Résumé
The genus Kalloconus of cone snails includes seven species separated in two groups, one endemic to the Cabo Verde Islands (K. venulatus group) and another distributed along the West African coast and the Canary Islands (K. pulcher group). K. pulcher is considered the largest-sized living cone snail, and specimens may reach shell lengths up to 250 mm. All species in genus Kalloconus are vermivorous. We have now obtained transcriptomic data for the venom glands of K. canariensis (3 individuals, 490 sequences) and K. pulcher (1 individual, 204 sequences), which add to the available data for K. trochulus from Cabo Verde (1 individual, 179 sequences). We have used these transcriptomic data as reference for a comprehensive proteomic analysis of the venom gland extracts of the seven species within Kalloconus. Tandem LC-MS/MS validated a total of 457 sequences in 264 protein groups. Conotoxin superfamilies T, M, O1 and O2, conkunitzins and con-ikot-ikot account for ca. 50% total diversity. Assorted venom proteins represent 9%. There is little variability in conotoxin superfamily distribution among the different species studied. Two novel somatostatin-like peptides (contulakins) were identified in the transcriptomes and proteomes of K. pulcher and K. canariensis. These peptides are very similar to consomatin ConSST-Ro1, very recently isolated from the deep-water cone snail Asprella rolani. Our work reveals that non-paralytic conotoxins including conkunitzins, con-ikot-ikot, and very specially the somatostatin-analog contulakin are abundant in the proteome of Kalloconus species. Hence, shallow-water West African cone snails constitute a rich source for the discovery of new conopeptides.