Proteomics Profiling of S-sulfurated Proteins in Acinetobacter baumannii

Hydrogen sulfide (H2S) is emerging as an important modulator in bacterial cytoprotection against the host immune response in infected animals, which may well be attributed to downstream highly oxidized sulfur species, termed reactive sulfur species (RSS), derived from H2S. One mechanism by which H2S/RSS may signal in the cell is through proteome S-sulfuration (persulfidation), which is the conversion of protein thiols (-SH) to protein persulfides (-SSH). While several analytical methods have been developed to profile sites of protein persulfidation, few have been applied to bacterial cells. The analytical workflow presented here was recently utilized to profile proteome persulfidation in the major human pathogen Acinetobacter baumannii treated with an exogenous sulfide source, Na2S. The data obtained using this protocol allow quantitation of the change in persulfidation status of each cysteine in the proteome normalized to the change in protein abundance, thus identifying sites of persulfidation that may constitute regulatory modifications. These can be validated using follow-up biochemical studies.

Automated summary

Hydrogen sulfide has been found to play a crucial role in bacterial cytoprotection against host immune response, possibly through the formation of reactive sulfur species derived from H2S. A new analytical method has been developed and successfully applied to studying protein persulfidation in bacterial cells, particularly in a major human pathogen. This method allows quantification and identification of persulfidation sites in the proteome, which may serve as regulatory modifications that can be validated through biochemical studies.