Lipid bilayer membranes are known to form various structures like large sheets or vesicles. To bridge the gap between what can be studied experimentally and what can be studied using atomistic models, we study these structures using coarse-grained molecular dynamics simulations. In first instance, we have used our coarse-grained lipid model to study spontaneous vesicle formation [1], showing the role of entropy in the bilayer-vesicle transition. Subsequently, such spontaneously formed vesicles have been used to study fusion [2,3] in which various mechanisms can be discerned. Finally, our coarse grained model is used to study mixtures of lipids. This shows that the positioning of domains with different lipid types opposite to each other induces spontaneous curvature in a membrane and that even small differences in the lipid-solvent interactions already result in such spontaneous curvature. This has a tremendous influence on vesicle shapes, resulting in ellipsoids, discoids, pear-shaped vesicles, cup- shaped vesicles, as well as budded vesicles [4].

[1] A.J. Markvoort et al., J. Phys. Chem. B, 2005, 109, 22649-22654
[2] A.F. Smeijers et al., J. Phys. Chem. B, 2006, 110, 13212-13219
[3] A.F. Smeijers et al., J. Phys. Chem. B, 2006, 110, 13614-13623
[4] A.J. Markvoort et al., J. Phys. Chem. B, 2006 (In press)