Easy IgG Isotype Fingerprinting with FabRICATOR® and Ion-Mobility MS

June 17, 2020 | References |

Researchers at Strasbourg University and Pierre-Fabre highlight the benefits of a middle-level approach to IgG isotype fingerprinting using native ion-mobility mass spectrometry.

 

FabRICATOR and ion mobility mass spectrometry

FabRICATOR and ion mobility mass spectrometry (Botzanowski et al. 2020)

 

In this new article by Botzanowski et al., a middle-level approach was compared to more classical intact methods for distinguishing IgG isotypes using native ion mobility mass spectrometry. Ion mobility mass spectrometry and collision induced unfolding (CIU) at the intact level is hampered by minimal variations that can be observed. The authors used FabRICATOR to digest adalimumab, panitumumab, and natalizumab down to Fc/2 and F(ab’)2 domains. The Fc domain provided only limited isotype information due to sequence similarity. However, the stability profile of F(ab’)2 and its’ unfolding pattern measured by CIU uncovered very clear differences between the isotypes that could not be achieved with full length, intact mAb.

 

Eculizumab, a humanized IgG2/4 hybrid, which gives conflicting isotype patterns using classical approaches, was also tested. With the middle-level CIU approach, eculizumab could be easily distinguished from reference isotypes. In summary, the authors clearly show how easy, reliable and clear-cut classification of mAb isotypes can be achieved using a middle-level approach with FabRICATOR digestion.

 

The full article is available here:

Botzanowski, T. et al., 2020. Middle Level IM-MS and CIU Experiments for Improved Therapeutic Immunoglobulin Subclass Fingerprinting. Analytical Chemistry. 10.1021/acs.analchem.0c00293