Czech Society for Mass Spectrometry

(Czech Mass Spectrometry Conference 2018 - PL-2)
Biological radicals in the gas phase

František Tureček ^1 *

1. University of Washington

Abstract

Mass spectrometry of radicals dates back to the pioneering studies of Fred Lossing in the early 1950's [1]. With the advent of tandem mass spectrometry, soft ionization methods, and ion spectroscopy, it has become possible to generate and study polyatomic radicals of relevance to biology. The general feature of the majority of methods used to produce gas-phase radicals for mass spectrometry studies is their reliance on oxidative or reductive electron transfer to biomolecular ions or their complexes. Femtosecond collisional electron transfer to closed-shell biomolecular ions was the first method developed and applied to this end [2]. A few examples will be presented regarding nucleobase radicals. Intramolecular oxidation of a biomolecular ligand in a ternary transition metal complex is another method that can be used to produce biological ion-radicals in the gas phase [3], as will be illustrated with nucleobase cation-radicals. Electron-transfer reduction of multiply charged biomolecular ions represents a yet different approach to ion-radicals of the hydrogen-rich type. Structure elucidation of gas-phase ion-radicals relies on the combination of ion spectroscopy, ion-molecule reactions, and quantum chemistry calculations, as will be illustrated with peptide and nucleotide cation-radicals.

* Corresponding author: turecek@chem.washington.edu

References

1. Lossing F.P.J.: Chem. Phys. 20, 907-914 (1952).
2. Wolken J.K. et al.: J. Am. Chem. Soc. 123, 5804-5805 (2000).
3. Chu I.K. et al.: J. Phys. Chem. B 104, 3393-3397 (2000).

Acknowledgement:

Research at University of Washington has been supported by the National Science Foundation Division of Chemistry (Grants CHE-1359810, CHE-1661815, and CHE-1624430), and Klaus and Mary Ann Saegebarth Endowment.