The systems were then solvated with water molecules and neutralized with chloride counterions using Gromacs tools. The simulations were started from two different kinds of starting structures. The small molecules were either placed in the water phase or a snapshot from an already existing simulation was used. The latter approach was used for systems where all molecules were bound to the membrane, as described below. The numbers of water molecules were tuned to produce the desired concentrations. Equilibration of the systems was monitored by analyzing the number of bound particles as a function of time. The simulation times of individual trajectories ranged between approximately 100 ns-5 µs, see tables S3-S13. For selected systems, we prepared also starting structures with all molecules bound in a membrane and confirmed that the number of bound molecules converged to the same value as from a starting configuration with all molecules in the water phase, see Figure .