Toggle Main Menu Toggle Search

Open Access padlockePrints

In vitro selection of macrocyclic peptide inhibitors containing cyclic γ2,4-amino acids targeting the SARS-CoV-2 main protease

Lookup NU author(s): Professor Akane Kawamura



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


γ-Amino acids can play important roles in the biological activities of natural products; however, ribosomal incorporation of γ-amino acids into peptides is challenging. Here we report how a selection campaign employing a non-canonical peptide library containing cyclic γ2,4-amino acids (cγAAs) resulted in the discovery of very potent inhibitors of the SARS-CoV-2 main protease (Mpro). Two kinds of cγAAs, cis-3-aminocyclobutane carboxylic acid (γ1) and (1R,3S)-3-aminocyclopentane carboxylic acid (γ2), were ribosomally introduced into a library of thioether-macrocyclic peptides. One resultant potent Mpro inhibitor (IC50 = 50 nM), GM4, comprising 13 residues with γ1 at the 4th position, manifests a 5.2 nM dissociation constant. An Mpro:GM4 complex crystal structure reveals the intact inhibitor spans the substrate binding cleft. γ1 interacts with the S1′ catalytic subsite and contributes to a 12-fold increase in proteolytic stability compared to its alanine-substituted variant. Knowledge of interactions between GM4 and Mpro enabled production of a variant with a 5-fold increase in potency.

Publication metadata

Author(s): Miura T, Malla TR, Owen CD, Tumber A, Brewitz L, McDonough MA, Salah E, Terasaka N, Katoh T, Lukacik p, Strain-Damerell C, Mikolajek H, Walsh MA, Kawamura A, Schofield CJ, Suga H

Publication type: Article

Publication status: Published

Journal: Nature Chemistry

Year: 2023

Pages: epub ahead of print

Online publication date: 22/05/2023

Acceptance date: 14/04/2023

Date deposited: 06/03/2023

ISSN (print): 1755-4330

ISSN (electronic): 1755-4349

Publisher: Springer Nature


DOI: 10.1038/s41557-023-01205-1

ePrints DOI: 10.57711/zjxz-as28


Altmetrics provided by Altmetric


Funder referenceFunder name