Key issues in the purification and characterization of recombinant proteins for therapeutic use

Abstract

Nonbacterial systems (e.g., mammalian cells) for expressing therapeutic proteins are generally selected because correct folding or post-translational modifications cannot be achieved in microorganisms such as Escherichia coli. In producing recombinant proteins for therapeutic use a number of ‘key’ issues must be considered during their purification and characterization. These issues include: N- and C-terminal heterogeneity; chemical modification and conformational changes; glycosylation status; purification techniques; proteolytic processing; detection and elimination of contaminants such as cellular DNA, viruses, or endotoxins; potency; and safety. Various scientific achievements and challenges in obtaining recombinant therapeutic proteins are also elaborated in this review.