Potent virucidal activity against Flaviviridae of a group IIA phospholipase A2 isolated from the venom of Bothrops asper

Publication date: Available online 12 December 2019Source: BiologicalsAuthor(s): Hebleen Brenes, Gilbert D. Loría, Bruno LomonteAbstractSecreted phospholipase A2 (sPLA2) molecules are small, calcium-dependent enzymes involved in many biological processes. Viperid venoms possess gIIA sPLA2s and sPLA2-like proteins, both having homology to human gIIA sPLA2, an innate immunity enzyme. We evaluated the antiviral action of Mt–I (catalytically-active sPLA2) and Mt-II (catalytically-inactive variant) isolated from the venom of Bothrops asper, against a diverse group of viruses. Yellow Fever and Dengue (enveloped) viruses were highly susceptible to inactivation by the snake proteins, in contrast to Sabin (non-enveloped; Polio vaccine strain), and Influenza A, Herpes simplex 1 and 2, and Vesicular Stomatitis (enveloped) viruses. Titration of the antiviral effect against Dengue virus revealed Mt–I to be highly potent (IC50 0.5–2 ng/mL), whereas Mt-II was 1000-fold weaker. This large difference suggested a requirement for PLA2 activity, which was confirmed by chemical inactivation of Mt–I. A synthetic peptide representing the membrane-disrupting region of Mt-II, previously shown to have bactericidal effect, lacked antiviral action, suggesting that the weak virucidal effect observed for Mt-II is likely caused by contamination with traces of Mt–I. On the other hand, Mt–I was demonstrated to act by a direct virucidal mechanism prior to infection, and not by an independent eff...
Source: Biologicals - Category: Biology Source Type: research