Venom peptides from two species of fish-hunting cone snails (Conus striatus and Conus catus) were characterized using microbore liquid chromatography coupled with matrix-assisted laser desorption/ionization-time of flight- mass spectrometry and electrospray ionization-ion

More than 500 species of marine snails comprise the genus Conus, and all are venomous predators. The venom of a typical cone snail contains small post-translationally modified peptides, many of which are directed towards voltageand ligand-gated ion channels and receptors with exquisite specificity (Olivera, 1997). A complex mixture of peptide toxins is produced in a long tubular venom duct containing secretory cells. Venom is ultimately discharged into prey by injection through a highly modified radular tooth, resembling a barbed hypodermic needle, which is gripped near the tip of an extensible proboscis. Mechanisms for transferring toxins from the venom duct into the proboscis for injection are not well understood, but in at least one species, C. californicus, peptides appear to be packaged into the radular teeth themselves (Marshall et al., 2002). In the fish-hunting species C. catus, and presumably in other species as well, the radular tooth is explosively propelled in a ballistic fashion into the prey prior to venom expulsion through the tooth (Schulz et al., 2004). Venoms of both C. striatus and C. catus induce an immediate tetanic paralysis of the harpooned fish, thereby enabling prey capture (Kohn, 1956). Isolation of venom peptides from Conus snails in the vast majority of cases has employed crude venom obtained from dissected venom ducts (duct venom, DV), with material being pooled from multiple animals. The use of DV enables peptide characterization based on conventional analytical and sequencing methods that require fairly large amounts of material. However, it is not clear how peptides in DV are related to those actually injected during prey capture. In several The Journal of Experimental Biology 208, 2873-2883 Published by The Company of Biologists 2005 doi:10.1242/jeb.01713