Fig. 1: Structure, ionic transport properties, and MD simulation of ferritin nanopore.

a, b Hydrophilic C3 channel (blue) and hydrophobic C4 channel (orange) of ferritin (grey). The C3 channel with the size of 3–5 Å is surrounded by three-folds of Cys126, Asp127, and Glu130, which plays the key role in ion transport. c Cartoon models of inserting ferritin nanopore into the lipid bilayer. d Electrical recording of ferritin nanopore showing voltage-dependent channel opening and closing. e I − V curve obtained from a single ferritin nanopore with nine independent experiments. The centre and error bar represent mean value and standard deviation (SD), respectively. f Histogram and Gaussian fitting of channel conductance obtained from 53 independent single-ferritin recordings at +40 mV. g The multiscale model of ferritin-lipid bilayer system before (left) and after (right) MD equilibrium. The fatty tails and the head group of 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) are colored yellow and red, respectively. Water molecules are marked green. h Relative displacement along three directions between the mass center of ferritin and all phospholipid molecules.