Isolation and functional characterization of proinflammatory acidic phospholipase A_2 from Bothrops leucurus snake venom

摘要

In the present study, an acidic PLA_2, designated Bl-PLA _2, was isolated from Bothrops leucurus snake venom through two chromatographic steps: ion-exchange on CM-Sepharose and hydrophobic chromatography on Phenyl-Sepharose. Bl-PLA2 was homogeneous on SDS-PAGE and when submitted to 2D electrophoresis the molecular mass was 15,000 Da and pI was 5.4. Its N-terminal sequence revealed a high homology with other Asp49 acidic PLA_2s from snake venoms. Its specific activity was 159.9 U/mg and the indirect hemolytic activity was also higher than that of the crude venom. Bl-PLA_2 induced low myotoxic and edema activities as compared to those of the crude venom. Moreover, the enzyme was able to induce increments in IL-12p40, TNF-α, IL-1β and IL-6 levels and no variation of IL-8 and IL-10 in human PBMC stimulated in vitro, suggesting that Bl-PLA_2 induces proinflammatory cytokine production by human mononuclear cells. Bothrops leucurus venom is still not extensively explored and knowledge of its components will contribute for a better understanding of its action mechanism.