Book of Abstracts: Albany 2011

category image Albany 2011
Conversation 17
June 14-18 2011
©Adenine Press (2010)

Development and Applications of the Fluorescent Tricyclic Cytosine Family - The First Nucleic Acid Base Analogue FRET-pair

The tricyclic cytosine family, tC, tCO, and tCnitro, has been increasingly used in biophysical and biochemical applications (1). The two fluorescent members of this family, tC and tCO, both have unique properties among fluorescent base analogues (2, 3). Furthermore, the three tricyclic base analogues all form stable base pairs with guanine and give minimal perturbations to the native structure of DNA. Importantly, we have recently utilized tCO as a donor and developed tCnitro as an acceptor and, thus, established the first nucleic acid base analogue FRET-pair (4). This pair enables accurate distinction between distance- and orientation-changes in nucleic acid systems using FRET (see Figure). In combination with the favorable base pairing properties this will facilitate detailed studies of nucleic acid structures and structural changes. Moreover, the placement of the FRET-pair inside the base stack will be a great advantage in studies where other (biomacro) molecules interact with the nucleic acid.

Figure. Efficiency of energy transfer for the base analogue FRET-pair tCO - tCnitro estimated using decreases in tCO emission (green circles) and tCO average lifetimes (purple squares) as the two analogues are separated by 2-13 bases in a DNA duplex.

This research is funded by the Swedish Research Council and Olle Engkvist Byggmästare Foundation.


  1. L. M. Wilhelmsson, Q. Rev. Biophys. 43, 159-183 (2010).
  2. P. Sandin., L. M. Wilhelmsson, P. Lincoln, V. E. C. Powers, T. Brown, B. Albinsson, Nucleic Acids Res. 33, 5019-5025 (2005).
  3. P. Sandin, K. Börjesson, H. Li, J. Mårtensson, T. Brown, L. M. Wilhelmsson, B. Albinsson, Nucleic Acids Res. 36, 157-167 (2008).
  4. K. Börjesson, S. Preus, A. H. El-Sagheer, T. Brown, B. Albinsson, L. M. Wilhelmsson, J. Am. Chem. Soc. 131, 4288-4293 (2009).

Karl Börjesson1
Søren Preus2
Kristine Kilså2
Afaf H. El-Sagheer3, 4
Tom Brown3
Bo Albinsson 1
L. Marcus Wilhelmsson1*

1 Department of Chemical and Biological Engineering/Physical Chemistry
Chalmers University of Technology
SE-41296 Gothenburg, Sweden
2 Department of Chemistry, University of Copenhagen
Universitetsparken 5
DK-2100 Copenhagen, Denmark
3 School of Chemistry
University of Southampton
Highfield, Southampton, SO17 1BJ, UK
4 Chemistry Branch
Department of Science and Mathematics
Faculty of Petroleum and Mining Engineering
Suez Canal University, Suez, Egypt

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