(A) Immunoblot of WT CaMKII and M281/282V mutant after no treatment, oxidation, or autophosphorylation probed with antibodies against total, autophosphorylated (p-T287), or oxidized CaMKII. Summary data shows relative band intensity using the oxidized CaMKII antibody (n = 3 trials/group, * p < 0.05 vs. band intensity of WT CaMKII treated with H2O2). (B) Immunoblot and summary data of oxidized WT CaMKII probed with antiserum against oxidized M281/282 with increasing ratios of oxidized antigen peptide. (n = 3 trials/group, * p < 0.05 vs. band intensity with no peptide). (C) Immunofluorescent staining of heart sections from mice treated with saline, AngII, or Iso and probed for oxidized or total CaMKII. Red staining is positive for oxidized or total CaMKII and blue staining is for nuclei. Calibration bars are 100 microns. (D) Immunoblot and summary data of heart lysates from mice treated with saline (Sal), Iso, or AngII probed with antibodies against total CaMKII, oxidized CaMKII, or actin (n = 3 hearts/group, * p < 0.05 vs. band intensity of saline treatment).