1P-26 PDF
Characterization of the Peptide Components in the Venom of the Egyptian Cone Snail Conus fulgetrum
Components of the venom of the vermivorous cone snail, Conusfulgetrum, werechemically characterized by using mass spectrometric techniques. First, LC/MS analysis was performed for the venom, and over 200 components, whose molecular mass ranged from 500 to 4000 Da, were found in the venom. Next, the number of disulfide bridges in each peptide was estimated based on the mass difference after derivatization of Cys residues, which revealed that peptides having 3 disulfide bridges were most abundant. One component, namedfu6a, was isolated by HPLC, and its primary structure was identified usingEdman degradation andMS/MS analysis.Fu6a is composed of 26 amino acid residues cross-linked with3 disulfide bonds, and contains two post-translationally modified residues. Fu6a belongs to the O-superfamily based on the arrangement of six Cys residues. Furthermore, fu6a was chemically synthesized by using the Fmoc-based solid-phase peptide synthesis technique to verify its structure. The synthesized peptide was shown to be identical to the native one, based on the comparison of the HPLC retention times. Fu6a elicited toxic effects in the snail Clithon retropictus after intramuscular injection, suggesting that fu6a plays an important role in defense against other snails.