*4.4. Native-MS Experiments*

Nano-ESI-MS data were taken from Konijnenberg [42]. In particular, nano-ESI-MS spectra were collected after 10-minute incubation of protein-ligand mixtures in 10 mM ammonium acetate, pH 7.4, at a final AS concentration of 20 μM. Quantification from native-MS data was based on Gaussian fitting of CSDs, upon transformation to x = z abscissa axis. The reported values refer to the area of the components obtained for the protein in the absence of ligand and for the 1:1 AS:ligand complexes, from three independent experiments.
