Yeast Protein Production (YPP)
Being a vital part of PPS, yeast provides a simple eukaryotic host system with the potential to produce very high yields of protein to a low cost, especially using the methylotrophic yeast P. pastoris as host system. In this system, the protein is produced from a stable clone, where the corresponding gene is integrated into the yeast genome, and when established, large amounts of cells can easily be collected from a small bioreactor.
Since P. pastoris has shown to be well-suited for efficient production of eukaryotic membrane proteins, the service includes verification of membrane localization and detergent screens for solubilization and purification. In the Biochemistry research infrastructure at the Department of Chemistry and Molecular Biology, University of Gothenburg, all instrumentation for the whole process from DNA design to growth and purification is available using reliable protocols for small-scale screening for high yielding clones, up-scaled growth in bioreactors as well as the common purification approaches optimized for individual targets.
Yeast is the simplest eukaryotic cell for protein production where the strains Saccharomyces cerevisiae and P. pastoris are commonly used. A large variety of eukaryotic proteins are produced to high levels in their functional form in the yeast cell, also integral membrane proteins. The main strength with yeast is that it is a simple unicellular eukaryotic cell that is easy, fast, safe and non-expensive to grow with most post-translational modifications possible. The main limitation is the glycosylation pattern which differs from the one in human cells, and this needs to be reflected on for certain target proteins.
P. pastoris is a methylotrophic yeast that is highly suitable for recombinant protein production, mainly due to the expression from the very strong and inducible Alcohol Oxidase 1 Promoter (AOX1) combined with the capacity to grow to high cell densities. This host therefore gives the possibility to produce large amounts of cells in a relatively small volume combined with a high production level per cell, an ideal starting point for subsequent protein purification. Importantly, this is not only time efficient, but it also increases reproducibility since one growth is enough for several rounds of purification.
A major advantage with P. pastoris is the ease of secretion, providing a first crude purification step. This also makes this yeast highly suitable to produce proteins designed for NMR studies, and isotopic labelling is well-established in this host system. High-level protein production in P. pastoris has been practiced in the Biochemistry research infrastructure at the University of Gothenburg for more than 20 years, mainly driven by the research of Kristina Hedfalk. Over the years, a wide variety of eukaryotic proteins have been produced for structural biology, biomaterial as well as medical applications and yields over 100 mg/L have been achieved for integral membrane proteins. Being part of PPS, collected experience and established protocols are now available as a service, to support a wide range of research projects. Throughout the whole process, we work in close communication with our users, to establish the best route forward for each individual target.
What PPS offers:
Being part of PPS, yeast protein production ideally complements the other host systems provided, giving a complete portfolio for the infrastructure and the system will be developed for a wider use of the P. pastoris production system for various applications. Since P. pastoris has shown to be well-suited for production of eukaryotic membrane proteins, the service includes verification of membrane localization and detergent screens for solubilization and purification. Furthermore, all instrumentation for the whole process from DNA design to growth and purification is available using reliable protocols for small-scale screening for high yielding clones, up-scaled growth in fermenters as well as subsequent protein purification and characterizations.
