Work

UV-Induced Proton Transfer between DNA Strands

Year: 2015

Type: article

Abstract: UV radiation creates excited states in DNA that lead to mutagenic photoproducts. Photoexcitation of single-stranded DNA can transfer an electron between stacked bases, but the fate of excited states in the double helix has been intensely debated. Here, photoinduced interstrand proton transfer (PT) triggered by intrastrand electron transfer (ET) is detected for the first time by time-resolved vibrational spectroscopy and quantum mechanical calculations. Long-lived excited states are shown to be oppositely charged base pair radical ions. In two of the duplexes, the base pair radical anions are present as tautomers formed by interstrand PT. Charge recombination occurs on the picosecond time scale preventing the accumulation of damaging radicals or mutagenic tautomers.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.5b03914

Authors: Yuyuan Zhang, Kimberly de La Harpe, Ashley A. Beckstead, Roberto Improta, Bern Kohler

Institutions: Montana State University, United States Air Force Academy, Institute of Biostructure and Bioimaging

Language: English

Topic: Photochemistry and Electron Transfer Studies

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: National Aeronautics and Space Administration, Agence Nationale de la Recherche, Division of Chemistry