FIGURE 7.

Test of HpRppH and HP0507 for selective 8-oxo-dGTPase activity. 8-Oxo-dGTP or dGTP (50 μm) was treated for 60 min with various concentrations of purified E. coli MutT, HpRppH, HP0507, EcRppH, or BsRppH (0, 1, 10, or 100 nm), and the reaction products were examined by thin layer chromatography on PEI-cellulose. GTP, GDP, and GMP served as mobility standards. Whereas MutT hydrolyzed 8-oxo-dGTP much faster than dGTP, the other enzymes either did not hydrolyze 8-oxo-dGTP detectably (EcRppH, BsRppH) or did so slowly and no faster than they hydrolyzed dGTP (HpRppH, HP0507).