Related ArticlesDetermination of de novo synthesized amino acids in cellular proteins revisited by 13C NMR spectroscopy.
NMR Biomed. 1997 Apr;10(2):50-8
Authors: Flögel U, Willker W, Leibfritz D
13C nuclear magnetic resonance spectroscopy was used to determine the absolute amounts to de novo synthesized amino acids in both the perchloric acid extracts and the hydrolyzed protein fractions of F98 glioma cells incubated for 2 h with 5 mmol/l [U-13C]glucose. 13C NMR spectra of the hydrolyzed protein fraction revealed a marked incorporation of 13C-labelled alanine, aspartate and glutamate into the proteins of F98 cells within the incubation period. Additionally, small amounts of 13C-labelled glycine, proline and serine could unambiguously be identified in the protein fraction. Astonishingly, approximately equal amounts of 13C-labelled glutamate and aspartate were incorporated into the cellular proteins, although the cytosolic steady-state concentration of aspartate was below 13C NMR detectability. Hypertonic stress decreased the incorporation of 13C-labelled amino acids into the total protein, albeit their cytosolic concentrations were increased, which reflects an inhibition of protein synthesis under these conditions. On the other hand, hypotonic stress increased the amount of 13C-labelled proline incorporated into the cellular proteins even though the cytosolic concentration of 13C-labelled proline was largely decreased. Apparently, hypoosmotic conditions stimulate the synthesis of proteins or peptides with a high proline content. The results show that already after 2 h of incubation with [U-13C]glucose there is a pronounced flux of 13C label into the cellular proteins, which is usually disregarded if cytosolic fluids are examined only. This means that calculations of metabolic fluxes based on 13C NMR spectroscopic data obtained from perchloric acid extracts of cells or tissues and also from in vivo measurements consider only the labelled 'NMR visible' cytosolic metabolites, which may have to be corrected for fast label flowing off into other compartments.
Uncovering symmetry-breaking vector and reliability order for assigning secondary structures of proteins from atomic NMR chemical shifts in amino acids
Uncovering symmetry-breaking vector and reliability order for assigning secondary structures of proteins from atomic NMR chemical shifts in amino acids
Abstract Unravelling the complex correlation between chemical shifts of 13 C α, 13 C β, 13 C�, 1 H α, 15 N, 1 H N atoms in amino acids of proteins from NMR experiment and local structural environments of amino acids facilitates the assignment of secondary structures of proteins. This is an important impetus for both determining the three-dimensional structure and understanding the biological function of proteins. The previous...
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11-14-2011 08:45 AM
[Question from NMRWiki Q&A forum] 13C quaternary centers in amino acids
13C quaternary centers in amino acids
I've got a sample of about 5mg of an amino acid that is the final product of a a synthesis. Due to the long relaxation time that the carboxylic and the alpha C we only got a 200 varian Mercury instrument and we're unable to obtain those signals. I was wondering if an APT is better than DEPT, because we're only interested in this signals and i've heard the overall pulse sequence is shorter than the DEPT, increasing the number of scans in the same period of time.
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09-01-2011 07:20 AM
[Question from NMRWiki Q&A forum] 13C cuaternary centers in amino acids
13C cuaternary centers in amino acids
I've got a sample of about 5mg of an amino acid that is the final product of a a synthesis. Due to the long relaxation time that the carboxilic and the alpha C we only got a 200 varian Mercury instrument and we're unable to obtain those signals. I was wondering if an APT is better than DEPT, because we're only interested in this signals and i've heart the overall pulse sequence is shorter than the DEPT, increasing the number of scans in the same period of time
Check if somebody has answered this question on NMRWiki QA forum
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08-31-2011 07:12 PM
[KPWU blog] Names of Atoms of Amino acids
Names of Atoms of Amino acids
I really hate the inconsistent nomenclature of atoms of amino acids between different programs/database. I finished all NOESY assignment on Sparky using PDB nomenclature and the Sparky XPLOR constraint plugin (shortcut xf) doesn’t take care of the differences between XPLOR and PDB. Thus I have to find a table showing me the differences of names http://stats.wordpress.com/b.gif?host=kpwu.wordpress.com&blog=76132&post=262&subd=kpwu&ref=&feed=1
Go to KPWU blog to read complete post.
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01-28-2011 04:52 AM
Site-specific labeling of proteins with NMR-active unnatural amino acids
Site-specific labeling of proteins with NMR-active unnatural amino acids
Abstract A large number of amino acids other than the canonical amino acids can now be easily incorporated in vivo into proteins at genetically encoded positions. The technology requires an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is added to the media while a TAG amber or frame shift codon specifies the incorporation site in the protein to be studied. These unnatural amino acids can be isotopically labeled and provide unique opportunities for site-specific labeling...
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01-09-2011 12:46 PM
[NMR paper] Selective 'unlabeling' of amino acids in fractionally 13C labeled proteins: an approa
Selective 'unlabeling' of amino acids in fractionally 13C labeled proteins: an approach for stereospecific NMR assignments of CH3 groups in Val and Leu residues.
Related Articles Selective 'unlabeling' of amino acids in fractionally 13C labeled proteins: an approach for stereospecific NMR assignments of CH3 groups in Val and Leu residues.
J Biomol NMR. 2001 Mar;19(3):267-72
Authors: Atreya HS, Chary KV
A novel methodology for stereospecific NMR assignments of methyl (CH3) groups of Val and Leu residues in fractionally 13C-labeled proteins is...
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11-19-2010 08:32 PM
[NMR paper] Assigning the NMR spectra of aromatic amino acids in proteins: analysis of two Ets po
Assigning the NMR spectra of aromatic amino acids in proteins: analysis of two Ets pointed domains.
Related Articles Assigning the NMR spectra of aromatic amino acids in proteins: analysis of two Ets pointed domains.
Biochem Cell Biol. 1998;76(2-3):379-90
Authors: Slupsky CM, Gentile LN, McIntosh LP
The measurement of interproton nuclear Overhauser enhancements (NOEs) and dihedral angle restraints of aromatic amino acids is a critical step towards determining the structure of a protein. The complete assignment of the resonances from aromatic...
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11-17-2010 11:06 PM
[NMR paper] Determination of de novo synthesized amino acids in cellular proteins revisited by 13
Determination of de novo synthesized amino acids in cellular proteins revisited by 13C NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_120x27.gif Related Articles Determination of de novo synthesized amino acids in cellular proteins revisited by 13C NMR spectroscopy.
NMR Biomed. 1997 Apr;10(2):50-8
Authors: Flögel U, Willker W, Leibfritz D
13C nuclear magnetic resonance spectroscopy was used to determine the absolute amounts to de novo...
Determination of de novo synthesized amino acids in cellular proteins revisited by 13
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