Fig. 6.

H₂O₂-induced S-glutathionylation of APE1 in cells of APE1 in cells (a) HeLa cells were exposed to 100 μM H₂O₂ for 10, 30, 60, or 120 min. An equal amount of total whole cell extract (10 μg) at the designated time point was then subjected to nonreducing SDS-PAGE and probed with antibodies specific to SSG or APE1. Shown is a representative gel (cropped to show only the molecular mass region relevant to APE1) of at least three independent experiments. (b) Cells were preincubated with 100 μM BioGEE for 1 h and subsequently exposed to 100 μM H₂O₂ for 10, 30, and 60 min. Biotin-bound proteins were extracted using streptavidin agarose and eluted with DTT. The eluent was subjected to nonreducing SDS-PAGE and probed with an antibody specific to APE1. The data are representative of at least three independent experiments. (c) Cells were incubated with or without BioGEE. Biotin-bound proteins were extracted using streptavidin agarose and eluted with DTT. The eluent was subjected to nonreducing SDS-PAGE and probed with an antibody specific to APE1.