Lookup NU author(s): Paul Thompson,
Professor Alastair Hawkins
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).
© the Partner Organisations 2019.Targeted irreversible inhibitors bearing electrophiles that become activated towards covalent bond formation upon binding to a specific protein/enzyme is an emerging area in drug discovery. Targeting lysine residues is challenging due to the intrinsically low reactivity of the amino group at physiological pH. Herein we report the first example of a hydroxylammonium derivative that causes a specific covalent modification of an active-site and a sterically inaccessible lysine residue of an enzyme. The described ligands, compounds 1-3, were rationally designed to be activated towards covalent bond formation upon binding to the type I dehydroquinase (DHQ1) enzyme for the development of new anti-virulence agents to combat the widespread resistance to antibiotics. Evidence in atomic detail for the covalent modifications caused by the ligands to the catalytic Lys170 by the formation of a stable secondary amine is provided by the resolution at 1.08-1.25 Å of the crystal structures of DHQ1 from Salmonella typhi enzyme adducts. In addition, the first crystal structure of the addition intermediate adduct at 1.4 Å of a Schiff base formation reaction by using an analog of the natural substrate, compound 4, is also reported. Molecular dynamics simulation studies on non-covalent enzyme/ligand complexes and a two-dimensional QM/MM umbrella sampling simulation study suggested that a direct displacement by Lys170 with the release of NH2OH would be feasible. These studies might open up new opportunities for the development of novel lysine-targeted irreversible inhibitors bearing a methylhydroxylammonium moiety as a latent electrophile.
Author(s): Maneiro M, Lence E, Sanz-Gaitero M, Otero JM, Van Raaij MJ, Thompson P, Hawkins AR, Gonzalez-Bello C
Publication type: Article
Publication status: Published
Journal: Organic Chemistry Frontiers
Online publication date: 23/07/2019
Acceptance date: 07/07/2019
Date deposited: 02/09/2019
ISSN (print): 2052-4110
ISSN (electronic): 2052-4129
Publisher: Royal Society of Chemistry
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