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Updated: May 16, 2026

Sequence-specific and Selective Recognition of Double-stranded RNAs over Single-stranded RNAs by Chemically Modified Peptide Nucleic Acids
Published on: September 21, 2017
DNA triplex-mediated assembly of polyaromatic chromophores
1Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
Abstract:
The synthesis and characterization of intramolecular triple-helical DNA structures containing polyaromatic pyrene and perylene (perylenetetracarboxylic acid diimide, PDI) building blocks are presented. Two 1,8-dialkynylpyrene units are located in the Watson-Crick stem of the construct, while a PDI or a natural thymidine is present in the Hoogsteen strand. The triple helical structures were investigated by UV/VIS absorbance, fluorescence spectroscopy, and circular dichroism (CD) measurements. The folding of the intramolecular triple helix can be monitored by changes in the vibronic transition ratios, as well as by a change in the alkynylpyrene fluorescence (monomer vs. excimer). It is shown that thymine in the third strand has a pronounced influence on the interaction and, thus, on the fluorescence properties of two pyrene building blocks.
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