Novel peroxiredoxin-based sensor for sensitive detection of hydrogen peroxide.

A series of genetically encoded sensors have been developed to detect the important signaling molecule H 2 O 2 in living cells. However, more responsive and sensitive biosensors need to be developed. To address these demands, we used E. coli as a platform to develop a novel fluorescent H 2 O 2 sensor, which we refer to as TScGP. This sensor employs a circularly permuted YFP (cpYFP) and is based on a redox relay between peroxiredoxin (Prx) and thioredoxin (Trx). Structurally, cpYFP is sandwiched between a fungal PrxA and a C-terminal cysteine mutated TrxA that can form a stabilized disulfide bond between PrxA and TrxA in response to H 2 O 2. We confirmed that TScGP can be used for detecting exogenous H 2 O 2 in the range of 0.5–5 μM with high selectivity and rapidly detecting H 2 O 2 within 30 s in E. coli. To demonstrate an application, cellular H 2 O 2 production by menadione was detected directly by TScGP. Our results demonstrated that using Prx-Trx combination as a sensing moiety is another strategy in designing H 2 O 2 sensor with high performance. • Prx-Trx redox relay was utilized to construct H 2 O 2 sensor TScGP for the first time. • TScGP exhibited higher responsiveness than the typical H 2 O 2 probes Hyper. • Application test of TScGP verified the menadione-catalyzed H 2 O 2 producing process. [ABSTRACT FROM AUTHOR]