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Okuno Y, Schwieters CD, Yang Z, Clore GM. Theory and Applications of Nitroxide-based Paramagnetic Cosolutes for Probing Intermolecular and Electrostatic Interactions on Protein Surfaces. J Am Chem Soc 2022; 144:21371-21388. [DOI: 10.1021/jacs.2c10035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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
| | - Charles D. Schwieters
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
- Computational Biomolecular Magnetic Resonance Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Zhilin Yang
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, 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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Lenard AJ, Mulder FAA, Madl T. Solvent paramagnetic relaxation enhancement as a versatile method for studying structure and dynamics of biomolecular systems. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 132-133:113-139. [PMID: 36496256 DOI: 10.1016/j.pnmrs.2022.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 06/17/2023]
Abstract
Solvent paramagnetic relaxation enhancement (sPRE) is a versatile nuclear magnetic resonance (NMR)-based method that allows characterization of the structure and dynamics of biomolecular systems through providing quantitative experimental information on solvent accessibility of NMR-active nuclei. Addition of soluble paramagnetic probes to the solution of a biomolecule leads to paramagnetic relaxation enhancement in a concentration-dependent manner. Here we review recent progress in the sPRE-based characterization of structural and dynamic properties of biomolecules and their complexes, and aim to deliver a comprehensive illustration of a growing number of applications of the method to various biological systems. We discuss the physical principles of sPRE measurements and provide an overview of available co-solute paramagnetic probes. We then explore how sPRE, in combination with complementary biophysical techniques, can further advance biomolecular structure determination, identification of interaction surfaces within protein complexes, and probing of conformational changes and low-population transient states, as well as deliver insights into weak, nonspecific, and transient interactions between proteins and co-solutes. In addition, we present examples of how the incorporation of solvent paramagnetic probes can improve the sensitivity of NMR experiments and discuss the prospects of applying sPRE to NMR metabolomics, drug discovery, and the study of intrinsically disordered proteins.
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Affiliation(s)
- Aneta J Lenard
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, 8010 Graz, Austria.
| | - Frans A A Mulder
- Interdisciplinary Nanoscience Center and Department of Chemistry, University of Aarhus, DK-8000 Aarhus, Denmark; Institute of Biochemistry, Johannes Kepler Universität Linz, 4040 Linz, Austria.
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Ageing, Molecular Biology and Biochemistry, Research Unit Integrative Structural Biology, Medical University of Graz, 8010 Graz, Austria; BioTechMed-Graz, 8010 Graz, Austria.
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3
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Parigi G, Ravera E, Fragai M, Luchinat C. Unveiling protein dynamics in solution with field-cycling NMR relaxometry. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 124-125:85-98. [PMID: 34479712 DOI: 10.1016/j.pnmrs.2021.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
Field-cycling NMR relaxometry is a well-established technique that can give information on molecular structure and dynamics of biological systems. It provides the nuclear relaxation rates as a function of the applied magnetic field, starting from fields as low as ~ 10-4 T up to about 1-3 T. The profiles so collected, called nuclear magnetic relaxation dispersion (NMRD) profiles, can be extended to include the relaxation rates at the largest fields achievable with high resolution NMR spectrometers. By exploiting this wide range of frequencies, the NMRD profiles can provide information on motions occurring on time scales from 10-6 to 10-9 s. 1H NMRD measurements have proved very useful also for the characterization of paramagnetic proteins, because they can help characterise a number of parameters including the number, distance and residence time of water molecules coordinated to the paramagnetic center, the reorientation correlation times and the electron spin relaxation time, and the electronic structure at the metal site.
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Affiliation(s)
- Giacomo Parigi
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy.
| | - Enrico Ravera
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy
| | - Marco Fragai
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) University of Florence, via Sacconi 6, Sesto Fiorentino, Italy; Department of Chemistry, "Ugo Schiff", University of Florence, via della Lastruccia 3, Sesto Fiorentino, Italy; Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy
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4
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Levien M, Reinhard M, Hiller M, Tkach I, Bennati M, Orlando T. Spin density localization and accessibility of organic radicals affect liquid-state DNP efficiency. Phys Chem Chem Phys 2021; 23:4480-4485. [PMID: 33599637 DOI: 10.1039/d0cp05796g] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report a large variation in liquid DNP performance of up to a factor of about five in coupling factor among organic radicals commonly used as polarizing agents. A comparative study of 1H and 13C DNP in model systems shows the impact of the spin density distribution and accessibility of the radical site by the target molecule.
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Affiliation(s)
- Marcel Levien
- ESR Spectroscopy Group, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, Göttigen, Germany.
