Acetylacetone-modified ubiquitin C-terminus enables specific capture of sulfenylated deubiquitinases

Abstract

Activity-based ubiquitin (Ub) probes have recently emerged as effective tools for profiling deubiquitinases (DUBs) in their reduced, catalytically active state; however, most existing Ub probes fail to capture oxidatively modified DUBs—such as sulfenylated DUBs, which are generated in cancer and inflammatory contexts and act as molecular switches to regulate DUB activity. Herein, we report a novel acetylacetone-modified Ub probe that selectively labels sulfenylated DUBs from distinct families in vitro and cell lysates, with no reactivity toward DUBs in their reduced state.