Monitoring the direct and indirect damage of DNA bases and polynucleotides by using time-resolved infrared spectroscopy

Kuimova, MK; Cowan, AJ; Matousek, P; PARKER, AW; Sun, XZ; Towrie, M; George, MW

Abstract

The nucleotide 5'-dGMP and polynucleotide poly(dGdC)·poly(dGdC) have been irradiated by using a 200-fs, 200-nm laser pulses and spectrally characterized by using time-resolved infrared spectroscopy. Under the experimental conditions, 200-nm excitation generates both electronic excited states and radical cations through photoionization; the former decay rapidly to vibrationally hot ground state. By using infrared signatures we have been able to follow these processes, and at time scales of >1 ns we observe an infrared marker band at 1,702 cm–1 within both 5'-dGMP and the polynucleotide assigned to a photoionized product of guanine. This transient has also been reproduced through indirect chemistry through the reaction with photogenerated carbonate radical with 5'-dGMP. The ability to use time-resolved infrared spectroscopy in this way paves the way for developing solution-phase studies to investigate both direct and indirect radiation chemistry of DNA.

DNA damage | electron transfer | guanine radical cation

Citation

Kuimova, M., Cowan, A., Matousek, P., PARKER, A., Sun, X., Towrie, M., & George, M. (2006). Monitoring the direct and indirect damage of DNA bases and polynucleotides by using time-resolved infrared spectroscopy. Proceedings of the National Academy of Sciences, 103(7), 2150-2153. https://doi.org/10.1073/pnas.0506860103

• Journal Article Type: Article
• Publication Date: Feb 14, 2006
• Deposit Date: Aug 10, 2007
• Journal: Proceedings of the National Academy of Sciences of the United States of America (PNAS) ISSN 1091-6490
• Publisher: National Academy of Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 103
• Issue: 7
• Pages: 2150-2153
• DOI: https://doi.org/10.1073/pnas.0506860103