ADP/ATP carrier. The protein structure (PDB ID 1OKC) was prepared as described above for Kir2.2. For Martini 3, two systems were prepared with a lipid bilayer consisting of 45% POPC, 35% POPE, and (i) 20% cardiolipins with PO tails (namely, POCL) or (ii) 20% tetra-linoleoyl cardiolipins (namely, TLCL). Martini 2 CG system: A Martini 2 system was prepared using the python3 version of the martinize.py script, version 2.6_3, available from the Martini website. The elastic network was applied with the same upper bond cutoff and force constant as for the Martini 3 systems, using the elnedyn22 option . The POCL lipid mixture and water and ions were added with insane .