x Impact of COVID-19 on the publication process
The COVID-19 disease outbreak has been declared a public health emergency of international concern and it affects us all. JVATiTD is aware that many researchers will have difficulty in meeting the deadlines associated with the peer review and revision processes. Therefore, we ask for your understanding that this exceptional situation might lead to some delays in the publication process.

JVATiTD - Articles

Official publication of CEVAP/UNESP

Identification and characterization of the first endogenous phospholipase A2 inhibitor from a non-venomous tropical snake, Boa constrictor (Serpentes: Boidae)

Consuelo L. Fortes-Dias1, Diego Henrique Fagundes Macedo1, Rafaella Pereira Barbosa1, Gabriel Souza-Silva1, Paula Ladeira Ortolani1  [ + show more ]

J Venom Anim Toxins incl Trop Dis, 2020, 26:e20190044
Received: 30 July 2019 | Accepted: 17 December 2019 | Published online: 13 March 2020


Background: Endogenous phospholipase A2 inhibitors from snake blood (sbPLIs) have been isolated from several species around the world, with the primary function of self-protection against the action of toxic phospholipases A2. In American snakes, sbPLIs were solely described in pit vipers, in which the natural protection role is justified. In this study, we described a sbPLI in Boa constrictor (popularly known as jiboia), a non-venomous snake species from America. Methods: PLA2 inhibitory activity was tested in the blood plasma of B. constrictor using C. d. terrificus venom as the enzyme source. Antibodies developed against CNF, a sbγPLI from Crotalus durissus terrificus, were used to investigate the presence of homologues in the blood plasma of B. constrictor. A CNF-like molecule with a PLA2 inhibitory activity was purified by column chromatography. The encoding gene for the inhibitor was cloned from B. constrictor liver tissue. The DNA fragment was cloned, purified and sequenced. The deduced primary sequence of interest was aligned with known sbγPLIs from the literature. Results: The blood plasma of B. constrictor displayed PLA2 inhibitory activity. A CNF-like molecule (named BcNF) was identified and purified from the blood plasma of B. constrictor. Basic properties such as molecular mass, composing amino acids, and pI were comparable, but BcNF displayed reduced specific activity in PLA2 inhibition. BcNF showed highest identity scores (ISs) with sbγPLIs from pit vipers from Latin America (90-100%), followed by gamma inhibitors from Asian viperid (80-90%). ISs below 70% were obtained for BcNF and non-venomous species from Asia. Conclusion: A functional sbγPLI (BcNF) was described in the blood plasma of B. constrictor. BcNF displayed higher primary identity with sbγPLIs from Viperidae than to sbγPLIs from non-venomous species from Asia. The physiological role played by sbγPLIs in non-venomous snake species remains to be understood. Further investigation is needed.


Keywords: Phospholipase A2 inhibitor; Phospholipase A2; Boidae; Snakes; Rattlesnake venom

Full Article PDF