Intraspecies variability and conopeptide profiling of the injected venom of Conus ermineus

Abstract

The venom of cone snails (ssp. Conus), a genus of predatory mollusks, is a vast source of bioactive peptides. Conus venom expression is complex, and venom composition can vary considerably depending upon the method of extraction and the species of cone snail in question. The injected venom from Conus ermineus, the only fish-hunting cone snail species that inhabits the Atlantic Ocean, was characterized using nanoNMR spectroscopy, MALDI-TOF mass spectrometry, RP-HPLC and nanoLC–ESI-MS. These methods allowed us to evaluate the variability of the venom within this species. Single specimens of C. ermineus show unchanged injected venom mass spectra and HPLC profiles over time. However, there was significant variability of the injected venom composition from specimen to specimen, in spite of their common biogeographic origin. Using nanoLC–ESI-MS, we determined that over 800 unique conopeptides are expressed by this reduced set of C. ermineus specimens. This number is considerably larger than previous estimates of the molecular repertoire available to cone snails to immobilize prey. These results support the idea of the existence of a complex regulatory mechanism to express specific venom peptides for injection into prey. These intraspecies differences can be a result of a combination of genetic and environmental factors. The differential expression of venom components represents a neurochemical paradigm that warrants further investigation.

Intraspecific variations in Conus purpurascens injected venom using LC/MALDI-TOF-MS and LC-ESI-TripleTOF-MS

“…1). All chromatograms display complex compositions and excellent resolution that compares to previously reported RP-HPLC profiles of injected venom from C. purpurascens [21,27] and other fish-hunting Conus species (C. geographus [28], C. consors [12], C. striatus [16], and C. ermineus [20]). There were between 97 and 150 fractions manually collected from the injected venom sample of each specimen.…”

“…The paired injected venom samples of specimens 1-8 had quantitatively and qualitatively matching venom profiles. However, one of the Bmilkingsô f specimen 9 had lower levels of conopeptide expression, which may be explained by a Bblank^venom injection that has been reported in C. purpurascens venom [21] and also other species [20].…”

“…Intraspecific variation has been previously described for the following cone snail species' dissected venom: Conus geographus [18], Conus striatus, Conus catus [16], Conus ventricosus [11], Conus textile, Conus imperialis, Conus marmoreus [9], and Conus vexillum [13]. Variations in the more biologically relevant injected venom of the fishhunting species C. striatus, C. catus [16], Conus consors [19], Conus ermineus [20], and Conus purpurascens [21] have been reported. Variations within an individual specimen's injected venom over time (C. consors [19], C. textile [22], C. purpurascens [21]) have also been observed.…”

Conotoxins: Structure, Therapeutic Potential and Pharmacological Applications

“…This sequence diversity is found both between the species as well as within the species [16][17][18][19]. Conotoxins are small peptides, mostly 10-40 amino acid residues in length.…”

CHAPTER 6. The Molecular Diversity of Conoidean Venom Peptides and their Targets: From Basic Research to Therapeutic Applications

“…Estimates range from several hundreds to thousands. 58-61 Intra-species variation in venom composition has been reported for Conus consors, 62 C. erminius, 63 and C. vexillum collected from two locations in the Red Sea. 64 Combined transcriptomic and mass spectrometric analysis of the milked venom from C. marmoreus revealed over 2000 unique peptides.…”