In situ removal of consensus dengue virus envelope protein domain III fused to hydrophobin in Pichia pastoris cultures.

This work describes a novel strategy for the integrated expression and purification of recombinant proteins in Pichia pastoris cultures. Hydrophobins can be used as fusion tags, proteins fused to them alter their hydrophobicity and can be purified by aqueous two-phase systems (ATPS) based on non-ionic surfactants. Here, the consensus dengue virus envelope protein domain III fused to hydrophobin I of Trichoderma reesei was expressed in Pichia pastoris cultures and an in situ product removal by an ATPS using a non-ionic detergent, (Triton X-114) was performed. The protein was produced and purified directly from the yeast culture supernatant both efficiently and with no loss. The purified protein was properly immobilized by adsorption in solid phase and recognized by anti-dengue antibodies, showing its potential for the development of an indirect immunoassay for dengue virus.