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Bodor A, Haller JD, Bouguechtouli C, Theillet FX, Nyitray L, Luy B. Power of Pure Shift HαCα Correlations: A Way to Characterize Biomolecules under Physiological Conditions. Anal Chem 2020; 92:12423-12428. [PMID: 32786451 DOI: 10.1021/acs.analchem.0c02182] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Intrinsically disordered proteins (IDPs) constitute an important class of biomolecules with high flexibility. Atomic-resolution studies for these molecules are essentially limited to NMR spectroscopy, which should be performed under physiological pH and temperature to populate relevant conformational ensembles. In this context, however, fundamental problems arise with established triple resonance NMR experiments: high solvent accessibility of IDPs promotes water exchange, which disfavors classical amide 1H-detection, while 13C-detection suffers from significantly reduced sensitivity. A favorable alternative, the conventional detection of nonexchangeable 1Hα, so far resulted in broad signals with insufficient resolution and sensitivity. To overcome this, we introduce here a selective Hα,Cα-correlating pure shift detection scheme, the selective Hα,Cα-HSQC (SHACA-HSQC), using extensive hetero- and homonuclear decoupling applicable to aqueous samples (≥90% H2O) and tested on small molecules and proteins. SHACA-HSQC spectra acquired on IDPs provide uncompromised resolution and sensitivity (up to fivefold increased S/N compared to the standard 1H,13C-HSQC), as shown for resonance distinction and unambiguous assignment on the disordered transactivation domain of the tumor suppressor p53, α-synuclein, and folded ubiquitin. The detection scheme can be implemented in any 1Hα-detected triple resonance experiment and may also form the basis for the detection of isotope-labeled markers in biological studies or compound libraries.
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Affiliation(s)
- Andrea Bodor
- Institute of Chemistry, Eötvös Loránd University, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
| | - Jens D Haller
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4-Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, Karlsruhe 76133, Germany
| | - Chafiaa Bouguechtouli
- Institute of Integrative Biology of the Cell, UMR9198, CNRS/CEA/ University of Paris Saclay, Gif-Sur-Yvette 911991, France
| | - Francois-Xavier Theillet
- Institute of Integrative Biology of the Cell, UMR9198, CNRS/CEA/ University of Paris Saclay, Gif-Sur-Yvette 911991, France
| | - László Nyitray
- Department of Biochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/c, Budapest 1117, Hungary
| | - Burkhard Luy
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4-Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, Karlsruhe 76133, Germany
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Aloui G, Bouabdallah S, Baltaze JP, Pucheta JEH, Touil S, Farjon J, Giraud N. Monitoring Conformational Changes in an Enzyme Conversion Inhibitor Using Pure Shift Exchange NMR Spectroscopy. Chemphyschem 2019; 20:1738-1746. [PMID: 31033157 DOI: 10.1002/cphc.201900244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/25/2019] [Indexed: 11/06/2022]
Abstract
We report the acquisition of 2D NMR EXSY spectra with ultrahigh resolution, which allows for probing the slow conformational exchange process in a pharmaceutical compound. The resolution enhancement is achieved by implementing interferogram based PSYCHE homonuclear decoupling to generate a pure shift proton spectrum along the direct domain of the resulting data. The performance of this pure shift EXSY pulse sequence is compared to the standard experiment recorded under identical conditions. It is found that although being less sensitive and requiring a longer acquisition time, the quality of pure shift spectra allows for extracting exchange rates values that are coherent with the ones determined by standard approach, on a temperature range that demonstrates the robustness of the chosen homonuclear decoupling method. The resolution enhancement provided by the simplification of proton line shape allows for probing a higher number of proton sites whose analysis would have been biased using a standard method. These results open the way to a thorough and accurate study of chemical exchange processes based on a multi-site analysis of 2D pure shift EXSY spectra.
