Isolation and expression of a hypotensive and anti-platelet acidic phospholipase A2 from Bothrops moojeni snake venom

Abstract

Phospholipases A2 are important components of snake venoms, the basic isoforms have been more extensively studied than the acidic groups, maybe due to their higher toxicity. Trying to better understand the role of the acidic isoforms on the envenomation process, an acidic phospholipase A2 was purified from Bothrops moojeni snake venom through two chromatographic steps (BmooPLA2). The enzyme showed a relative molecular mass of 13,601 Da, pI 5.2, high phospholipase activity, bactericidal effect, moderate cytotoxic activity and was able to inhibit platelet aggregation. Moreover, BmooPLA2 induced moderate in vivo edema and hypotensive effect. The 414 bp cDNA encoding the BmooPLA2 was cloned and expressed in Escherichia coli. The recombinant BmooPLA2 showed phospholipase and inhibitory activities on platelet aggregation similar to those of the native protein. A comparative study between BmooPLA2, the acidic (BthA-I) and basic (BthTX-II) PLA2 from B. jararacussu venom showed that the effects of BmooPLA2 and BthA-I-PLA2 are similar. BmooPLA2 is the first isolated and characterized non-myotoxic PLA2 from B. moojeni snake venom. The recombinant PLA2 can substitute the native toxin in studies aiming its biotechnological application in order to help the preservation of this endangered species. These data along with the preliminary structural studies here reported will provide a better understanding of this important class of proteins.