Interaction of long-chain n-alcohols with fluid DOPC bilayers: A neutron diffraction study

Abstract

Lamellar phases composed of fluid dioleoylphosphatidylcholine (DOPC) bilayers containing alkan-1-ols (CnOH, n = 8,10,14,16,18 is the number of carbon atoms) at CnOH : DOPC = 0.3 molar ratio and hydrated with heavy water at 20.2 ≥ D2O : DOPC ≥ 14.4 molar ratio were studied by neutron diffraction. The bilayer thickness dL and the bilayer surface area AL per DOPC at the bilayer-water interface were obtained from the lamellar repeat period d using molecular volumes of DOPC, CnOH and D 2O, and the Luzatti's method. Both the dL and A L increase with the CnOH chain length n at CnOH : DOPC = 0.3 molar ratio: dL = (3.888 ± 0.066) + (0.016 ± 0.005)·n (in nm), AL= (0.6711±0.0107) + (0.0012±0.0008)·n (in nm2).