Abstract: To study insecticidal activity of Conotoxin ImI,the conotoxin linear peptide was synthesized by chemical method,and conotoxin ImI was identified by mass spectrometry after oxidative folding.The insecticidal activity of conotoxin was evaluated by MTT method and insect injection method.The results show that conotoxins linear peptides were successfully synthesized by chemical synthesis method,and two disulfide bonds were identified by mass spectrometry after oxidative folding.The activity test showed conotoxin ImI could inhibit the growth of sf9 in insect cells,and the half effective dose was 0.13 nM.It had a killing effect on Tenebrio molitor,with a median lethal dose was 0.11 μg/mg.Therefore,the conotoxin ImI can be synthesized by chemical synthesis,which has the insecticidal activity and can lay the foundation for the development of new peptide bio-pesticides.

Key words: conotoxin, chemical synthesis, oxidative folding, insecticidal activity