Sulfenic acids and peroxiredoxins in oxidant defense and signaling

Abstract

In recent years, there has been tremendous growth in awareness of the importance of sulfenic acids to biological processes. This is in part related to reactive oxygen species in general and hydrogen peroxide in particular becoming widely recognized as intermediates or second messengers crucial to signaling processes that guide cell growth and development. Thus a picture is emerging of sulfenic acids being important both for defending against oxidative stress and for normal growth. Although the work is challenging due to the fleeting and localized nature of some of the intermediates involved, substantial progress has been made in identifying modified proteins and the roles they play. The landscape of modifications uncovered thus far suggests that we have barely scratched the surface of the many stress-induced and regulatory oxidation events taking place in cells on a regular basis. This chapter recounts the chemistry of sulfenic acids and their effects in modulating function in a few recently-studied proteins. We also discuss cysteine-based peroxidases in more depth, with a focus on the structural and biochemical features of the peroxiredoxin family.