Non-structural protein 1 from Zika virus: Heterologous expression, purification, and potential for diagnosis of Zika infections.

Zika virus (ZIKV) infections were associated with neurological disorders only after the Brazilian outbreak in 2015. The lack of vaccines and precise diagnosis requires a precise method to detect ZIKV infection. This study aimed to evaluate three ZIKV recombinant proteins for the development of ZIKV infections. Here, it was purified stable recombinant ZIKV Capsid (r-ZIKV-c), non-structural proteins NS1 (r-ZIKV-NS1), and NS3 (r-ZIKV-NS3) for detection of the infection by ZIKV in blood sera of patients. A commercial polyclonal antibody recognized the r-ZIKV-NS1. Here, among three proteins, NS1 showed the best result for diagnostic purposes using serum samples, despite the high similarity with NS1 from DENV, and could differentiate the infections. The recombinant NS1 was used to produce a monoclonal antibody to differentiate between DENV and ZIKV NS1. As for recombinant proteins, the result for r-ZIKV-NS1 values showed 77% and 100% sensitivity and specificity, respectively, in the IgM assay. Our data showed the protein could successfully differentiate between sera of ZIKV infected patients from sera of those not infected with the virus and differentiate from sera of DENV infected patients. Thus, the generated recombinant proteins have great potential for serological diagnosis of ZIKV in Brazil, where it is indispensable.