Discovery of Electrophiles and Profiling of Enzyme Cofactors.

Reverse-polarity activity-based protein profiling (RP-ABPP) is a chemical proteomics approach that uses nucleophilic probes amenable to "click" chemistry deployed into living cells in culture to capture, immunoprecipitate, and identify protein-bound electrophiles. RP-ABPP is used to characterize the structure and function of reactive electrophilic post-translational modifications (PTMs) and the proteins harboring them, which may uncover unknown or novel functions. RP-ABPP has demonstrated utility as a versatile method to monitor the metabolic regulation of electrophilic cofactors, using a pyruvoyl cofactor in S-adenosyl-L-methionine decarboxylase (AMD1), and to discover novel types of electrophilic modifications on proteins in human cells, such as the glyoxylyl modification on secernin-3 (SCRN3).