Let us now examine if the collision cross section distribution of specific charge states is correlated with the solution folding state (Figure ). From now on we will use the supercharging conditions (the CCS distributions without supercharging are shown in Supplementary Figure ) because, as we will see below, significant differences in CCS or CIU are only observable at charge states higher than 6-. The CCS ranges of ions from 6-to 8-are similar for the 4 sequences, and similar whatever the pH. Bimodal CCSDs at low collision energy start to appear at charge state 9-.