ω-6 and ω-3 fatty acids: Monolayer packing and effects on bilayer permeability and cholesterol exchange

Abstract

It has been suggested that the polyunsaturated ω-3 fatty acid, docosahexaenoic acid (DHA), can adopt unique closely packed arrays in lipid bilayers (Glomset and Applegate. (1986) J. Lipid Res. 27, 658-680). These conformations are predicted on the basis of molecular dynamics calculations and are in contrast to the expanded conformations characteristic of ω-6 unsaturated fatty acids. It has also been suggested that close packing of ω-3 acyl chains could have a substantial affect on the physical properties of lipid bilayers (e.g. permeability). We report here some experimental tests of these predictions. Surface pressure-area experiments have been carried out on DHA and its mixtures with stear..