Stimulation of OGG1 glycosylase
activity by mutant APE1 proteins and Nfo. OGG1 (25 nM) was incubated
with 500 nM 8-oxoG·C substrate in the presence of AP endonucleases.
Reactions 1 and 2, OGG1 alone. Reaction 1 was terminated with SDS
and glycerol without heating. Reactions 2–9 were terminated as
described in Figure 1. APE1 was added to reactions 3–8
as follows: 3, 125 nM ND40 APE1; 4, 125 nM ND60
APE1; 5, 125 nM C65S APE1; 6 and 7, 125 nM APE1; 8, 1.25 µM
APE1. Reactions 1–6 and 9 contained 1 mM MgCl2.
Reactions 7 and 8 contained 1 mM EDTA, reaction 9 125 nM Nfo.