Figure 5.

SOD1 binding to DNA depends on redox environments and its conformation. (A and B) The treatment with H₂O₂ for 4 h reduced not only the activity of SOD1 (A) but also the formation of S1-SOD1 complexes (B). (C and D) The treatment with GSH for 4 h slightly reduced the activity of SOD1 (C) but significantly elevated the formation of S1-SOD1 complexes (D). (E and H) The specific inhibitor of SOD1 (LD100, E) and the chelator of Zn²⁺ (TPEN, H) both prevented SOD1 from interactions with DNA under tested conditions. (F and G) The formation of S1-A4V (F) and S1-H46R/H48Q (G) complexes were dependent on concentrations of SOD1 in 10 mM pH 7.4 PBS. Data are mean of triplicate samples ± SD (*P < 0.05, **P < 0.01, ***P < 0.001; unpaired Student's t test), and all error bars are SD.