A persulfide analogue of the nitrosothiol SNAP: formation, characterization and reactivity.

The proposal of the post-translational modification "S-sulfhydration" as a major pathway for H2 S-induced signaling has recently shed light on persulfides. However, the study of these species is hampered by their instability under biologically relevant conditions; this requires generating them in situ immediately prior to use. The current methods to prepare persulfides in aqueous solution suffer from several drawbacks. In particular, their formation requires (or generates) hydrogen sulfide, thus resulting in difficulties in distinguishing polysulfide reactivity from that of H2 S. Here we report the H2 S-free formation, characterization, and some biologically relevant reactions of a water-soluble persulfide analogue of the nitrosothiol SNAP, a widely used nitric oxide donor.