1
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Okuno Y, Clore GM. Extending the Experimentally Accessible Range of Spin Dipole-Dipole Spectral Densities for Protein-Cosolute Interactions by Temperature-Dependent Solvent Paramagnetic Relaxation Enhancement Measurements. J Phys Chem B 2023; 127:7887-7898. [PMID: 37681752 DOI: 10.1021/acs.jpcb.3c05301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Longitudinal (Γ1) and transverse (Γ2) solvent paramagnetic relaxation enhancement (sPRE) yields field-dependent information in the form of spectral densities that provides unique information related to cosolute-protein interactions and electrostatics. A typical protein sPRE data set can only sample a few points on the spectral density curve, J(ω), within a narrow frequency window (500 MHz to ∼1 GHz). However, complex interactions and dynamics of paramagnetic cosolutes around a protein make it difficult to directly interpret the few experimentally accessible points of J(ω). In this paper, we show that it is possible to significantly extend the experimentally accessible frequency range (corresponding to a range from ∼270 MHz to 1.8 GHz) by acquiring a series of sPRE experiments at different temperatures. This approach is based on the scaling property of J(ω) originally proposed by Melchior and Fries for small molecules. Here, we demonstrate that the same scaling property also holds for geometrically far more complex systems such as proteins. Using the extended spectral densities derived from the scaling property as the reference dataset, we demonstrate that our previous approach that makes use of a non-Lorentzian Ansatz spectral density function to fit only J(0) and one to two J(ω) points allows one to obtain accurate values for the concentration-normalized equilibrium average of the electron-proton interspin separation ⟨r-6⟩norm and the correlation time τC, which provide quantitative information on the energetics and timescale, respectively, of local cosolute-protein interactions. We also show that effective near-surface potentials, ϕENS, obtained from ⟨r-6⟩norm provide a reliable and quantitative measure of intermolecular interactions including electrostatics, while ϕENS values obtained from only Γ1 or Γ2 sPRE rates can have significant artifacts as a consequence of potential variations and changes in the diffusive properties of the cosolute around the protein surface. Finally, we discuss the experimental feasibility and limitations of extracting the high-frequency limit of J(ω) that is related to ⟨r-8⟩norm and report on the extremely local intermolecular potential.
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Affiliation(s)
- Yusuke Okuno
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
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2
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Abstract
Glycans, carbohydrate molecules in the realm of biology, are present as biomedically important glycoconjugates and a characteristic aspect is that their structures in many instances are branched. In determining the primary structure of a glycan, the sugar components including the absolute configuration and ring form, anomeric configuration, linkage(s), sequence, and substituents should be elucidated. Solution state NMR spectroscopy offers a unique opportunity to resolve all these aspects at atomic resolution. During the last two decades, advancement of both NMR experiments and spectrometer hardware have made it possible to unravel carbohydrate structure more efficiently. These developments applicable to glycans include, inter alia, NMR experiments that reduce spectral overlap, use selective excitations, record tilted projections of multidimensional spectra, acquire spectra by multiple receivers, utilize polarization by fast-pulsing techniques, concatenate pulse-sequence modules to acquire several spectra in a single measurement, acquire pure shift correlated spectra devoid of scalar couplings, employ stable isotope labeling to efficiently obtain homo- and/or heteronuclear correlations, as well as those that rely on dipolar cross-correlated interactions for sequential information. Refined computer programs for NMR spin simulation and chemical shift prediction aid the structural elucidation of glycans, which are notorious for their limited spectral dispersion. Hardware developments include cryogenically cold probes and dynamic nuclear polarization techniques, both resulting in enhanced sensitivity as well as ultrahigh field NMR spectrometers with a 1H NMR resonance frequency higher than 1 GHz, thus improving resolution of resonances. Taken together, the developments have made and will in the future make it possible to elucidate carbohydrate structure in great detail, thereby forming the basis for understanding of how glycans interact with other molecules.
