Unnatural imidazopyridopyrimidine:naphthyridine base pairs: selective incorporation and extension reaction by DNA polymerases.

We describe herein the results of (i) enzymatic recognition for imidazopyridopyrimidine (Im):naphthyridine (Na) base pairs and (ii) further primer extension reactions after the Im:Na base pairs by DNA polymerases. Among the base pairs examined, ImN(O):NaO(N) base pair was rather selectively recognized by Klenow fragment exo(-) [F(exo(-))]as complementary base. However, this DNA polymerase did not catalyze primer extension reactions after the ImN(O):NaO(N) base pair.

Unnatural imidazopyridopyrimidine:naphthyridine base pairs: selective incorporation and extension reaction by Deep Vent (exo- ) DNA polymerase.

In our previous communication we reported the enzymatic recognition of unnatural imidazopyridopyrimidine:naphthyridine (Im:Na) base pairs, i.e. ImO(N):NaN(O) and ImN(O):NaO(N), using the Klenow fragment exo(-) [KF (exo(-))].

Selective recognition of unnatural imidazopyridopyrimidine:naphthyridine base pairs consisting of four hydrogen bonds by the Klenow fragment.

In this work, we investigated how thermally stable ImO(N):NaN(O) and ImN(O):NaO(N) pairs are recognized by the Klenow fragment (KF). As a result, these complementary base pairs, especially the ImN(O):NaO(N) pair, were recognized selectively due to the four hydrogen bonds between the nucleobases and the shape complementarity of the Im:Na pair similar to the purine:pyrimidine base pair.

Hybridization properties and enzymatic recognitions of naphthyridine:imidazopyridopyrimidine base pairs.

We describe the synthesis of 1,8-naphthyridine C-nucleosides, Na-N(O) and Na-O(N), and full details of hybridization properties of the duplexes containing naphthyridine:imidazopyridopyrimidine pairs. The desired compounds were obtained from Na-O(N) derivative 1 via conversions of the substituents of 2- and 7-positions, respectively. The 17mer duplex containing one Na-O(O):Im-N(N) pair in the center was stabilized by +11.

Synthesis and characterization of oligodeoxynucleotides containing naphthyridine:imidazopyridopyrimidine base pairs at their sticky ends. Application as thermally stabilized decoy molecules.

We describe the synthesis and properties of oligodeoxynucleotides (ODNs) containing 1,8-naphthyridine C-nucleoside (Na-NO) and imidazo[5',4':4,5]pyrido[2,3-d]pyrimidine nucleoside (Im-ON) at the termini. The modified ODNs were more resistant (6 to 40 times) than natural DNA to snake venom phosphodiesterase (SVPD). Although incorporation of one pair each of Na-NO:Im-ON on the sticky ends of the duplex was insufficient for thermal stabilization (+2.