Interaction of gramicidin with DPPC/DODAB bilayer fragments

► In large DPPC/DODAB 1:1vesicles, gramicidin senses a apolar medium and is in the functional channel conformation. ► KCl and glucose freely permeate through gramicidin dimeric channels in the LV bilayer. ► In DPPC/DODAB 1:1 bilayer fragments, gramicidin senses a polar medium and is intertwined. ► Interdigitation in the bilayer might have avoided Gr hydrophobic mismatch.