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5
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Okuno Y, Szabo A, Clore GM. Quantitative Interpretation of Solvent Paramagnetic Relaxation for Probing Protein-Cosolute Interactions. J Am Chem Soc 2020; 142:8281-8290. [PMID: 32286812 DOI: 10.1021/jacs.0c00747] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Protein-small cosolute molecule interactions are ubiquitous and known to modulate the solubility, stability, and function of many proteins. Characterization of such transient weak interactions at atomic resolution remains challenging. In this work, we develop a simple and practical NMR method for extracting both energetic and dynamic information on protein-cosolute interactions from solvent paramagnetic relaxation enhancement (sPRE) measurements. Our procedure is based on an approximate (non-Lorentzian) spectral density that behaves exactly at both high and low frequencies. This spectral density contains two parameters, one global related to the translational diffusion coefficient of the paramagnetic cosolute, and the other residue specific. These parameters can be readily determined from sPRE data, and then used to calculate analytically a concentration normalized equilibrium average of the interspin distance, ⟨r-6⟩norm, and an effective correlation time, τC, that provide measures of the energetics and dynamics of the interaction at atomic resolution. We compare our approach with existing ones, and demonstrate the utility of our method using experimental 1H longitudinal and transverse sPRE data recorded on the protein ubiquitin in the presence of two different nitroxide radical cosolutes, at multiple static magnetic fields. The approach for analyzing sPRE data outlined here provides a powerful tool for deepening our understanding of extremely weak protein-cosolute interactions.
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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
| | - Attila Szabo
- 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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6
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Levien M, Hiller M, Tkach I, Bennati M, Orlando T. Nitroxide Derivatives for Dynamic Nuclear Polarization in Liquids: The Role of Rotational Diffusion. J Phys Chem Lett 2020; 11:1629-1635. [PMID: 32003568 PMCID: PMC7307959 DOI: 10.1021/acs.jpclett.0c00270] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 01/31/2020] [Indexed: 06/07/2023]
Abstract
Polarization transfer efficiency in liquid-state dynamic nuclear polarization (DNP) depends on the interaction between polarizing agents (PAs) and target nuclei modulated by molecular motions. We show how translational and rotational diffusion differently affect the DNP efficiency. These contributions were disentangled by measuring 1H-DNP enhancements of toluene and chloroform doped with nitroxide derivatives at 0.34 T as a function of either the temperature or the size of the PA. The results were employed to analyze 13C-DNP data at higher fields, where the polarization transfer is also driven by the Fermi contact interaction. In this case, bulky nitroxide PAs perform better than the small TEMPONE radical due to structural fluctuations of the ring conformation. These findings will help in designing PAs with features specifically optimized for liquid-state DNP at various magnetic fields.
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Affiliation(s)
- M. Levien
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
- Department
of Chemistry, Georg-August University, Göttingen 37077, Germany
| | - M. Hiller
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
| | - I. Tkach
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
| | - M. Bennati
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
- Department
of Chemistry, Georg-August University, Göttingen 37077, Germany
| | - T. Orlando
- Research
Group EPR Spectroscopy, Max Planck Institute
for Biophysical Chemistry, Göttingen 37077, Germany
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7
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Flämig M, Hofmann M, Lichtinger A, Rössler EA. Application of proton field-cycling NMR relaxometry for studying translational diffusion in simple liquids and polymer melts. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2019; 57:805-817. [PMID: 30604576 DOI: 10.1002/mrc.4823] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
With the availability of commercial field-cycling relaxometers together with progress of home-built instruments nuclear magnetic resonance relaxometry has gained new momentum as a method of investigating the dynamics in viscous liquids and polymer melts. The method provides the frequency dependence of the spin-lattice relaxation rate. In the case of protons, one distinguishes intramolecular and intermolecular relaxation pathways. Whereas the intramolecular contribution prevails at high frequencies and reflects rotational dynamics, the often ignored intermolecular relaxation contribution dominates at low-frequency and provides access to translational dynamics. A universal low-frequencies dispersion law holds which in pure systems allows determining the diffusion coefficient in a straightforward way. In addition, the rotational time constant is extracted from the high-frequency relaxation contribution. This is demonstrated for simple and ionic liquids and for polymer melts.
