Orientational and dynamical heterogeneity of rhodamine 6G terminally attached to a DNA helix revealed by NMR and single-molecule fluorescence spectroscopy

  • Neubauer H
  • Gaiko N
  • Berger S
 et al. 
  • 73


    Mendeley users who have this article in their library.
  • 45


    Citations of this article.


The comparison of Förster resonance energy transfer (FRET) efficiencies between two fluorophores covalently attached to a single protein or DNA molecule is an elegant approach for deducing information about their structural and dynamical heterogeneity. For a more detailed structural interpretation of single-molecule FRET assays, information about the positions as well as the dynamics of the dye labels attached to the biomolecule is important. In this work, Rhodamine 6G (2-[3'-(ethylamino)-6'-(ethylimino)-2',7'-dimethyl-6'H-xanthen-9'-yl]-benzoic acid) bound to the 5'-end of a 20 base pair long DNA duplex is investigated by both single-molecule multiparameter fluorescence detection (MFD) experiments and NMR spectroscopy. Rhodamine 6G is commonly employed in nucleic acid research as a FRET dye. MFD experiments directly reveal the equilibrium of the dye bound to DNA between three heterogeneous environments, which are characterized by distinct fluorescence lifetime and intensity distributions as a result of different guanine-dye excited-state electron transfer interactions. Sub-ensemble fluorescence autocorrelation analysis shows the highly dynamic character of the dye-DNA interactions ranging from nano- to milliseconds and species-specific triplet relaxation times. Two-dimensional NMR spectroscopy corroborates this information by the determination of the detailed geometric structures of the dye-nucleobase complex and their assignment to each population observed in the single-molecule fluorescence experiments. From both methods, a consistent and detailed molecular description of the structural and dynamical heterogeneity is obtained.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Heike Neubauer

  • Natalia Gaiko

  • Sylvia Berger

  • Jörg Schaffer

  • Christian Eggeling

  • Jennifer Tuma

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free