Cell-free protein synthesis using E. coli cell extract for NMR studies.

The use of cell-free protein production systems for producing isotope labeled proteins generates new opportunities to perform unprecedented NMR studies. As compared with conventional cellular expression systems, the scrambling and dilution of amino acids are highly suppressed in the cell-free reaction, allowing the production of proteins with a wide variety of residue and site-specific isotope labeling patterns. In this chapter, the procedure for cell-free protein synthesis for NMR studies, using an E. coli extract, is introduced.