Book of Abstracts: Albany 2011
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 Department of Chemical and Biological Engineering/Physical Chemistry