High-density peptide microarray technology can be used to map epitope-paratope interactions between linear elements of protein epitopes and antibodies in a high-throughput fashion. In the Tropical Pharmacology Lab, we employ this technology for identifying antivenom-recognized epitopes in snake venom toxins. This enables us not only to identify important antibody recognition sites, but also to better understand the cross-reacognition patterns that antivenoms display on a molecular level.
When performing a high-density peptide microarray experiment, we first construct a library of overlapping peptides (7-16 amino acid residues) using the amino acid sequences of toxins. In addition, we have the option of expanding the peptide library with single mutated versions of these peptides. Then, we synthesize all the resulting peptides onto a small glass slide and allow antivenom antibodies to bind. By detecting antivenom binding with secondary fluorophore-coupled antibodies and mapping the signals of individual spots (corresponding to each peptide) back to crystal structures of the investigated toxins, we are able to identify antivenom-recognized epitopes and predict antivenom cross-recognition to homologous toxins from other toxin families and even other snake species.