Comparative analysis of proteases in the injected and dissected venom of cone snail species

Abstract

The venom of cone snails has been the subject of intense studies because it contains small neuroactive peptides of therapeutic value. However, much less is known about their larger proteins counterparts and their role in prey envenomation. Here, we analyzed the proteolytic enzymes in the injected venom of Conus purpurascens and Conus ermineus (piscivorous), and the dissected venom of Conus purpurascens, Conus marmoreus (molluscivorous) and Conus virgo (vermivorous). Zymograms show that all venom samples displayed proteolytic activity on gelatin. However, the electrophoresis patterns and sizes of the proteases varied considerably among these four species. The protease distribution also varied dramatically between the injected and dissected venom of C. purpurascens. Protease inhibitors demonstrated that serine and metalloproteases are responsible for the gelatinolytic activity. We found fibrinogenolytic activity in the injected venom of C. ermineus suggesting that this venom might have effects on the hemostatic system of the prey. Remarkable differences in protein and protease expression were found in different sections of the venom duct, indicating that these components are related to the storage granules and that they participate in venom biosynthesis. Consequently, different conoproteases play major roles in venom processing and prey envenomation.

Combined Peptidomic and Proteomic Analysis of Electrically Stimulated and Manually Dissected Venom from the South American Bullet Ant Paraponera clavata

“…This mass range of peptides is not unique to ant venoms, as cone snail venom contains mostly low molecular weight peptides in their venoms 55 . Nevertheless, other venomous organisms such as spiders 13 and scorpions have peptides in the higher molecular weight range of approximately 3-10 kDa 9,56 . However, comparison of individual masses within ant venom LC fractions found that each collection method resulted in venoms with unique peptide masses.…”

“…For example, 12% of the dry weight of bumblebee venom are PLA2s 75 . The lipase property of phospholipases may also facilitate further spreading of venom through the host tissue 13 .…”

“…Ant venom is conventionally obtained by venom gland dissection, however it can also be collected by electrical stimulation, which can be considered a more efficient method of collection since ants remain alive following venom collection. These two collection methods have been employed with spider 26 , cone snail 13 , wasp 27 , scorpion 28 and bee venoms 3 and differences in the venom components have been seen between these two collection methods [29][30][31] . The dissection technique has been used for many years for a variety of different arthropods after it was first introduced in 1961 32 .…”

“…If mass milking is not possible, as is the case with vespid venoms 27 , then automated methods of milking individual venoms have also been proposed 35 . Previous work suggests that dissected venom contains most of the proteins that are in electrically stimulated venom but also other proteins that are usually contaminants from the venom gland including cellular proteins used in metabolic machinery or toxin maturation and processing 13,27,36,37 .…”

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

“…Since both forms of the venom reside in the venom duct, the dissected venom is a mix of predatory venom vs. defensive venom [17] and thus more complex for this reason alone. We have previously shown that conoproteins are important components in the injected venom of C. purpurascens and C. ermineus [49], but evaluating the differential expression of proteins in the venom requires more elaborated approaches.…”