3EYV image
Deposition Date 2008-10-22
Release Date 2009-11-03
Last Version Date 2024-10-09
Entry Detail
PDB ID:
3EYV
Keywords:
Title:
Anti-Lewis Y Fab fragment with Lewis Y antigen in the presence of zinc ions
Biological Source:
Source Organism:
MUS MUSCULUS (Taxon ID: 10090)
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.50 Å
R-Value Free:
0.26
R-Value Work:
0.21
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:hu3S193 Fab, heavy chain
Chain IDs:B (auth: H), D (auth: B)
Chain Length:222
Number of Molecules:2
Biological Source:MUS MUSCULUS
Polymer Type:polypeptide(L)
Molecule:hu3S193 Fab, light chain
Chain IDs:A (auth: L), C (auth: A)
Chain Length:219
Number of Molecules:2
Biological Source:MUS MUSCULUS
Peptide-like Molecules
PRD_900124
Primary Citation
A possible role for metallic ions in the carbohydrate cluster recognition displayed by a lewis y specific antibody.
Plos One 4 e7777 e7777 (2009)
PMID: 19901987 DOI: 10.1371/journal.pone.0007777

Abstact

BACKGROUND Lewis Y (Le(y)) is a blood group-related carbohydrate that is expressed at high surface densities on the majority of epithelial carcinomas and is a promising target for antibody-based immunotherapy. A humanized Le(y)-specific antibody (hu3S193) has shown encouraging safety, pharmacokinetic and tumor-targeting properties in recently completed Phase I clinical trials. METHODOLOGY/PRINCIPAL FINDINGS We report the three-dimensional structures for both the free (unliganded) and bound (Le(y) tetrasaccharide) hu3S193 Fab from the same crystal grown in the presence of divalent zinc ions. There is no evidence of significant conformational changes occurring in either the Le(y) carbohydrate antigen or the hu3S193 binding site, which suggests a rigid fit binding mechanism. In the crystal, the hu3S193 Fab molecules are coordinated at their protein-protein interface by two zinc ions and in solution aggregation of Fab can be initiated by zinc, but not magnesium ions. Dynamic light scattering revealed that zinc ions could initiate a sharp transition from hu3S193 Fab monomers to large multimeric aggregates in solution. CONCLUSIONS/SIGNIFICANCE Zinc ions can mediate interactions between hu3S193 Fab in crystals and in solution. Whether metallic ion mediated aggregation of antibody occurs in vivo is not known, but the present results suggest that similar clustering mechanisms could occur when hu3S193 binds to Le(y) on cells, particularly given the high surface densities of antigen on the target tumor cells.

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Primary Citation of related structures