These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
4 files

Irreversible Inhibition of BoNT/A Protease: Unique Warhead Reactivity and Function Contingent upon a Bifunctional Approach

submitted on 18.01.2021, 21:31 and posted on 20.01.2021, 07:35 by Lewis Turner, Alexander Lund Nielsen, Lucy Lin, Sabine Pellett, Takashi Sugane, Margaret Olsen, Eric Johnson, Kim janda
We describe a comprehensive screening campaign of warheads, linked to a hydroxamate chelating anchor, for the modification of Cys165 within the BoNT/A protease.
Engaging thorough enzyme kinetics, we detail a remarkable proximity-driven covalent bond with an epoxide warhead, a weak electrophile; yet, one that possessed superior irreversible inhibition, and pharmacological properties, when compared to intrinsically higher reactive warheads. This directed, selective covalent bond was contingent upon the crucial hydroxamate-Zn2+ chelating interaction as exemplified by examining non-chelating compounds.
We discuss previous approaches using non-target selective cysteine-reactive warheads to modify the BoNT/A protease of which none present any therapeutic potential – our bifunctional strategy allows the use of intrinsically less reactive warheads to intercept the cysteine, which will allow for less off-target modifications of such inhibitors. Moreover, we also broach that this bifunctional approach is not a one-off strategy that we believe can be broadly translated to other metalloproteases that possess non-catalytic, yet, nucleophilic residues within the enzymes catalytic sphere.


R01 AI153298

R21 AI137709

F32 DA044692



Email Address of Submitting Author


The Scripps Research Institute



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest