title: Using 31P MAS NMR to monitor a gel phase thermal disorder transition in sphingomyelin/cholesterol bilayers.
abstract: The impact of low cholesterol concentrations on an egg sphingomyelin bilayer is investigated using 31P magic angle spinning (MAS) NMR spectroscopy. The magnitude of the isotropic 31P MAS NMR line width is used to monitor the main gel to liquid crystalline phase transition, along with a unique gel phase pretransition. In addition, the 31P chemical shift anisotropy (CSA) and spin-spin relaxation times (T2), along with the effects of spinning speed, proton decoupling and magnetic field strength, are reported. The variation of this unique gel phase thermal pretransition with the inclusion of 5 through 21 mol% cholesterol is presented and discussed.
authors.affiliation: Department of Nanostructured and Electronic Materials, Sandia National Laboratories, Albuquerque, NM 87185-0886, USA.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Costello
authors.forename: Todd M
authors.initials: TM
authors.lastname: Alam
mesh_terms: D002152:Calorimetry, Differential Scanning; D002784:Cholesterol / Q000378:metabolism* / Q000494:pharmacology; D003198:Computer Simulation; D005782:Gels / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D044367:Phase Transition / Q000187:drug effects; D010759:Phosphorus Isotopes; D011522:Protons; D013109:Sphingomyelins / Q000378:metabolism*; D013696:Temperature
chemical_list: D005782:Gels; D008051:Lipid Bilayers; D010759:Phosphorus Isotopes; D011522:Protons; D013109:Sphingomyelins; D002784:Cholesterol