Characterization of domain instabilities in lipid bilayers by Karhunen-Loeve analysis

We study the stability of lipid bilayers with artificial domains. In investigating different domain structures, we identify scenarios of stable and unstable arrangements of patches of mixed phospholipids. These are then characterized using Karhunen-Loeve Expansion (KLE), a special form of Principal Components Analysis (PCA). The simulation data are interrogated using KLE to reveal spatiotemporal patterns that explain relevant motions in the bilayer system. By projecting the high-dimensional dataset onto a small number of key modes, KLE reveals specific dynamic signatures that can help distinguish and characterize various domain instability mechanisms. We find that typically very few modes are responsible for describing a mechanism of instability to a reasonable extent and can clearly distinguish between stable and unstable arrangements. Different instability modes are characterized as they exhibit unique features like global deformation or local mixing modes.