pH profiles of 3-chymotrypsin-like protease (3CLpro) from SARS-CoV-2 elucidate its catalytic mechanism and a histidine residue critical for activity

Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved..

3-Chymotrypsin-like protease (3CLpro) is a promising drug target for coronavirus disease 2019 and related coronavirus diseases because of the essential role of this protease in processing viral polyproteins after infection. Understanding the detailed catalytic mechanism of 3CLpro is essential for designing effective inhibitors of infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Molecular dynamics studies have suggested pH-dependent conformational changes of 3CLpro, but experimental pH profiles of SARS-CoV-2 3CLpro and analyses of the conserved active-site histidine residues have not been reported. In this work, pH-dependence studies of the kinetic parameters of SARS-CoV-2 3CLpro revealed a bell-shaped pH profile with 2 pKa values (6.9 ± 0.1 and 9.4 ± 0.1) attributable to ionization of the catalytic dyad His41 and Cys145, respectively. Our investigation of the roles of conserved active-site histidines showed that different amino acid substitutions of His163 produced inactive enzymes, indicating a key role of His163 in maintaining catalytically active SARS-CoV-2 3CLpro. By contrast, the H164A and H172A mutants retained 75% and 26% of the activity of WT, respectively. The alternative amino acid substitutions H172K and H172R did not recover the enzymatic activity, whereas H172Y restored activity to a level similar to that of the WT enzyme. The pH profiles of H164A, H172A, and H172Y were similar to those of the WT enzyme, with comparable pKa values for the catalytic dyad. Taken together, the experimental data support a general base mechanism of SARS-CoV-2 3CLpro and indicate that the neutral states of the catalytic dyad and active-site histidine residues are required for maximum enzyme activity.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:299

Enthalten in:

The Journal of biological chemistry - 299(2023), 2 vom: 07. Feb., Seite 102790

Sprache:

Englisch

Beteiligte Personen:

Al Adem, Kenana [VerfasserIn]
Ferreira, Juliana C [VerfasserIn]
Fadl, Samar [VerfasserIn]
Rabeh, Wael M [VerfasserIn]

Links:

Volltext

Themen:

3-chymotrypsin-like protease
3C-like proteinase, SARS-CoV-2
4QD397987E
COVID-19
Catalytic dyad
Conserved histidine
Coronavirus 3C Proteases
EC 3.4.22.-
EC 3.4.22.28
Histidine
Initial velocity studies
Journal Article
PH studies
Research Support, Non-U.S. Gov't
SARS-CoV-2
Thermodynamic stability

Anmerkungen:

Date Completed 01.03.2023

Date Revised 01.03.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jbc.2022.102790

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM350212627