２０１３年１０月３日 Antti Lamberg氏 （終了）

日時： ２０１３年１０月３日（木）１１：００〜
場所： 首都大学東京　８号館３０４号室
講師： Antti Lamberg氏（京都大学）
題目： Gel-fluid transition in asymmetric lipid bilayers

要旨： The most obvious part of a cell is the cell membrane, which on the microscopic scale is made up of a lipid bilayer. This bilayer, as the name implies, is a structure of two opposing lipid leaflets and self-assembles in water. There are two main approaches to doing experiments on pure bilayers: One can either prepare vesicles, i.e. spherical structures, or grow a planar membrane on a support. Both methods, due to vesicle curvature or due to the support being very close to one side of the membrane, have the leaflets in an unequal standing. While few rigorous studies of bilayer asymmetry have been conducted, this effect is in fact also present in real cells, where a failure to keep up a compositional asymmetry signals apoptosis, cell death. Here we introduce a minimalistic mathematical model of freezing of lipid bilayers, show that asymmetry not only explains some outstanding problems, but also gives rise to novel phenomena, which we suggest to have relevance in thermosensitive protein gating. Finally, we use molecular simulations to verify our predictions and find them in qualitative agreement.