Structure-based design of conformation- and sequence-specific antibodies against amyloid ?.

ABSTRACT: Conformation-specific antibodies that recognize aggregated proteins associated with several conformational disorders (e.g., Parkinson and prion diseases) are invaluable for diagnostic and therapeutic applications. However, no systematic strategy exists for generating conformation-specific antibodies that target linear sequence epitopes within misfolded proteins. Here we report a strategy for designing conformation- and sequence-specific antibodies against misfolded proteins that is inspired by the molecular interactions governing protein aggregation. We find that grafting small amyloidogenic peptides (6-10 residues) from the A?42 peptide associated with Alzheimer's disease into the complementarity determining regions of a domain (V(H)) antibody generates antibody variants that recognize A? soluble oligomers and amyloid fibrils with nanomolar affinity. We refer to these antibodies as gammabodies for grafted amyloid-motif antibodies. Gammabodies displaying the central amyloidogenic A? motif (18VFFA21) are reactive with A? fibrils, whereas those displaying the amyloidogenic C terminus (34LMVGGVVIA42) are reactive with A? fibrils and oligomers (and weakly reactive with A? monomers). Importantly, we find that the grafted motifs target the corresponding peptide segments within misfolded A? conformers. A? gammabodies fail to cross-react with other amyloidogenic proteins and scrambling their grafted sequences eliminates antibody reactivity. Finally, gammabodies that recognize A? soluble oligomers and fibrils also neutralize the toxicity of each A? conformer. We expect that our antibody design strategy is not limited to A? and can be used to readily generate gammabodies against other toxic misfolded proteins.

SUBMITTER: Perchiacca JM 

PROVIDER: S-EPMC3252897 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature