Juan Carlos Quintana Castillo

Extraction and partial characterization of venom from the Colombian spider Pamphobeteus aff. nigricolor (Aranae:Theraphosidae).

We report the first studies of characterization and extraction of the Pamphobeteus aff. nigricolor (Pocock, 1901) (Aranae:Theraphosidae) venom done in Colombia using the electro-stimulation technique previous anesthesia with isofluorane. After each extraction process, a low viscosity, colorless venom was obtained. This venom showed a 1.01 mg/μl density and a pH of 5. The humidity percentage did not show a significance difference between males and females (P > 0.05) with a general media of 77.49 ± 1.74%. In all cases the venom yielded was variable between males and females, with a media of 22.45 ± 5.17 mg (wet weight) and 4.58 ± 0.94 mg (dry weigh), obtaining larger amounts in females, 28.34 ± 7.49 mg and 5.69 ± 1.36 (wet and dry weight respectively). Venom showed a hemolytic activity dependent of enzymatic active phospholipase and neither coagulant nor proteolytic activities were observed. Electrophoretic profile showed a main protein content with a molecular mass below 14 kDa. RP-HPLC venom profile revealed a difference among male and female venoms content where 17 and 21 main fractions were obtained respectively. Three peptides, Theraphotoxin-Pn1a, Theraphotoxin-Pn1b and Theraphotoxin-Pn2a, were identified using HPLC-nESI-MS/MS. These peptides showed a high identity with other peptides found on Theraphosides which are proved to affect voltage-gated calcium channels.

Venom from Opisthacanthus elatus scorpion of Colombia, could be more hemolytic and less neurotoxic than thought

We report the first biochemical, biological, pharmacological and partial proteomic characterization studies of the Opisthancanthus elatus venom (Gervais, 1844) from Colombia. The Reverse Phase High-Performance Liquid Chromatography venom profile showed 28 main well-defined peaks, most eluting between 20 and 45min (18-30% of acetonitrile, respectively). High-resolution mass analysis indicates the presence of 106 components ranging from 806.59742Da to 16849.4139Da. O. elatus venom showed hemolytic activity and hydrolyzed the specific substrate BapNa suggesting the presence of proteins with serine-protease activity. Collected RP-HPLC fractions eluting at 52.6, 55.5, 55.8, 56.2, and 63.9min (PLA2 region between 33 and 40% of acetonitrile), showed hemolytic activity and hydrolyzed the synthetic substrate 4-nitro-3-octanoyloxy-benzoic acid, indicating the presence of compounds with phospholipases A2 activity. These RP-HPLC fractions, showed molecular masses values up to 13978.19546Da, corroborating the possible presence of the mentioned enzymes. Tryptic digestion and MS/MS analysis showed the presence of a phospholipase like fragment, similar to on described in other Opisthacanthus genus studies. No coagulant activity was observed. No larvicidal or antimicrobial activity was observed at concentrations evaluated. Lethal and toxic activity is expected at doses above 100mg/kg, no neurotoxic effects were detected at lower doses. In conclusion, O. elatus exhibits a venom with a predominant phospholipase A2 activity than thought; mammals neurotoxic activity is expected above the 100mg/kg, which is very high compared to the venom from other neurotoxic scorpions.