Fig. 4: Sub-MIC Dap on POPG at 37 °C. Tens of minutes.

Intermediate stages a A new structure appeared: dimples, zones of thinner membrane thickness, whose diameter was in the range 7 ± 2 nm. Most dimples diffuse, but some remained static (colour scale: 3 nm). Movie details: frame rate 97 ms; zoom of a full image of 150 nm × 90 nm and 256 × 160 pixels. b The dimple diffusion consisted of swinging trajectories, implying membrane-mediated dimple-dimple attraction (colour scale: 3 nm). b, right, Energy profile of the interaction of the dimples obtained derived from 120 centre-to-centre distance measurements that contains as the oligomers two energy minima. Movie details: frame rate 83 ms; full image of 150 nm × 150 nm and 256 × 256 pixels. c In some membrane zones, clusters of dimples, reminiscent of cubic phases, developed (colour scale: 4 nm). Movie details: frame rate 74 ms; full image of 90 nm × 60 nm and 256 × 160 pixels. d The clusters of dimples were moderately dynamical in time, with moderate internal rearrangements (colour scale: 4 nm). Movie details: frame rate 74 ms; full image of 25 nm × 16 nm and 256 × 160 pixels. e The other deformation found was elongated-humps on top of the POPG membrane. e, left, An elongated-hump in the proximity of a cluster of dimples (colour scale: 4 nm). e, right, A close-up and a profile of an elongated-hump. Additional images of elongated-humps on Supplementary Fig. 1. Movie details: frame rate 479 ms; zoom of full image of 250 nm × 200 nm and 300 × 256 pixels. f It was observed that the dimples and the elongated-humps fused and gave yield to pores of toroidal structure where a protruding ring surrounds the pore (colour scale: 4 nm). Movie details: frame rate 74 ms; full image of 40 nm × 40 nm and 256 × 160 pixels.