ABSTRACT
Cell-free protein synthesis makes use of cellular lysates containing all the necessary biological and chemical components required to direct protein synthesis from added DNA or mRNA template(s) (Figure 6.1). In general, extracts from any cells can be made or reconstituted for synthesis of proteins.To date, the successful cell-free lysates prepared for protein synthesis include E. coli; yeast; rabbit reticulocyte; wheat germ; ahyperthermophile; Drosophila embryo; hybridoma; Xenopus oocyte or egg; and insect, mammalian, and human cells (Endoh et al., 2006; Mikami et al., 2006). Some of them (E. coli, rabbit reticulocyte, wheat germ, and insect cells) are commercially available. Cell-free systems have been made in either coupled or uncoupled format. While coupled systems generally use DNA as the template, uncoupled systems only translate mRNA molecule(s). Lysates from different cell origins may contain specic cellular factors to promote protein expression, folding, or posttranslational modications, and a wide range of co-or posttranslational modication activities has already been demonstrated in eukaryotic lysates (Jackson et al., 2004). The availabilityof avariety of cell-free lysates makes it possible to produce proteins under achoice of different cellular environments (prokaryotic or eukaryotic) or conditions.
