Figure 6

Digestion of 5'-phosphorylated and non-phosphorylated oligonucleotides by SXT-Exo, monitored by size exclusion chromatography. Panel A: Overlay of three size exclusion chromatograms of the time-wise digestion of a non-phosphorylated synthetic 75 mer of oligothymidine (dT₇₅, 400 pmol) by SXT-Exo (100 pmol of trimers) in 25 mM Tris-HCl pH7.4, 50 mM NaCl, 10 mM MgCl₂; incubated at 37°C. Black-coloured trace: amounts of oligo-dT₇₅ present immediately after addition of SXT-Exo; red and blue-coloured traces: oligo-dT₇₅ present 3 minutes, and 25 minutes after the addition of SXT-Exo, respectively. Panel B: Overlay of three size exclusion chromatograms of the time-wise digestion of a 5'-phosphorylated 75-mer of oligothymidine (5'-P-dT₇₅, 400 pmol) by SXT-Exo (100 pmol of trimers) in 25 mM Tris-HCl pH7.4, 50 mM NaCl, 10 mM MgCl₂; incubated at 37°C. Black-coloured trace: 5'-phosphorylated oligo-dT₇₅ present immediately after the addition of SXT-Exo; red and blue-coloured traces: 5'-phosphorylated oligo-dT₇₅ present 3 minutes, and 25 minutes after the addition of SXT-Exo, respectively.