Expression feasibility in microbial systems
Each protein requires specific conditions for expression and purification, and these conditions are little predictable.
The expression feasibility step allows to rapidly identify suitable conditions for expressing your protein and evaluate production and purification performances.
Your gene is cloned in appropriate Proteus' vectors to allow the subsequent expression profiling (in a single or multiple hosts).
A tag can be added in the construct to facilitate the purification of the protein after production, as well as a proteolytic cleavage site.
2. Expression profiling
Because each protein requires specific conditions for expression, Protéus has developed an optimised approach for rapid identification of the optimal expression conditions.
A variety of parameters known to influence protein expression are tested in parallel, such as: host system, construction, temperature, induction, tags, intra-cellular, periplasmic or secreted expression, helpers...
Building on our extensive experience in expressing hundreds of proteins, Protéus' Expression Profiling brings reliable results to rapidly focus on the best expression system for scaleable production of your proteins.
A panel of expression profiling services (multi-host or single host) is available. Please see the services below, or enquire.
The expression levels are then compared by SDS-PAGE analysis with Coomassie blue staining.
Optionally, the solubility can also be analysed.
4. Small-scale validation
A small-scale fermentation is then performed is a 50mL shake flask for the two best conditions. Provided that a tag has been added to the construct, the protein is purified by affinity chromatography. The global yield after production and purification is then evaluated by SDS-PAGE analysis.
The remaining amount of purified protein can then be transferred to you for validation.
Optionally, Protéus can also provide MALDI analysis of your protein.