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Affiliation(s)
- Carolina Fontana
- Departamento
de Química del Litoral, CENUR Litoral Norte, Universidad de la República, Paysandú 60000, Uruguay
| | - Göran Widmalm
- Department
of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden,
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3
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Marchand A, Mishra R, Bernard A, Dumez J. Online Reaction Monitoring with Fast and Flow‐Compatible Diffusion NMR Spectroscopy. Chemistry 2022; 28:e202201175. [DOI: 10.1002/chem.202201175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Indexed: 11/08/2022]
Affiliation(s)
| | - Rituraj Mishra
- Nantes Université CNRS CEISAM UMR 6230 44000 Nantes France
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4
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Jacquemmoz C, Mishra R, Guduff L, van Heijenoort C, Dumez JN. Optimisation of spatially-encoded diffusion-ordered NMR spectroscopy for the analysis of mixtures. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2022; 60:121-138. [PMID: 34269476 DOI: 10.1002/mrc.5194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/25/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Diffusion-ordered NMR spectroscopy (DOSY NMR) is a widely used method for the analysis of mixtures. It can be used to separate the spectra of a mixture's components and to analyse interactions. The classic implementation of DOSY experiments, based on an incrementation of the diffusion-encoding gradient area, requires several minutes or more to collect a 2D data set. Spatially-encoded (SPEN) DOSY makes it possible to collect a complete data set in less than 1 s, by spatial parallelisation of the effective gradient area. While several short descriptions of SPEN DOSY experiments have been reported, a thorough characterisation of its features and its practical use is missing, and this hinders the use of the method. Here, we present the unusual principles and implementation of the SPEN DOSY experiment, an understanding of which is useful to make optimal use of the method. The encoding and acquisition steps are described, and the parameter relations that govern the setup of SPEN DOSY experiments are discussed. The influence of key parameters, including on sensitivity, is illustrated experimentally on mixtures of small molecules. This study should be useful for the setup of SPEN DOSY experiments, which are particularly useful for systems that evolve in time.
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Affiliation(s)
| | - Rituraj Mishra
- Université de Nantes, CNRS, CEISAM, UMR 6230, Nantes, France
| | - Ludmilla Guduff
- Université Paris-Saclay, CNRS, ICSN, UPR 2301, Gif-sur-Yvette, France
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5
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Aghelnejad B, Bodenhausen G, Pelupessy P. A Direct NMR Method To Measure Self-Diffusion Coefficients in Liquids by Monitoring Diffusing Molecules through One-Dimensional Imaging. Chemphyschem 2021; 23:e202100786. [PMID: 34914864 DOI: 10.1002/cphc.202100786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Indexed: 11/08/2022]
Abstract
Diffusion processes can be followed directly by recording one-dimensional images of a selected slice at variable intervals after selective inversion of the magnetization. The resulting diffusion coefficients of H2 O and DMSO are consistent with earlier studies at different temperatures, obtained by monitoring the attenuation of NMR signals as a function of the gradient amplitude in gradient echo sequences.
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Affiliation(s)
- Behdad Aghelnejad
- Department of chemistry, École normale supérieure, PSL University, 24 Rue Lhomond, 75005, Paris, France.,Bruker Biospin SAS, 34 Rue de l'Industrie, 67160, Wissembourg, France.,Current address: School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Geoffrey Bodenhausen
- Department of chemistry, École normale supérieure, PSL University, 24 Rue Lhomond, 75005, Paris, France
| | - Philippe Pelupessy
- Department of chemistry, École normale supérieure, PSL University, 24 Rue Lhomond, 75005, Paris, France
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6
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Šulskis D, Thoma J, Burmann BM. Structural basis of DegP protease temperature-dependent activation. SCIENCE ADVANCES 2021; 7:eabj1816. [PMID: 34878848 PMCID: PMC8654288 DOI: 10.1126/sciadv.abj1816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/16/2021] [Indexed: 05/21/2023]
Abstract
Protein quality control is an essential cellular function mainly executed by a vast array of different proteases and molecular chaperones. One of the bacterial high temperature requirement A (HtrA) protein family members, the homo-oligomeric DegP protease, plays a crucial role in the Escherichia coli protein quality control machinery by removing unfolded proteins or preventing their aggregation and chaperoning them to their final folded state within the periplasm. DegP contains two regulatory PDZ domains, which play key roles in substrate recognition and in the transformation of DegP between inactive hexameric and proteolytic active cage-like structures. Here, we analyze the interaction and dynamics of the DegP PDZ domains underlying this transformation by high-resolution NMR spectroscopy complemented with biochemical cleavage assays. We identify an interdomain molecular lock, which controls the interactions between the two PDZ domains, regulated by fine-tuned temperature-dependent protein dynamics, and which is potentially conserved in proteins harboring tandem PDZ domains.
