Here we examine by computer simulation what effect adding a small cell-signalling protein does to a model ternary lipid mixture that has been shown before to phase separate. This paper was presented at the 169th Faraday Discussion meeting in Nottingham in May 2014, the theme of which was Molecular simulations and visualization. We followed the progress of the phase separation of the lipid bilayer by measuring the length of the interface using an edge detection algorithm from image processing. An example python script can be downloaded here.
We found that the protein, NRas, indeed slows down the rate at which the bilayer phase separates. The protein also tends to localise to the interface between the domains which is consistent with it acting to reduce the line tension between the phases.
The questions asked during the discussion (and my answers) will be posted on the journal’s website soon. I’ll update this post when that happens. This paper is open access so is free to download.