Abstrakt
The continuum description of lipid membranes via the Helfrich functional and its extensions is widely employed in the modeling of membranes at the mesoscopic scale. A major problem in the application of this theory to membrane remodeling by proteins and other adsorbates is the local modification of membrane shape, lipid composition and elastic properties by adsorbates, such as proteins.
We address this problem by direct incorporation of specific interactions into the local parametrization of the continuum model. For these purposes, we have developed methods to extract the local parameters from molecular simulations at atomic resolution.
Bridging the scales in this way we were able, to explain the lipid specificity of fusion of membrane fusion in presence of Ca2þ via a stalk-mechanism. In order to generalize this approach to complex systems, we have developed a solver based on a quasi-G1 continuous surface representation.
This approach is sufficiently flexible to accommodate contact deformations and lipid demixing phenomena and allows us to explore the origins of mesoscopic membrane deformations. We show a first application to specific effects in the endosomal escape of cell penetrating peptides.