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Affiliation(s)
- Max Flämig
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| | - Marius Hofmann
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| | - Anne Lichtinger
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
| | - Ernst A Rössler
- Experimentalphysik and Nordbayerisches NMR-Zentrum, Universität Bayreuth, Bayreuth, Germany
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8
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Fragai M, Ravera E, Tedoldi F, Luchinat C, Parigi G. Relaxivity of Gd-Based MRI Contrast Agents in Crosslinked Hyaluronic Acid as a Model for Tissues. Chemphyschem 2019; 20:2204-2209. [PMID: 31298452 DOI: 10.1002/cphc.201900587] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/11/2019] [Indexed: 12/12/2022]
Abstract
The efficiency of MRI contrast agents depends on the relaxation rate enhancement that they can induce at imaging fields. It is well known that, at these fields, large relaxation rates are obtained by binding of gadolinium(III) ions to large molecules. By the same token, the interaction of the gadolinium(III) complexes with macromolecules that are found in biological tissues can be responsible for an increase of the relaxation rate with respect to the value observed in liquids. We investigate here the relaxation enhancement of gadoteridol (Gd-HP-DO3A) in crosslinked hyaluronic acid, taken as model tissue, using fast field-cycling relaxometry. The analysis of the relaxation profiles as a function of the magnetic fields indicates that a sizable increase in the relaxation rates is due to a modest interaction of the contrast agent with the hydrogel and to the slower mobility of the water molecules outside the first-coordination sphere of the gadolinium(III) ion.
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Affiliation(s)
- Marco Fragai
- Magnetic Resonance Center (CERM), University of Florence, and Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy.,Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Enrico Ravera
- Magnetic Resonance Center (CERM), University of Florence, and Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy.,Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Fabio Tedoldi
- Bracco Imaging Spa, Bracco Research Centre, Via Ribes 5, 10010, Colleretto Giacosa (TO), Italy
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM), University of Florence, and Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy.,Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM), University of Florence, and Consorzio Interuniversitario Risonanze Magnetiche di Metalloproteine (CIRMMP), via Sacconi 6, Sesto Fiorentino, Italy.,Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
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9
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Orlando T, Dervişoğlu R, Levien M, Tkach I, Prisner TF, Andreas LB, Denysenkov VP, Bennati M. Dynamic Nuclear Polarization of 13
C Nuclei in the Liquid State over a 10 Tesla Field Range. Angew Chem Int Ed Engl 2018; 58:1402-1406. [DOI: 10.1002/anie.201811892] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Tomas Orlando
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Rıza Dervişoğlu
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Marcel Levien
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| | - Igor Tkach
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Loren B. Andreas
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Marina Bennati
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
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10
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Orlando T, Dervişoğlu R, Levien M, Tkach I, Prisner TF, Andreas LB, Denysenkov VP, Bennati M. Dynamic Nuclear Polarization of 13
C Nuclei in the Liquid State over a 10 Tesla Field Range. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201811892] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tomas Orlando
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Rıza Dervişoğlu
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Marcel Levien
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
| | - Igor Tkach
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Thomas F. Prisner
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Loren B. Andreas
- Department of NMR Based Structural Biology; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
| | - Vasyl P. Denysenkov
- Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance; Goethe University; Max-von-Laue-Strasse 7 Frankfurt am Main Germany
| | - Marina Bennati
- Research Group of EPR Spectroscopy; Max Planck Institute for Biophysical Chemistry; Am Fassberg 11 Göttingen Germany
- Department of Chemistry; Georg-August-University; Tammannstrasse 4 Göttingen Germany
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11
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Franck JM, Han S. Overhauser Dynamic Nuclear Polarization for the Study of Hydration Dynamics, Explained. Methods Enzymol 2018; 615:131-175. [PMID: 30638529 DOI: 10.1016/bs.mie.2018.09.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We outline the physical properties of hydration water that are captured by Overhauser Dynamic Nuclear Polarization (ODNP) relaxometry and explore the insights that ODNP yields about the water and the surface that this water is coupled to. As ODNP relies on the pairwise cross-relaxation between the electron spin of a spin probe and a proton nuclear spin of water, it captures the dynamics of single-particle diffusion of an ensemble of water molecules moving near the spin probe. ODNP principally utilizes the same physics as other nuclear magnetic resonance (NMR) relaxometry (i.e., relaxation measurement) techniques. However, in ODNP, electron paramagnetic resonance (EPR) excites the electron spins probes and their high net polarization acts as a signal amplifier. Furthermore, it renders ODNP parameters highly sensitive to water moving at rates commensurate with the EPR frequency of the spin probe (typically 10GHz). Also, ODNP selectively enhances the NMR signal contributions of water moving within close proximity to the spin label. As a result, ODNP can capture ps-ns movements of hydration waters with high sensitivity and locality, even in samples with protein concentrations as dilute as 10 µM. To date, the utility of the ODNP technique has been demonstrated for two major applications: the characterization of the spatial variation in the properties of the hydration layer of proteins or other surfaces displaying topological diversity, and the identification of structural properties emerging from highly disordered proteins and protein domains. The former has been shown to correlate well with the properties of hydration water predicted by MD simulations and has been shown capable of evaluating the hydrophilicity or hydrophobicity of a surface. The latter has been demonstrated for studies of an interhelical loop of proteorhodopsin, the partial structure of α-synuclein embedded at the lipid membrane surface, incipient structures adopted by tau proteins en route to fibrils, and the structure and hydration profile of a transmembrane peptide. This chapter focuses on offering a mechanistic understanding of the ODNP measurement and the molecular dynamics encoded in the ODNP parameters. In particular, it clarifies how the electron-nuclear dipolar coupling encodes information about the molecular dynamics in the nuclear spin self-relaxation and, more importantly, the electron-nuclear spin cross-relaxation rates. The clarification of the molecular dynamics underlying ODNP should assist in establishing a connection to theory and computer simulation that will offer far richer interpretations of ODNP results in future studies.
