National Institute of Health
Live broadcast available:
Our lab at the NIH uses molecular simulation to study the role of lipids in membrane reshaping processes. In particular, we focus on how lipid chemistry determines the mechanical properties of lipid bilayers. A major target of our analysis is the work required from the cell to reshape membranes into new shapes, such as the vesicles it uses to traffic cargo. The energy required to create a vesicle is typically understood in terms of membrane stiffness, analogous to the Young’s modulus but treated somewhat differently, as membranes are closer to thin liquid crystals than solid materials. With hundreds of different types of lipids diffusing on the membrane surface, its fluctuations and softness are extremely complex. I will discuss our latest simulation efforts to determine how individual lipids, as well as the interactions between them, determine the shapes that a membrane will form. Our analysis isolates the influence of hydrogen bonding and cation-mediated interactions that perturb stresses locally, acting as defects that soften biological membranes. Finally, I will report our labs finding of the unexpected way that cholesterol perturbs the structure, and thus stability, of fusion pores. Such pores are intermediates in membrane reshaping, including viral entry and exit.
Dr. Sodt received degrees in chemistry and physics (B.S.) from the University of Washington, Seattle, performing undergraduate research with Prof. Bart Kahr. He then electronic structure theory and quantum chemistry with Prof. Martin Head-Gordon at the University of California, Berkeley, earning his Ph.D. in 2007. Following a post-doc with Prof. Teresa Head-Gordon developing coarse-grained models of lipids and transmembrane protein structure, he moved to the NHLBI of the NIH to study the properties of lipids with Dr. Richard Pastor.