4QT5

Crystal Structure of 3BD10: A Monoclonal Antibody against the TSH Receptor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.235 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Crystal structure of a TSH receptor monoclonal antibody: insight into Graves' disease pathogenesis.

Chen, C.R.Hubbard, P.A.Salazar, L.M.McLachlan, S.M.Murali, R.Rapoport, B.

(2015) Mol.Endocrinol. 29: 99-107

  • DOI: 10.1210/me.2014-1257

  • PubMed Abstract: 
  • The TSH receptor (TSHR) A-subunit is more effective than the holoreceptor in inducing thyroid-stimulating antibodies (TSAb) that cause Graves' disease. A puzzling phenomenon is that 2 recombinant, eukaryotic forms of A-subunits (residues 22-289), ter ...

    The TSH receptor (TSHR) A-subunit is more effective than the holoreceptor in inducing thyroid-stimulating antibodies (TSAb) that cause Graves' disease. A puzzling phenomenon is that 2 recombinant, eukaryotic forms of A-subunits (residues 22-289), termed active and inactive, are recognized mutually exclusively by pathogenic TSAb and mouse monoclonal antibody 3BD10, respectively. Understanding the structural difference between these TSHR A-subunit forms could provide insight into Graves' disease pathogenesis. The 3-dimensional structure of the active A-subunit (in complex with a human TSAb Fab, M22) is known, but the structural difference with inactive A-subunits is unknown. We solved the 3BD10 Fab 3-dimensional crystal structure. Guided by prior knowledge of a portion of its epitope, 3BD10 docked in silico with the known active TSHR-289 monomeric structure. Because both TSAb and 3BD10 recognize the active TSHR A-subunit monomer, this form of the molecule can be excluded as the basis for the active-inactive dichotomy, suggesting, instead a role for A-subunit quaternary structure. Indeed, in silico analysis revealed that M22, but not 3BD10, bound to a TSHR-289 trimer. In contrast, 3BD10, but not M22, bound to a TSHR-289 dimer. The validity of these models is supported experimentally by the temperature-dependent balance between active and inactive TSHR-289. In summary, we provide evidence for a structural basis to explain the conformational heterogeneity of TSHR A-subunits (TSHR-289). The pathophysiologic importance of these findings is that affinity maturation of pathogenic TSAb in Graves' disease is likely to involve a trimer of the shed TSHR A-subunit.


    Organizational Affiliation

    Thyroid Autoimmune Disease Unit (C-R.C., L.M.S., S.M.M., B.R.) and Department of Biomedical Sciences (P.H., R.M.), Cedars-Sinai Research Institute and UCLA School of Medicine, Los Angeles, California 90048.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
3BD10 mouse monoclonal antibody, light chain
L, A
216N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
3BD10 mouse monoclonal antibody, heavy chain
H, B
213N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.235 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 43.979α = 90.00
b = 136.979β = 90.00
c = 149.071γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
Aimlessdata scaling
HKL-3000data collection
REFMACrefinement
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-04-01
    Type: Initial release