Choose the most cost-effective eukaryotic protein expression! ProteoGenix combines its
long-standing expertise in protein production and a complete toolbox to optimize your
yeast protein expression.

Our yeast expression process

Expression vector construction(optional)

  • Gene design including codon optimization
  • Gene Synthesis
  • Subcloning in an expression vector

Small scale protein expression

  • Transfection and selection of yeast clones
  • Determination of top expressing clones
  • Expression Optimization
  • SDS/page + WB if necessary
  • Purification tests

Protein expression scale up and purification

  • Protein expression and purification with optimized conditions previously determined.
Step Content Timeline Deliverables
Pilot study
  • Transfection of yeast cells
  • Selection of the best expressing clones
  • Protein expression optimization
  • Purification tests
4 to 5 weeks
  • Test protein sample
Transient protein expression and purification
  • Large scale protein expression
  • Purification
  • QC analysis: SDS-PAGE, concentration
2 weeks
  • Purified protein
  • Detailed report
  • Gene synthesis including codon optimization for protein expression and subcloning in an expression vector
  • Size exclusion chromatography
  • Polishing (DNA, HCP, endotoxins)
  • Endotoxin removal
  • Analytics : WB, analytical SEC

Why choose Pichia pastoris protein expression?

The choice of the host organism is of primary importance once the decision to perform yeast protein expression is taken. A lot of host cells are described in the literature. However, S. cerevisiae and P. pastoris are the most widely used.

This latest offers several advantages when it comes to protein expression such as:

  • Very low level of native protein secretion: Pichia pastoris expresses a very low amount of secreted proteins meaning the majority of proteins in the media represent the recombinant protein of interest. This property clearly simplifies the downstream protein purification process.
  • High titer protein expression: Pichia pastoris can be grown at high cell density. Thus,this host organism allows for high yield protein production.
  • Post-translational modifications: Pichia pastoris possesses the complete post-translational machinery characteristic of eukaryotic cells. Thus, this host organism is able to perform phosphorylations and glycosylations (different from those observed in mammalian cells protein expression).
  • Endotoxin free

To conclude, Pichia pastoris protein expression is the first choice for the production of secreted proteins. Pichia pastoris remains also a relevant option when it comes to therapeutic protein production. This organism was used as yeast host for the expression of several therapeutic proteins reaching the market such as:

  • Human serum albumin
  • Collagen
  • Ecallantide
  • Insulin

Why choose Saccharomyces cerevisiae protein expression?

As a unicellular organism, S. cerevisiae and other yeasts include the same advantages as prokaryotic systems such as E. coli. Thus, S. cerevisiae is characterized by short generation times, high biomass yields and well-characterized tools for DNA manipulation.

Among all these advantages, protein expression offers also additional benefits compared to E. coli expression.  This includes:

  • Post translational modifications: S. cerevisiae has been shown to perform disulfide bond formation and most of post-translational glycosylation found in mammalian expression systems. However, some differences are observed as S. cerevisiae is known for hypermannosylation (more prominent than in P. pastoris).
  • GRAS status: S. cerevisiae benefits from the GRAS status meaning it is recognized as safe by the FDA.
  • Endotoxin free

Overall, S.cerevisiae has been extensively studied and benefits from a wide range of tools (strains, expression vectors…). Taking these aspects into consideration, S. cerevisiae is the perfect host for projects requiring testing of several conditions. As Pichia pastoris, S. cerevisiae has been widely used for therapeutic protein expression. However, if more “human”-like glycosylation would be necessary, baculovirus or mammalian cell protein expression will be preferred.