Monoclonal antibodies against the presynaptic calcium channel antagonist ω-conotoxin GVI A from cone snail poison

Monoclonal antibodies have been prepared against co-conotoxin GVI A, a peptide isolated from marine snails of the genus Conus (Conus geographus and Conus magus). This toxin is a blocker of select presynaptic Ca²⁺ channels in the central nervous system. Antigenic ω-conotoxin GVI A was synthesized as a covalent conjugate with bovine serum albumin and injected s.c. An ELISA assay combined with a competitive inhibition assay was used to select and characterize monoclonal antibodies able to recognize and bind the free toxin. Several of the antibodies were found to block ω-conotoxin GVI A inhibition of ⁴⁵Ca transport into rat brain synaptosomes and to block ω-conotoxin GVI A binding to membranes from the same preparation. The antibodies recognize native, synthetic toxin, and are useful for analysis of toxin in biological fluids.