Cyclization of α-conotoxinA10LPnIA with lysine assisted cyanuric chloride linker

The cyanuric chloride linkers have been used for cyclizing polypeptide, but not used for α-conotoxin, the peptides with rich disulfide bonds and more amino acid residues. In this study, cyclic peptides cA10LPnIA-1-4 were synthesized efficiently by lysine assisted cyanuric chloride linkers with 28.92%-52.00% yields. The activity evaluation showed that the IC₅₀ values of cA10LPnIA-1 against α7 and α3β2 nAChR subtypes were 5 and 7 times higher thanA10LPnIA respectively, and the subtype selectivity was maintained. The results of circular dichroism show that this cyclization method had no significant effect on its secondary structure. Compared with the commonly used head-to-tail cyclization in conotoxin cyclization, this method has the advantages of rapid reaction and high yield, which is expected to be further applied to the cyclization study of various α-conotoxins.