Figure 4: EPR spectra and simulations of TOAC-labelled peptides in buffer (red), in SUV (blue), and in suspension of T67 cells (magenta).

In the top part of the figure, we show that the spectrum of [TOAC1] TG interacting with cells can be simulated as the sum of the peptide in aqueous solution and bound to the membrane (the salient parameters of the simulations are reported in Table 2). In the bottom part of the figure, we show the spectra and the simulations of the other three selected peptides interacting with T67 cells. The side wings of the spectrum of [TOAC1, Api4] TG are also shown enlarged to better highlight the membrane-bound component. The width of each spectrum is 14 mT. The cartoon shows the folding and the binding equilibrium of the peptide.