Aryl Fluorosulfate Based Inhibitors That Covalently Target the SIRT5 Lysine Deacylase

The sirtuin enzymes are a family of lysine deacylases that regulate gene transcription and metabolism. Sirtuin 5 (SIRT5) hydrolyzes malonyl, succinyl, and glutaryl ϵ‐N‐carboxyacyllysine posttranslational modifications and has recently emerged as a vulnerability in certain cancers. However, chemical probes to illuminate its potential as a pharmacological target have been lacking. Here we report the harnessing of aryl fluorosulfate‐based electrophiles as an avenue to furnish covalent inhibitors that target SIRT5. Alkyne‐tagged affinity‐labeling agents recognize and capture overexpressed SIRT5 in cultured HEK293T cells and can label SIRT5 in the hearts of mice upon intravenous injection of the compound. This work demonstrates the utility of aryl fluorosulfate electrophiles for targeting of SIRT5 and suggests this as a means for the development of potential covalent drug candidates. It is our hope that these results will serve as inspiration for future studies investigating SIRT5 and general sirtuin biology in the mitochondria. SuFEx warheads installed into a previously developed inhibitor scaffold that targets the sirtuin 5 (SIRT5) deacylase, furnish covalently labeling inhibitors that pull down the enzyme from cells and tissue. With further optimization of the compound's potencies, this proof‐of‐concept study may provide the foundation for development of highly efficient covalent chemical probes and/or drug lead compounds targeting SIRT5.