19 F-substituted amino acids as an alternative to fluorophore labels: monitoring of degradation and cellular uptake of analogues of penetratin by 19 F NMR
19 F-substituted amino acids as an alternative to fluorophore labels: monitoring of degradation and cellular uptake of analogues of penetratin by 19 F NMR
Current methods for assessment of cellular uptake of cell-penetrating peptides (CPPs) often rely on detection of fluorophore-labeled CPPs. However, introduction of the fluorescent probe often confers changed physicochemical properties, so that the fluorophore-CPP conjugate may exhibit cytotoxic effects and membrane damage not exerted by the native CPP. In the present study, introduction of fluorine probes was investigated as an alternative to fluorophore labeling of a CPP, since this only confers minor changes to its overall physicochemical properties. The high sensitivity of 19F NMR spectroscopy and the absence of background signals from naturally occurring fluorine enabled detection of internalized CPP. Also, degradation of fluorine-labeled peptides during exposure to Caco-2 cells could be followed by using 19F NMR spectroscopy. In total, five fluorinated analogues of the model CPP penetratin were synthesized by using commercially available fluorinated amino acids as labels, including one analogue also carrying an N-terminal fluorophore. The apparent cellular uptake was considerably higher for the fluorophore-penetratin conjugate indicating that the fluorophore moiety promoted uptake of the peptide. The use of 19F NMR spectroscopy enabled monitoring of the fate of the CPPs over time by establishing molar balances, and by verifying CPP integrity upon uptake. Thus, the NMR-based method offers several advantages over currently widespread methods relying on fluorescence detection. The present findings provide guidelines for improved labeling strategies for CPPs, thereby expanding the repertoire of analytical techniques available for studying degradation and uptake of CPPs.
[NMR paper] Pyruvate cellular uptake and enzymatic conversion probed by dissolution DNP-NMR: the impact of overexpressed membrane transporters.
Pyruvate cellular uptake and enzymatic conversion probed by dissolution DNP-NMR: the impact of overexpressed membrane transporters.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--media.wiley.com-assets-7315-19-Wiley_FullText_120x30_orange.png Related Articles Pyruvate cellular uptake and enzymatic conversion probed by dissolution DNP-NMR: the impact of overexpressed membrane transporters.
Magn Reson Chem. 2017 Jun;55(6):579-583
Authors: Balzan R, Fernandes L, Pidial L, Comment A, Tavitian B, Vasos PR
Abstract
...
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04-27-2018 10:26 PM
Pyruvate cellular uptake and enzymatic conversion probed by dissolution DNP-NMR: the impact of overexpressed membrane transporters
From The DNP-NMR Blog:
Pyruvate cellular uptake and enzymatic conversion probed by dissolution DNP-NMR: the impact of overexpressed membrane transporters
p.p1 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 12.0px Helvetica}
Balzan, R., et al., Pyruvate cellular uptake and enzymatic conversion probed by dissolution DNP-NMR: the impact of overexpressed membrane transporters. Magn Reson Chem, 2017. 55(6): p. 579-583.
https://www.ncbi.nlm.nih.gov/pubmed/27859555
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09-29-2017 10:01 PM
[NMR paper] Chiral discrimination of ?-hydroxy acids and N-Ts-?-amino acids induced by tetraaza macrocyclic chiral solvating agents by using (1)H NMR spectroscopy.
Chiral discrimination of ?-hydroxy acids and N-Ts-?-amino acids induced by tetraaza macrocyclic chiral solvating agents by using (1)H NMR spectroscopy.
Related Articles Chiral discrimination of ?-hydroxy acids and N-Ts-?-amino acids induced by tetraaza macrocyclic chiral solvating agents by using (1)H NMR spectroscopy.
Org Biomol Chem. 2017 Jan 27;:
Authors: Lv C, Feng L, Zhao H, Wang G, Stavropoulos P, Ai L
Abstract
In the field of chiral recognition, reported chiral discrimination by (1)H NMR spectroscopy has mainly focused on...
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01-28-2017 08:29 PM
[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.
Check if somebody has answered this question on NMRWiki QA forum
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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
[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...
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08-22-2010 03:31 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...