Cell-free protein synthesis systems provide facile access to proteins in a nascent state that enables formation of soluble, native protein-protein complexes even if one of the protein components is prone to self-aggregation and precipitation. Combined with selective isotope-labeling, this allows the rapid analysis of protein-protein interactions with few 15N-HSQC spectra. The concept is demonstrated with binary and ternary complexes between the chi, psi and gamma subunits of Escherichia coli DNA polymerase III: nascent, selectively 15N-labeled psi produced in the presence of chi resulted in a soluble, correctly folded chi-psi complex, whereas psi alone precipitated irrespective of whether gamma was present or not. The 15N-HSQC spectra showed that the N-terminal segment of psi is mobile in the chi-psi complex, yet important for its binding to gamma. The sample preparation was greatly enhanced by an autoinduction strategy, where the T7 RNA polymerase needed for transcription of a gene in a T7-promoter vector was produced in situ.
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
[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] Quantitation of protein expression in a cell-free system: Efficient detection of yiel
Quantitation of protein expression in a cell-free system: Efficient detection of yields and 19F NMR to identify folded protein.
Related Articles Quantitation of protein expression in a cell-free system: Efficient detection of yields and 19F NMR to identify folded protein.
J Biomol NMR. 2005 Jan;31(1):11-9
Authors: Neerathilingam M, Greene LH, Colebrooke SA, Campbell ID, Staunton D
We have developed an efficient and novel filter assay method, involving radioactive labelling and imaging, to quantify the expression of soluble proteins from a...
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11-24-2010 11:14 PM
[NMR paper] Optimization of an Escherichia coli system for cell-free synthesis of selectively N-l
Optimization of an Escherichia coli system for cell-free synthesis of selectively N-labelled proteins for rapid analysis by NMR spectroscopy.
Related Articles Optimization of an Escherichia coli system for cell-free synthesis of selectively N-labelled proteins for rapid analysis by NMR spectroscopy.
Eur J Biochem. 2004 Oct;271(20):4084-93
Authors: Ozawa K, Headlam MJ, Schaeffer PM, Henderson BR, Dixon NE, Otting G
Cell-free protein synthesis offers rapid access to proteins that are selectively labelled with amino acids and suitable for...
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11-24-2010 10:01 PM
[NMR paper] NMR and modeling studies of protein-carbohydrate interactions: synthesis, three-dimen
NMR and modeling studies of protein-carbohydrate interactions: synthesis, three-dimensional structure, and recognition properties of a minimum hevein domain with binding affinity for chitooligosaccharides.
Related Articles NMR and modeling studies of protein-carbohydrate interactions: synthesis, three-dimensional structure, and recognition properties of a minimum hevein domain with binding affinity for chitooligosaccharides.
Chembiochem. 2004 Sep 6;5(9):1245-55
Authors: Aboitiz N, Vila-Perelló M, Groves P, Asensio JL, Andreu D, Cañada FJ, Jiménez-Barbero...
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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...