Fig. 3.

Reaction of protein Gpx3 sulfenic acid with chemical probes. A) In situ oxidation of C64,82S Gpx3 with quantitative H₂O₂ resulted in a sulfenic acid that was labeled by probes (green). Gpx3 sulfinic acid (orange) and the unreacted thiol form (blue) were also observed. B–I) Deconvoluted mass spectra of Gpx3 labeling by DYn-2 (B–C), BTD (D), BCN (E–F), TCO (G–H) and Norb (I). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)