Search

Snake venoms contain various proteins, especially phospholipases A 2 (PLA 2 s), which present potential applications in diverse areas of health and medicine. In this study, a new basic PLA 2 from Bothrops marajoensis with parasiticidal activity was purified and characterized biochemically and biologically. B. marajoensis venom was fractionated through cation exchange followed by reverse phase chromatographies. The isolated toxin, BmajPLA 2 -II, was structurally characterized with MALDI-TOF (Matrix-assisted laser desorption/ionization-time of flight) mass spectrometry, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), followed by two-dimensional electrophoresis, partial amino acid sequencing, an enzymatic activity assay, circular dichroism, and dynamic light scattering assays. These structural characterization tests presented BmajPLA 2 -II as a basic Lys49 PLA 2 homologue, compatible with other basic snake venom PLA 2 s (svPLA 2 ), with a tendency to form aggregations. The in vitro anti-parasitic potential of B. marajoensis venom and of BmajPLA 2 -II was evaluated against Leishmania infantum promastigotes and Trypanosoma cruzi epimastigotes, showing significant activity at a concentration of 100 μg/mL. The venom and BmajPLA 2 -II presented IC 50 of 0.14 ± 0.08 and 6.41 ± 0.64 μg/mL, respectively, against intraerythrocytic forms of Plasmodium falciparum with CC 50 cytotoxicity values against HepG2 cells of 43.64 ± 7.94 and >150 μg/mL, respectively. The biotechnological potential of these substances in relation to leishmaniasis, Chagas disease and malaria should be more deeply investigated. [ABSTRACT FROM AUTHOR]

Phospholipases A 2 inhibitors (PLIs) produced by venomous and non-venomous snakes play essential role in this resistance. These endogenous inhibitors may be classified by their fold in PLIα, PLIβ and PLIγ. Phospholipases A 2 (PLA 2 s) develop myonecrosis in snake envenomation, a consequence that is not efficiently neutralized by antivenom treatment. This work aimed to identify and characterize two PLIs from Amazonian snake species, Bothrops atrox and Micrurus lemniscatus. Liver tissues RNA of specimens from each species were isolated and amplified by RT-PCR using PCR primers based on known PLIγ gene sequences, followed by cloning and sequencing of amplified fragments. Sequence similarity studies showed elevated identity with inhibitor PLIγ gene sequences from other snake species. Molecular models of translated inhibitors' gene sequences resemble canonical three finger fold from PLIγ and support the hypothesis that the decapeptide (residues 107-116) may be responsible for PLA 2 inhibition. Structural studies and action mechanism of these PLIs may provide necessary information to evaluate their potential as antivenom or as complement of the current ophidian accident treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)