Sulfur (VI) fluoride exchange (SuFEx): a versatile tool to profile protein-biomolecule interactions for therapeutic development

Sulfur (VI) fluoride exchange (SuFEx), a new generation of click chemistry, enables the creation of a stable covalent linkage between a protein and its interacting biomolecule. This transformative process converts the transient and reversible protein-biomolecule interaction into a stable binding complex, which allows the subsequent pull-down assay to identify unknown interactors. Therefore, SuFEx has emerged as a versatile tool to investigate protein-biomolecule interactions and facilitate new therapeutic development. SuFEx warheads such as aryl fluorosulfates and aryl sulfonyl fluorides can be appended to small molecules to investigate protein-ligand interactions. Furthermore, they can be incorporated into proteins site-specifically to probe protein-protein interactions (PPIs) and protein-RNA interactions with pinpoint accuracy. Here, we describe the principles of SuFEx, summarize its application in profiling protein-biomolecule interactions, and delve into the kinetics of SuFEx. This overview can serve as a roadmap to understanding the application of SuFEx in biomedical research.