2NZ9

Crystal structure of botulinum neurotoxin type A complexed with monoclonal antibody AR2

Summary for 2NZ9

• Entry DOI: 10.2210/pdb2nz9/pdb
• Related: 2NYY
• Descriptor: Botulinum neurotoxin type A, AR2 monoclonal antibody, ZINC ION, ... (5 entities in total)
• Functional Keywords: botulinum, neurotoxin, fab, protein antibody complex, toxin-immune system complex, toxin/immune system
• Biological source: Homo sapiens (human); More
• Cellular location: Botulinum neurotoxin A light chain: Secreted. Botulinum neurotoxin A heavy chain: Secreted: P10845
• Total number of polymer chains: 6
• Total formula weight: 395138.93

Authors

Stevens, R.C.,Arndt, J.W. (deposition date: 2006-11-22, release date: 2006-12-26, Last modification date: 2024-11-13)

Primary citation

Garcia-Rodriguez, C.,Levy, R.,Arndt, J.W.,Forsyth, C.M.,Razai, A.,Lou, J.,Geren, I.,Stevens, R.C.,Marks, J.D.
Molecular evolution of antibody cross-reactivity for two subtypes of type A botulinum neurotoxin.
Nat.Biotechnol., 25:107-116, 2007

PubMed Abstract: Broadening antibody specificity without compromising affinity should facilitate detection and neutralization of toxin and viral subtypes. We used yeast display and a co-selection strategy to increase cross-reactivity of a single chain (sc) Fv antibody to botulinum neurotoxin type A (BoNT/A). Starting with a scFv that binds the BoNT/A1 subtype with high affinity (136 pM) and the BoNT/A2 subtype with low affinity (109 nM), we increased its affinity for BoNT/A2 1,250-fold, to 87 pM, while maintaining high-affinity binding to BoNT/A1 (115 pM). To find the molecular basis for improved cross-reactivity, we determined the X-ray co-crystal structures of wild-type and cross-reactive antibodies complexed to BoNT/A1 at resolutions up to 2.6 A, and measured the thermodynamic contribution of BoNT/A1 and A2 amino acids to wild-type and cross-reactive antibody binding. The results show how an antibody can be engineered to bind two different antigens despite structural differences in the antigen-antibody interface and may provide a general strategy for tuning antibody specificity and cross-reactivity.

PubMed: 17173035
DOI: 10.1038/nbt1269

Experimental method

X-RAY DIFFRACTION (3.79 Å)