Crystal Structure of Human KEAP1 BTB Domain in Complex with isoxazoline-based inhibitor

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.293 
  • R-Value Work: 0.253 
  • R-Value Observed: 0.257 

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Effects of 3-Bromo-4,5-dihydroisoxazole Derivatives on Nrf2 Activation and Heme Oxygenase-1 Expression.

Pinto, A.El Ali, Z.Moniot, S.Tamborini, L.Steegborn, C.Foresti, R.De Micheli, C.

(2018) ChemistryOpen 7: 858-864

  • DOI: https://doi.org/10.1002/open.201800185
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Natural and synthetic electrophilic compounds have been shown to activate the antioxidant protective Nrf2 (nuclear factor erythroid 2-related factor 2)/heme oxygenase-1 (HO-1) axis in cells and tissues. Here, we tested the ability of different isoxazoline-based electrophiles to up-regulate Nrf2/HO-1. The potency of activation is dependent on the leaving group at the 3-position of the isoxazoline nucleus, and an additional ring on the molecule limits the Nrf2/HO-1 activating properties. Among the synthetized compounds, we identified 3-bromo-5-phenyl-4,5-dihydroisoxazole 1 as the derivative with best activating properties in THP-1 human monocytic cells. We have confirmed that the target of our compounds is the Cys151 of the BTB domain of Keap1 by using mass spectrometry analyses and X-ray crystallography. Our findings demonstrate that these compounds affect the Nrf2/HO-1 axis and highlight a positive activity that can be of relevance from a therapeutic perspective in inflammation and infection.

  • Organizational Affiliation

    Department of Food, Environmental and Nutritional Sciences (DeFENS) University of Milan viaCeloria 2 20133 Milan Italy.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Kelch-like ECH-associated protein 1136Homo sapiensMutation(s): 1 
Gene Names: KEAP1INRF2KIAA0132KLHL19
UniProt & NIH Common Fund Data Resources
Find proteins for Q14145 (Homo sapiens)
Explore Q14145 
Go to UniProtKB:  Q14145
PHAROS:  Q14145
GTEx:  ENSG00000079999 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14145
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
D8N (Subject of Investigation/LOI)
Query on D8N

Download Ideal Coordinates CCD File 
B [auth A]~{N}-[4-[(5~{R})-4,5-dihydro-1,2-oxazol-5-yl]phenyl]ethanamide
C11 H12 N2 O2
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.293 
  • R-Value Work: 0.253 
  • R-Value Observed: 0.257 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.491α = 90
b = 42.491β = 90
c = 265.213γ = 120
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2018-11-14
    Type: Initial release
  • Version 1.1: 2024-01-17
    Changes: Data collection, Database references, Refinement description