High-throughput discovery and characterisation of pentafluorobenzene sulfonamide modifiers of Aurora A kinase.

Covalent modification can enable understanding and modulation of protein function, and the identification of new therapeutic opportunities. A "direct to biology" workflow was developed that harnesses sulfonylation as a connective reaction for the synthesis of diverse sets of reactive fragments. The workflow expanded the diversity of accessible reactive fragment sets, and facilitated the discovery of pentafluorobenzene sulfonamides that modify Aurora A kinase, NEK7 kinase, and UbcH5B. Characterisation of several of the Aurora A-modifying reactive fragments revealed both their modification rates and sites. Furthermore, Cys247, a residue typically buried in Aurora A crystal structures, was identifed as a modifable residue. These findings underscore the importance of protein dynamics in determining cysteine reactivity and highlight the utility of reactive fragment sets for identifying cryptic pockets. Sulfonylation is therefore a useful complement to amide formation in "direct to biology" workflows aimed at identifying novel opportunities for targeted protein modification.