10.1021/ol051143z
This research aims to develop a novel method for attaching fluorophores to peptide nucleic acids (PNAs) without compromising their DNA binding affinity. The study introduces a strategy involving the use of γ-lysine PNA monomers, which allow fluorophores to be covalently attached to the PNA backbone. Key chemicals used in this research include Fmoc-protected lysine-derived side chains, MiniPEG linkers, and 9-fluoreneacetic acid. The researchers synthesized PNA oligomers incorporating these modified monomers and demonstrated that these modifications did not adversely affect the thermal stability or binding affinity of the PNA to DNA. Upon annealing with complementary DNA, the modified PNA oligomers exhibited a 4-fold increase in fluorescence intensity, indicating successful quenching and activation of the fluorophore. The study concludes that this new method of PNA modification could facilitate the design of more efficient PNA-based molecular beacons and biosensors, potentially leading to improved tools for nucleic acid detection in various diagnostic applications.