9H7K | pdb_00009h7k

Human Transthyretin in Complex with 8-(3,5-dimethyl-1H-pyrazol-4-yl)quinoline

  • Classification: TRANSPORT PROTEIN
  • Organism(s): Homo sapiens
  • Expression System: Homo sapiens
  • Mutation(s): No 

  • Deposited: 2024-10-27 Released: 2025-03-12 
  • Deposition Author(s): Chen, W.
  • Funding Organization(s): University of College London, Other private

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 
    0.236 (Depositor), 0.244 (DCC) 
  • R-Value Work: 
    0.176 (Depositor), 0.190 (DCC) 
  • R-Value Observed: 
    0.179 (Depositor) 

Starting Model: experimental
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Ligand Structure Quality Assessment 


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Literature

Fragment-based drug discovery for transthyretin kinetic stabilisers using a novel capillary zone electrophoresis method.

Chen, W.

(2025) PLoS One 20: e0323816-e0323816

  • DOI: https://doi.org/10.1371/journal.pone.0323816
  • Primary Citation of Related Structures:  
    9H7A, 9H7B, 9H7C, 9H7D, 9H7E, 9H7F, 9H7G, 9H7H, 9H7I, 9H7J, 9H7K, 9H7L, 9H7M, 9H7N, 9H7O, 9H7P

  • PubMed Abstract: 

    A Capillary Zone Electrophoresis (CZE) fragment screening methodology was developed and applied to the human plasma protein Transthyretin (TTR), normally soluble, but could misfold and aggregate, causing amyloidosis. Termed Free Probe Peak Height Restoration (FPPHR), it monitors changes in the level of free ligand known to bind TTR (the Probe Ligand) in the presence of competing fragments. 129 fragments were screened, 12 of the 16 initial hits (12.4% hit rate) were co-crystallised with TTR, 11 were found at the binding site (92% confirmation rate). Subsequent analogue screens have identified a novel TTR-binding scaffold 4-(3H-pyrazol-4-yl)quinoline and its derived compounds were further studied by crystallography, circular dichroism (CD), isothermal titration calorimetry (ITC) and radiolabelled 125I-Thyroxine displacement assay in neat plasma. Two lead molecules had similar ITC Kd and 125I-Thyroxine displacement IC50 values to that of Tafamidis, adding another potential pipeline for transthyretin amyloidosis. The methodology is reproducible, procedurally simple, automatable, label-free without target immobilisation, non-fluorescence based and site-specific with low false positive rate, which could be applicable to fragment screening of many drug targets.


  • Organizational Affiliation

    Laboratory for Protein Crystallography, Centre for Amyloidosis and Acute Phase Proteins, Division of Medicine, UCL Medical School Royal Free Campus, London, United Kingdom.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Transthyretin
A, B
127Homo sapiensMutation(s): 0 
Gene Names: TTRPALB
UniProt & NIH Common Fund Data Resources
Find proteins for P02766 (Homo sapiens)
Explore P02766 
Go to UniProtKB:  P02766
PHAROS:  P02766
GTEx:  ENSG00000118271 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02766
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free:  0.236 (Depositor), 0.244 (DCC) 
  • R-Value Work:  0.176 (Depositor), 0.190 (DCC) 
  • R-Value Observed: 0.179 (Depositor) 
Space Group: P 21 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.107α = 90
b = 63.069β = 90
c = 83.837γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PROTEUM PLUSdata reduction
PROTEUM PLUSdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data

  • Released Date: 2025-03-12 
  • Deposition Author(s): Chen, W.

Funding OrganizationLocationGrant Number
University of College LondonUnited KingdomBXTX
Other privateHN9A

Revision History  (Full details and data files)

  • Version 1.0: 2025-03-12
    Type: Initial release
  • Version 1.1: 2025-05-28
    Changes: Database references