Free energy profile: In order to comprehend and quantify the process of CCBu internalizing into the membrane, enhanced sampling methods allowing the calculation of the related free energy profiles has been performed. In particular, and coherently with the strategy previously used we relied to the combination of extended adaptive biased force (eABF) with metadynamics leading to the meta-eABF strategy which allows an efficient and faster exploration of complex and rough free energy potentials. As a collective variable (CV) we chose, for the system comprising only one CCBu unit, the distance along the Z-axis between the centers of mass of the CCBu and the lipid bilayer as our CV. The highest boundary of the system (55.0 Å on Oz axis) and the center of the lipid bilayer (0.0 Å on Oz axis) were used as limits for the meta-eABF procedure. The meta-eABF was propagated for 660 ns to ensure proper sampling of the conformational space and obtain a well-converged potential of mean force, also checking that the full collective variable has been explored. Free energy calculations have been performed using NAMD and the Colvar module. Simulation of E/Z-photoisomerization: