TY - JOUR

T1 - DNA as UV light-harvesting antenna

AU - Volkov, Ivan L.

AU - Reveguk, Zakhar V.

AU - Serdobintsev, Pavel Yu

AU - Ramazanov, Ruslan R.

AU - Kononov, Alexei I.

N1 - Funding Information: Russian Science Foundation (RSF) [16-13-10090]. Funding for open access charge: RSF [16-13-10090]. Conflict of interest statement. None declared. Publisher Copyright: © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

PY - 2018

Y1 - 2018

N2 - The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly efficient directional energy transfer. The possible role of coherent excitons in energy transport in DNA remains debated. Meanwhile, energy transport properties are greatly important for understanding the mechanisms of photochemical reactions in cellular DNA and for DNA-based artificial nanostructures. Here, we studied energy transfer in DNA complexes formed with silver nanoclusters and with intercalating dye (acridine orange). Steady-state fluorescence measurements with two DNA templates (15-mer DNA duplex and calf thymus DNA) showed that excitation energy can be transferred to the clusters from 21 and 28 nucleobases, respectively. This differed from the DNA-acridine orange complex for which energy transfer took place from four neighboring bases only. Fluorescence up-conversion measurements showed that the energy transfer took place within< -100 fs. The efficient energy transport in the Ag-DNA complexes suggests an excitonic mechanism for the transfer, such that the excitation is delocalized over at least four and seven stacked bases, respectively, in one strand of the duplexes stabilizing the clusters. This result demonstrates that the exciton delocalization length in some DNA structures may not be limited to just two bases.

AB - The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly efficient directional energy transfer. The possible role of coherent excitons in energy transport in DNA remains debated. Meanwhile, energy transport properties are greatly important for understanding the mechanisms of photochemical reactions in cellular DNA and for DNA-based artificial nanostructures. Here, we studied energy transfer in DNA complexes formed with silver nanoclusters and with intercalating dye (acridine orange). Steady-state fluorescence measurements with two DNA templates (15-mer DNA duplex and calf thymus DNA) showed that excitation energy can be transferred to the clusters from 21 and 28 nucleobases, respectively. This differed from the DNA-acridine orange complex for which energy transfer took place from four neighboring bases only. Fluorescence up-conversion measurements showed that the energy transfer took place within< -100 fs. The efficient energy transport in the Ag-DNA complexes suggests an excitonic mechanism for the transfer, such that the excitation is delocalized over at least four and seven stacked bases, respectively, in one strand of the duplexes stabilizing the clusters. This result demonstrates that the exciton delocalization length in some DNA structures may not be limited to just two bases.

UR - http://www.scopus.com/inward/record.url?scp=85052067967&partnerID=8YFLogxK

U2 - 10.1093/nar/gkx1185

DO - 10.1093/nar/gkx1185

M3 - Article

C2 - 29186575

AN - SCOPUS:85052067967

VL - 46

SP - 3543

EP - 3551

JO - Nucleic Acids Research

JF - Nucleic Acids Research

SN - 0305-1048

IS - 7

ER -