The role of electrostatics in PI(4,5)P 2 -dependent FGF2 membrane recruitment. (A) Electric field integrated from the charge density analysis of Fig. 2 C. (B) Size-aggregation frequency analysis for PM-like membrane composition systems without (gray color) and with 30 mol% of cholesterol (brown color). The analysis was averaged over the two membrane leaflets considering the last 1,000 ns of simulations. Data are shown as the average of both bilayer leaflets, and the error bar represent the standard deviation. Two monomers were considered as a dimer if any of their atoms had a distance of <1.2 nm. (C) Adaptive Poisson-Boltzmann Solver (APBS) calculations on the electrostatic surface of FGF2. (D) PI(4,5)P2 head group localization expressed as mass density for the systems containing either 0 or 30 mol% cholesterol in the presence (upper panel) or absence (lower panel) of interactions with FGF2. Data were averaged over the last 500 ns of the simulations.