Nucleic Acid Base Analog FRET-Pair Facilitating Detailed Structural Measurements in Nucleic Acid Containing Systems

Publikation: Bidrag til tidsskriftTidsskriftartikelfagfællebedømt

  • Karl Börjesson
  • Søren Preus
  • Afaf El-Sagheer
  • Tom Brown
  • Bo Albinsson
  • Marcus Wilhelmsson
We present the first nucleobase analog fluorescence resonance energy transfer (FRET)-pair. The pair consists of tCO, 1,3-diaza-2-oxophenoxazine, as an energy donor and the newly developed tC(nitro), 7-nitro-1,3-diaza-2-oxophenothiazine, as an energy acceptor. The FRET-pair successfully monitors distances covering up to more than one turn of the DNA duplex. Importantly, we show that the rigid stacking of the two base analogs, and consequently excellent control of their exact positions and orientations, results in a high control of the orientation factor and hence very distinct FRET changes as the number of bases separating tCO and tC(nitro) is varied. A set of DNA strands containing the FRET-pair at wisely chosen locations will, thus, make it possible to accurately distinguish distance- from orientation-changes using FRET. In combination with the good nucleobase analog properties, this points toward detailed studies of the inherent dynamics of nucleic acid structures. Moreover, the placement of FRET-pair chromophores inside the base stack will be a great advantage in studies where other (biomacro)molecules interact with the nucleic acid. Lastly, our study gives possibly the first truly solid experimental support to the dependence of energy transfer efficiency on orientation of involved transition dipoles as predicted by the Forster theory.
OriginalsprogEngelsk
TidsskriftJournal of the American Chemical Society
Vol/bind131
Udgave nummer12
Sider (fra-til)4288-4293
Antal sider6
ISSN0002-7863
DOI
StatusUdgivet - 2009

ID: 14276229