8IRW | pdb_00008irw

Structure of nanobody Nb9 against parathion


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 
    0.225 (Depositor), 0.220 (DCC) 
  • R-Value Work: 
    0.193 (Depositor), 0.190 (DCC) 
  • R-Value Observed: 
    0.195 (Depositor) 

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


Literature

Molecular Evolution of Antiparathion Nanobody with Enhanced Sensitivity and Specificity Based on Structural Analysis.

Li, J.D.Shen, X.Xu, Z.L.Liang, Y.F.Shen, Y.D.Yang, J.Y.Wang, H.

(2023) J Agric Food Chem 71: 14758-14768

  • DOI: https://doi.org/10.1021/acs.jafc.3c05176
  • Primary Citation of Related Structures:  
    8IRW

  • PubMed Abstract: 

    Nanobody (Nb) has gained significant attention in immunoassays owing to its numerous advantages, particularly its ease of molecular evolution. However, the limited understanding of how high sensitivity and specificity attained for antihapten Nbs hamper the development of high-performance Nbs. Herein, the antiparathion Nb (Nb9) we prepared previously was chosen as the model, and an approach based on X-ray crystallography, molecular docking, and rational site-directed saturation mutation for constructing a rapid and effective platform for nanobody evolution was described. Based on the structural analysis, two mutants, namely Nb-D5 (IC 50 = 2.4 ± 0.2 ng/mL) and Nb-D12 (IC 50 = 2.7 ± 0.1 ng/mL), were selected out from a six-sites directed saturation mutation library, 3.5-fold and 3.1-fold sensitivity enhancement over Nb9 to parathion, respectively. Besides, Nb-D12 exhibited improved sensitivity for quinalphos, triazophos, and coumaphos (5.4-35.4 ng/mL), indicating its broader detection potential. Overall, our study advances an effective strategy for the future rational evolution of Nbs with desirable performance.


  • Organizational Affiliation
    • Guangdong Provincial Key Laboratory of Food Quality and Safety, National-Local Joint Engineering Research Center for Processing and Safety Control of Livestock and Poultry Products, College of Food Science, South China Agricultural University, Guangzhou 510642, China.

Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
nanobody Nb9 against parathion
A, B
168Camelus bactrianusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free:  0.225 (Depositor), 0.220 (DCC) 
  • R-Value Work:  0.193 (Depositor), 0.190 (DCC) 
  • R-Value Observed: 0.195 (Depositor) 
Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.662α = 90
b = 50.397β = 96.39
c = 56.123γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Science and Technology (MoST, China)China2019YFE0116600

Revision History  (Full details and data files)

  • Version 1.0: 2024-03-20
    Type: Initial release
  • Version 1.1: 2024-11-20
    Changes: Structure summary
  • Version 1.2: 2025-04-02
    Changes: Database references