Expression in Pichia pastoris and immunological evaluation of a truncated Dengue envelope protein

Among the Dengue virus structural proteins, the Envelope glycoprotein is the most important because of its antigenic characteristics. In this work, the E protein from Dengue-2 virus truncated at the C-terminus region was successfully expressed in Pichia pastoris. The E2trunc gene was cloned under the AOX1 promoter from P. pastoris and the signal peptide of the sucrose invertase gene from Saccharomyces cerevisiae. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of expression revealed the presence of a protein with the expected size, which was completely associated to the insoluble fraction after cellular disruption. The recombinant N-glycosylated protein reacted with two conformational antibodies against Dengue-2, indicating a proper folding of it. In addition, it was able to induce antiviral antibodies after mice immunization.