The Zika virus (ZIKV) Envelope (E) protein is a major structural and immunogenic component essential for viral attachment, receptor engagement, and membrane fusion. As part of the flavivirus envelope complex, E forms homodimers on the virion surface and comprises three functional domains: EDI, which provides structural flexibility; EDII, containing the fusion loop; and EDIII, which mediates receptor binding. Acidification within endosomes triggers conformational rearrangements of these domains, driving membrane fusion and viral genome release. Owing to its central role in viral entry and immune recognition, the E protein is the principal target of neutralizing antibodies and a critical antigen for diagnostics, structural studies, and vaccine development. Catalina’s Zika virus Envelope antibodies deliver high specificity and sensitivity, supporting advanced research in flavivirus biology, immunopathogenesis, and translational vaccine design.