Factor analysis of transient spectra. Free radicals in cyclic dipeptides containing methionine

The use of the methods of radiolysis to explore the mechanisms of free radical modifications in proteins

The method of radiolysis is based upon the interaction of ionising radiation with the solvent (water). One can form the same free radicals as in conditions of oxidative stress ((•)OH, O2(•)(-), NO2(•)…). Moreover, the quantity of reactive oxygen (ROS) or nitrogen (RNS) species formed in the irradiated medium can be calculated knowing the dose and the radiation chemical yield, G, thus this method is quantitative. The use of the method of radiolysis has provided a wealth of data, especially about the kinetics of the oxidation by various free radicals and their mechanisms, the identification of transients formed, their lifetimes and the possibility to repair them by the so-called antioxidants. In this review we have collected the most recent data about protein oxidation that might be useful to a proteomic approach. This article is part of a Special Issue entitled: Posttranslational Protein modifications in biology and Medicine.