Venomics and antivenomics of the poorly studied Brazil's lancehead, (Hoge, 1954), from the Brazilian State of Pará.

BACKGROUND

The Brazil's lancehead, , is a poorly studied pit viper distributed in lowlands of the equatorial rainforests of southern Colombia, northeastern Peru, eastern Ecuador, southern and southeastern Venezuela, Guyana, Suriname, French Guiana, Brazil, and northern Bolivia. Few studies have been reported on toxins isolated from venom of Ecuadorian and Brazilian . The aim of the present study was to elucidate the qualitative and quantitative protein composition of venom from Pará (Brazil), and to carry out a comparative antivenomics assessment of the immunoreactivity of the Brazilian antibothropic pentavalent antivenom [ (SAB) in Portuguese] against the venoms of and reference species, .

METHODS

We have applied a quantitative snake venomics approach, including reverse-phase and two-dimensional electrophoretic decomplexation of the venom toxin arsenal, LC-ESI-MS mass profiling and peptide-centric MS/MS proteomic analysis, to unveil the overall protein composition of venom from Pará (Brazil). Using third-generation antivenomics, the specific and paraspecific immunoreactivity of the Brazilian SAB against homologous () and heterologous () venoms was investigated.

RESULTS

The venom proteome of the Brazil's lancehead (Pará) is predominantly composed of two major and three minor acidic (19%) and two major and five minor basic (14%) phospholipase A molecules; 7-11 snake venom metalloproteinases of classes PI (21%) and PIII (6%); 10-12 serine proteinases (14%), and 1-2 L-amino acid oxidases (6%). Other toxins, including two cysteine-rich secretory proteins, one C-type lectin-like molecule, one nerve growth factor, one 5'-nucleotidase, one phosphodiesterase, one phospholipase B, and one glutaminyl cyclase molecule, represent together less than 2.7% of the venom proteome. Third generation antivenomics profile of the Brazilian pentabothropic antivenom showed paraspecific immunoreactivity against all the toxin classes of venom with maximal binding capacity of 132.2 mg venom/g antivenom. This figure indicates that 19% of antivenom's F(ab') antibodies bind venom toxins.

CONCLUSION

The proteomics outcome contribute to a deeper insight into the spectrum of toxins present in the venom of the Brazil's lancehead, and rationalize the pathophysiology underlying this snake bite envenomings. The comparative qualitative and quantitative immunorecognition profile of the Brazilian pentabothropic antivenom toward the venom toxins of and (the reference venom for assessing the bothropic antivenom's potency in Brazil), provides clues about the proper use of the Brazilian antibothropic polyvalent antivenom in the treatment of bites by the Brazil's lancehead.