4NKI

Crystal structure of a Fab


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Epitope characterization of an anti-PD-L1 antibody using orthogonal approaches.

Hao, G.Wesolowski, J.S.Jiang, X.Lauder, S.Sood, V.D.

(2015) J Mol Recognit 28: 269-276

  • DOI: 10.1002/jmr.2418
  • Primary Citation of Related Structures:  
    4NKI

  • PubMed Abstract: 
  • The binding of programmed death ligand 1 protein (PD-L1) to its receptor programmed death protein 1 (PD-1) mediates immunoevasion in cancer and chronic viral infections, presenting an important target for therapeutic intervention. Several monoclonal ...

    The binding of programmed death ligand 1 protein (PD-L1) to its receptor programmed death protein 1 (PD-1) mediates immunoevasion in cancer and chronic viral infections, presenting an important target for therapeutic intervention. Several monoclonal antibodies targeting the PD-L1/PD-1 signaling axis are undergoing clinical trials; however, the epitopes of these antibodies have not been described. We have combined orthogonal approaches to localize and characterize the epitope of a monoclonal antibody directed against PD-L1 at good resolution and with high confidence. Limited proteolysis and mass spectrometry were applied to reveal that the epitope resides in the first immunoglobulin domain of PD-L1. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) was used to identify a conformational epitope comprised of discontinuous strands that fold to form a beta sheet in the native structure. This beta sheet presents an epitope surface that significantly overlaps with the PD-1 binding interface, consistent with a desired PD-1 competitive mechanism of action for the antibody. Surface plasmon resonance screening of mutant PD-L1 variants confirmed that the region identified by HDX-MS is critical for the antibody interaction and further defined specific residues contributing to the binding energy. Taken together, the results are consistent with the observed inhibitory activity of the antibody on PD-L1-mediated immune evasion. This is the first report of an epitope for any antibody targeting PD-L1 and demonstrates the power of combining orthogonal epitope mapping techniques.


    Organizational Affiliation

    EMD Serono Research and Development Institute, Inc., 45A Middlesex Turnpike, Billerica, MA, 02144, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Fab light chainH232Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Fab heavy chainL216Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EDO
Query on EDO

Download CCD File 
H
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.200 
  • Space Group: P 43 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 115.944α = 90
b = 115.944β = 90
c = 78.92γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
BUSTERrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

  • Deposited Date: 2013-11-12 
  • Released Date: 2014-11-12 
  • Deposition Author(s): Jiang, X.

Revision History 

  • Version 1.0: 2014-11-12
    Type: Initial release
  • Version 1.1: 2015-04-22
    Changes: Database references