High Speed Intact Protein Characterization Using 4X Frequency Multiplication, Ion Trap Harmonization, and 21 Tesla FTICR-MS

Journal Article · Tue May 01 04:00:00 EDT 2018 · Analytical Chemistry

DOI:https://doi.org/10.1021/acs.analchem.7b04606· OSTI ID:1557725

Shaw, Jared B. ^[1]; Gorshkov, Mikhail ^[2]; Wu, Qinghao ^[1]; Pasa Tolic, Ljiljana ^[1]

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1. BATTELLE (PACIFIC NW LAB)
2. Russian Academy of Sciences

Mass spectrometric characterization of large biomolecules, such as intact proteins, requires the specificity afforded by ultra-high resolution mass measurements performed at both the intact mass and product ion levels. Although the performance of time-of-flight mass analyzers is steadily increasing, the choice of mass analyzer for large biomolecules (e.g. proteins >50 kDa) is generally limited to the Fourier transform family of mass analyzers, such as Orbitrap and ion cyclotron resonance (FTICR-MS) with the latter providing unmatched mass resolving power and measurement accuracy. Yet, protein analyses using FTMS are largely hindered by the low acquisition rates of ultra-high resolution spectra. Frequency multiple detection schemes enable FTICR-MS to overcome this fundamental barrier and achieve resolving powers and acquisition speeds 4X greater than the limits imposed by magnetic field strength. Here we expand upon earlier work on the implementation of this technique for biomolecular characterization. We report the coupling of 21T FTICR-MS, 4X frequency multiplication, ion trapping field harmonization technology, and spectral data processing methods to achieve unprecedented acquisition rates and resolving power in mass spectrometry of large intact proteins. Isotopically resolved spectra of multiply charged ubiquitin ions were acquired using detection periods as short as 12 ms. Large proteins such as apo-transferrin (MW=78 kDa) and monoclonal antibody (MW=150 kDa) were isotopically resolved with detection periods of 384 ms and 768 ms, respectively. These results illustrate the future capability of accurate characterization of large proteins on time-scales compatible with online separations.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1557725
• Report Number(s): PNNL-SA-133517
• Journal Information: Analytical Chemistry, Journal Name: Analytical Chemistry Journal Issue: 9 Vol. 90
• Country of Publication: United States
• Language: English