A Functional Proteomic Strategy to Discover Inhibitors for Uncharacterized Hydrolases

摘要

We have described herein a functional proteomic strategy to develop inhibitors for uncharacterized SHs, and its application to create a potent and selective inhibitor of ABHD6. The enriched expression of ABHD6 in brain tissue suggests a role for this enzyme in nervous system metabolism and/or signaling. ABHD6 is also highly elevated in Epstein-Barr virus-transformed B cells, indicating that it may contribute to cancer pathogenesis. These expression patterns thus designate cell and organ targetsrnwhere the future application of 70, in conjunction with metabolomic methods, may reveal endogenous biochemical and (patho)-physiological functions for ABHD6. Projecting beyond ABHD6, it is noteworthy to emphasize that the development of 70 required screening fewer than 75 compounds. This achievement reinforces the idea that carbamates may offer a privileged molecular scaffold for the streamlined development of SH inhibitors that display an excellent combination of potency and selectivity. Of course, our competitive ABPP studies only speak to the specificity of carbamates within the SH family; potential protein targets outside of this enzyme class are not discriminated. Conversion of carbamates into probes using bio-orthogonal reactions such as the Cu(I)-catalyzed Huisgen's azide-alkyne cycloaddition (click chemistry) provides a complementary route to directly visualize protein targets of carbamates. We anticipate that continued efforts to screen structurally diverse libraries of carbamates against the daunting number of uncharacterized SHs that populate eukaryotic and prokaryotic proteomes will engender a suite of valuable pharmacological tools for annotating new biochemical pathways.