The presence of this bimodal kinetics may be attributed to the fact that the experiment is conducted below the critical temperature for the crystalline gel/liquid membrane transition, which may affect both the binding of indolicidin and the lipid flipping kinetics. Experimental evidence of very fast iondischarge at T > T m (top right plot of figure ) suggests that, for the same membrane composition, the fluid phase facilitates the lipid flipping and thus the opening of the transient pores necessary for ion translocation. On the contrary, below T m , only a fraction of the vesicles responds to the presence of the AMP. In particular, the broad peak of the heat capacity, as previously determined by DSC , suggests the presence of partially melted areas constituting the fast decaying population. Furthermore, this is also consistent with the small degree of deformation observed in the SAXS curves of the equilibrated samples at low temperatures and high salt concentration (Fig. and 2C), which are attributed to deformations in some vesicles potentially connected to an uneven distribution of peptides across vesicles. That again would explain the important contribution of the curves with a very low initial number of pores. The experimental and computational results show that even a small number of short-lived transient pores is enough to rapidly equilibrate the large salt gradients, without the need for structural membrane perturbations or pores.