A prokaryote-based cell-free translation system that efficiently synthesizes glycoproteins

Asparagine-linked (N-linked) protein glycosylation has been observed in all domains of life, including most recently in bacteria and is now widely considered a universal post-translational modification. However, cell-based production of homogeneous glycoproteins for laboratory and preparative purposes remains a significant challenge due in part to the complexity of this process in vivo. To address this issue, an easily available and highly controllable Escherichia coli-based cell-free system for the production of N-linked glycoproteins was developed. The method was created by coupling existing in vitro translation systems with an N-linked glycosylation pathway reconstituted from defined components. The translation/glycosylation system yielded efficiently glycosylated target proteins at a rate of hundreds of micrograms/milliliters in half a day. This is the first time a prokaryote-based cell-free protein synthesis system has generated N-linked glycoproteins.