Characterization of photophysical and base-mimicking properties of a novel fluorescent adenine analogue in DNA

摘要

To increase the diversity of fluorescent base analogues with improved properties, we here present the straightforward click-chemistry-based synthesis of a novel fluorescent adenine-analogue triazole adenine (A^T) and its photophysical characterization inside DNA. A^T shows promising properties compared to the widely used adenine analogue 2-aminopurine. Quantum yields reach >20% and >5% in single- and double-stranded DNA, respectively, and show dependence on neighbouring bases. Moreover, A^T shows only a minor destabilization of DNA duplexes, comparable to 2-aminopurine, and circular dichroism investigations suggest that A^T only causes minimal structural perturbations to normal B-DNA. Furthermore, we find that A^T shows favourable base-pairing properties with thymine and more surprisingly also with normal adenine. In conclusion, A^T shows strong potential as a new fluorescent adenine analogue for monitoring changes within its microenvironment in DNA.