Use of synthetic biology techniques to site-selective introduce posttranslational modifications in proteins
Unravelling the influence of posttranslational modifications (PTMs) on protein functioning is of key interest to get understanding how complex cellular networks are regulated. The current biological toolbox to synthesize these modified proteins in a single form in decent quantities is insufficient, therefore new chemical techniques are required. This chapter highlights the different synthetic techniques to introduce site-selective PTMs in proteins. First a brief discussion of the most common PTMs is given. Then techniques are discussed yielding proteins with natural synthetic modifications. Examples discussed include nonsense codon suppression and native chemical ligation. Finally, the synthetic approach termed ‘tag-and-modify’ technique is elaborated on. The usage of a reactive handle synthetically introduced in the protein allows for a selective reaction with a desired modification, yielding synthetic proteins featuring mimics of the PTMs under study.