Fig. 3.

Native ESI-IMS–MS spectra of (a) Im7, (b) DM Im7, and (c) TM Im 7. (d and e) CCSs of the Im7 constructs, using the colour scheme in (a) to (c). Arrival Time Distributions (ATDs) of (d) 5+ and (e) 6+ charge states are shown. The theoretical CCS from the Im7 structure (PDB accession 1AYI [41] is 1165 Å²). The measured CCSs of the 5+ ions are within 7% of the estimated value from the crystal structure, indicating good agreement with the theoretical CCS value (the error associated with the calibration of CCSs is ⩽7.5%) [30].