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Affiliation(s)
- Darius Šulskis
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Johannes Thoma
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Björn M. Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
- Corresponding author.
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7
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Chemically-powered swimming and diffusion in the microscopic world. Nat Rev Chem 2021; 5:500-510. [PMID: 37118434 DOI: 10.1038/s41570-021-00281-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2021] [Indexed: 12/20/2022]
Abstract
The past decade has seen intriguing reports and heated debates concerning the chemically-driven enhanced motion of objects ranging from small molecules to millimetre-size synthetic robots. These objects, in solutions in which chemical reactions were occurring, were observed to diffuse (spread non-directionally) or swim (move directionally) at rates exceeding those expected from Brownian motion alone. The debates have focused on whether observed enhancement is an experimental artefact or a real phenomenon. If the latter were true, then we would also need to explain how the chemical energy is converted into mechanical work. In this Perspective, we summarize and discuss recent observations and theories of active diffusion and swimming. Notably, the chemomechanical coupling and magnitude of diffusion enhancement are strongly size-dependent and should vanish as the size of the swimmers approaches the molecular scale. We evaluate the reliability of common techniques to measure diffusion coefficients and finish by considering the potential applications and chemical to mechanical energy conversion efficiencies of typical nanoswimmers and microswimmers.
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8
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Wang H, Huang T, Granick S. Using NMR to Test Molecular Mobility during a Chemical Reaction. J Phys Chem Lett 2021; 12:2370-2375. [PMID: 33656893 DOI: 10.1021/acs.jpclett.1c00066] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We evaluate critically the use of pulsed gradient spin-echo nuclear magnetic resonance to measure molecular mobility during chemical reactions. With raw NMR spectra available in a public depository, we confirm the boosted mobility during the click chemical reaction (Wang et al. Science 2020 369, 537-541) regardless of the order of magnetic field gradient (linearly increasing, linearly decreasing, random sequence). We also confirm boosted mobility for the Diels-Alder chemical reaction. The conceptual advantage of the former chemical system is that a constant reaction rate implies a constant catalyst concentration, whereas that of the latter is the absence of a paramagnetic catalyst, precluding paramagnetism as an objection to the measurements. The data and discussion in this paper show the reliability of experiments when one avoids convection, allows decay of nuclear spin magnetization between successive pulses and recovery of its intensity between gradients, and satisfies quasi-steady state during the time window to acquire each datum. Especially important is to make comparisons on the time scale of the actual chemical reaction kinetics. We discuss possible sources of mistaken conclusions that are desirable to avoid.
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Affiliation(s)
- Huan Wang
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Tian Huang
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea
| | - Steve Granick
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea
- Departments of Chemistry and Physics, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
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9
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Therapeutic Targeting of Fumaryl Acetoacetate Hydrolase in Hereditary Tyrosinemia Type I. Int J Mol Sci 2021; 22:ijms22041789. [PMID: 33670179 PMCID: PMC7916972 DOI: 10.3390/ijms22041789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 12/30/2022] Open
Abstract
Fumarylacetoacetate hydrolase (FAH) is the fifth enzyme in the tyrosine catabolism pathway. A deficiency in human FAH leads to hereditary tyrosinemia type I (HT1), an autosomal recessive disorder that results in the accumulation of toxic metabolites such as succinylacetone, maleylacetoacetate, and fumarylacetoacetate in the liver and kidney, among other tissues. The disease is severe and, when untreated, it can lead to death. A low tyrosine diet combined with the herbicidal nitisinone constitutes the only available therapy, but this treatment is not devoid of secondary effects and long-term complications. In this study, we targeted FAH for the first-time to discover new chemical modulators that act as pharmacological chaperones, directly associating with this enzyme. After screening several thousand compounds and subsequent chemical redesign, we found a set of reversible inhibitors that associate with FAH close to the active site and stabilize the (active) dimeric species, as demonstrated by NMR spectroscopy. Importantly, the inhibitors are also able to partially restore the normal phenotype in a newly developed cellular model of HT1.
