Superoxide dismutase activity and novel reactions with hydrogen peroxide of histidine-containing nickel(II)-oligopeptide complexes and nickel(II)-induced structural changes in synthetic DNA

At physiologic pH values, histidine-containing nickel(II) oligopeptides reduced the flux of superoxide anion (O2) generated in the hypoxanthine/xanthine oxidase system. The postulated involvement of the Ni(III)/Ni(II) redox couple in this apparent dismutation receives indirect support from electron-spin resonance data. These complexes also catalyzed the disproportionation of hydrogen peroxide, a process which generates active intermediates …