Figure 1. BTD-based quantitative S-sulfenylome analysis.

(A) Workflow for proteome-wide analysis of protein S-sulfenylation in RKO cells. S-sulfenylated proteins in cells treated with or without H₂O₂ are labeled with the BTD probe in vitro or in situ. Cell proteins then were digested with trypsin and labeled peptides are further conjugated with light (H₂O₂ treated) and heavy (vehicle control) azido biotin with a photocleavable linker, cleaned with SCX spin columns, captured with streptavidin beads, and photoreleased. The resulting peptides were analyzed by LC-MS/MS. (B) Chemical transformation of BTD-labeled form in the entire chemoproteomic workflow.