Biological characterization and inhibitors action of Phospholipase A₂ from Lachesis muta venom

In the present study, phospholipase A2 (PLA₂) from Lachesis muta (Linnaeus, 1766), is isolated, purified and characterized biochemically and biologically. Purification was performed by liquid chromatography (LC) using CM-Sephadex C-50 and Sephadex G-50, homogenized enzyme had a molecular weight of 18749 Da. Trials with egg yolk phospholipids, and commercial lecithin showed that EDTA, PMSF, glutathione and cysteine inhibited the activity with values greater than 50%. The PLA₂ had a significant anticoagulant effect, showing a delay of 2'30" on the coagulation time with 9.6 µg of the enzyme. The indirect impact on human erythrocyte hemolysis gave an equivalent of 4.35 µg as HD₅₀. Mean edematic dose and minimum myotoxic dose were 91.5 mg and 125.89 mg / mL respectively, these values were below enzymes phospholipase A2 from others poisons. There was no hemorrhagic activity. Immunodiffusion tests and immunoelectrophoresis revealed that the PLA₂ of L. muta was immunogenic reactivity against lachesic monovalent antivenom (INS-Peru). However, the neutralization by the antivenom was partial.