Cholesterol enhances PI(4,5)P ₂ head group visibility stabilizing FGF2 membrane recruitment. (A) Potential of mean force (PMF) along with the z component of the distance between the center of masses of the protein and the P atoms of phospholipids in the closest leaflet. 39 windows with 0.1 nm spacing were simulated for 400 ns. The first 200 ns have been discarded from the PMF calculation and considered as equilibration time. (B and C) Charge density profiles along the perpendicular axis of the bilayers, averaged over the last 500 ns of the pure bilayer simulations (no FGF2) without (B) and with 30 mol% cholesterol (C). (D) Charge density profiles for all lipid composition analyzed in this study. (E) Deuterium order parameter (-S_CH) of POPC sn-1 chains calculated from MD simulations for pure POPC membrane and for PI(4,5)P₂-enriched (5 mol%) POPC-based membranes containing either 0, 10, 15, 30, or 50 mol% of cholesterol, respectively. S_CH was evaluated as averaged over the last 500 ns of simulations by taking both leaflets into account. (F) Membrane thickness for a pure POPC membrane and PI(4,5)P₂-enriched (5 mol%) POPC-based membranes containing either 0, 10, 15, 30, or 50 mol% of cholesterol, respectively. The thickness was calculated by measuring the z-component of the center of the mass distance between the two leaflets’ phosphate atoms. The data were averaged over the last 500 ns of the simulations with the error given as SD.