Complex Local Dynamics in DNA on the Picosecond and Nanosecond Time Scales

Eric B. Brauns; Mihaela L. Madaras; Robert S. Coleman; Catherine J. Murphy; Mark A. Berg

doi:10.1103/PhysRevLett.88.158101

Complex Local Dynamics in DNA on the Picosecond and Nanosecond Time Scales

Eric B. Brauns, Mihaela L. Madaras, Robert S. Coleman, Catherine J. Murphy, and Mark A. Berg

Phys. Rev. Lett. 88, 158101 – Published 29 March 2002

Abstract

Time-resolved Stokes shift measurements of the local structural relaxation of three DNA oligonucleotides are presented. Logarithmic relaxation is seen for over three decades in time (40 ps–40 ns), indicating a complex relaxation among a large number of conformational substates. The observed relaxation is the same in all the sequences. Sequence dependence of the localized dynamics of DNA does not appear within this time range. We infer that $30 % - 50 %$ of the relaxation is faster than 40 ps, has a nonlogarithmic decay and has a sequence dependent amplitude.

Received 28 June 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.158101

Authors & Affiliations

Eric B. Brauns¹, Mihaela L. Madaras², Robert S. Coleman^2,*, Catherine J. Murphy^1,†, and Mark A. Berg^1,‡

¹Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
²Department of Chemistry, The Ohio State University, Columbus, Ohio 43210

^*Email address: coleman@chemistry.ohio-state.edu
^†Email address: murphy@mail.chem.sc.edu
^‡Email address: berg@mail.chem.sc.edu