A perspective on cysteine-reactive activity-based probes

Activity-based protein profiling (ABPP) is a powerful method to investigate protein function, identify protein targets and determine the mechanisms-of-action of chemical probes as well as small molecule drugs. Our perspective provides an overview of the design of covalent cysteine-targeted activity-based probes (ABPs) that rely on reactive elements ('chemotypes' or 'warheads') as well as functional handles and describes their use in mass spectrometry-based chemoproteomics analysis. These segments are followed by strategies for the development of advanced ABPs that are employed in live cells for chemoproteomics analyses and to install post-translational modifications. Our discussion extends to their potential, limitations and opportunities, followed by perspectives on advancing the reach of ABPP and its implications for the pharmaceutical industry.