Reactive molecular species (RMS) can damage DNA, lipids, and proteins but as signaling molecules they also affect the regulatory state of the cell. RMS consist of reactive oxygen (ROS), nitrogen (RNS), and carbonyl species (RCS). Besides their potentially destructive nature, RMS are able to modify proteins at the posttranslational level, resulting in regulation of structure, activity, interaction as well as localization. This chapter addresses methods to analyze and quantify posttranslational redox modifications in vitro and ex vivo, such as sulfenic acid generation of cysteine residues and oxidative carbonylation of proteins. In addition, by use of isothermal titration calorimetry, redox-dependent interaction studies of proteins will be described.
Keywords: Carbonylation; DNPH; Dimedone; Hydrogen peroxide; Isothermal titration calorimetry; Peroxiredoxin; Posttranslational redox modifications; Sulfenylation.