title: Transmembrane asymmetry of vesicle lipids.
abstract: The role of fatty acyl chain unsaturation in promoting asymmetry in phospholipid vesicle bilayers was investigated in mixed lipid systems with differing acyl chains and a constant phosphatidylcholine headgroup. Ratios of outside to inside components were determined by nuclear magnetic resonance spectroscopy of 13C-enriched egg phosphatidylcholine. An asymmetry or disproportionation ratio is defined and used to express quantitatively how a mixture of two lipids distributes in the outer and inner vesicle surfaces. In mixed systems with 13C-enriched egg phosphatidylcholine as one component, increasing fatty acyl unsaturation in the other component results in an increasing preference of the unsaturated chains for the outer surface.
mesh_terms: D001665:Binding Sites; D005227:Fatty Acids; D009682:Magnetic Resonance Spectroscopy; D008567:Membranes, Artificial; D008954:Models, Biological; D008968:Molecular Conformation; D010713:Phosphatidylcholines; D014465:Ultrasonics
chemical_list: D005227:Fatty Acids; D008567:Membranes, Artificial; D010713:Phosphatidylcholines