title: Comparison between orientational and conformational orders in fluid lipid bilayers.
abstract: The orientational order as determined by 2H NMR and the infrared frequencies of the C--H stretching modes of the methylene groups have been measured for several systems (POPC, POPC/cholesterol and POPE), all in the fluid phase, and then were compared; this work reveals an unexpected linear correlation between them. This experimental result shows that both measurements are essentially sensitive to a common motion, most likely trans/gauche isomerisation. This new correlation with those already found in the literature suggest that several measurements related to the hydrophobic core of the fluid bilayer describe different aspects of a universal behavior. The correlation presented here does not extend to the lipid in gel phase where slower motions affect the NMR lineshape.
authors.affiliation: Département de chimie, Université de Montréal, Québec, Canada.
authors.forename: V R
authors.initials: VR
authors.lastname: Kodati
authors.forename: M
authors.initials: M
authors.lastname: Lafleur
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D002784:Cholesterol / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008560:Membrane Fluidity; D008567:Membranes, Artificial; D008968:Molecular Conformation; D010743:Phospholipids / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010743:Phospholipids; D002784:Cholesterol