MscL gating in liposome


Publication in Proc. Nat. Acad. Sci. USA

M. Louhivuori, H.J. Risselada, E. van der Giessen, S.J. Marrink
Release of content through mechano-sensitive gates in pressurized liposomes.
PNAS, 107 (46) 19856-19860, 2010. open access

Abstract: Mechano-sensitive channels are ubiquitous membrane proteins that activate in response to increasing tension in the lipid membrane. They facilitate a sudden, nonselective release of solutes and water that safeguards the integrity of the cell in hypo- or hyper-osmotic shock conditions. We have simulated the rapid release of content from a pressurized liposome through a particular mechano-sensitive protein channel, MscL, embedded in the liposomal membrane. We show that a single channel is able to relax the liposome, stressed to the point of bursting, in a matter of microseconds. We map the full activation–deactivation cycle of MscL in near-atomic detail and are able to quantify the rapid decrease in liposomal stress as a result of channel activation. This provides a computational tool that opens the way to contribute to the rational design of functional nano-containers.