Synthetic trehalose glycolipids confer desiccation resistance to supported lipid monolayers

Lipid-derived desiccation resistance in membranes is a rare, unique ability previously observed only with trehalose dimycolate (TDM), an abundant mycobacterial glycolipid. Here we present the first synthetic trehalose glycolipids capable of providing desiccation protection to membranes of which they are constituents. The synthetic glycolipids consist of a simple trehalose disaccharide headgroup, similar to TDM, with hydrophobic tail groups of two 15- or 18-carbon chains. The synthetic trehalose glycolipids protected supported monolayers of phospholipids against dehydration even as minority components of the overall membrane, down to as little as 20 mol % trehalose glycolipid as assessed by assays of membrane fluidity. The dependence of the desiccation protection on the synthetic trehalose glycolipid fraction is nearly identical to that of TDM. The striking similarity of the desiccation resistance observed with TDM and the synthetic trehalose glycolipids, despite the variety of hydrophobic tail structures employed, suggests that interactions between the trehalose headgroup and surrounding molecules are the determining factor in dehydration protection.