Figure 9:

Results of molecular dynamics simulations. (A) Potentials of mean force (PMFs) of 3-oxo-C12-AHL (blue) and 3-oxo-C12-HS (orange) as a function of the distance along the DOPC bilayer normal (z). The midplane of the membrane is at z = 0 nm and the PMF is set to zero at z = 4 nm. Each curve shows the average of two independent PMFs and error bars show the standard deviation. The plots also illustrate the definition of ΔG_par as the free energy difference between the PMF minimum and the value in solution and ΔG_trans as the free energy difference between the PMF minimum and maximum. (B) Snapshots showing configurations of AHLs and bilayers for different characteristic values of z in the PMF of 3-oxo-C12-AHL. A snapshot for z = 0 nm for 3-oxo-C12-HS is shown to highlight the local bilayer disruption that contributes to the larger value of ΔG_trans. Lipid head groups are yellow/orange, AHL heads are red, AHL tail groups are cyan, and water is drawn as red and white. Lipid tail groups are not shown for clarity. (C) Table showing ΔG_par and ΔG_trans values for all molecules simulated here.