Long-range vibrational dynamics are directed by Watson-Crick base pairing in duplex DNA

Gordon Hithell, Daniel J. Shaw, Paul M. Donaldson, Gregory M. Greetham, Michael Towrie, Glenn A. Burley, Anthony W. Parker, Neil T. Hunt*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Ultrafast two-dimensional infrared (2D-IR) spectroscopy of a 15-mer A-T DNA duplex in solution has revealed structure-dependent vibrational coupling and energy transfer processes linking bases with the sugar-phosphate backbone. Duplex melting induces significant changes in the positions of off-diagonal peaks linking carbonyl and ring-stretching vibrational modes of the adenine and thymine bases with vibrations of the phosphate group and phosphodiester linkage. These indicate that Watson-Crick hydrogen bonding and helix formation lead to a unique vibrational coupling arrangement of base vibrational modes with those of the phosphate unit. On the basis of observations from time-resolved 2D-IR data, we conclude that rapid energy transfer processes occur between base and backbone, mediated by additional modes located on the deoxyribose moiety within the same nucleotide. These relaxation dynamics are insensitive to duplex melting, showing that efficient intramolecular energy relaxation to the solvent via the phosphate groups is the key to excess energy dissipation in both single- and double-stranded DNA.

Original languageEnglish
Pages (from-to)4009-4018
Number of pages10
JournalJournal of Physical Chemistry B
Issue number17
Publication statusPublished - 15 Apr 2016

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