Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8318951 | Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology | 2018 | 12 Pages |
Abstract
In this work, we examined the proteolytic and phospholipase A2 (PLA2) activities of venom from the opisthoglyphous colubrid Pseudoboa neuwiedii. Proteolytic activity (3 and 10â¯Î¼g of venom) was comparable to that of Bothrops neuwiedii venom but less than Bothrops atrox. This activity was inhibited by EDTA and 1,10-phenanthroline but only slightly affected (â¤30% inhibition) by PMSF and AEBSF, indicating it was mediated by snake venom metalloproteinases (SVMPs). The pH and temperature optima for proteolytic activity were 8.0 and 37â¯Â°C, respectively. The venom had no esterase activity, whereas PLA2 activity was similar to B. atrox, greater than B. neuwiedii but less than B. jararacussu. SDS-PAGE revealed venom proteins >100â¯kDa, 45-70â¯kDa, 21-24â¯kDa and ~15â¯kDa, and mass spectrometry of protein bands revealed SVMPs, cysteine-rich secretory proteins (CRISPs) and PLA2, but no serine proteinases. In gelatin zymography, the most active bands occurred at 65-68â¯kDa (seen with 0.05-0.25â¯Î¼g of venom). Caseinolytic activity occurred at 50-66â¯kDa and was generally weaker than gelatinolytic activity. RP-HPLC of venom yielded 15 peaks, five of which showed gelatinolytic activity; peak 7 was the most active and apparently contained a P-III class SVMP. The venom showed α-fibrinogenase activity, without affecting the β and γ chains; this activity was inhibited by EDTA and 1,10-phenanthroline. The venom did not clot rat citrated plasma but reduced the rate and extent of coagulation after plasma recalcification. In conclusion, P. neuwiedii venom is highly proteolytic and could potentially affect coagulation in vivo by degrading fibrinogen via SVMPs.
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Authors
Kristian A. Torres-Bonilla, Débora Andrade-Silva, Solange M.T. Serrano, Stephen Hyslop,