title: Probing the gel to liquid-crystalline phase transition and relevant conformation changes in liposomes by (13)C magic-angle spinning NMR spectroscopy.
abstract: A straightforward way to visualize gel to liquid-crystalline phase transition in phospholipid membranes is presented by using ¹³C magic-angle spinning NMR. The changes in the 13C isotropic chemical shifts with increasing temperature are shown to be a sensitive probe of the main thermotropic phase transition related to lipid hydrocarbon chain dynamics and relevant conformational changes. The average value of the energy difference between trans and gauche states in the central C4–11 fragment of the DMPC acyl chain was estimated to be 4.02 ± 0.2 kJ mol⁻¹ in the liquid crystalline phase. The reported spectral features will be useful in 13C solid state NMR studies for direct monitoring of the effective lipid chain melting allowing rapid uniaxial rotation of membrane proteins in the biologically relevant liquid-crystalline phase.
authors.affiliation: École Normale Supérieure, PSL Research University, Paris, France; Sorbonne Universités, UPMC University, Paris, France; CNRS, UMR 7203 LBM, Paris, France.
authors.forename: Rudra N
authors.initials: RN
authors.lastname: Purusottam
authors.affiliation: Sorbonne Universités, UPMC University, Paris, France; CNRS, UMR 7203 LBM, Paris, France.
authors.forename: Lucile
authors.initials: L
authors.lastname: Sénicourt
authors.affiliation: Sorbonne Universités, UPMC University, Paris, France; CNRS, UMR 7203 LBM, Paris, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Lacapère
authors.affiliation: École Normale Supérieure, PSL Research University, Paris, France; Sorbonne Universités, UPMC University, Paris, France; CNRS, UMR 7203 LBM, Paris, France. Electronic address: Piotr.Tekely@ens.fr.
authors.forename: Piotr
authors.initials: P
authors.lastname: Tekely
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D003460:Crystallization; D008081:Liposomes; D008968:Molecular Conformation; D015335:Molecular Probes
chemical_list: D008081:Liposomes; D015335:Molecular Probes
keywords: Conformational changes; DMPC; Membrane proteins; Phase transition; Phospholipids; Solid-state (13)C NMR