Rapid detection of thioredoxin reductase with a fluorescent probe via a Tag-Sec method

Thioredoxin reductase (TrxR), which plays a key role in cellular regulations including cell growth, redox signaling pathways and differentiation, belongs to the selenocysteine-containing protein family. Numerous human diseases are associated with thioredoxin reductase/selenocysteine deficiency or overdose. Thus, there is an urgent need to develop new tools for thioredoxin reductase detection. Small molecule fluorescent probes, which have been studied for decades, are powerful chemical tools for biomolecule detection and diagnosis within a bio-system. However, there still remains a challenge in finding a specific target site when designing a new probe. In this work, we presented a Tag-Sec fluorescent probe that could detect both thioredoxin reductase and selenocysteine with high sensitivity, selectivity, broad pH tolerance and good water solubility. We hope that the concept described in this work could serve as a useful guide to design probes for detecting Sec-containing proteins and clinical diagnosis.