Proximity‐driven, Regioselective Chemical Modification of Peptides and Proteins

Abstract

Chemical methods to covalently modify recombinant peptides and proteins are becoming increasingly valuable as the development of biological therapeutics accelerates. Rapid advances in chemoselectivity have been achieved to modify desired proteogenic and non-proteogenic amino acids. However, regioselectivity, in which a specific amino acid can be modified in the presence of chemically identical residues, has been much more difficult to achieve. This mini-review focuses on recent advances in regioselective chemical modification of peptides and proteins utilizing microenvironment and/or proximity-driven effects to achieve selectivity. While the chemistries and applications involving enzyme active site modification are still being steadily developed, such a concept has also been expanded to the modification of residues

oxSTEF Reagents Are Tunable and Versatile Electrophiles for Selective Disulfide-Rebridging of Native Proteins

“…The STEF reagents are modified vinylogous thioesters that enable irreversible conjugation to lysine residues via a proximal cysteine having undergone initial, fast thiol-exchange with the STEF-reagent (Figure B). In addition to such proximity-guided conjugation, − STEF reagents can also undergo direct lysine conjugation with the specific thiol leaving group, providing selectivity for certain lysines through non-covalent interactions with surrounding residues …”

oxSTEF reagents are tunable and versatile electrophiles for selective disulfide-rebridging of native proteins

“…1B). In addition to such proximity-guided conjugation 36,37,38,39 , STEF reagents can also undergo direct lysine conjugation with the specific thiol leaving group providing selectivity for certain lysines through non-covalent interactions with surrounding residues. 35 We hypothesized that the reactivity of the STEF-scaffold could be completely altered by introduction of an additional sulfide-substituent to C1 thereby reducing the electrophilicity sufficiently to effectively shut down reactivity towards lysines, while still preserving the reactivity towards cysteines.…”