Post-Translational Modifications in the Context of Therapeutic Proteins: An Introductory Overview

Many proteins, particularly those derived from eukaryotic sources, undergo covalent modification either during their ribosomal synthesis or (more usually) after synthesis is complete, giving rise to the concept of co-translational and post-translational modification. While the stage during protein synthesis/maturation at which the coor post-translational modification occurs obviously differs, both are often referred to in the literature simply as post-translational modifications (PTMs), a convention also followed in this chapter. These modifications invariably influence some structural aspect or functional role of the affected protein. Themain aims of this first chapter is to provide an introductory overview of suchmodifications, particularly in the context of therapeutic proteins. As such it serves to contextualize the remaining chapters, each of which focuses in detail upon some specific aspect or type of post-translational modification. The initial portion of this chapter serves to introduce biopharmaceuticals and the biopharmaceutical sector. A brief overview of the more common protein PTMs is next provided. The final section then builds upon these two initial sections and overviews issues concerning the PTM complement of therapeutic proteins.