ROS react primarily with the free 34Cysteine (34Cys) residue of albumin to form two reversible intermediate derivatives, sulfenic-(SOH-alb) and sulfinic acid (SO2H-alb), resulting in sulfonic acid (SO3H-alb), the final stable product of the reaction.
Upon stable oxidation (SO3H-alb), albumin properties are altered: the protein becomes more susceptible to trypsin digestion and is degraded faster compared to the non-oxidized counterpart.
The present review focuses on the characterization of albumin chemical changes induced by ROS, their relevance in human pathology and the most recent advances in the approach to oxidation adduct analysis.