Protein hydroperoxides as new reactive oxygen species

There is convincing evidence for the involvement of Reactive Oxygen Species (ROS) in the initiation and development of various forms of damage in living organisms. Attempts to prevent or limit such damage have been largely unsuccessful, principally because most of the pathways linking the formation of ROS with the end-point pathology are unknown. Evidence summarized in this review suggests that proteins are the most likely initial targets of ROS in cells and that protein hydroperoxides are major products of this interaction. Recent research has shown that the protein hydroperoxides can in turn generate new free radicals, inactivate enzymes, destroy antioxidants, and crosslink with DNA. This suggests that protein hydroperoxides may constitute an important intermediate stage in the development of ROS-induced biological damage, and that they should therefore be regarded as a new form of reactive oxygen species.