Protein-Protein Interaction-Guided Peptides Interfere with Early Zika Virus Entry-Associated Events

Zika virus (ZIKV) remains a public health concern because of its association with neurological complications and congenital disease, yet no specific antiviral therapy has been approved. Since the envelope (E) protein mediates viral attachment and early entry-associated membrane events, it represents an attractive antiviral target. Here, we used a protein-protein interaction-guided strategy to design peptides to interfere with predicted interfaces between the ZIKV E protein and cellular receptors involved in attachment. After in silico filtering and preliminary screening, six peptides (PZ1-PZ6) were selected. These peptides showed heterogeneous physicochemical profiles, low cytotoxicity and hemolytic activity under the tested conditions, and docking-predicted interactions with functional E protein regions. In HTR-8/SVneo cells, antiviral activity depended on the timing of exposure, with greater reductions in infectious titers during co-treatment and post-treatment. All peptides also reduced titers in anti-adsorption assays, supporting interference with viral attachment or early entry-associated events. Consistently, DiOC18 fluorescence signals were reduced in a peptide-specific manner, particularly for PZ3 and PZ6. Nuclease protection assays showed no extensive exposure of the viral genome, whereas transmission electron microscopy revealed ultrastructural alterations without generalized particle disruption. Overall, PZ1-PZ6 are promising protein-protein interaction-guided anti-ZIKV peptide candidates with activity against early viral entry-associated events.