Reactions of iron(II) nucleotide complexes with hydrogen peroxide

The rate constants for the reactions of hydrogen peroxide with ferrous complexes of ATP, ADP, UTP, citrate and pyrophosphate were measured at pH 7.2. These ligands are potential chelators of iron(II) in the low‐molecular weight iron pool that may catalyze oxidative degradation of tissues. The second‐order rate constants range from 5.5 × 10 3 M −1 s −1 (UTP) to 1 × 10 5 M −1 s −1 (pyrophosphate) at pH 7.2. The kinetic dependences of the ATP reaction are consistent with a mechanism involving a ‘ferryl’ (Fe IV ) transient which decays to the hydroxyl radical and ferric ATP.