Mass spectrometric assays reveal discrepancies in inhibition profiles for the SARS‐CoV‐2 papain‐like protease

DOI: 10.1002/cmdc.202200016

Authors: Lennart Brewitz (University of Oxford) , Jos J. A. G. Kamps (University of Oxford) , Petra Lukacik (Diamond Light Source) , Claire Strain-Damerell (Diamond Light Source) , Yilin Zhao (University of Oxford) , Anthony Tumber (University of Oxford) , Tika R. Malla (University of Oxford) , Allen M. Orville (Diamond Light Source) , Martin A. Walsh (Diamond Light Source) , Christopher Schofield (University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemmedchem

State: Published (Approved)
Published: January 2022

Abstract: The two SARS-CoV-2 proteases, i.e. the main protease (M pro ) and the papain-like protease (PL pro ), which hydrolyze the viral polypeptide chain giving functional non-structural proteins, are essential for viral replication and are medicinal chemistry targets. We report a high-throughput mass spectrometry (MS)-based assay which directly monitors PL pro catalysis in vitro . The assay was applied to investigate the effect of reported small-molecule PL pro inhibitors and selected M pro inhibitors on PL pro catalysis. The results reveal that some, but not all, PL pro inhibitor potencies differ substantially from those obtained using fluorescence-based assays. Some substrate-competing M pro inhibitors, notably PF-07321332 (nirmatrelvir) which is in clinical development, do not inhibit PL pro . Less selective M pro inhibitors, e.g. auranofin, inhibit PL pro , highlighting the potential for dual PL pro /M pro inhibition. MS-based PL pro assays, which are orthogonal to widely employed fluorescence-based assays, are of utility in validating inhibitor potencies, especially for inhibitors operating by non-covalent mechanisms.

Journal Keywords: Nucleophilic cysteine protease; PF-07321332 / pro nirmatrelvir; SARS-CoV-2 papain-like protease / PL; SARS- CoV-2 main protease / Mpro; viral protease inhibition

Diamond Keywords: COVID-19

Subject Areas: Biology and Bio-materials, Chemistry, Medicine


Technical Areas:

Added On: 31/01/2022 09:14

Discipline Tags:

Health & Wellbeing Biochemistry Chemistry Organic Chemistry Drug Discovery Life Sciences & Biotech

Technical Tags: