Fig. 2.

Example designs for a roGFP-based (A, B) and a cpYFP-based Prx probe (C, D). Schematic representation of the roGFP-Prx probe (A), and Trx(CXXS)-cpYFP-Prx probe (C) with the reporter moiety in green, flexible linkers in grey and the Prx moiety in red. The Trx moiety lacking its resolving cysteine in the Trx(CXXS)-cpYFP-Prx probe is shown in blue. Cysteine residues involved in the reaction mechanism are denoted. (B, D) Hypothetical reaction scheme of the suggested probes. For simplicity, both schemes are based on a monomeric atypical 2-Cys Prx. Howerer, similar schemes apply to dimeric typical 2-Cys Prxs. Possible reduction pathways are indicated.