Novel Venom Peptides From Hawaiian Native Conus catus

Abstract

This project focused on finding novel venom peptides from Hawaiian Conus catus. C. catus are marine venomous gastropods. They paralyze their prey by injecting venom into their prey through a ballistically propelled spear-like radular tooth. Current research involving the identification of DNA sequences of Conus conotoxins shows that these peptides are undergoing intense selective pressure, causing rapid diversification in the genes that encode for conotoxins. This study focused on A-superfamily conotoxins, specifially α-conotoxins and neuroexcitatory peptides. α-conotoxins are compeptive antagonists of acetylcholine receptors resulting in flaccid paralysis while neuroexcitatory peptides cause tetanic paralysis. By studying mature toxin sequences from individual Hawaiian C. catus we plan to observe intraspecies differences that we can attribute to as allelic differences. Through PCR and A-superfamily specific primers we amplified genomic DNA collected from preserved C. catus that only corresponds to the mature toxin sequences of interest. Then through TOPO-cloning and plasmid isolation mini-preps we collected purified DNA from bacterial colonies containing plasmids carrying the PCR products of interest. We then sequenced the purified DNA samples, calculated the mature peptide masses with known post-translation modifications and compared the masses to known mature peptide masses. By finding novel venom peptides we can better understand the importance of venom peptide microevolution and its relationship to intraspecies diversification and evolution.