A bead-based method for the removal of the amino acid lysine from cell-free transcription-translation systems

• Published in: Journal of biotechnology 2020-01, Vol.324, p.100024-100024, Article 100024
• Main Authors: Finkler, Marc, Kurt, Ömer, Grimm, Florent, Hartz, Philip, Ott, Albrecht
• Format: Article
• Language: English
• Subjects: biotechnology; Cell-free expression; DNA; Escherichia coli cell extract; gene expression; Lysine; Microbeads; Separation
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.btecx.2020.100024

•Monomeric lysine separation from a cell-free expression system.•Preserving the system ability to express genes.•Low amount of lysine useful for incorporation of non-canonical analogs. Cell-free transcription-translation systems are a versatile tool to study gene expression, enzymatic reactions and biochemical regulation mechanisms. Because cell-free transcription-translation systems are often derived from cell lysates, many different substances, among them amino acids, are present. However, experiments concerning the incorporation of non-canonical amino acids into proteins require a system with negligible amounts of canonical analogs. Here we propose a two-step method for the removal of residual free lysine in an all Escherichia coli-based cell-free expression system. The first step consists of the expression of a high-lysine dummy protein. The second step consists of direct removal via binding between lysine and DNA. The presented method is an efficient, fast and simple way to remove residual lysine without altering the system ability to perform gene expression.