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10
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Abstract
The extent to which cations and anions in ionic liquids (ILs) and ionic liquid solutions are dissociated is of both fundamental scientific interest and practical importance because ion dissociation has been shown to impact viscosity, density, surface tension, volatility, solubility, chemical reactivity, and many other important chemical and physical properties. When mixed with solvents, ionic liquids provide the unique opportunity to investigate ion dissociation from infinite dilution in the solvent to a completely solvent-free state, even at ambient conditions. The most common way to estimate ion dissociation in ILs and IL solutions is by comparing the molar conductivity determined from ionic conductivity measurements such as electrochemical impedance spectroscopy (EIS) (which measure the movement of only the charged, i.e., dissociated, ions) with the molar conductivity calculated from ion diffusivities measured by pulse field gradient nuclear magnetic resonance spectroscopy (PFG-NMR, which gives movement of all of the ions). Because the NMR measurements are time-consuming, the number of ILs and IL solutions investigated by this method is relatively limited. We have shown that use of the Stokes-Einstein equation with estimates of the effective ion Stokes radii allows ion dissociation to be calculated from easily measured density, viscosity, and ionic conductivity data (ρ, η, λ), which is readily available in the literature for a much larger number of pure ILs and IL solutions. Therefore, in this review, we present values of ion dissociation for ILs and IL solutions (aqueous and nonaqueous) determined by both the traditional molar conductivity/PFG-NMR method and the ρ, η, λ method. We explore the effect of cation and anion alkyl chain length, structure, and interaction motifs of the cation and anion, temperature, and the strength of the solvent in IL solutions.
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Affiliation(s)
- Oscar Nordness
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
| | - Joan F Brennecke
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States
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11
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Change of network structure in agarose gels by aging during storage studied by NMR and electrophoresis. Carbohydr Polym 2020; 245:116497. [DOI: 10.1016/j.carbpol.2020.116497] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 11/20/2022]
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12
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Ramanujam V, Alderson TR, Pritišanac I, Ying J, Bax A. Protein structural changes characterized by high-pressure, pulsed field gradient diffusion NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 312:106701. [PMID: 32113145 PMCID: PMC7153785 DOI: 10.1016/j.jmr.2020.106701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/16/2020] [Accepted: 02/17/2020] [Indexed: 06/10/2023]
Abstract
Pulsed-field gradient NMR spectroscopy is widely used to measure the translational diffusion and hydrodynamic radius (Rh) of biomolecules in solution. For unfolded proteins, the Rh provides a sensitive reporter on the ensemble-averaged conformation and the extent of polypeptide chain expansion as a function of added denaturant. Hydrostatic pressure is a convenient and reversible alternative to chemical denaturants for the study of protein folding, and enables NMR measurements to be performed on a single sample. While the impact of pressure on the viscosity of water is well known, and our water diffusivity measurements agree closely with theoretical expectations, we find that elevated pressures increase the Rh of dioxane and other small molecules by amounts that correlate with their hydrophobicity, with parallel increases in rotational friction indicated by 13C longitudinal relaxation times. These data point to a tighter coupling with water for hydrophobic surfaces at elevated pressures. Translational diffusion measurement of the unfolded state of a pressure-sensitized ubiquitin mutant (VA2-ubiquitin) as a function of hydrostatic pressure or urea concentration shows that Rh values of both the folded and the unfolded states remain nearly invariant. At ca 23 Å, the Rh of the fully pressure-denatured state is essentially indistinguishable from the urea-denatured state, and close to the value expected for an idealized random coil of 76 residues. The intrinsically disordered protein (IDP) α-synuclein shows slight compaction at pressures above 2 kbar. Diffusion of unfolded ubiquitin and α-synuclein is significantly impacted by sample concentration, indicating that quantitative measurements need to be carried out under dilute conditions.
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Affiliation(s)
- Venkatraman Ramanujam
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | - T Reid Alderson
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | - Iva Pritišanac
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | - Jinfa Ying
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, 60438 Frankfurt am Main, Germany.
