Pharmacological characterization of venoms obtained from Mexican toxoglossate gastropods on isolated guinea pig ileum

Abstract

ABSTRACT:The protein-containing extracts prepared from the venom ducts of Conus austini, Conus spurius and Polystira albida caused a concentration-dependent inhibition of spontaneous contractions in guinea pig ileum. The most potent extract was obtained from P. albida venom ducts (IC 50 = 0.11 ± 0.02 µg protein/mL). The three extracts produced a moderate inhibition of contractions elicited by acetylcholine (ACh 1 µM), suggesting the presence of anticholinergic compounds. The contractile response elicited by nicotine (10 µM) was significantly reduced by the extracts prepared from the ducts of C. austini and P. albida, which indicates that the venom produced by these species contains toxins that target neuronal nicotinic receptors. All three extracts significantly inhibited contractions evoked by histamine (0.5 µM), particularly those from C. spurius and P. albida. These findings reveal the presence of antihistaminergic compounds not previously described in any conoidean venom. Finally, we found that only the extract prepared from C. spurius ducts decreased KCl (60 mM)-induced contractions, indicating that the venom of this snail contains compounds that block voltage-dependent Ca 2+ or Na + channels.

Molecular Phylogeny, Classification and Evolution of Conopeptides

“…To a lesser extent, species in the small major clade of Conus, may also contain several novel conotoxins, as suggested by an original Cys-pattern (XIII) found in the species C. delessertii (Aguilar et al 2005). In addition to the family Conidae, original toxins have already been reported in several other species of Conoidea, such as Polystira albida (Lopez-Vera et al 2004;Rojas et al 2008), Gemmula periscelida (Lopez-Vera et al 2004), G. speciosa, G. sogodensis, G. diomedea, G. kieneri (Heralde et al 2008), Lophiotoma olangoensis (Watkins et al 2006), Terebra subulata (Imperial et al 2003), Hastula hectica (Imperial et al 2007) and Crassispira cerithina (Cabang et al 2011). Furthermore, taxonomic surveys (Bouchet et al 2009) and phylogenetic analyses (Puillandre et al 2011) suggest that the superfamily Conoidea actually comprises a number of deeply divergent clades, whose species diversity is currently largely underestimated.…”

Direct palladium-mediated on-resin disulfide formation from Allocam protected peptides

“…1 Nature has capitalized on these properties, in combination with the diversity of amino acids, to produce vast libraries of stable, selective polypeptides with defined structures and biological activities. 2 Meanwhile, peptide-based pharmaceuticals are becoming increasingly important 3 because of their greater specificity, potency and lower toxicity profile over traditional small molecule pharmaceuticals. 3b,4 Additionally, new biological entities benefit from a higher regulatory approval rate than traditional small molecule targets.…”