SOLUTION STRUCTURE OF OMEGA-CONOTOXIN-MVIIC DETERMININED BY NMR

The solution structure of the P- and Q-type Ca2+ channel blocker, omeg a-conotoxin MVIIC (a peptidic neurotoxin composed of 26 amino acid res idues), has been determined by H-1-NMR and simulated annealing calcula tions. The resulting calculated structures converged very well to a co nformation with an average value of pairwised RMSD for N, C alpha and C' of 0.62 Angstrom. Lys-25 is buried in the molecule and less flexibl e so that among the four Lys residues, its side chain provides the low est reactivity on biotinylation and the mono-biotinylation in this res idue less influences the biological activity. (C) 1995 Academic Press, Inc.