Novel Venom Peptides From Hawaiian Native Conus catus

Abstract

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 focuses on A-superfamily conotoxins, specifically α-conotoxins and neuroexcitatory peptides. α-conotoxins are competitive 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 amplify 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 collect purified DNA from bacterial colonies containing plasmids carrying the PCR products of interest. We then sequence the purified DNA samples, calculate the mature peptide masses with known post-translation modifications and compare the masses to known mature peptide masses. Thus far I have found three novel neuroexcitatory peptides and four novel α-conotoxins in Hawaiian Conus catus . By finding novel venom peptides we can not only better understand the importance of venom peptide microevolution and its relationship to intraspecies diversification, but also how these peptides can be utilized in other fields such as biomedicine.