Computer-Assisted Vaccine Design by Analysis of Zika Virus E ProteinsObtained either from Humans or from Aedes Mosquitos

Information entropy (H) and predicted B cell epitope score (Bepipred) were determined for the envelope E protein of Zika viruses (ZIKV) isolated from infected humans and Aedes mosquitos with the aim of identifying E protein regions that may be useful as immunological targets of anti-ZIKV vaccines. Total H of mosquito origin E proteins was 4.2380 greater than that of E proteins of human origin, suggestive of constraints on ZIKV mutation in the human host. Seven invariant peptides (H=0.0) of length 10 amino acids, or greater, were identified. These peptide sequences where H=0.0 were screened for predicted epitopes. The seven invariant peptides were comprised of 93 amino acid residues, 31 of which demonstrated predicted B-cell epitopic activity. The predicted epitopic residues were distributed predominantly to 5 of the 7 invariant peptides. It is proposed that these 5 invariant (H=0) peptides in the E proteins of both human and Aedes mosquito ZIKV represent domains with constrained mutational/evolutionary potential and that epitopes predicted to reside in such invariant domains thus may be stable immunological targets for development of an anti-ZIKV vaccine.