We study structural and dynamical properties of biomembranes, especially the role of cholesterol in these membranes and also the interactions of peptides and proteins with biomembranes. We use computer simulation techniques to perform our studies. Membranes of modern cells have come to serve many roles outside that of a simple barrier. They are not simply aggregates of amphipathic lipids, but are mosaics containing multiple molecular components such as phospholipids, sphingolipids, various forms of cholesterol, and anchored or embedded proteins. The goal of our research on structural and dynamical properties of membranes containing cholesterol is to gain knowledge about the nature of phospholipid-cholesterol interactions that play an important role in functioning of membranes, in cell communications and in formation of domains called lipid rafts. Detailed knowledge of the membrane properties helps us to understand the normal functioning of cells and it is instrumental in the search for a cure from a large variety of diseases.

We also study the interaction of peptides and membranes. Specifically we study the interaction of the A-beta peptide with lipids in the membrane. It is well known that Alzheimer’s is an aggregation disorder with A-beta being the aggregating species. However, it is unknown what initiates this aggregation. Experimental evidence has shown that A-beta peptides will undergo a conformational change to an aggregate structure when interacting with surfaces of certain lipid membranes. It is of interest to our group to understand what causes this conformational change and what properties of lipids most promote this effect.