Identification of S -Nitrosothiols by the Sequential Cysteine Blocking Technique

Here, we describe a procedure for the identification of S-nitrosothiols that has been used in our laboratory to study the roles of protein S-nitrosylation in the immune responses of Arabidopsis thaliana and other organisms. It employs a modified version of the biotin-switch technique, which we termed the sequential cysteine blocking technique, encompassing the sequential redox-blocking of recombinant proteins followed by LC-MS/MS analysis.