Neutron Reflection Studies for the Strong Insertion of Sphingosine in Lipid Membrane at the Solid/Liquid Interface

Sphingosine, an important component of the sphingolipids, serves as the backbone of the sphingolipids, and works as the signal molecule to regulate cell fate. The incursion of sphingosine into membranes is always accompanied by an increase of membrane permeability, which results in the leakage from the cytosol, and eventually the cell death. The reason why the sphingosine increases the membrane permeability is currently unclear, but structural changes in the membrane after incorporating sphingosine must play an important role. We propose to use neutron reflectivity (NR) combining with deuterium labelling technique to investigate the planar lipid membrane structure at the solid/water interface in the presence of sphingosine with two various hydrophobic chains. This study will provide the basic understanding of the interfacial behaviour of sphingosine and will give constructive support to elucidate how the unique structure of sphingosine affect the membrane.