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13
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McCarney ER, Dykstra R, Galvosas P. Evaluation of benchtop NMR Diffusion Ordered Spectroscopy for small molecule mixture analysis. Magn Reson Imaging 2019; 56:103-109. [DOI: 10.1016/j.mri.2018.09.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/26/2018] [Accepted: 09/28/2018] [Indexed: 10/28/2022]
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14
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Dal Poggetto G, Castañar L, Foroozandeh M, Kiraly P, Adams RW, Morris GA, Nilsson M. Unexploited Dimension: New Software for Mixture Analysis by 3D Diffusion-Ordered NMR Spectroscopy. Anal Chem 2018; 90:13695-13701. [DOI: 10.1021/acs.analchem.8b04093] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Guilherme Dal Poggetto
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Laura Castañar
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Mohammadali Foroozandeh
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Peter Kiraly
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Ralph W. Adams
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Gareth A. Morris
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Mathias Nilsson
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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15
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Kiraly P, Nilsson M, Morris GA. Practical aspects of real-time pure shift HSQC experiments. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2018; 56:993-1005. [PMID: 29274287 PMCID: PMC6175388 DOI: 10.1002/mrc.4704] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/12/2017] [Accepted: 12/13/2017] [Indexed: 05/28/2023]
Abstract
Pure shift NMR spectroscopy has become an efficient tool for improving resolution in proton NMR spectra by removing the effect of homonuclear couplings. The introduction of real-time acquisition methods has allowed the main drawback of pure shift NMR, the long experiment times needed, to be circumvented. Real-time methods use periodic application of J-refocusing pulse sequence elements, acquiring a single free induction decay, in contrast to previous methods that construct a pure shift interferogram by concatenating excerpts from multiple free induction decays. In the important heteronuclear single-quantum correlation experiment, implementing real-time pure shift data acquisition typically leads to the simultaneous improvement of both resolution and sensitivity. The current limitations of and problems with real-time pure shift acquisition methods are discussed here in the context of heteronuclear single-quantum correlation experiments. We aim to provide a detailed account of the technical challenges, together with a practical guide to exploiting the full potential of such methods.
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Affiliation(s)
- Peter Kiraly
- School of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Mathias Nilsson
- School of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Gareth A. Morris
- School of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
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16
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Moutzouri P, Kiraly P, Foroozandeh M, Phillips AR, Coombes SR, Nilsson M, Morris GA. Suppression of 13C satellites in 1H DOSY spectra. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 295:6-11. [PMID: 30081299 DOI: 10.1016/j.jmr.2018.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
Diffusion-ordered spectroscopy (DOSY) is a valuable tool for the analysis of intact mixtures, since it can separate the signals of components according to their apparent diffusion coefficients. However, DOSY experiments are acutely sensitive to spectral quality, and especially to signal overlap, which can lead to misleading apparent diffusion coefficients. Here, we introduce a new NMR experiment to reduce signal overlap in mixtures with a wide range of concentrations, by removing one-bond 13C satellites. In such high dynamic range mixtures, 13C isotopomer signals from major components can overlap with signals from minor components, causing problematic distortions in the diffusion domain of a DOSY spectrum. The new method, Oneshot-iDISPEL, is a combination of the Oneshot and DISPEL experiments, and its performance has been demonstrated on a Greek alcoholic beverage, ouzo, which contains small amounts of anise flavour components and sucrose. Ethanol is a major component, and the suppression of its 13C satellites reduces signal overlap with minor components, offering significant improvement in DOSY spectra.
