Characterizing the scope of nucleophile reactivities to develop cofactor-selective probes.
We would like to develop cofactor-selective probes. We will characterize the scope of reactivity of a-nucleophiles toward representative members of protein classes known to harbor electrophilic cofactors potentially susceptible to covalent capture. Understanding this protein chemistry through a probe-development effort is important for biochemical annotation of protein function because active enzymes, but not their inactive forms, can be selectively labeled to resolve activity from transcript or protein levels. By deploying a suite of cofactor-selective probes in cells, new members of enzyme families can be discovered through chemical discrimination of different classes, as previous work has shown for proteins with nucleophilic functionality. Results from this work will afford robust new tools for enzyme and PTM discovery and serve as preliminary data for the expansion of reverse-polarity activity-based protein profiling technologies.