SANS study for the distribution and aggregation of Sphingosine in the membrane of large unilamellar vesicles (LUVs)

The incursion of sphingosine in membrane always accompanies with the increase of membrane permeability, which results in the leakage of the substance in cell organelle, and eventually the cell death. The reason why the sphingosine increases the membrane permeability is currently unclear, but changes in the structure of the membrane after incorporating sphingosine must play an important role. A convincing hypothesis is that sphingosine interacts with membrane components, forming nanoscale aggregates in membrane. However, it cannot be fully confirmed due to experimental limitations. We propose to use SANS to reveal the effects of sphingosine with different chain structures on the LUVs model membranes, to obtain the distribution of sphingosine molecules in the membrane, and to determine whether there are nanoscale aggregates formed on the membrane. This study will provide support for elucidating how the molecular structure of sphingosine affects membrane structure and provide evidence for the reason why sphingosine increases membrane permeability.