Skip to main content
. Author manuscript; available in PMC: 2017 Feb 28.
Published in final edited form as: J Phys Chem B. 2010 Mar 4;114(8):2790–2797. doi: 10.1021/jp909640g

Figure 3.

Figure 3

Distribution of the average number of Na+ counterions involved in the formation of Na+-lipid complexes, known as “ion bonds” in the (1:3) mixed POPG:POPE membrane, averaged over a 4 ns simulation without peptide. SSSP state is the solvent-separated solute pair state, where a water molecule is shared between counterion and any lipid head group oxygen and CSP is the contact solute pairs state. For our system we define the existence of an “ion bond” when any lipid head group oxygen is found within 3.5 Å of a Na+ ion (the CSP state) or within 6.0 Å of Na+ (the SSSP state).