Strategies and Tools for Detection of Protein S-Nitrosylation and S-Sulfhydration

H2S interacts with the free thiol group in the active cysteine residues from target proteins and forms a hydropersulfide moiety (-SSH), termed as S-sulfhydration, which is similar to nitric oxide (NO) regulation of protein by S-nitrosylation. Protein S-sulfhydration now is proposed to mediate most of H2S bioactivities in various cellular functions. A number of methods have been developed for detection of S-nitrosylation and S-sulfhydration. Selective recognition of hydropersulfide (SSH) is a main target for the detection of S-sulfhydration. Protein Ssulfhydration can be detected by biotin switch assay, which is developed and further modified based on the detection approaches for protein S-nitrosylation. Here we highlight the different tools for detection of protein S-sulfhydration and S-nitrosylation, and provide strategies for developing new methods to locate the modified cysteine residues.