The production of technical enzymes as well as of peptide- and protein-based pharmaceuticals are in large scale being performed in specially designed host organisms. The aim of the course is to educate the students in processes associated with heterologous expression. The students will upon completion of this course be able to design and perform a strategy for the expression of a given gene. This includes considerations about amount, quality and downstream applications of the product.

Topics that will be covered in the theoretical part of the course:
The intelligent choice of a host organism / Cloning strategies envisioned by an “in silico” multistep cloning / Promoter strength and induction / Copy number and silencing problems in heterologous hosts / Expression vectors / mRNA stability and introns / Choice of, and placement of purification tags / Stability of the product / Secretion of proteins and signal trapping / Post-translational modifications in different host organisms / Inclusion bodies and folding of proteins / Expression of membrane proteins compared to soluble proteins / Design of drug screening assays/ Heterologous expression for production of antibodies / Expression of toxic proteins / Transient expression / Optimisation of expression level / Fermentation and large scale production.

In the course we will work with a range of different expression organisms.

• Escherichia coli
• Saccharomyces cerevisiae
• Pichia pastoris
• Xenopus oocytes
• Mammalian cell lines
• Algae
• Higher plants
• Aspergillus (only theoretically)
• Bacillus 

We will express different types of proteins, determine the amount and activity of produced protein and discuss ways to optimize the expression level. 
In the practical part we will also cover a broad aspect of typical problems related to the production of recombinant protein.

Topics from the practical part of the course:
Expression and assembly of a multi subunit protein complex / The effect of alcohol and temperature on expression level / Expression of a secreted protein / Sub-cellular fractionation / Detection of post-translated modifications / The use of protein homologs from thermophilic bacteria /Yeast two-hybrid system/ Split-Ubiquitin system / Electrophysiological measurement on ion-transporters/Design of drug screening assays.