Membrane interactions of two arginine-rich peptides with different cell internalization capacities

► Two cell penetrating peptides with opposite cell uptake capacities are investigated. ► Their binding, insertion and perturbation of model membranes are studied. ► The peptides share many similarities regarding lipid membrane interaction. ► Subtle differences concern insertion depth, effect on lipid ordering and kinetics. ► Some peptide molecules flipped their orientation with arginines serving as hinges.