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OXIDATIVE MODIFICATION OF PROTEINS: FROM DAMAGE TO CATALYSIS, SIGNALING AND BEYOND.

SIGNIFICANCE
The systematic investigation of oxidative modification of proteins by reactive oxygen species started in 1980. Later, it was shown that reactive nitrogen species could also modify proteins. Some protein oxidative modifications promote loss of protein function, cleavage or aggregation, and some result in proteotoxicity and cellular homeostasis disruption. However, not all oxidative modifications are necessarily associated with damage, as with Met and Cys protein residue oxidation. In these cases, redox state changes can alter protein structure, catalytic function, signaling processes in response to metabolic and/or environmental alterations. This review aims to integrate the present knowledge on redox modifications of proteins with their fate and role in redox signaling and human pathological conditions.


CRITICAL ISSUES
It is hypothesized that protein oxidation participates in the development and progression of many pathological conditions. However, no quantitative data has been correlated with specific oxidized proteins or the progression or severity of pathological conditions. Hence, the comprehension of the mechanisms underlying these modifications, their importance in human pathologies and, the fate of the modified proteins is of clinical relevance.


FUTURE DIRECTIONS
We discuss new tools to cope with protein oxidation and suggest new approaches for integrating knowledge about protein oxidation and redox processes with human pathophysiological conditions.