9PHT | pdb_00009pht

Crystal structure of the A/Vietnam/1203/2004 (H5N1) influenza virus hemagglutinin in complex with fusion inhibitor cyclic peptide CP141085 (CP1)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.76 Å
  • R-Value Free: 
    0.291 (Depositor), 0.291 (DCC) 
  • R-Value Work: 
    0.261 (Depositor), 0.264 (DCC) 
  • R-Value Observed: 
    0.263 (Depositor) 

Starting Model: experimental
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This is version 1.1 of the entry. See complete history


Literature

V H H antibody loop guides design of a synthetic macrocyclic peptide that potently blocks influenza virus membrane fusion.

Kadam, R.U.Juraszek, J.Brandenburg, B.Garg, D.Zhu, X.Jongeneelen, M.Schepens, W.B.G.Stoops, B.Vermond, J.Goutier, W.Tang, C.Blokland, S.Vogels, R.Friesen, R.H.E.van Dongen, M.J.P.Wilson, I.A.

(2025) Npj Viruses 3: 83-83

  • DOI: https://doi.org/10.1038/s44298-025-00166-1
  • Primary Citation of Related Structures:  
    9PHD, 9PHQ, 9PHS, 9PHT

  • PubMed Abstract: 

    Miniaturizing biologically complex structural motifs to produce synthetic functional mimetics holds significant promise for development of new therapeutic modalities. Here, we demonstrate a unique approach using the key binding loop of the single variable domain of a heavy chain (V H H) llama antibody as a starting point for peptide design. V H H antibodies of camelids and sharks generally have longer, but more ligand-efficient complementarity determining region 3 (CDR3) loops and are relatively stable structures. We harnessed these attributes as templates for design of a series of synthetic macrocyclic peptides. The designed peptides exhibit nanomolar binding to influenza hemagglutinin (HA) and heterosubtypic in vitro neutralization breadth against influenza A viruses by inhibiting the low pH mediated HA conformational changes that lead to membrane fusion. X-ray structures of peptide-HA complexes reveal high structural mimicry with the parent V H H antibody. One such macrocycle peptide candidate is promising for further development of broad protection against influenza A group 1 viruses.


  • Organizational Affiliation
    • Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA. rkadam3@its.jnj.com.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Hemagglutinin334Influenza A virus (A/Viet Nam/1203/2004(H5N1))Mutation(s): 0 
Gene Names: HA
UniProt
Find proteins for Q5EP31 (Influenza A virus (strain A/Vietnam/1203/2004 H5N1))
Explore Q5EP31 
Go to UniProtKB:  Q5EP31
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ5EP31
Glycosylation
Glycosylation Sites: 3
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Hemagglutinin175Influenza A virus (A/Viet Nam/1203/2004(H5N1))Mutation(s): 0 
Gene Names: HA
UniProt
Find proteins for Q5EP31 (Influenza A virus (strain A/Vietnam/1203/2004 H5N1))
Explore Q5EP31 
Go to UniProtKB:  Q5EP31
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ5EP31
Sequence Annotations
Expand
  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
cyclic peptide CP141085C [auth G]19synthetic constructMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.76 Å
  • R-Value Free:  0.291 (Depositor), 0.291 (DCC) 
  • R-Value Work:  0.261 (Depositor), 0.264 (DCC) 
  • R-Value Observed: 0.263 (Depositor) 
Space Group: P 3 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 116.388α = 90
b = 116.388β = 90
c = 141.506γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2025-12-24
    Type: Initial release
  • Version 1.1: 2025-12-31
    Changes: Database references