Recombinant Protein Expression in Mammalian Cells (HEK293/CHO)

Many proteins can be expressed at high level in Escherichia coli. However, pro­kary­otic expression systems fail to generate correctly folded functional forms of many eukaryotic proteins, and hence a variety of eukaryotic-based expression systems have been developed [1].

Mammalian cell expression systems are the ideal choice to produce eukaryotic proteins as they enable post-translational modifications which are crucial for the correct folding of many eukaryotic proteins. Secreted mammalian proteins have been successfully produced in a large-scale format in Chinese hamster ovary (CHO) cells [2] and human embryonic kidney (HEK) 293 cells [3-5]. Glycoproteins are also generally synthesized in mammalian cells, because common microbial hosts like E.coli lack the requisite machinery to synthesize appropriate glycoforms. Despite the availability of a plentitude of cell lines, nearly 70% of all recombinant protein therapeutics produced today are made in CHO cells [7].

Recombinant Protein Expression in Mammalian Cells (HEK293/CHO)