Effect of Co-Expression of Protein Folding Factor on Expression of Fusion Protein IFNβ-HSA in Pichia pastoris

Abstract:

To explore the expression level of co-expression of folding factors Ero1, PDI and BiP on production of IFNβ-HSA by Pichia pastoris GS115. The pGAP-Ero1, pGAP-PDI, pGAP-BiP expression plasmids and the empty plasmid pGAPZ B(control) were linearized and integrated into the genome of P.pastoris GS115-IFNβ-HSA by electroporation. The recombinant yeasts were screened with 400 μg/mL zeocin. Positive recombinants were identified by genomic PCR and Western blot. The transformants were fermented in flask and the expression products were confirmed by SDS-PAGE and Western blot. The expression levels of IFNβ-HSA co-expressed with Ero1, PDI and BiP were analysed. The results indicated that Ero1, PDI and BiP were successfully expressed in recombinants with no effect on growth. Compared with Bip, co-expressed with Ero1 and PDI significantly improved the expression level of IFNβ-HSA, the expression level was 80%(Ero1) and 90%(PDI) higher than control.