Identification of Novel Conopeptides and Distinct Gene Superfamilies in the Marine Cone Snail Conus quercinus

Conopeptides from marine cone snails are a mixture of cysteine-rich active peptides, representing a unique and fertile resource for neuroscience research and drug discovery. The ConoServer database includes 8,134 conopeptides from 122 Conus species, but many natural conopeptides have yet to be discovered. Here, we identified 517 distinct conopeptide precursors in Conus quercinus using de novo deep transcriptome sequencing. Ten of these precursors were verified at the protein level using liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Combined gene and protein analyses revealed two novel gene superfamilies (Que-MNCLQ and Que-MAMNV), and three other gene superfamilies (N, P, and I1) were reported for the first time from C. quercinus. From the Que-MAMNV superfamily, a novel conotoxin, Que-0.1, was obtained via cloning and prokaryotic expression. We also documented a new purification process that can be used to induce the expression of conopeptides containing multiple pairs of disulfide bonds. Animal experiments showed that Que-0.1 strongly inhibited neuroconduction; the effects of Que-1.0 were 6.25 times stronger than those of pethidine hydrochloride. In addition, a new cysteine framework (CC-C-C-C-C-C-CC-C-C-C-C-C) was found in C. quercinus. These discoveries will accelerate our understanding of thehelp to clarify conopeptide diversity in the genus,Conus and supply promising materials for medical research.