Unraveling the peptidome of the South African cone snails Conus pictus and Conus natalis.

Venoms from cone snails (genus Conus) can be seen as an untapped cocktail of biologically active compounds, being increasingly recognized as an emerging source of peptide-based therapeutics. Cone snails are considered to be specialized predators that have evolved the most sophisticated peptide chemistry and neuropharmacology system for their own biological purposes by producing venoms which contains a structural and functional diversity of neurotoxins. These neurotoxins or conotoxins are often small cysteine-rich peptides which have shown to be highly selective ligands for a wide range of ion channels and receptors. Local habitat conditions have constituted barriers preventing the spreading of Conus species occurring along the coast of South Africa. Due to their scarceness, these species remain, therefore, extremely poorly studied. In this work, the venoms of two South African cone snails, Conus pictus, a vermivorous snail and Conus natalis, a molluscivorous snail, have been characterized in depth. In total, 26 novel peptides were identified. Comparing the venoms of both snails, interesting differences were observed regarding venom composition and molecular characteristics of these components.