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Votkina DE, Rollet M, Trusova ME, Audran G, Marque SRA, Petunin PV, Postnikov PS. 2,4,5,6-Substituted 4,5-dihydro-1,2,4,5-tetrazin-3(2H)-ones as non-classical initiators of controlled radical polymerization of styrene. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3563-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Parzy E, Boudries D, Jacoutot S, Albalat M, Vanthuyne N, Franconi JM, Mellet P, Thiaudiere E, Audran G, Marque SRA, Massot P. Enzymatic activity monitoring through dynamic nuclear polarization in Earth magnetic field. J Magn Reson 2021; 333:107095. [PMID: 34749037 DOI: 10.1016/j.jmr.2021.107095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 09/21/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Cost-effective and portable MRI systems operating at Earth-field would be helpful in poorly accessible areas or in developing nations. Furthermore Earth-field MRI can provide new contrasts opening the way to the observation of pathologies at the biochemical level. However low-field MRI suffers from a dramatic lack in detection sensitivity even worsened for molecular imaging purposes where biochemical specificity requires detection of dilute compounds. In a preliminary spectroscopic approach, it is proposed here to detect protease-driven hydrolysis of a nitroxide probe thanks to electron-nucleus Overhauser enhancement in a home-made double resonance system in Earth-field. The combination of the Overhauser effect and the specific enzymatic modification of the probe provides a smart contrast reporting the enzymatic activity. The nitroxide probe is a six-line nitroxide which lines are shifted according to its substrate/product state, which requires quantum mechanical calculations to predict EPR line frequencies and Overhauser enhancements at Earth field. The NMR system is equipped with a 13-mT prepolarization coil, a 153-MHz EPR coil and a 2-kHz NMR coil. Either prepolarized NMR or DNP-NMR without prepolarization provide NMR spectra within 3 min. The frequency dependence of Overhauser enhancement was in agreement with theoretical calculations. Protease-mediated catalysis of the nitroxide probe could only be measured through the Overhauser effect with 5 min time resolution. Future developments shall open the way for the design of new low-field DNP-MRI systems.
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Affiliation(s)
- E Parzy
- Magnetic Resonance of Biological Systems, UMR5536 University of Bordeaux-CNRS, Bordeaux, France.
| | - D Boudries
- Magnetic Resonance of Biological Systems, UMR5536 University of Bordeaux-CNRS, Bordeaux, France
| | - Samuel Jacoutot
- Aix Marseille Univ, CNRS, ICR, Case 551, 13397 Marseille, France
| | | | | | - J-M Franconi
- Magnetic Resonance of Biological Systems, UMR5536 University of Bordeaux-CNRS, Bordeaux, France
| | - P Mellet
- Magnetic Resonance of Biological Systems, UMR5536 University of Bordeaux-CNRS, Bordeaux, France; INSERM, Bordeaux
| | - E Thiaudiere
- Magnetic Resonance of Biological Systems, UMR5536 University of Bordeaux-CNRS, Bordeaux, France
| | - G Audran
- Aix Marseille Univ, CNRS, ICR, Case 551, 13397 Marseille, France
| | - S R A Marque
- Aix Marseille Univ, CNRS, ICR, Case 551, 13397 Marseille, France
| | - P Massot
- Magnetic Resonance of Biological Systems, UMR5536 University of Bordeaux-CNRS, Bordeaux, France
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Le Breton N, Longhi S, Rockenbauer A, Guigliarelli B, Marque SRA, Belle V, Martinho M. Probing the dynamic properties of two sites simultaneously in a protein–protein interaction process: a SDSL-EPR study. Phys Chem Chem Phys 2019; 21:22584-22588. [DOI: 10.1039/c9cp04660g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Probing two sites simultaneously in a protein–protein interaction process combining spin labels of different EPR signatures.
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Affiliation(s)
| | - S. Longhi
- Aix Marseille Univ
- CNRS
- AFMB
- Marseille
- France
| | - A. Rockenbauer
- Research Center of Natural Sciences
- Budapest University of Technology and Economics
- Budapest
- Hungary
| | | | | | - V. Belle
- Aix Marseille Univ., CNRS, BIP
- Marseille
- France
| | - M. Martinho
- Aix Marseille Univ., CNRS, BIP
- Marseille
- France
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