Chemical Synthesis of Activity‐Based Ubiquitin Probes for Profiling <i>Arabidopsis thaliana</i> Deubiquitinases

Abstract Abnormalities in deubiquitinating enzymes (DUBs) activity can lead to growth defects and reduced ability to respond to environmental stress in Arabidopsis thaliana ( A. thaliana ). However, there is currently a lack of adequate tools to profile active DUBs in plants such as A. thaliana . Here, we developed Ub ABPs that could be efficiently prepared to label A. thaliana DUBs. A total of 7 DUBs in plant lysates were labelled and identified in combination with label‐free quantification (LFQ) mass spectrometry. This work demonstrated the universality of ABP tools in plants and mammals.