Pro- and Antioxidant Activity of Selenomethionine: Preventative Measures against Metal-Mediated DNA Oxidation

DNA damage by reactive oxygen species (ROS) has been linked to several diseases. Antioxidants are one method of combating the effects of ROS; selenium-containing antioxidants have shown promise in alleviating in vitro DNA damage. This study aims toelucidate the effects of selenomethionine (SeMet) on DNA damage mediated by Cu(II),Fe(II), or Cr(III) metal ions. HPLC analysis was used to probe the oxidative effects of SeMet by quantifying the oxidative damage marker, 8-hydroxy-2’-deoxyguanosine. Prior literature indicates that the antioxidant activity of SeMet is potentially concentration dependent; however, HPLC results in this study indicate a metal-ion dependency. In order to better understand the metal-ion dependence, ITC studies were used to identify if metal coordination plays a role in the observed oxidative effects of SeMet. Cu(II) and Cr(III) ITC results indicate different degrees of metal coordination. This suggests that metal coordination to SeMet may play a role in the metal-ion dependence of the system. In order to more fully understand the metal-ion dependence, SeMet was modeled computationally to determine the most favorable metal binding site to the structure