title: Structure of 1-acyl lysophosphatidylcholine and fatty acid complex in bilayers.
abstract: The phase transition characteristics of bilayers formed in a codispersion of 1-acyl lysophosphatidylcholine and a fatty acid depend on the chain length of both the components and on the pH of the aqueous medium. Incorporation of cholesterol as a third component abolishes the transition. It is suggested that acyl chain interactions between fatty acid and 1-acyl lysophosphatidylcholine molecules in their aqueous codispersions are maximized by close-packing such that the acyl chains of both molecules are aligned parallel to each other and the carboxyl group is located in the vicinity of the 2-hydroxyl group of lysophosphatidylcholine. The shape and size of a functional dimer thus formed are similar but not identical to those of 1,2-diacyl phosphatidylcholine. Several predictions arising from this suggestion, including phase separation in codispersions of fatty acid + 1-acyl lysophosphatidylcholine + diacyl phosphatidylcholine, are experimentally confirmed.
mesh_terms: D002152:Calorimetry, Differential Scanning; D005614:Freeze Fracturing; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers; D008244:Lysophosphatidylcholines; D008854:Microscopy, Electron; D010169:Palmitic Acids; D013329:Structure-Activity Relationship
chemical_list: D008051:Lipid Bilayers; D008244:Lysophosphatidylcholines; D010169:Palmitic Acids