Although there have been many studies of proteins whose primary function is to ‘sculpt’ the surface of membranes e.g. BAR domains, there have been very few investigations of what effect regular membrane proteins have on the stiffness of membranes. Here we show via very large simulations, using the MARTINI coarse-grained forcefield, that ‘regular’ integral membrane proteins, such as an ion channel or a beta-barrel, reduce the stiffness of the membrane, leading to larger fluctuations. The systems studied push the boundaries of what is currently achievable with biomolecular simulation, containing around 50,000 lipids and 100 proteins. We had access to the French supercomputer CURIE, through the EU PRACE network, for this work.

This is the second in a set of three papers that bring my research on cell signalling and membranes in the SBCB group within the Department of Biochemistry to a close and is available to download here.