Cell-free translation

A wheat germ, cell-free, translation extract was fractionated into three concentrated parts using ammonium sulfate the 0 - 40 % saturated fraction, the 40 - 60 % saturated fraction, and the ribosome fraction. These fractions were tested for their ability to enhance the translational activity of the wheat germ, cell-free extract for dihydrofolate reductase. The fortified cell-free system supplemented with the 0 - 40 % ammonium sulfate fraction enhanced the efficiency of protein synthesis by 50 %. 

Cell-free translation system, used for the identification of cloned genes and gene expression, has been investigated extensively as a preparative production system of commercially interesting proteins after the development of continuous-flow cell-free translation system. Many efforts have been devoted to improve the productivity of cell-free system [1], but the relatively low productivity of cell-free translation system still limits its potential as an alternative to the protein production using recombinant cells. One approach to enhance the translational efficiency is to use a condensed cell-free translation extract. However, simple addition of a condensed extract to a continuous-flow cell-free system equipped with an ultrafiltration membrane can cause fouling. Therefore, it needs to be developed a selective condensation of cell-free extract for the improvement of translational efficiency without fouling problem. 

Spirin, A.S., Baranov, V.I., Ryabova, L.A. et al. (1988) A continuous cell-free translation system capable of producing polypeptides in high yield. Science, 242 (4882), 1162-1164. 

Shimizu, Y., Inoue, A., Tomari, Y. et al. (2001) Cell-free translation reconstituted with purified components. Nature Biotechnology, 19 (8), 751-755. 

Tarui, H., Murata, M., Tani, I. et al. (2001) Establishment and characterization of cell-free translation/ glycosylation in insect cell (Spodopterafrugiperda 21) extract prepared with high pressure treatment. Applied Microbiology and Biotechnology, 55 (4), 446 453. 

Mikami, S., Masutani, M., Sonenberg, N., Yokoyama, S., and Imataka, H. (2006). An efficient mammalian cell-free translation system supplemented with translation factors. Protein Expr. PuriJ. 46, 348—357. 

Properties of ARCAs and ARCA-Capped mRNAs [/ in Cell-Free Translation Systems... 

The reagent also has been used in a unique tRNA-mediated method of labeling proteins with biotin for nonradioactive detection of cell-free translation products (Kurzchalia et al., 1988), in creating one- and two-step noncompetitive avidin-biotin immunoassays (Vilja, 1991), for immobilizing streptavidin onto solid surfaces using biotinylated carriers with subsequent use in a protein avidin-biotin capture system (Suter and Butler, 1986), and for the detection of DNA on nitrocellulose blots (Leary et al., 1983). 

Kurzchalia, T.V., Wiedmann, M., Breter, H., Zimmermann, W., Bauschke, E., and Rapoport, T.A. (1988) tRNA-mediated labeling of proteins with biotin. A nonradioactive method for the detection of cell-free translation products. Eur. J. Biochem. 172, 663-668. 

Recently it was found that obelin mRNA can be a useful tool for evaluating the efficiency of cell-free translation and for screening of translation inhibitors. 

Spirin, A S. Cell-Free Translation Systems Springer Verlag Berlin, 2002. 

Fernholz, E. Zaiss, K. Besir, H. Mutter, W. In Cell-Free Translation Systems Spirin,... 

Kuruma, Y., Nishiyama, K., Shimizu, Y., Muller, M. and Ueda, T. Development of a minimal cell-free translation system for the synthesis of presecretory and integral membrane proteins. Biotechnol Prog 21 1243-1251, 2005. 

The protein truncation test is a way of testing large genes (e.g., NEl) for which an antibody is available. PTT can detect nonsense mutations that are peptide chain terminating. These show up, after reverse transcription/cell-free translation, as shorter-than-normal peptides in an electrophoretic gel (Eig. 3C). 

Suzuki, T., Ito, M., Ezure, T., Kobayashi, S., Shikata, M., Tanimizu, K, and Nishimura, O. (2006) Performance of expression vector, pTDl, in insect cell-free translation system. J. Biosci. Bioen0. 102, 69-71. 

Olson, E.N. Lathrop, B.K. Glaser, L. Purification and cell-free translation of a unique high molecular weight form of the brain isozyme of creatine phosphokinase from mouse. Biochem. Biophys. Res. Commun., 108, 715-723 (1982)... 

Le Tinevez, R., Mishra, R.K. and Toulme, J.J. (1998) Selective inhibition of cell-free translation by oligonucleotides targeted to amRNA structure. Nucleic Acids Res., 26, 2273-2278. 

The next step is the preparation of mRNA. Cell-free translation of proteins can be achieved mainly by three different modes—batch (11,12), bilayer (16), and continous-flow cell-free (18). Appropriate volumes of transcription products can be produced depending on the mode of translation. 

Cell-free translation systems can produce proteins with high speed and accuracy, approaching in vivo rates (9,10), and they can express proteins that seriously interfere with cell physiology. 

---