Recombinant Protein Expression Service in Yeast

Historically, Pichia pastoris was reassigned to the genus Komagataella in 1995, with Komagataella pastoris being the initial designation for the species. However, further genetic studies in 2005 distinguished Komagataella phaffii as a separate species, which is predominantly used in industrial and research settings and used as very potent expression system. Despite this reclassification, the name Pichia pastoris is still commonly used, especially in applied sciences, while fundamental research tends to use. the correct nomenclature, Komagataella phaffii.

The Pichia pastoris expression system is a widely used tool in molecular biology for producing recombinant proteins. It utilizes the methylotrophic yeast Komagataella phaffii, formerly known as Pichia pastoris, as the host organism. This Pichia expression system is particularly favored due to its ability to perform complex post-translational modifications similar to those in mammalian cells, such as glycosylation, disulfide bond formation, and proteolytic processing. It combines the benefits of an eukaryotic expression system with the simplicity and rapid growth of a microbial system.

Pichia pastoris grows quickly and reaches very high cell densities. It achieves high levels of protein expression, often reaching grams per liter, facilitated by the strong AOX1 promoter. The system secretes proteins into the culture supernatant with minimal endogenous proteins, simplifying purification. Furthermore, P. pastoris is FDA and EMA approved for biopharmaceutical production, ensuring safety and compliance. Its flexibility and versatility allow it to be used for a wide range of proteins, including complex glycoproteins and membrane proteins. Overall, these features make P. pastoris an attractive host for producing high-quality recombinant proteins, which are often not possible to produce in bacterial systems like E. coli.

The P. pastoris expression system uses simple and inexpensive culture media and can be grown in high-density fermenters, maximizing protein production. Its scalability makes it an attractive option for industrial applications. Furthermore, P. pastoris is a well-defined expression system, making it easy to manipulate and create stable cell lines. This reduces the time and costs required for strain development compared to more complex systems. Pichia pastoris is also approved by regulatory bodies such as the FDA and EMA for the production of biopharmaceuticals, ensuring compliance with safety standards and facilitating its use in commercial applications.

Pichia pastoris is ideal for production of secreted proteins such as enzymes, antibody fragments, and other recombinant proteins that require post-translational modifications. Since Pichia pastoris can secrete proteins directly into the culture medium, purification is easier compared to protocols based on intracellular expression.

While Pichia pastoris allows for eukaryotic modifications, its glycosylation patterns differ from those of human cells, which may be a concern for some targets like therapeutic proteins. In such cases, mammalian cell expression systems like CHO or HEK might be more suitable.

Saccharomyces cerevisiae, commonly known as baker’s yeast, is a eukaryotic expression system widely used for recombinant protein production. It combines the advantages of rapid microbial growth with the ability to perform post-translational modifications.

It is easy to cultivate, grows quickly, and can be used for both intracellular and extracellular protein expression. As a eukaryote, it can perform post-translational modifications such as glycosylation and disulfide bond formation, making it superior to bacterial systems like E. coli for certain proteins.

Saccharomyces cerevisiae expression system is ideal for the production of secreted proteins like enzymes, hormones, and vaccine antigens, particularly when post-translational modifications are required. Its natural secretion pathways also facilitate the purification process for secreted proteins.