Trapped Ion Mobility Spectrometry of Native Macromolecular Assemblies

• Published in: Analytical chemistry (Washington) Vol. 93; no. 5; pp. 2933 - 2941
• Main Authors: Jeanne Dit Fouque, Kevin, Garabedian, Alyssa, Leng, Fenfei, Tse-Dinh, Yuk-Ching, Ridgeway, Mark E, Park, Melvin A, Fernandez-Lima, Francisco
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 09.02.2021
• Subjects: Alcohol dehydrogenase; analytical chemistry; antibodies; Assemblies; Bovine serum albumin; carbonate dehydratase; Carbonic anhydrase; Carbonic anhydrases; Chemistry; Cytochrome c; Cytochromes; Deoxyribonucleic acid; DNA; DNA topoisomerase; DNA-directed RNA polymerase; electric field; Electric fields; Electrodes; Gas flow; geometry; IgG antibody; Immunoglobulin G; Indigenous species; Ion Mobility Spectrometry; Ionic mobility; Ions; Lysozyme; Macromolecules; Mass Spectrometry; Mass spectroscopy; Mobility; Monoclonal antibodies; Oligomers; Proteins; RNA polymerase; Scientific imaging; Serum albumin; spectrometers; Spectroscopy; standard deviation; Trapping; Ubiquitin
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.0c04556

The structural elucidation of native macromolecular assemblies has been a subject of considerable interest in native mass spectrometry (MS), and more recently in tandem with ion mobility spectrometry (IMS-MS), for a better understanding of their biochemical and biophysical functions. In the present work, we describe a new generation trapped ion mobility spectrometer (TIMS), with extended mobility range (K 0 = 0.185–1.84 cm2·V–1·s–1), capable of trapping high-molecular-weight (MW) macromolecular assemblies. This compact 4 cm long TIMS analyzer utilizes a convex electrode, quadrupolar geometry with increased pseudopotential penetration in the radial dimension, extending the mobility trapping to high-MW species under native state (i.e., lower charge states). The TIMS capabilities to perform variable scan rate (Sr) mobility measurements over short time (100–500 ms), high-mobility resolution, and ion-neutral collision cross-section (CCSN2 ) measurements are presented. The trapping capabilities of the convex electrode TIMS geometry and ease of operation over a wide gas flow, rf range, and electric field trapping range are illustrated for the first time using a comprehensive list of standards varying from CsI clusters (n = 6–73), Tuning Mix oligomers (n = 1–5), common proteins (e.g., ubiquitin, cytochrome C, lysozyme, concanavalin (n = 1–4), carbonic anhydrase, β clamp (n = 1–4), topoisomerase IB, bovine serum albumin (n = 1–3), topoisomerase IA, alcohol dehydrogenase), IgG antibody (e.g., avastin), protein–DNA complexes, and macromolecular assemblies (e.g., GroEL and RNA polymerase (n = 1–2)) covering a wide mass (up to m/z 19 000) and CCS range (up to 22 000 Å2 with <0.6% relative standard deviation (RSD)).