Novel Venom Peptides from Hawaiian Conus catus

Abstract

Intense competitive selection has produced prodigious interspecific variation in venom peptide distribution among the piscivorous cone snails, Conus catus . These snails occupy a unique niche among mollusks by utilizing a ballistic radular tooth through which venom is injected to induce paralysis of target fish. The neuroexcitatory peptide, c4a, is thought to be present in all C. Catus injected venom and hypothesized to be responsible for the rapid, repetitive action potentials that cause spastic paralysis of motor neurons. This project presents a protocol to separate and characterize known and novel component venom peptides with the aim of obtaining a greater insight into the target and post-translational modifications of c4a. Reverse-phase high pressure liquid chromatography resolution and recovery was refined though the use of peptide standards. Future investigation hopes to obtain the cellular and sub-cellular target of c4a in vivo by attaching a fluorescent label following enzyme mediated oxidation. To create a control for c4a, fetuin was digested by trypsin to create a peptide of comparable size and post-translational modification. To quickly confirm modified peptide activity or characterize novel peptides, the concentration limitations of a zebrafish ( Danio rerio) spinal motility assay were probed. Interaction of fluorescent probe Alexa Fluor 488 with C18 Ziptip matrix was found to be sufficiently compatible with fractionated peptide solvent conditions to justify its use in a glycosylation identification assay.