Fig. 1.

General workflow for isotope-coded dimedone/iododimedone labeling of proteins. In the case of recombinant protein assays, prereduced protein was removed of reductant, exposed to varying concentrations of H₂O₂, and coincubated with d₆-dimedone to label sulfenic acids. Additionally, microsomes were incubated with d₆-dimedone. After incubation, samples were then reduced with TCEP and free thiols were counter-alkylated with (d₀)-iododimedone. Samples were then subjected to LC-MS/MS analysis.