Melting of lipid chains during simulations. Lipid disorder was calculated from the order parameters of the acyl chains of (A) cardiolipin, (B) POPC, and (C) POPE. The simulations were performed twice, shown as solid and dashed lines. The lines corresponding to different simulations are colored as follows: gray, no c-ring; dark blue, native c8-ring; cyan, demethylated c8-ring; orange, c10-ring; green, c11-ring. The order parameters for cardiolipin were averaged over all four chains; they are shown separately for phosphatidyl POPC and POPE that have chains of differing lengths.