Supplementary Figure 4: Native Protein Complexes.

Ensemble ion spectra plotted in m/z space (a,d) and their corresponding I2MS mass spectra (b,e) for the ~232 kDa pyruvate kinase (left) and 801 kDa groEL (right) complexes with labeled charge states in panels (a) and (d). The implementation of I2MS yields accurate spectra in the mass domain with resolution (Res) comparable to the various charge states collected in m/z space. Charge state values and relative charge state intensity assignments (c,f) agreed on average within <5% with their corresponding m/z-domain spectra (a,d).