Activity-based protein profiling of protein tyrosine phosphatases.

The ability to accurately monitor the dynamics involved with the activity and state of a specific protein population in a complex biological system represents one of the major technological challenges in studying systems biology. Over the past several years a number of groups have attempted to spearhead this new frontier of systems biology by developing enzyme family-specific activity-based chemical probes linked to appropriate reporter groups that by nature only target and subsequently tag the active form of these enzymes. In this work, we will highlight the methods used to characterize activity-based probes as to their utility in biological contexts. Specifically, we will address activity-based protein profiling of the protein tyrosine phosphatases, a highly conserved enzyme family responsible for the phospho-tyrosine hydrolysis reaction, a ubiquitous reaction that is absolutely essential to the regulation of a myriad of cellular processes.