Synthesis and characterization of PNA oligomers containing preQ as a positively charged guanine analogue.

We report the synthesis of a peptide nucleic acid (PNA) monomer containing preQ, a positively charged guanine analogue. The new monomer was incorporated into PNA oligomers using standard Fmoc-chemistry-based solid-phase synthesis. The preQ unit-containing PNA oligomers exhibited improved affinity for their complementary DNA through electrostatic attraction, and their sequence specificity was not compromised.