Utilizing Natural and Engineered Peroxiredoxins As Intracellular Peroxide Reporters

It is increasingly apparent that nature evolved peroxiredoxins not only as H(2)O(2) scavengers but also as highly sensitive H(2)O(2) sensors and signal transducers. Here we ask whether the H(2)O(2) sensing role of Prx can be exploited to develop probes that allow to monitor intracellular H(2)O(2) levels with unprecedented sensitivity. Indeed, simple gel shift assays visualizing the oxidation of endogenous 2-Cys peroxiredoxins have already been used to detect subtle changes in intracellular H(2)O(2) concentration. The challenge however is to create a genetically encoded probe that offers real-time measurements of H(2)O(2) levels in intact cells via the Prx oxidation state. We discuss potential design strategies for Prx-based probes based on either the redox-sensitive fluorophore roGFP or the conformation-sensitive fluorophore cpYFP. Furthermore, we outline the structural and chemical complexities which need to be addressed when using Prx as a sensing moiety for H(2)O(2) probes. We suggest experimental strategies to investigate the influence of these complexities on probe behavior. In doing so, we hope to stimulate the development of Prx-based probes which may spearhead the further study of cellular H(2)O(2) homeostasis and Prx signaling.