Development of Substrate-Selective Probes for Affinity Pulldown of

ABSTRACT: JmjC-domain containing histone demethylases (JHDMs) play critical roles in many key cellular processes and have been implicated in multiple disease conditions. Each enzyme within this family is known to have a strict substrate scope, specifically the position of the lysine within the histone and its degree of methylation. While much progress has been made in determining the substrates of each enzyme, new methods with which to systematically profile each histone mark are greatly needed. Novel chemical tools have the potential to fill this role and, furthermore, can be used as probes to answer fundamental questions about these enzymes and serve as potential therapeutic leads. In this work, we first investigated three small-molecule probes differing in the degree of “methylation state ” and their differential bindings to JHDM1A (an H3K36me1/2 demethylase) using a fluorescence polarization-based competition assay. We then applied this specificity toward the “methylation state ” and combined it with specificity toward lysine position in the design and synthesis of a peptidic probe targeting H3K36me2 JHDMs. The probe is further functionalized with a benzophenone cross-linking moiety and a bioti