4GRM

The crystal structure of the high affinity TCR A6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.295 
  • R-Value Work: 0.234 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Increased Peptide Contacts Govern High Affinity Binding of a Modified TCR Whilst Maintaining a Native pMHC Docking Mode.

Cole, D.K.Sami, M.Scott, D.R.Rizkallah, P.J.Borbulevych, O.Y.Todorov, P.T.Moysey, R.K.Jakobsen, B.K.Boulter, J.M.Baker, B.M.Li, Y.I.

(2013) Front Immunol 4: 168-168

  • DOI: 10.3389/fimmu.2013.00168

  • PubMed Abstract: 
  • Natural T cell receptors (TCRs) generally bind to their cognate pMHC molecules with weak affinity and fast kinetics, limiting their use as therapeutic agents. Using phage display, we have engineered a high affinity version of the A6 wild-type TCR (A6 ...

    Natural T cell receptors (TCRs) generally bind to their cognate pMHC molecules with weak affinity and fast kinetics, limiting their use as therapeutic agents. Using phage display, we have engineered a high affinity version of the A6 wild-type TCR (A6wt), specific for the human leukocyte antigen (HLA-A(∗)0201) complexed with human T cell lymphotropic virus type 111-19 peptide (A2-Tax). Mutations in just 4 residues in the CDR3β loop region of the A6wt TCR were selected that improved binding to A2-Tax by nearly 1000-fold. Biophysical measurements of this mutant TCR (A6c134) demonstrated that the enhanced binding was derived through favorable enthalpy and a slower off-rate. The structure of the free A6c134 TCR and the A6c134/A2-Tax complex revealed a native binding mode, similar to the A6wt/A2-Tax complex. However, concordant with the more favorable binding enthalpy, the A6c134 TCR made increased contacts with the Tax peptide compared with the A6wt/A2-Tax complex, demonstrating a peptide-focused mechanism for the enhanced affinity that directly involved the mutated residues in the A6c134 TCR CDR3β loop. This peptide-focused enhanced TCR binding may represent an important approach for developing antigen specific high affinity TCR reagents for use in T cell based therapies.


    Organizational Affiliation

    Cardiff University School of Medicine, Heath Park , Cardiff , UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
A6 alpha chain
A, C
194N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
A6 beta chain
B, D
245N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.295 
  • R-Value Work: 0.234 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 90.491α = 90.00
b = 51.969β = 104.94
c = 95.218γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data scaling
REFMACrefinement
MOLREPphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-07-10
    Type: Initial release
  • Version 1.1: 2018-01-24
    Type: Database references