8AI7

Structure of carbamoylated human butyrylcholinesterase upon reaction with 3-(((2-cycloheptylethyl)(methyl)amino)methyl)-1H-indol-7-yl N,N-dimethylcarbamate

Summary for 8AI7

• Entry DOI: 10.2210/pdb8ai7/pdb
• Descriptor: Cholinesterase, alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose, ... (10 entities in total)
• Functional Keywords: butyrylcholinesterase, complex, inhibitor, carbamate, hydrolase
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 63127.75

Authors

Brazzolotto, X.,Meden, A.,Knez, D.,Gobec, S.,Nachon, F. (deposition date: 2022-07-25, release date: 2023-02-01, Last modification date: 2024-02-07)

Primary citation

Meden, A.,Knez, D.,Brazzolotto, X.,Modeste, F.,Perdih, A.,Pislar, A.,Zorman, M.,Zorovic, M.,Denic, M.,Pajk, S.,Zivin, M.,Nachon, F.,Gobec, S.
Pseudo-irreversible butyrylcholinesterase inhibitors: Structure-activity relationships, computational and crystallographic study of the N-dialkyl O-arylcarbamate warhead.
Eur.J.Med.Chem., 247:115048-115048, 2023

PubMed Abstract: Alongside reversible butyrylcholinesterase inhibitors, a plethora of covalent butyrylcholinesterase inhibitors have been reported in the literature, typically pseudo-irreversible carbamates. For these latter, however, most cases lack full confirmation of their covalent mode of action. Additionally, the available reports regarding the structure-activity relationships of the O-arylcarbamate warhead are incomplete. Therefore, a follow-up on a series of pseudo-irreversible covalent carbamate human butyrylcholinesterase inhibitors and the structure-activity relationships of the N-dialkyl O-arylcarbamate warhead are presented in this study. The covalent mechanism of binding was tested by IC time-dependency profiles, and sequentially and increasingly confirmed by kinetic analysis, whole protein LC-MS, and crystallographic analysis. Computational studies provided valuable insights into steric constraints and identified problematic, bulky carbamate warheads that cannot reach and carbamoylate the catalytic Ser198. Quantum mechanical calculations provided further evidence that steric effects appear to be a key factor in determining the covalent binding behaviour of these carbamate cholinesterase inhibitors and their duration of action. Additionally, the introduction of a clickable terminal alkyne moiety into one of the carbamate N-substituents and in situ derivatisation with azide-containing fluorophore enabled fluorescent labelling of plasma human butyrylcholinesterase. This proof-of-concept study highlights the potential of this novel approach and for these compounds to be further developed as clickable molecular probes for investigating tissue localisation and activity of cholinesterases.

PubMed: 36586299
DOI: 10.1016/j.ejmech.2022.115048

Experimental method

X-RAY DIFFRACTION (2.13 Å)