Figure 5.

Primer extension assay of non-alkylated and alkylated G-4 DNA. Alkylation was carried out with the G-4-template ODN4 (2.5 μM) and compound 3-SPh (50 μM) in K⁺ buffer or Na⁺ buffer for 72 h. The alkylated template DNA was then annealed with primer-9 (ODN5). The primer extension reactions were performed by incubating the G-4 template (5 μM) and primer DNA (0.15 μM), Klenow Fragment (exo⁻) (0.1 U/μl) and dNTP (0.2 mM) in NEbuffer pH 7.9 at 37°C for 5 min.