4H0I image
Entry Detail
PDB ID:
4H0I
Keywords:
Title:
Crystal Structure of Scfv-2D10 in Complex with Methyl Alpha-D-Mannopyranoside
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2012-09-08
Release Date:
2013-06-19
Method Details:
Experimental Method:
Resolution:
2.40 Å
R-Value Free:
0.24
R-Value Work:
0.22
R-Value Observed:
0.22
Space Group:
P 31 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:2D10 scFv
Chain IDs:A
Chain Length:251
Number of Molecules:1
Biological Source:Mus musculus
Primary Citation
Structural evaluation of a mimicry-recognizing paratope: plasticity in antigen-antibody interactions manifests in molecular mimicry.
J.Immunol. 191 456 463 (2013)
PMID: 23733869 DOI: 10.4049/jimmunol.1203260

Abstact

Molecular mimicry manifests antagonistically with respect to the specificity of immune recognition. However, it often occurs because different Ags share surface topologies in terms of shape or chemical nature. It also occurs when a flexible paratope accommodates dissimilar Ags by adjusting structural features according to the antigenic epitopes or differential positioning in the Ag combining site. Toward deciphering the structural basis of molecular mimicry, mAb 2D10 was isolated from a maturing immune response elicited against methyl α-d-mannopyranoside and also bound equivalently to a dodecapeptide. The physicochemical evidence of this carbohydrate-peptide mimicry in the case of mAb 2D10 had been established earlier. These studies had strongly suggested direct involvement of a flexible paratope in the observed mimicry. Surprisingly, comparison of the Ag-free structure of single-chain variable fragment 2D10 with those bound to sugar and peptide Ags revealed a conformationally invariant state of the Ab while binding to chemically and structurally disparate Ags. This equivalent binding of the two dissimilar Ags was through mutually independent interactions, demonstrating functional equivalence in the absence of structural correlation. Thus, existence of a multispecific, mature Ab in the secondary immune response was evident, as was the plasticity in the interactions while accommodating topologically diverse Ags. Although our data highlight the structural basis of receptor multispecificity, they also illustrate mechanisms adopted by the immune system to neutralize the escape mutants generated during pathogenic insult.

Legend

Protein

Chemical

Disease

Primary Citation of related structures