Co-expressing GroEL–GroES, Ssa1–Sis1 and Bip–PDI chaperones for enhanced intracellular production and partial-wall breaking improved stability of porcine growth hormone

Abstract

Porcine growth hormone (pGH) is a class of peptide hormones secreted from the pituitary gland, which can significantly improve growth and feed utilization of pigs. However, it is unstable and volatile in vitro. It needs to be encapsulated in liposomes when feeding livestock, whose high cost greatly limits its application in pig industry. Therefore we attempted to express pGH as intracellular soluble protein in Pichia pastoris and feed these yeasts with partial wall-breaking for swine, which could release directly pGH in intestine tract in case of being degraded in intestinal tract with low cost. In order to improve the intracellular soluble expression of pGH protein in Pichia pastoris and stability in vitro, we optimized the pGH gene, and screened molecular chaperones from E. coli and Pichia pastoris respectively for co-expressing with pGH. In addition, we had also explored conditions of mechanical crushing and fermentation. The results showed that the expression of intracellular soluble pGH protein was significantly increased after gene optimized and co-expressed with Ssa1-Sis1 chaperone from Pichia pastoris. Meanwhile, the optimal conditions of partial wall-breaking and fermentation of Pichia pastoris were confirmed, the data showed that the intracellular expression of the optimized pGH protein coexpressed with Ssa1-Sis1 could reach 340 mg/L with optimal conditions of partial wall-breaking and fermentation. Animal experiments verified that the optimized pGH protein co-expression with Ssa1-Sis1 had the best promoting effects on the growth of piglets. Our study demonstrated that Ssa1-Sis1 could enhance the intracellular soluble expression of pGH protein in Pichia pastoris and that partial wall-breaking of yeast could prevent pGH from degradation in vitro, release targetedly in the intestine and play its biological function effectively. Our study could provide a new idea to cut the cost effectively, establishing a theoretical basis for the clinic application of unstable substances in vitro.

Enhanced production of recombinant proteins in <i>Corynebacterium glutamicum </i>using a molecular chaperone

“…Fine examination of recombinant protein production revealed that chaperone co-expression, as an effective strategy for protein production, showed different effects on target proteins under different chaperone types and levels. For example, GroES-GroEL co-expression improved the expression level of porcine growth hormone (Deng et al, 2020) and the yield of the Fab antibody fragment (Levy et al, 2001).…”

Growth hormone receptor agonists and antagonists: From protein expression and purification to long‐acting formulations

“…Addition of 10 mmol ascorbic acid to sorbitol/methanol co-feeding significantly increased the biomass of rhGH to 162.5 g/L (DCW) and total protein 1.14 g/L (Azadi et al, 2018). To express other GH from other species in the P. pastoris system (e.g., porcine, canine, Ailuropoda melanoleuca, and fish), codon optimized gene sequences are often used (Cho et al, 1987;Ascacio-Martínez & Barrera-Saldaña, 2004;Deng et al, 2020;Rothan et al, 2014). For example, porcine GH was produced more effectively in P. pastoris when using an optimized gene sequence, with expression levels reaching 10% of the total intracellular protein (Cho et al, 1987).…”

Industrial Production of Proteins with Pichia pastoris—Komagataella phaffii

“…In comparison with the recently advancing attempts to phototrophically produce target proteins with microalgae, interestingly, the space-time yield (STY) utilizing yeasts is generally higher [ 58 , 59 , 60 ].…”