(102e) Atomistic Simulations of the Action of Trehalose On Dehydrated Membranes the Water Replacement Hypothesis Revisited

Trehalose is known to stabilize dry membranes by interactions with the polar groups of phospholipids. Interactions with trehalose maintain spacing between membrane lipids and prevent membrane phase transitions. In this study, we use molecular dynamics simulations (MD) to investigate the influence of trehalose on the structural properties of dehydrated bilayers in atomic details. The starting conformation of palmitoyloleolylphosphatidylcholine (POPC) lipid bilayer in excess water has been obtained by self-assembly. A series of MD of POPC with different degrees of dehydration (11.7 and 5.4 waters per lipid) and different trehalose:lipid ratios (<1:1; 1:1; >1:1) were carried out in NPT ensemble. We studied membrane fluidity mainly using area per lipid (APL). The influence of water content and trehalose on APL and related structural properties is modified by interpenetration of interfaces via periodic boundary conditions (PBC). The headgroup reorients from pointing outwards to inwards with dehydration, which is a possible mechanism of the interfaces interpenetration in the stack bilayer.