Dr. Volker Knecht "Combining computational and experimental approaches in studies of lipid membranes"
Biomolecular Dynamics Group, Institute of Physics, University of Freiburg, Germany
What |
|
---|---|
When |
Nov 19, 2014 from 04:00 PM to 04:45 PM |
Where | Seminarraum A, FMF, Stefan-Meier-Str. 21, Freiburg, 4:00 PM |
Add event to calendar |
vCal iCal |
We have studied lipid bilayers as models for biomembranes using molecular dynamics (MD) simulations as well as experimental techniques. Here we found that experimental short-range repulsion pressures between tension-free lipid bilayers are reproduced by the MARTINI coarse grained model which in addition reveals the
competing interactions involved. Exposing lipid bilayers to external electric fields we have (i) shown that the still widely used continuum theory by Helmholtz is questionable here, (ii) refined the theory, and (iii) discovered a serious force field issue with the interaction of NaCl with phosphocholine (PC) bilayers which questions a range of
previously published simulation studies. Combining MD results with data from electrophoretic and calorimetric experiments we have inferred separate binding constants for Na+ and Cl- ions, revealing that both ions show similar affinities for PC bilayers, with many implications at a molecular scale. Finally, using MD simulations and electrophoresis experiments we quantify the relative affinity of the antimicrobial peptide for charged versus uncharged lipid bilayers. Our work demonstrates the fruitful synergy between computational and experimental
approaches for studies of biomolecular systems.