7UEN image
Deposition Date 2022-03-22
Release Date 2022-06-29
Last Version Date 2024-11-20
Entry Detail
PDB ID:
7UEN
Keywords:
Title:
Genetic and structural basis of the human anti-alpha-galactosyl antibody response
Biological Source:
Source Organism:
Mus musculus (Taxon ID: 10090)
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.55 Å
R-Value Free:
0.17
R-Value Work:
0.12
R-Value Observed:
0.12
Space Group:
P 32 2 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:M86 antibody Fab heavy chain
Chain IDs:B (auth: H)
Chain Length:229
Number of Molecules:1
Biological Source:Mus musculus
Polymer Type:polypeptide(L)
Molecule:M86 antibody Fab light chain
Chain IDs:A (auth: L)
Chain Length:219
Number of Molecules:1
Biological Source:Mus musculus
Primary Citation
Genetic and structural basis of the human anti-alpha-galactosyl antibody response.
Proc.Natl.Acad.Sci.USA 119 e2123212119 e2123212119 (2022)
PMID: 35867757 DOI: 10.1073/pnas.2123212119

Abstact

Humans lack the capacity to produce the Galα1-3Galβ1-4GlcNAc (α-gal) glycan, and produce anti-α-gal antibodies upon exposure to the carbohydrate on a diverse set of immunogens, including commensal gut bacteria, malaria parasites, cetuximab, and tick proteins. Here we use X-ray crystallographic analysis of antibodies from α-gal knockout mice and humans in complex with the glycan to reveal a common binding motif, centered on a germline-encoded tryptophan residue at Kabat position 33 (W33) of the complementarity-determining region of the variable heavy chain (CDRH1). Immunoglobulin sequencing of anti-α-gal B cells in healthy humans and tick-induced mammalian meat anaphylaxis patients revealed preferential use of heavy chain germline IGHV3-7, encoding W33, among an otherwise highly polyclonal antibody response. Antigen binding was critically dependent on the presence of the germline-encoded W33 residue for all of the analyzed antibodies; moreover, introduction of the W33 motif into naive IGHV3-23 antibody phage libraries enabled the rapid selection of α-gal binders. Our results outline structural and genetic factors that shape the human anti-α-galactosyl antibody response, and provide a framework for future therapeutics development.

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