Immunoreactivity, epitope mapping and protection studies with anti-conotoxin GI sera and various conotoxins.

Goat or rabbit anti-conotoxin GI sera recognized native or dithiothreitol-reduced alpha-conotoxins GI, MI and SI in an enzyme-linked immunosorbent assay (ELISA). Native mu-conotoxin GIIIA or omega-conotoxin GVIA did not react with either anti-conotoxin GI serum in the assay. The goat anti-conotoxin GI serum neutralized 2.5 LD50S of alpha-conotoxins GI or MI in mouse lethal assays, while the rabbit antiserum had little protective capabilities. Epitope mapping of synthesized conotoxin peptide fragments revealed that both anti-conotoxin GI sera recognized linear sequences from five different alpha-conotoxins: GI, GIA, GII, MI and SI. The CCNPAC sequence was optimally recognized by both antisera.