Peptides as Therapeutic Agents for Dengue Virus

Chew, Miaw-Fang; Poh, Keat-Seong; Poh, Chit-Laa

DENV is an enveloped, positive, single-stranded (ss) RNA virus classified under the genus Flavivirus of the Flaviridae family [28] . Other closely related viruses classified under the Flavivirus include yellow fever virus (YFV), west nile virus (WNV), japanese encephalitis virus (JEV) and zika virus. The dengue virion is a spherical particle, approximately 50 nm in diameter with envelope (E) and precursor-membrane (prM) / membrane (M) proteins located on its surface, while the capsid (C) proteins sit underneath the lipid bilayer, encapsulating the viral genome [29] . The DENV genome (~11 kb) constitutes a single open reading frame (ORF), encoding three structural proteins (C, prM/M and E proteins) followed by seven non-structural (NS) proteins (NS1, NS2A and 2B, NS3, NS4A and 4B, NS5) ( Figure 1 ) [30] . The translated polyprotein is then cleaved by cellular signal peptidases and virally encoded protease (NS2B and NS3) to generate individual proteins. The structural proteins form the viral particle while the non-structural proteins participate in replication and invasion of the immune system [30] . To design peptides with therapeutic potential against dengue virus, it is necessary to understand the viral replication cycle.