Extracellular Production of the Taiwan-Native Norovirus P Domain Overexpressed in Pichia pastoris

Many efforts in norovirus vaccine development have focused on subunit or recombinant protein vaccines, such as subviral P particles formed by the protruding (P) domain of VP1. are immunogenic and a region with human histo-blood group antigen binding site, an interaction critical for infecting host. In past, only intracellular NoV proteins expressed Escherichia coli Pichia pastoris were reported, low yield difficulty purification limited their applications. this study, Taiwan-native was successfully secreted P. pastoris. The secretion efficiency greatly enhanced integrating oligosaccharyl transferase (Ost1) into α-factor signal peptide coexpressing Hac1. production fermentation cultures reached 345 mg/L, purity recovery 94.8% 66.9%, respectively, after ion-exchange chromatography. Transmission electron microscopy analysis showed that small mostly ring-, square-, triangle-shaped, diameters 10-15 nm. biological activity confirmed saliva-binding assay using antigen. This study describes characterization Particles from similar size, morphology, ability to those intracellularly. strategy described provides great potential scale-up antiviral development.