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Affiliation(s)
- G Aloui
- Université Paris Saclay, Institut de Chimie Moléculaire et des Matériaux d'Orsay Equipe RMN en Milieu Orienté UMR CNRS-UPS 8182, 91405, Orsay, France.,Laboratory of Hetero-Organic Compounds and Nanostructured Materials, University of Carthage, Faculty of Sciences of Bizerte, 7021, Jarzouna, Tunisia
| | - S Bouabdallah
- Laboratory of Hetero-Organic Compounds and Nanostructured Materials, University of Carthage, Faculty of Sciences of Bizerte, 7021, Jarzouna, Tunisia
| | - J P Baltaze
- Université Paris Saclay, Institut de Chimie Moléculaire et des Matériaux d'Orsay Equipe RMN en Milieu Orienté UMR CNRS-UPS 8182, 91405, Orsay, France
| | - J E H Pucheta
- Consejo Nacional de Ciencia y Tecnología - Laboratorio Nacional de Investigación y Servicio Agroalimentario y Forestal, Universidad Autónoma Chapingo, Km. 38.5 Carretera México-Texcoco, Chapingo, 56230, Estado de México, México
| | - S Touil
- Laboratory of Hetero-Organic Compounds and Nanostructured Materials, University of Carthage, Faculty of Sciences of Bizerte, 7021, Jarzouna, Tunisia
| | - J Farjon
- CEISAM UMR CNRS 6230, Faculté des Sciences et Techniques, 2 rue de la Houssinière, BP, 92208, 44322 Nantes cedex 3, France
| | - N Giraud
- Université Paris Saclay, Institut de Chimie Moléculaire et des Matériaux d'Orsay Equipe RMN en Milieu Orienté UMR CNRS-UPS 8182, 91405, Orsay, France.,Laboratory of Pharmacological and Toxicological Chemistry and Biochemistry, Université Paris Descartes, Sorbonne Paris Cité, 45 rue des Saints Pères, 75006, Paris, France
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Haller JD, Bodor A, Luy B. Real-time pure shift measurements for uniformly isotope-labeled molecules using X-selective BIRD homonuclear decoupling. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 302:64-71. [PMID: 30965191 DOI: 10.1016/j.jmr.2019.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 06/09/2023]
Abstract
We introduce a novel selective inversion element for chunked homonuclear decoupling that combines isotope selection via BIRD-filtering with band-selective inversion on the X-heteronucleus and allows efficient real-time decoupling of homonuclear and heteronuclear couplings. It is especially suitable for uniformly isotope-labeled compounds. We discuss in detail the inversion element based on band-selective refocusing on the X-nuclei (BASEREX), highlighting in particular the role of appropriate band-selective shaped refocusing pulses and the application of broadband X-pulses for an effective BIRDd element during homodecoupling. The approach is experimentally verified and studied in detail using uniformly 13C-labeled glucose and a uniformly 15N,13C-labeled amino acid mixture.
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Affiliation(s)
- Jens D Haller
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4 - Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76133 Karlsruhe, Germany
| | - Andrea Bodor
- Eötvös Loránd University, Institute of Chemistry, Laboratory of Structural Chemistry and Biology, Pázmány Péter sétány 1/a, Budapest 1117, Hungary
| | - Burkhard Luy
- Institut für Organische Chemie and Institut für Biologische Grenzflächen 4 - Magnetische Resonanz, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76133 Karlsruhe, Germany.
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Becker J, Koos MRM, Schulze-Sünninghausen D, Luy B. ASAP-HSQC-TOCSY for fast spin system identification and extraction of long-range couplings. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 300:76-83. [PMID: 30711785 DOI: 10.1016/j.jmr.2018.12.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
Based on Ernst-angle-type excitation and Acceleration by Sharing Adjacent Polarization (ASAP), a fast HSQC-TOCSY experiment is introduced. In the approach, the DIPSI-2 isotropic mixing period of the ASAP-HSQC is simply shifted, which provides a TOCSY period without additional application of rf-energy. The ASAP-HSQC-TOCSY allows the acquisition of a conventional 2D in about 30 s. Alternatively, it allows the acquisition of highly carbon-resolved spectra (several Hz digital resolution) on the order of minutes. An ASAP-HSQC-TOCSY-IPAP variant, finally, allows the sign-sensitive extraction of heteronuclear long-range coupling constants from a pair of highly resolved spectra in less than an hour. Pulse sequences, several example spectra, and a discussion of results are given.
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Affiliation(s)
- Johanna Becker
- Institut für Organische Chemie and Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Martin R M Koos
- Institut für Organische Chemie and Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - David Schulze-Sünninghausen
- Institut für Organische Chemie and Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Burkhard Luy
- Institut für Organische Chemie and Institut für Biologische Grenzflächen, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
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