title: Cholesterol rotation in phospholipid vesicles as observed by 13C-NMR.
abstract: 13C-NMR spectra of cholesterol 90% enriched at C-4 with 13C have been obtained in CHCl3 and in sonicated egg phosphatidylcholine vesicles. 13C spin-lattice relaxation times, nuclear Overhauser effects and spin-spin relaxation times have been measured for the C-4 carbon of cholesterol in phosphatidylcholine bilayers as a function of cholesterol content and temperature. All the data are consistent with a correlation time for axial rotation of about 10(-10) s. This rotation is one or two orders of magnitude faster than axial rotation of the phospholipid molecule.
mesh_terms: D002784:Cholesterol; D008051:Lipid Bilayers; D009682:Magnetic Resonance Spectroscopy; D008433:Mathematics; D008968:Molecular Conformation; D010713:Phosphatidylcholines
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D002784:Cholesterol