Escherichia coli-mediated protein expression
Bacterial expression is the most commonly used expression system for the production of recombinant proteins. The organism is relatively simple to manipulate, inexpensive to culture, and the amount of time necessary to generate a recombinant protein is short. However, since it is a prokaryotic based system, heterologously expressed eukaryotic proteins are not modified correctly, and it can also be difficult to facilitate the secretion of large amounts of expressed protein. Furthermore, proteins expressed in large amounts can precipitate, forming inclusion bodies, whilst large complex proteins can also be difficult to propagate.
Baculovirus-mediated insect cell protein expression
Baculovirus-mediated insect cell expression has become one of the most popular vehicles for the productionof large quantities of recombinant protein for structural and functional studies of therapeutically relevant bio-molecules. Baculovirus protein expression is a eukaryotic based expression system and thus provides protein modification and processing patterns similar to those in higher eukaryotic cells. In addition, the baculovirus-mediated system uses a helper-independent virus that can be propagated to very high titres and is easily adapted to suspension culture, making it possible to generate large amounts of recombinant protein with relative ease.
Mammalian cell expression
The expression of heterologous proteins in a mammalian cell expression systems provides several advantages to their production in E. coli or insect cells, including correct post-translational modification and folding. In this system, it is used often the mammalian cells CHO or HEK293. The system utilizes often episomally replicating plasmids featuring the Epstein– Barr virus (EBV) oriP driven by EBNA-1 protein generated from a gene integrated into the HEK293 genome. In most cases, transient protein expression is driven by the strong CMV promoter.
We offer a list of custom protein expression services including gene synthesis, vector construction, pilot expression, process optimization, fermentation and protein purification. Our suppliers has expertise in different expression systems, including cell-free, bacterial, yeast, baculovirus / insect mammalian cell systems. Each protein can be expressed differently in different systems. Each recombinant proten are produced according to our customer specifications or by developing customized protocols in house.
Vrisko Ltd offers a variety of Custom Services to fit your research and production needs including Protein production services. Ask for a quote and additional specific details according to your needs in our “contact us” page.