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Affiliation(s)
- Pinelopi Moutzouri
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Peter Kiraly
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | | | - Andrew R Phillips
- Early Product Development, Pharmaceutical Sciences, IMED Biotech Unit, AstraZeneca, Macclesfield SK10 2NA, UK
| | - Steven R Coombes
- Pharmaceutical Technology and Development, AstraZeneca, Silk Road Business Park, Macclesfield SK10 2NA, UK
| | - Mathias Nilsson
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Gareth A Morris
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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17
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Kakita VMR, Jerripothula KM, Vemulapalli SPB, Bharatam J. Selective measurement of 1 H- 1 H scalar couplings from crowded chemical shift regions: Combined pure shift and spin-echo modulation approach. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2018; 56:941-946. [PMID: 29488247 DOI: 10.1002/mrc.4726] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 02/14/2018] [Accepted: 02/15/2018] [Indexed: 06/08/2023]
Abstract
JHH scalar couplings carry rich structural information and their measurements are fundamental in the 1 H NMR based elucidation of small and medium molecules, which, however, are hampered in the presence of large J-coupling network. Further, enhanced spectral resolution is often essential for precise determination of a specific set of 1 H-1 H J-couplings among the complex J-multiplets. In the light of the recent advancements in homodecoupling pure shift strategies, here, we report absorption mode, band-selective refocused pure shift spin-echo method, which helps in determining 1 H-1 H J-couplings from crowded spectral regions. The importance of the present band-selective refocused pure shift spin-echo experiment is exemplified for 2 steroid molecules, estradiol and testosterone.
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Affiliation(s)
- Veera Mohana Rao Kakita
- Centre for NMR & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad, 500007, India
- UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Kalina Campus, Santa Cruz, Mumbai, 400098, India
| | - Kanaka Mahalakshmi Jerripothula
- Centre for NMR & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad, 500007, India
| | - Sahithya Phani Babu Vemulapalli
- Centre for NMR & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad, 500007, India
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18
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Mykhailiuk PK, Kishko I, Kubyshkin V, Budisa N, Cossy J. Selective19F-Labeling of Functionalized Carboxylic Acids with Difluoromethyl Diazomethane (CF2HCHN2). Chemistry 2017; 23:13279-13283. [DOI: 10.1002/chem.201703446] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Indexed: 01/18/2023]
Affiliation(s)
- Pavel K. Mykhailiuk
- Taras Shevchenko National University of Kyiv; Chemistry Department; Volodymyrska 64 01601 Kyiv Ukraine
| | - Igor Kishko
- Taras Shevchenko National University of Kyiv; Chemistry Department; Volodymyrska 64 01601 Kyiv Ukraine
- Enamine Ltd.; Chervonotkatska 78 02094 Kyiv Ukraine
| | - Vladimir Kubyshkin
- Institute of Chemistry; Technical University of Berlin; Müller-Breslau-Str., 10 10623 Berlin Germany
| | - Nediljko Budisa
- Institute of Chemistry; Technical University of Berlin; Müller-Breslau-Str., 10 10623 Berlin Germany
| | - Janine Cossy
- Laboratoire de Chimie Organique, Institute of Chemistry, Biology and Innovation (CBI); ESPCI Paris/ (UMR 8231) CNRS/PSL Research University; 10 rue Vauquelin Paris 75231 Cedex 05 France)
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Pagès G, Gilard V, Martino R, Malet-Martino M. Pulsed-field gradient nuclear magnetic resonance measurements (PFG NMR) for diffusion ordered spectroscopy (DOSY) mapping. Analyst 2017; 142:3771-3796. [DOI: 10.1039/c7an01031a] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The advent of Diffusion Ordered SpectroscopY (DOSY) NMR has enabled diffusion coefficients to be routinely measured and used to characterize chemical systems in solution. Indeed, DOSY NMR allows the separation of the chemical entities present in multicomponent systems and provides information on their intermolecular interactions as well as on their size and shape.
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Affiliation(s)
- G. Pagès
- INRA
- AgroResonance – UR370 Qualité des Produits Animaux
- Saint Genès Champanelle
- France
| | - V. Gilard
- Groupe de RMN Biomédicale
- Laboratoire de Synthèse et Physicochimie de Molécules d'Intérêt Biologique
- UMR CNRS 5068
- Université de Toulouse
- 31062 Toulouse cedex 9
| | - R. Martino
- Groupe de RMN Biomédicale
- Laboratoire de Synthèse et Physicochimie de Molécules d'Intérêt Biologique
- UMR CNRS 5068
- Université de Toulouse
- 31062 Toulouse cedex 9
| | - M. Malet-Martino
- Groupe de RMN Biomédicale
- Laboratoire de Synthèse et Physicochimie de Molécules d'Intérêt Biologique
- UMR CNRS 5068
- Université de Toulouse
- 31062 Toulouse cedex 9
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