From sulfenylation to sulfhydration: what a thiolate needs to tolerate.

There is a growing appreciation that oxidants such as hydrogen peroxide (H(2)O(2)) and gases such as nitric oxide (NO) and hydrogen sulfide (H(2)S) can act as modulators of various signaling pathways. Much of this signaling occurs through the modifications of specific, critical cysteine residues in target proteins. How such small, diffusible molecules (H(2)O(2), NO, H(2)S) can achieve the required specificity is incompletely understood. Now, new findings provide considerable insight into these and related questions.