persulfidated

Persulfidated is an adjective describing a molecule, typically a cysteine residue in a protein, that has undergone persulfidation, a post-translational modification in which a sulfur atom is added to a thiol group to form a persulfide (R-SSH).

Persulfidation is commonly produced when reactive sulfur species, including hydrogen sulfide (H2S), polysulfides, or sulfane sulfur donors, react with thiols under oxidative or redox-active conditions. The modification yields a persulfide linkage (R-SSH) that can alter the chemical reactivity of the cysteine residue.

Biologically, persulfidation has been observed in a wide range of organisms and proteins. It is proposed to modulate enzyme activity, protein–protein interactions, and subcellular localization. In some contexts persulfidation protects cysteines from irreversible oxidation and participates in redox signaling pathways driven by H2S biology.

Detection and study of persulfidation rely on mass spectrometry and sulfhydration-specific labeling approaches, such as activity-based or chemical-switch assays. These methods aim to distinguish persulfidated cysteines from other redox modifications, but challenges remain due to potential artifacts during sample handling and the lability of persulfide bonds.

Terminology varies in the literature; the term persulfidation or S-sulfhydration is commonly used to describe the modification. The field continues to clarify the physiological relevance and detection standards of persulfidated proteins.