Phospholipase A2 Isolated from the Venom of Crotalus durissus terrificus Inactivates Dengue virus and Other Enveloped Viruses by Disrupting the Viral Envelope

Abstract

The Flaviviridae family includes several virus pathogens associated with human diseases worldwide. Within this family, Dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. Currently, there are no vaccines or specific antiviral drugs against Dengue virus or against most of the viruses of this family. Therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses remain a global public health priority. We previously showed that phospholipase A2 isolated from the venom of Crotalus durissus terrificus was able to inhibit Dengue virus and Yellow fever virus infection in Vero cells. Here, we present evidence that phospholipase A2 has a direct effect on Dengue virus particles, inducing a partial exposure of genomic RNA, which strongly suggests inhibition via the cleavage of glycerophospholipids at the virus lipid bilayer envelope. This cleavage might induce a disruption of the lipid bilayer that causes a destabilization of the E proteins on the virus surface, resulting in inactivation. We show by computational analysis that phospholipase A2 might gain access to the Dengue virus lipid bilayer through the pores found on each of the twenty 3-fold vertices of the E protein shell on the virus surface. In addition, phospholipase A2 is able to inactivate other enveloped viruses, highlighting its potential as a natural product lead for developing broad-spectrum antiviral drugs.

Development of a DNA microarray platform for the detection of viruses transmitted by small mammals and arthropods

“…The RoboArboVirusChip was able to detect a minimum of 21-67 RNA copies/mL of DENV-1 to -4, which is similar to the sensitivity described by other DNA microarray platforms (Grubaugh, Mcmenamy, et al, 2013;Huang et al, 2013), and to the sensitivity of a real-time RT-PCR describes by our group and which has been used to detect DENV in serum and saliva samples (Dos Santos et al, 2008;Poloni et al, 2010;Muller et al, 2014). These data suggest that the RoboArboVirusChip could be use to analyze clinical samples, which was confirmed by the detection of DENV in four clinical samples.…”

Vipericidins, Snake Venom Cathelicidin-Related Peptides, in the Milieu of Reptilian Antimicrobial Polypeptides

“…Thus, the blockade of virus disassembly, independent of the catalytic activity and virus phenotype, was the main mechanism of cell protection against HIV that was intermediated by svPLA 2 s, such as taipoxin (from Naja mossambica mossambica) and nigexine (from N. nigricollis). However, this mechanism that was observed for taipoxin and nigexine against HIV viruses contrasts to that of Crotalus durissus terrificus svPLA 2 against dengue and yellow fever viruses, in which a disruptive mechanism of the viral envelope is involved (Muller et al 2014). Surely, structural differences between the diverse svPLA 2 s as well as the compositional variation between virus envelopes and capsids influence the distinct mechanisms of antiviral action.…”

“…In venom, type II-secreted PLA2s are found in the acidic and basic forms as well as in monomeric, homodimeric, or heterodimeric toxin structures (Guarnieri et al 2009). Snake venom PLA 2 exhibits antibacterial (Perumal Samy et al 2007;Samy et al 2012) and antiviral activity (Muller et al 2014). For example, the basic svPLA2 from the venom of the eastern diamondback rattlesnake (Crotalus adamanteus) -CaTx-II -is a potent non-cytotoxic bactericide that kills pathogenic Staphylococcus aureus, Burkholderia pseudomallei, and Enterobacter aerogenes by inducing pore formation and membrane disruption (Samy et al 2014).…”

Heterologous Expression and Purification of Recombinant Crotoxin B, the Phospholipase A2 Subunit of Crotoxin

“…The chemical modification of the CB subunit did not influence its antibacterial activity on E. coli, suggesting that this effect is not linked with the enzymatic activity of the protein, as other molecular mechanisms might be involved in the bacterial membrane disruption [17]. In a different study, CTX and the CB subunit showed antiviral activity against dengue and yellow fever viruses, possibly by disrupting the virus lipid bilayer envelope [18,19].…”