and Biophysics, University of Leipzig , Härtelstrasse 16-18, 04107 Leipzig, Germany.
authors.forename: Sören
authors.initials: S
authors.lastname: Stahlberg
authors.affiliation: Institute of Pharmacy, Martin Luther University Halle-Wittenberg , Wolfgang-Langenbeck-Strasse 4, 06120 Halle, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Lange
authors.affiliation: Institute of Pharmacy, Martin Luther University Halle-Wittenberg , Wolfgang-Langenbeck-Strasse 4, 06120 Halle, Germany.
authors.forename: Bodo
authors.initials: B
authors.lastname: Dobner
authors.affiliation: Institute of Medical Physics and Biophysics, University of Leipzig , Härtelstrasse 16-18, 04107 Leipzig, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Huster
mesh_terms: D002518:Ceramides / Q000737:chemistry*; D002784:Cholesterol / Q000737:chemistry; D003903:Deuterium; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D046911:Macromolecular Substances / Q000737:chemistry*; D015394:Molecular Structure; D009943:Organophosphorus Compounds; D066244:Proton Magnetic Resonance Spectroscopy; D013110:Sphingosine / Q000031:analogs & derivatives; D013229:Stearic Acids / Q000737:chemistry; D013696:Temperature; D014230:Triazoles
chemical_list: D002518:Ceramides; D046911:Macromolecular Substances; D009943:Organophosphorus Compounds; D013229:Stearic Acids; D014230:Triazoles; C496388:benzotriazol-1-yloxtri (pyrrolidinol)phosphonium hexafluorophosphate; C031183:stearic acid; D002784:Cholesterol; D003903:Deuterium; C012491:phytosphingosine; D013110:Sphingosine