Figure 5.

Attempted isolation of 2-AP* using reversed-phase HPLC chromatography. Duplex 4 (i.e. containing 2-AP at the CH₃ target site in a hemi-methylated context) was incubated with M.EcoKI and AdoMet to form 2-AP* and the mixture denatured and analysed by HPLC. (A) HPLC eluate monitored by fluorescence excitation and emission of 310/380 nm (solid line) and 350/450 nm (dashed line). (B) As (A) but with the addition of the starting oligodeoxynucleotide containing 2-AP (i.e. the top strand of duplex 1). The added standard co-elutes with the fluorescent product obtained from the mixture of DNA duplex 4 with M.EcoKI and AdoMet. (C) As (A) but eluate monitored by absorption at 254 nm.