Molecular volumes in lipid bilayers and the biophysics of lipids in the lungs

Professor Harper and Brian Seper report on their summer research

First we’ll delve into the phase behavior and temperature dependent volumes of a series of monoglycerides that form lipid bilayers.   From our data, we’ll show that the methylene (CH₂) groups in bilayers occupy a volume about 2% larger than the methylenes in liquid alkanes.  For a rough sense of scale, we note that to effect a 2% reduction in volume requires of order 200 atmospheres of pressure; pressures of this magnitude are biologically relevant. For instance, this amount of pressure is sufficient to reverse the effect of anesthesia.  Next, we’ll look at the crucial role that lipids and proteins play in healthy lung function.   We know that the proteins are essential and that they have strong interactions with lipids, but we don’t know (as of yet) how they perform their key functions.   We have begun a project to determine what the proteins do and we’ll discuss our initial steps and outline plans for future research.