Platelet aggregation inhibitors from Bothrops alternatus snake venom

Area of Science:

• Biochemistry
• Toxicology
• Pharmacology

Background:

• Snake venoms are complex mixtures of proteins and peptides.
• These components can modulate platelet aggregation, impacting hemostasis.
• Bothrops alternatus venom contains metalloproteinases (SVMPs), serinoproteinases (SVSPs), and phospholipases A2 (PLA2s).

Purpose of the Study:

• To investigate the effects of SVMPs, SVSPs, PLA2s, and baltergin from B. alternatus venom on platelet aggregation.
• To elucidate the mechanisms of action of these venom components on platelet function.
• To explore the potential of venom components as biotechnological tools.

Main Methods:

• Turbidimetric method using a microplate reader to assess platelet aggregation.
• Use of inhibitor cocktails to selectively target enzyme families (SVMPs, SVSPs, PLA2s).
• Assay of purified baltergin (a PIII SVMP) using various agonists (ristocetin, collagen, ADP, thrombin).

Main Results:

• Inhibitor cocktails targeting SVMPs and PLA2s significantly reduced platelet aggregation induced by specific agonists.
• SVSP-targeting cocktails showed mild activation, suggesting low thrombin-like enzyme activity.
• Baltergin exhibited inhibitory effects, with distinct mechanisms depending on the agonist, and did not disaggregate platelet thrombi.

Conclusions:

• B. alternatus venom possesses natural inhibitors of platelet aggregation, primarily SVMPs and PLA2s.
• Minor venom components, like C-type lectins, likely contribute to the antiplatelet effects.
• Understanding venom's impact on platelet function is crucial for both snakebite pathophysiology and biotechnological applications.