Abstract
The gasotransmitter hydrogen sulfide (H(2)S) is thought to be involved in the post-translational modification of cysteine residues to produce reactive persulfides. A persulfide-specific chemoselective proteomics approach with mammalian cells has identified a broad range of zinc finger (ZF) proteins as targets of persulfidation. Parallel studies with isolated ZFs show that persulfidation is mediated by Zn(II), O(2), and H(2)S, with intermediates involving oxygen- and sulfur-based radicals detected by mass spectrometry and optical spectroscopies. A small molecule Zn(II) complex exhibits analogous reactivity with H(2)S and O(2), giving a persulfidated product. These data show that Zn(II) is not just a biological structural element, but also plays a critical role in mediating H(2)S-dependent persulfidation. ZF persulfidation appears to be a general post-translational modification and a possible conduit for H(2)S signaling. This work has implications for our understanding of H(2)S-mediated signaling and the regulation of ZFs in cellular physiology and development.