Figure 1.

Development of a protein persulfidation model system. A)–D) Whole protein mass spectra of Trx1CS (13.5 μM) treated with A) GS³⁴SSG (300 μM), B) H₂O₂ (50 μM) plus Na₂ ³⁴S (500 μM), C) MPST (10 μM) plus 3MP (40 μM), or D) Na₂S₂ (300 μM), and subsequently alkylated with either 1 mM MBB (left panels) or IAM (right panels). Peaks corresponding to unmodified or thiol‐alkylated proteins are highlighted in blue and peaks corresponding to per‐/polysulfide‐alkylated proteins are highlighted in yellow.