Pichia pastoris secretes recombinant proteins less efficiently than Chinese hamster ovary cells but allows higher space‐time yields for less complex proteins

Abstract

Chinese hamster ovary (CHO) cells are currently the workhorse of the biopharmaceutical industry. However, yeasts such as Pichia pastoris are about to enter this field. To compare their capability for recombinant protein secretion, P. pastoris strains and CHO cell lines producing human serum albumin (HSA) and the 3D6 single chain Fv-Fc anti-HIV-1 antibody (3D6scFv-Fc) were cultivated in comparable fed batch processes. In P. pastoris, the mean biomass-specific secretion rate (qp) was 40-fold lower for 3D6scFv-Fc compared to HSA. On the contrary, qp was similar for both proteins in CHO cells. When comparing both organisms, the mean qp of the CHO cell lines was 1011-fold higher for 3D6scFv-Fc and 26-fold higher for HSA. Due to the low qp of the 3D6scFv-Fc producing strain, the space-time yield (STY) was 9.6-fold lower for P. pastoris. In contrast, the STY of the HSA producer was 9.2-fold higher compared to CHO cells because of the shorter process time and higher biomass density. The results indicate that the protein secretion machinery of P. pastoris is much less efficient and the secretion rate strongly depends on the complexity of the recombinant protein. However, process efficiency of the yeast system allows higher STYs for less complex proteins.

High yield of recombinant human Apolipoprotein A‐I expressed in Pichia pastoris by using mixed‐mode chromatography

“…This production is higher than that reported in CHO cells. Similar results have been observed with Pichia pastoris during the production of less complex proteins .…”

Genome‐scale metabolic model of Pichia pastoris with native and humanized glycosylation of recombinant proteins

“…FSEOF was performed using both native and humanized N‐glycosylation. Experimental protein production rates were set at 0.064 µmol gDCW −1 h −1 for EPO (Eskitoros and Çalık, ) and 0.00169 µmol gDCW −1 h −1 human serum albumin (Maccani et al, ) (used here as a proxy for Alb‐Redhill). Given the reported carbon uptake rates, the theoretical production rates of humanized N‐glycosylated proteins were calculated as 6.1 µmol gDCW −1 h −1 for EPO and 0.84 µmol gDCW −1 h −1 for Alb‐Redhill (Supplementary Information 4) representing a 95 and 501 fold‐change increase over the experimental production rates.…”

“…In addition to EPO, FSEOF was also performed for Alb‐Redhill, which contains less glycosylation sites per amino acid, has a different amino acid composition, and the experimental data used for the experimental yield was based on growth on glucose instead of methanol and mannitol (Maccani et al, ). Regardless of these differences, amplification targets suggested by FSEOF were similar for both proteins.…”

Overview

“…A genomic comparison of the secretory pathway of 8 yeast species indicates that S. cerevisiae and its close relatives have lost some functions of secretory protein quality control [36]. Engineering of folding and secretion related genes is a valuable strategy to enhance the secretory capacity of yeasts [35,[37][38][39], however the comparison to mammalian cells like Chinese hamster ovary cells shows that there is still a lot of room for improvement [40].…”