Recombinant dengue virus type 3 envelope domain III protein from Escherichia coli

Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. The envelope protein of dengue virus is the major antigen to elicit neutralizing antibody response and protective immunity in hosts. Optimization of culture media was carried out for enhanced production of recombinant dengue virus type 3 envelope domain III (rDen 3 EDIII) protein in E. coli. Further, batch and fed-batch cultivation process were also developed in optimized medium. After fed-batch cultivation, the dry cell weight was about 22.80 g/L of culture. The rDen 3 EDIII protein was purified using immobilized metal affinity chromatography. This process produced ～649 mg of purified rDen 3 EDIII protein per liter of culture. The purity of the protein was determined by SDS-PAGE analysis and the reactivity was checked by Western blotting as well as ELISA. These results show that the purified protein may be used for the dengue diagnosis or further prophylactic studies for dengue infection.