Synthesis and Application of Activity-Based Probes for Serine Proteases.

Activity-based probes (ABPs) are chemical molecules that covalently react with the active form of the targeted enzyme. These probes are useful for target and biomarker identification, as well as drug discovery. This chapter describes the creation of an ABP library tailored to serine proteases, featuring a bioorthogonal tag and a range of diphenyl phosphonate warheads to improve selectivity and reactivity. We detail a protocol for synthesizing substituted warheads, enhancing probe affinity. The effectiveness of these ABPs is validated biochemically through analyses of their inhibitory potencies and kinetic behaviors. Furthermore, we illustrate their application in labeling serine proteases, using fluorescence scanning for detection.