Figure 4: HPLC analysis of hAGT activity over double- and single-stranded TBA before and after incubation with hAGT. (a) Repair of double-stranded 5-O6-MeG-TBA by hAGT. The peak labelled as cTBA corresponds to the complementary sequence of 5-O6-MeG-TBA. The top right panel shows HPLC chromatogram in absence of hAGT. The gradient was from 10%–40% acetonitrile for 20 min at 6 0 C . (b) Repair of single- stranded 5-O6-MeG-TBA by hAGT. The inserted panel shows HPLC chromatogram in the absence of hAGT. Gradient used: 10%–40% acetonitrile, 20 min at room temperature.