title: NMR-based conformational analysis of sphingomyelin in bicelles.
abstract: Sphingomyelin (SM) is a common sphingolipid in mammalian membranes and is known to be substantially involved in cellular events such as the formation of lipid rafts. Despite its biological significance, conformation of SM in a membrane environment remains unclear because the noncrystalline property and anisotropic environment of lipid bilayers hampers the application of X-ray crystallography and NMR measurements. In this study, to elucidate the conformation of SM in membranes, we utilized bicelles as a substitute for a lipid bilayer membrane. First, we demonstrated through (31)P NMR, (2)H NMR, and dynamic light scattering experiments that SM forms both oriented and isotropic bicelles by changing the ratio of SM/dihexanoyl phosphatidylcholine. Then, we determined the conformation of SM in isotropic bicelles on the basis of coupling constants and NOE correlations in (1)H NMR and found that the C2-C6 and amide groups of SM take a relatively rigid conformation in bicelles.
authors: Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors: Toshiyuki
authors: T
authors: Yamaguchi
authors: Takashi
authors: T
authors: Suzuki
authors: Tomokazu
authors: T
authors: Yasuda
authors: Tohru
authors: T
authors: Oishi
authors: Nobuaki
authors: N
authors: Matsumori
authors: Michio
authors: M
authors: Murata
mesh_terms: D018360:Crystallography, X-Ray; D008027:Light; D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D012542:Scattering, Radiation; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D008051:Lipid Bilayers; D013109:Sphingomyelins