KSPublications - Molecular evolution of antibody cross-reactivity...

Title

Molecular evolution of antibody cross-reactivity for two subtypes of type A botulinum neurotoxin

Authors

Garcia-Rodriguez C, et al.

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 Å, 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.

Journal

Nature Biotechnology

Date

12/17/2006

Link

DOI:10.1038/nbt1269

Reference

Garcia-Rodriguez C, Levy R, Arndt JW, Forsyth CM, Razai A, Lou J, Geren I, Stevens RC, Marks JD. “Molecular evolution of antibody cross-reactivity for two subtypes of type A botulinum neurotoxin” Nature Biotechnol. 25, 107-116 (2006).

PMID

17173035

Keyword

BoNT

TSRI Number

Attachments

Kuhn Lab at The Scripps Research Institute.