Activity-based proteomics

Activity-based proteomics, or activity-based protein profiling (ABPP) is a chemoproteomic strategy that employs modular probes to directly assess the functional state of enzymes within complex proteomes. Unlike expression-based proteomics, which measures protein abundance, ABPP provides information about catalytic activity, thereby enabling researchers to distinguish between active and inactive forms of enzymes. This functional perspective has proven valuable for identifying drug targets, mapping ligandable sites, and understanding enzyme regulation in physiological and pathological contexts. By covalently modifying active sites, activity-based probes (ABPs) allow selective tagging, enrichment, and isolation of proteins, reducing the complexity of proteomic samples and facilitating downstream analysis. ABPP has been applied across diverse biological systems, including cells, tissues, and whole organisms, and has contributed to advances in biomarker discovery, drug development, and in vivo imaging.