Stiffening transition in asymmetric lipid bilayers: The role of highly ordered domains and the effect of temperature and size

Cellular membranes consist of a large variety lipids and proteins, with composition that generally differs between the two leaflets same bilayer. One consequence this asymmetry is thought to be emergence differential stress, i.e., mismatch in lateral tension leaflets. This can affect membrane’s mechanical properties; for instance, it increase bending rigidity once stress exceeds critical threshold. Using coarse-grained molecular dynamics simulations based on MARTINI model, we show effect arises due formation more highly ordered domains compressed leaflet. The threshold increases temperature, indicating transition stiffened regime might restricted limited temperature range above gel transition. We also stiffening occurs readily larger smaller typical curvatures, suggesting easier observe experimentally than small-scale systems accessible simulation.