Cone snailsCone snails (family Conoidea) are venomous marine gastropods typically found in tropical marine waters. There are over 500 species of cone snails, and they use their venom to capture prey and defend against predators. Cone snails are grouped according to their preferred prey: worms, generally polychaetes; fish; and other gastropod molluscs (Olivera, 2002). The venom is composed of biologically active peptides, which are produced in the venom channel of the snail venom apparatus (Figure 1, Olivera 2002) and are pumped by the venom bulb through the proboscis.Figure 1. Apparatus with conical venom: the venom bulb, the venom canal and the radular sac with the harpoons (radular teeth). (Olivera 2002)Conus venom and conotoxinsConus venoms contain biologically active components, called conotoxins (conopeptides) that target different molecular receptors. They generally contain 10 to 35 amino acids. They are stabilized by disulfide bonds, usually via cysteine ​​residues. Post-translational modifications of amino acids are common, such as C-terminal amidation, 4-hydroxyproline, and gamma-carboxylic acid glutamic acid. Mature peptide toxins present in the venom are processed in the endoplasmic reticulum (ER) and Golgi apparatus. Conopeptides are expressed as precursor proteins and are organized as such in Figure 2. The ER signal is highly conserved and is used to define conopeptide gene superfamilies (Kaas et al. 2010, 2012). Figure 2. A example of a protein precursor conopeptide, precursor Ms20.1, indicating its signal sequence (pre region), its pro region and the mature peptide region. Based on the characteristics of conopeptides and their biological activity, they are classified...... middle of article ......Lluisma, A. (2012). Adaptive radiation of venomous marine snail lineages and accelerated evolution of venom peptide genes. Annals of the New York Academy of Sciences, 1267(1), 61-70.Olivera, B., Imperial, J., and Concepcion, G. (2013). Snail peptides. Handbook of Biologically Active Peptides (2nd ed., pp. 437-450). San Diego: Elsevier. Peracchia, C. (1994). Handbook of Membrane Channels: Molecular and Cellular Physiology. San Diego, CA: Academic Press. Schmidtko, A., Lötsch, J., Freynhagen, R. and Geisslinger, G. (2010). Ziconotide for the treatment of severe chronic pain. The Lancet, 375(9725), 1569-1577. Via, M. C. (2008). [Executive summary of the book Neurodegenerative Diseases: Next Generation Drugs for Four Major Disorders]. Insight Pharma Reports.