Binding of chimeric analogs of w-conotoxin MVIIA and MVIIC to the N-and P/Q-type calcium channels

Abstract : Despite their high sequence homology, the peptide neurotoxins ¢o-conotoxin MVIIA and MVIIC selectively block N-and P/Q-type calcium channels, respectively. To study the recognition mechanism of calcium channel subtypes, two chimeric analogs of ¢o-conotoxin MVIIA and MVIIC were synthesized by exchanging their N-and C-terminal halves. Binding assay for both N-and P/Q-type calcium channels showed that amino acid residues restricted to the N-terminal half are important for the recognition of N-type channels, whereas essential residues for P/Q-type channel recognition are widely spread over the whole ¢o-conotoxin molecule.