Open AccessBoaγPLI: Structural and functional characterization of the gamma phospholipase A2 plasma inhibitor from the non-venomous Brazilian snake Boa constrictor
Author(s) -
Caroline Fabri Bittencourt Rodrigues,
Caroline Serino-Silva,
Karen de Morais-Zani,
Victor Koiti Kavazoi,
Marcelo Pires Nogueira de Carvalho,
Kathleen Fernandes Grego,
Tássia Monique Chiarelli,
Alexandre Keiji Tashima,
Marcos H. Toyama,
Anita Mitico Tanaka-Azevedo
Publication year - 2020
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0229657
Subject(s) - snake venom , envenomation , venom , biology , phospholipase a2 , antivenom , enzyme , biochemistry , phospholipase a , phospholipase , ophidia
Plasma in several organisms has components that promote resistance to envenomation by inhibiting specific proteins from snake venoms, such as phospholipases A 2 (PLA 2 s). The major hypothesis for inhibitor’s presence would be the protection against self-envenomation in venomous snakes, but the occurrence of inhibitors in non-venomous snakes and other animals has opened new perspectives for this molecule. Thus, this study showed for the first time the structural and functional characterization of the PLA 2 inhibitor from the Boa constrictor serum (BoaγPLI), a non-venomous snake that dwells extensively the Brazilian territory. Therefore, the inhibitor was isolated from B . constrictor serum, with 0.63% of recovery. SDS-PAGE showed a band at ~25 kDa under reducing conditions and ~20 kDa under non-reducing conditions. Chromatographic analyses showed the presence of oligomers formed by BoaγPLI. Primary structure of BoaγPLI suggested an estimated molecular mass of 22 kDa. When BoaγPLI was incubated with Asp-49 and Lys-49 PLA 2 there was no severe change in its dichroism spectrum, suggesting a non-covalent interaction. The enzymatic assay showed a dose-dependent inhibition, up to 48.2%, when BoaγPLI was incubated with Asp-49 PLA 2 , since Lys-49 PLA 2 has a lack of enzymatic activity. The edematogenic and myotoxic effects of PLA 2 s were also inhibited by BoaγPLI. In summary, the present work provides new insights into inhibitors from non-venomous snakes, which possess PLIs in their plasma, although the contact with venom is unlikely.