Alanyl-PNA homoduplex: A-T pairing with the N7-regioisomer of adenine

The N7-regioisomer of adeninyl alanine can be used as a building block for the synthesis of alanyl-PNA. By changing the nucleobase connectivity from N9 to N7, pairing with the Hoogsteen side is no longer possible and the order of donor/acceptor positions at the Watson-Crick side is reversed. This influences the pairing selectivity but not the stability of alanyl-PNA self-pairing complexes, as shown by UV and CD spectroscopy.