New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy

Sophie Thétiot-Laurent, Gaëlle Gosset, Jean Louis Clément, Mathieu Cassien, Anne Mercier, Didier Siri, Anouk Gaudel-Siri, A. Rockenbauer, Marcel Culcasi, Sylvia Pietri

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (ΔaX) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α′-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α′)-C−H bond. In buffer, the three main hfs (aN, aH, and aP) of their EPR spectra vary reversibly with pH and, from aP or aH titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pKa ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers.

Original languageEnglish
Pages (from-to)300-315
Number of pages16
JournalChemBioChem
Volume18
Issue number3
DOIs
Publication statusPublished - Feb 1 2017

Fingerprint

Electron Spin Resonance Spectroscopy
Biological systems
Paramagnetic resonance
Spectrum Analysis
Spectroscopy
Amino Acids
Imidazolidines
Imidazolines
Cytotoxicity
Titration
Acidity
Rats
Stomach
Buffers

Keywords

  • EPR spectroscopy
  • molecular dynamics
  • nitroxide
  • sensors
  • stomach acidity

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Medicine
  • Molecular Biology
  • Organic Chemistry

Cite this

Thétiot-Laurent, S., Gosset, G., Clément, J. L., Cassien, M., Mercier, A., Siri, D., ... Pietri, S. (2017). New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy. ChemBioChem, 18(3), 300-315. https://doi.org/10.1002/cbic.201600550

New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy. / Thétiot-Laurent, Sophie; Gosset, Gaëlle; Clément, Jean Louis; Cassien, Mathieu; Mercier, Anne; Siri, Didier; Gaudel-Siri, Anouk; Rockenbauer, A.; Culcasi, Marcel; Pietri, Sylvia.

In: ChemBioChem, Vol. 18, No. 3, 01.02.2017, p. 300-315.

Research output: Contribution to journalArticle

Thétiot-Laurent, S, Gosset, G, Clément, JL, Cassien, M, Mercier, A, Siri, D, Gaudel-Siri, A, Rockenbauer, A, Culcasi, M & Pietri, S 2017, 'New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy', ChemBioChem, vol. 18, no. 3, pp. 300-315. https://doi.org/10.1002/cbic.201600550
Thétiot-Laurent S, Gosset G, Clément JL, Cassien M, Mercier A, Siri D et al. New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy. ChemBioChem. 2017 Feb 1;18(3):300-315. https://doi.org/10.1002/cbic.201600550
Thétiot-Laurent, Sophie ; Gosset, Gaëlle ; Clément, Jean Louis ; Cassien, Mathieu ; Mercier, Anne ; Siri, Didier ; Gaudel-Siri, Anouk ; Rockenbauer, A. ; Culcasi, Marcel ; Pietri, Sylvia. / New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy. In: ChemBioChem. 2017 ; Vol. 18, No. 3. pp. 300-315.
@article{0c282f2ddd9a4b3f860f710e7939ebdd,
title = "New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy",
abstract = "There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (ΔaX) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α′-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α′)-C−H bond. In buffer, the three main hfs (aN, aH, and aP) of their EPR spectra vary reversibly with pH and, from aP or aH titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pKa ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers.",
keywords = "EPR spectroscopy, molecular dynamics, nitroxide, sensors, stomach acidity",
author = "Sophie Th{\'e}tiot-Laurent and Ga{\"e}lle Gosset and Cl{\'e}ment, {Jean Louis} and Mathieu Cassien and Anne Mercier and Didier Siri and Anouk Gaudel-Siri and A. Rockenbauer and Marcel Culcasi and Sylvia Pietri",
year = "2017",
month = "2",
day = "1",
doi = "10.1002/cbic.201600550",
language = "English",
volume = "18",
pages = "300--315",
journal = "ChemBioChem",
issn = "1439-4227",
publisher = "Wiley-VCH Verlag",
number = "3",

}

TY - JOUR

T1 - New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy

AU - Thétiot-Laurent, Sophie

AU - Gosset, Gaëlle

AU - Clément, Jean Louis

AU - Cassien, Mathieu

AU - Mercier, Anne

AU - Siri, Didier

AU - Gaudel-Siri, Anouk

AU - Rockenbauer, A.

AU - Culcasi, Marcel

AU - Pietri, Sylvia

PY - 2017/2/1

Y1 - 2017/2/1

N2 - There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (ΔaX) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α′-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α′)-C−H bond. In buffer, the three main hfs (aN, aH, and aP) of their EPR spectra vary reversibly with pH and, from aP or aH titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pKa ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers.

AB - There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (ΔaX) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α′-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α′)-C−H bond. In buffer, the three main hfs (aN, aH, and aP) of their EPR spectra vary reversibly with pH and, from aP or aH titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pKa ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers.

KW - EPR spectroscopy

KW - molecular dynamics

KW - nitroxide

KW - sensors

KW - stomach acidity

UR - http://www.scopus.com/inward/record.url?scp=85008249135&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85008249135&partnerID=8YFLogxK

U2 - 10.1002/cbic.201600550

DO - 10.1002/cbic.201600550

M3 - Article

VL - 18

SP - 300

EP - 315

JO - ChemBioChem

JF - ChemBioChem

SN - 1439-4227

IS - 3

ER -