Journal article

Gas-phase structure and reactivity of the keto tautomer of the deoxyguanosine radical cation

Linda Feketeova, Bun Chan, George N Khairallah, Vincent Steinmetz, Philippe Maitre, Leo Radom, Richard AJ O'Hair

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | ROYAL SOC CHEMISTRY | Published : 2015

Abstract

Guanine radical cations are formed upon oxidation of DNA. Deoxyguanosine (dG) is used as a model, and the gas-phase infrared (IR) spectroscopic signature and gas-phase unimolecular and bimolecular chemistry of its radical cation, dG˙(+), A, which is formed via direct electrospray ionisation (ESI/MS) of a methanolic solution of Cu(NO3)2 and dG, are examined. Quantum chemistry calculations have been carried out on 28 isomers and comparisons between their calculated IR spectra and the experimentally-measured spectra suggest that A exists as the ground-state keto tautomer. Collision-induced dissociation (CID) of A proceeds via cleavage of the glycosidic bond, while its ion–molecule reactions wit..

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Grants

Awarded by ARC


Awarded by National FT-ICR network


Funding Acknowledgements

Funding from the ARC (CoE program for RAJO and LR, APD for LF (CE0561607), ARF for GNK, and APF for LR), generous grants of computer time (to LR) from NCI NF and Intersect Australia Ltd, and (to RAJO) from VPAC, UPSud for a visiting Scholar Fellowship (to GNK). Financial support from the National FT-ICR network (FR 3624 CNRS) for conducting the research is gratefully acknowledged.