Rapid Access to ω-Conotoxin Chimeras using Native Chemical Ligation

Abstract

Grafting different regions of related peptides together to form a single protein chimera is a valuable tool in rapidly elucidating regions of activity or selectivity in peptides and proteins. To conveniently evaluate the contributions of the N- and C-terminal segments of ω-conotoxins CVID and MVIIC to activity, we employed native chemical ligation in CVID-MVIIC chimera design. Assembly of these peptide segments via the ligation method improved overall yield and coupling efficiency, with no difficult sequences encountered in contrast to the traditional full-length chain assembly of CVID. Radio-ligand binding assays revealed regions of importance for receptor recognition.