2,6-Diaminonaphthyridine derivatives bind to a single nucleotide bulge in DNA.

Abstract

2,6-Diamino-1,8-naphthyridine derivative (daNpt), which possesses hydrogen bonding groups in an alignment of donor-acceptor-acceptor-donor binds to a single nucleotide bulge in the duplex. The melting temperatures (Tm) of all duplexes containing a bulge were increased, especially for the cytosine (C) and thymine (T) bulges, in the presence of daNpt, whereas only a small increase of Tm was observed for the fully matched duplexes. It was suggested by pH dependency of Tm and UV spectra, that a protonation of daNpt should play an important role for the recognition of C and T bulges.