FSK drochloride is fluorosulfonyloxybenzoyl-l-lysine, with a long and flexible aryl fluorosulfate-containing side chain that can reach protein sites that are difficult to reach by covalent linkage. FSK drochloride is a modified nanomolecule that targets the epidermal growth factor receptor (EGFR), creating a covalent binding that results in irreversible binding. FSK drochloride captures unknown enzyme-substrate interactions in living cells through genetically encoded chemical cross-linking, targeting residues beyond Cys, and cross-linking at the binding periphery. FSK drochloride enables the construction of bioreactive SuFEx systems for creating covalent bonds in different proteins in vitro and in vivo.
References:
[1]. Liu J, et al. A Genetically Encoded Fluorosulfonyloxybenzoyl-l-lysine for Expansive Covalent Bonding of Proteins via SuFEx Chemistry. J Am Chem Soc. 2021 Jul 14;143(27):10341-10351.