A cysteine-triggered fluorogenic donor base on native chemical ligation for tracking H2S delivery in vivo

A hydrogen sulfide (H2S) donor is a fundamental molecular tool used as an exogenous source in biological studies and therapies. However, finding a controllable and visual fluorescent H2S donor is difficult. We report a new H2S donor, HSD560, the H2S release of which is triggered by cysteine. Importantly, the H2S generation is accompanied with enhanced green fluorescence, which could be utilized to track H2S release in cells using microscopy. H2S release from HSD560 undergoes a non-enzymatic native chemical ligation (NCL) process, which provides an accurate match with activated fluorescence and localization of H2S in zebrafish.