Persulfide or polysulfide formation on Cys residues is emerging as an abundant protein posttranslational modification, with important regulatory functions. However, as many other Cys oxidative modifications, per- and polysulfides are relatively labile, dynamically interchanging species, which makes their intracellular detections challenging. Here we report our recently developed highly selective method, Protein Persulfide Detection Protocol (ProPerDP), which can detect protein per- and polysulfide species in isolated protein systems, in blood plasma, or in cells and tissue samples. The method is easy to use and relatively inexpensive and requires only readily commercially available reagents. The biggest advantage of ProPerDP compared to other previously published persulfide detecting methods is the fact that in this protocol, all thiol and persulfide species are appropriately alkylated before any cell lysis step. This greatly reduces the potential of detecting lysis-induced oxidation-driven artifact persulfide formation.
Keywords: Biotin pulldown assay; Detection method; ProPerDP; Protein persulfide; Selective reduction.