Observation of Undulation Motion of Lipid Bilayers by Neutron Spin Echo

Abstract

Aqueous solutions of synthesized phospholipids have been well investigated as model biomembranes. These lipids usually self-assemble into regular stacks of bilayers with a characteristic repeat distance on the order of nm, whereas real biomembranes exist as single bilayers. The key phenomenon in understanding the formation of single isolated bilayers is "unbinding" of lipid bilayers, in which the inter-bilayer distance of lipid bilayers diverges by the steric interaction due to the membrane undulation. In this paper, we show some results of neutron spin-echo (NSE) experiments to investigate the effect of the steric interaction on unbinding and related phenomena.