8ZBP | pdb_00008zbp

The crystal structure of SARS-CoV-2 main protease in complex with chebulagic acid (CHLA)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.41 Å
  • R-Value Free: 
    0.209 (Depositor), 0.208 (DCC) 
  • R-Value Work: 
    0.184 (Depositor), 0.192 (DCC) 
  • R-Value Observed: 
    0.185 (Depositor) 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Targeting SARS-CoV-2 main protease for the discovery of a broad-spectrum COVID-19 inhibitor by intensive multi-tiered validation.

Zhang, M.Wang, C.Feng, L.Yang, Q.Cao, Y.Zhao, Y.Zhang, J.Wang, Y.Rao, Z.Zhang, B.

(2025) Acta Pharm Sin B 15: 5789-5802

  • DOI: https://doi.org/10.1016/j.apsb.2025.09.033
  • Primary Citation of Related Structures:  
    8ZBP

  • PubMed Abstract: 

    SARS-CoV-2 and its emerging variants continue to pose a significant global public health threat. The SARS-CoV-2 main protease (M pro ) is a critical target for the development of antiviral agents that can inhibit viral replication and transcription. In this study, we identified chebulagic acid (CHLA), isolated from Terminalia chebula Retz., as a potent non-peptidomimetic and non-covalent M pro inhibitor. CHLA exhibited intermolecular interactions and provided significant protection to Vero E6 cells against a range of SARS-CoV-2 variants, including the wild-type, Delta, Omicron BA.1.1, BA.2.3, BA.4, and BA.5, with EC 50 values below 2 μmol/L. Moreover, in vivo studies confirmed the antiviral efficacy of CHLA in K18-hACE2 mice. Notably, CHLA bound to a unique groove at the interface between M pro domains I and II, which was revealed by the high-resolution crystal structure (1.4 Å) of the M pro -CHLA complex, shrinking the substrate binding pocket of M pro and inducing M pro aggregation. CHLA was proposed to act as an allosteric inhibitor. Pharmacokinetic profiling and safety assessments underscore CHLA's potential as a promising broad-spectrum antiviral candidate. These findings report a novel binding site on M pro and identify antiviral activity of CHLA, providing a robust framework for lead compounds discovery and elucidating the underlying molecular mechanisms of inhibition.


  • Organizational Affiliation
    • State Key Laboratory of Chinese Medicine Modernization, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
3C-like proteinase nsp5306Severe acute respiratory syndrome coronavirus 2Mutation(s): 0 
EC: 3.4.22.69
UniProt
Find proteins for P0DTC1 (Severe acute respiratory syndrome coronavirus 2)
Explore P0DTC1 
Go to UniProtKB:  P0DTC1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DTC1
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1D76 (Subject of Investigation/LOI)
Query on A1D76

Download Ideal Coordinates CCD File 
B [auth A]2-[(4R,5S,7R,25S,26R,29R,30S,31R)-13,14,15,18,19,20,21,31,35,36-decahydroxy-2,10,23,28,32-pentaoxo-5-(3,4,5-trihydroxybenzoyl)oxy-3,6,9,24,27,33-hexaoxaheptacyclo[28.7.1.04,25.07,26.011,16.017,22.034,38]octatriaconta-1(37),11,13,15,17(22),18,20,34(38),35-nonaen-29-yl]acetic acid
C41 H30 O27
HGJXAVROWQLCTP-BLHDDPQFSA-N
DMS
Query on DMS

Download Ideal Coordinates CCD File 
C [auth A]DIMETHYL SULFOXIDE
C2 H6 O S
IAZDPXIOMUYVGZ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.41 Å
  • R-Value Free:  0.209 (Depositor), 0.208 (DCC) 
  • R-Value Work:  0.184 (Depositor), 0.192 (DCC) 
  • R-Value Observed: 0.185 (Depositor) 
Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 43.34α = 90
b = 61.475β = 90
c = 104.843γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XSCALEdata scaling
XDSdata reduction
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China32200131

Revision History  (Full details and data files)

  • Version 1.0: 2025-11-05
    Type: Initial release
  • Version 1.1: 2025-11-12
    Changes: Database references, Structure summary
  • Version 1.2: 2025-12-10
    Changes: Database references