Related ArticlesCell-free synthesis and amino acid-selective stable isotope labeling of proteins for NMR analysis.
J Biomol NMR. 1995 Sep;6(2):129-34
Authors: Kigawa T, Muto Y, Yokoyama S
For the application of multidimensional NMR spectroscopy to larger proteins, it would be useful to perform selective labeling of one of the 20 amino acids. For some amino acids, however, amino acid metabolism drastically reduces the efficiency and selectivity of labeling in in vivo expression systems. In the present study, a cell-free protein synthesis system was optimized, so that highly efficient and selective stable isotope labeling of proteins can be achieved in the absence of amino acid metabolism. The productivity of the E. coli cell-free coupled transcription-translation system was first improved, by about fivefold, by using the T7 RNA polymerase for transcription and also by improving the translation conditions. Thus, about 0.1 mg protein per 1 ml reaction mixture was synthesized. Then, this improved cell-free system was used for Asp- or Ser-selective 15N-labeling of the human c-Ha-Ras protein. With a 15 ml cell-free reaction, using less than 1 mg of 15N-labeled amino acid, 1 mg of the Ras protein was obtained. 1H-15N HSQC experiments confirmed that the Ras protein was efficiently labeled with high selectivity. These results indicate that this cell-free protein synthesis system is useful for NMR studies.
A simple protocol for amino acid type selective isotope labeling in insect cells with improved yields and high reproducibility
A simple protocol for amino acid type selective isotope labeling in insect cells with improved yields and high reproducibility
Abstract An easy to use and robust approach for amino acid type selective isotope labeling in insect cells is presented. It relies on inexpensive commercial media and can be implemented in laboratories without sophisticated infrastructure. In contrast to previous protocols, where either high protein amounts or high incorporation ratios were obtained, here we achieve both at the same time. By supplementing media with a well considered amount of yeast extract,...
Suppression of isotope scrambling in cell-free protein synthesis by broadband inhibition of PLP enymes for selective 15N-labelling and production of perdeuterated proteins in H2O
Suppression of isotope scrambling in cell-free protein synthesis by broadband inhibition of PLP enymes for selective 15N-labelling and production of perdeuterated proteins in H2O
Abstract Selectively isotope labelled protein samples can be prepared in vivo or in vitro from selectively labelled amino acids but, in many cases, metabolic conversions between different amino acids result in isotope scrambling. The best results are obtained by cell-free protein synthesis, where metabolic enzymes are generally less active, but isotope scrambling can never be suppressed completely. We show that...
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02-16-2011 09:34 PM
Cell-free expression and stable isotope labelling strategies for membrane proteins
Cell-free expression and stable isotope labelling strategies for membrane proteins
Abstract Membrane proteins are highly underrepresented in the structural data-base and remain one of the most challenging targets for functional and structural elucidation. Their roles in transport and cellular communication, furthermore, often make over-expression toxic to their host, and their hydrophobicity and structural complexity make isolation and reconstitution a complicated task, especially in cases where proteins are targeted to inclusion bodies. The development of cell-free expression systems...
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01-09-2011 12:46 PM
[NMR paper] Cell-free synthesis of 15N-labeled proteins for NMR studies.
Cell-free synthesis of 15N-labeled proteins for NMR studies.
Related Articles Cell-free synthesis of 15N-labeled proteins for NMR studies.
IUBMB Life. 2005 Sep;57(9):615-22
Authors: Ozawa K, Dixon NE, Otting G
Modern cell-free in vitro protein synthesis systems present powerful tools for the synthesis of isotope-labeled proteins in high yields. The production of selectively 15 N-labeled proteins from 15 N-labeled amino acids is particularly economic and yields are often sufficient to analyze the proteins very quickly by two-dimensional NMR...
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12-01-2010 06:56 PM
[NMR paper] Amino acid type selective isotope labelling of the multidrug ABC transporter LmrA for
Amino acid type selective isotope labelling of the multidrug ABC transporter LmrA for solid-state NMR studies.
Related Articles Amino acid type selective isotope labelling of the multidrug ABC transporter LmrA for solid-state NMR studies.
FEBS Lett. 2004 Jun 18;568(1-3):117-21
Authors: Mason AJ, Siarheyeva A, Haase W, Lorch M, van Veen H, Glaubitz C
The ABC transporter LmrA in Lactococcus lactis confers resistance to a wide range of antibiotics and cytotoxic drugs and is a functional homologue of P-glycoprotein. Recently, solid-state NMR...
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11-24-2010 09:51 PM
A simple method for amino acid selective isotope labeling of recombinant proteins in E. coli
A simple method for amino acid selective isotope labeling of recombinant proteins in E. coli
Kit I. Tong, Masayuki Yamamoto and Toshiyuki Tanaka
Journal of Biomolecular NMR; 2008; 42(1); pp 59-67
Abstract:
A simple and user-friendly method of labeling protein selectively with amino acids in vivo is introduced. This technique does not require the use of transaminase-deficient or auxotrophic strains. By manipulating the product feedback inhibitory loops of the E. coli amino acid metabolic pathways and, if necessary, by using enzyme inhibitors, proteins were labeled efficiently in vivo...
Brian
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09-17-2008 10:20 PM
Cell-free protein synthesis of perdeuterated proteins for NMR studies
Cell-free protein synthesis of perdeuterated proteins for NMR studies
Touraj Etezady-Esfarjani, Sebastian Hiller, Cristina Villalba and Kurt Wüthrich
Journal of Biomolecular NMR; 2007; 39(3); pp 229-238
Abstract:
Cell-free protein synthesis protocols for uniformly deuterated proteins typically yield low, non-uniform deuteration levels. This paper introduces an E. coli cell-extract, D-S30, which enables efficient production of proteins with high deuteration levels for all non-labile hydrogen atom positions. Potential applications of the new protocol may include production of proteins...