Protein expression

The four main in vivo expression systems used by PEF are:

Bacteria

E. coli is frequently the first expression host chosen for producing a recombinant protein, owing to the rapid, affordable and technically straightforward culturing associated with its use.

Read More

Yeast

Yeast is a single-celled eukaryotic organism capable of producing vast quantities of recombinant protein. PEF offers P. pastoris as the strain of choice for yeast expression.

Read More

Baculovirus/Insect Cell Expression Vector System (BEVS)

The Baculovirus/Insect cell expression vector system (BEVS) is a popular choice for producing recombinant proteins, particularly those requiring complex post-translational modifications.

Read More

Mammalian cell

Mammalian cell-based expression is the dominant system for producing therapeutic recombinant proteins. Their capacity to handle complex post-translational modifications, folding and assembly of recombinant proteins and protein complexes is superior to other systems.

Read More

Cell-Free In Vitro protein expression - Coming soon

Cell-free in vitro translation (IVT) systems are a rapid, convenient, flexible and cost-effective tool to produce recombinant proteins for biochemical, biophysical and structural analysis. Several IVT systems are being set up within PEF and will be available as a service soon.

For all protein expression services, please contact us.
To view our list of available vectors, please visit our UQ Resource Centre.

E. coli is one of the most widely used expression hosts for the production of recombinant proteins.

The advantages of this system include:

  • Inexpensive setup and running costs
  • High recombinant protein production levels 
  • Short timeframe for protein expression
  • Limited technical knowledge required for culturing
  • Scalability from small (1 mL) to very large culture (>10,000 L) volumes

One of the main drawbacks of this expression system however is its limited capability for post-translational modifications (PTMs). 

Yeast are a single-celled eukaryotic organisms that combine high levels of recombinant protein production with eukaryotic post-translational modifications (PTMs).

Some advantages of using yeast over other host systems for protein expression include: 

  • Relatively inexpensive setup and running costs
  • Very high levels of recombinant protein production
  • Able to perform many PTMs e.g. N-glycosylation
  • Simplified downstream processing for secreted proteins
  • Amenable to large-scale fermentation

Some drawbacks of yeast as a host cell expression system include:

  • PTMs are less complex when compared to higher eukaryotic systems (e.g. insect and mammalian cells)
  • Yeast’s tough cell wall is cumbersome to disrupt when processing intracellular proteins

The insect cell/baculovirus expression vector system (BEVS) is becoming increasingly popular for the production of recombinant proteins. 

The system offers a number of advantages, including:

  • Ability to perform complex post-translational modifications (PTMs)
  • High success rate of soluble protein recovery
  • Suitable for the production of large protein complexes, e.g. virus like particles (VLPs)
  • High protein expression levels compared to other higher eukaryotes

One of the main drawbacks of the system is longer timeframes for protein expression in comparison to other host systems.

 

The dominant host system for producing therapeutic recombinant proteins over the last few decades has been the mammalian expression system.

The benefit of this system includes: 

  • Highest capacity for generating complex post-translational modifications (PTMs) compared to other expression systems
  • High success rate of soluble protein recovery
  • Suitable for antibody production

One of the main drawbacks of the system is the increased expense when compared to other systems such as bacteria. 

 

Listed below are a number of articles that provide a broad overview about using different expression systems for the production of recombinant proteins.