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Affiliation(s)
- John M Franck
- Department of Chemistry, Syracuse University, Syracuse, NY, United States.
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA, United States; Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, United States
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12
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Kimmich R, Fatkullin N. Self-diffusion studies by intra- and inter-molecular spin-lattice relaxometry using field-cycling: Liquids, plastic crystals, porous media, and polymer segments. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 101:18-50. [PMID: 28844220 DOI: 10.1016/j.pnmrs.2017.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/02/2017] [Accepted: 04/02/2017] [Indexed: 06/07/2023]
Abstract
Field-cycling NMR relaxometry is a well-established technique for probing molecular dynamics in a frequency range from typically a few kHz up to several tens of MHz. For the interpretation of relaxometry data, it is quite often assumed that the spin-lattice relaxation process is of an intra-molecular nature so that rotational fluctuations dominate. However, dipolar interactions as the main type of couplings between protons and other dipolar species without quadrupole moments can imply appreciable inter-molecular contributions. These fluctuate due to translational displacements and to a lesser degree also by rotational reorientations in the short-range limit. The analysis of the inter-molecular proton spin-lattice relaxation rate thus permits one to evaluate self-diffusion variables such as the diffusion coefficient or the mean square displacement on a time scale from nanoseconds to several hundreds of microseconds. Numerous applications to solvents, plastic crystals and polymers will be reviewed. The technique is of particular interest for polymer dynamics since inter-molecular spin-lattice relaxation diffusometry bridges the time scales of quasi-elastic neutron scattering and field-gradient NMR diffusometry. This is just the range where model-specific intra-coil mechanisms are assumed to occur. They are expected to reveal themselves by characteristic power laws for the time-dependence of the mean-square segment displacement. These can be favorably tested on this basis. Results reported in the literature will be compared with theoretical predictions. On the other hand, there is a second way for translational diffusion phenomena to affect the spin-lattice relaxation dispersion. If rotational diffusion of molecules is restricted, translational diffusion properties can be deduced even from molecular reorientation dynamics detected by intra-molecular spin-lattice relaxation. This sort of scenario will be relevant for adsorbates on surfaces or polymer segments under entanglement and chain connectivity constraints. Under such conditions, reorientations will be correlated with translational displacements leading to the so-called RMTD relaxation process (reorientation mediated by translational displacements). Applications to porous glasses, protein solutions, lipid bilayers, and clays will be discussed. Finally, we will address the intriguing fact that the various time limits of the segment mean-square displacement of polymers in some cases perfectly reproduce predictions of the tube/reptation model whereas the reorientation dynamics suggests strongly deviating power laws.
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Affiliation(s)
| | - Nail Fatkullin
- Institute of Physics, Kazan Federal University, Kazan 420008 Tatarstan, Russia
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13
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Effect of gel matrix confinement on the solvent dynamics in supramolecular gels. J Colloid Interface Sci 2016; 472:60-8. [DOI: 10.1016/j.jcis.2016.03.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 03/13/2016] [Accepted: 03/16/2016] [Indexed: 02/07/2023]
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14
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Bornet A, Jannin S. Optimizing dissolution dynamic nuclear polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:13-21. [PMID: 26920826 DOI: 10.1016/j.jmr.2015.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 12/01/2015] [Accepted: 12/14/2015] [Indexed: 05/15/2023]
Abstract
This article is a short review of some of our recent developments in dissolution dynamic nuclear polarization (d-DNP). We present the basic principles of d-DNP, and motivate our choice to step away from conventional approaches. We then introduce a modified d-DNP recipe that can be summed up as follows. (i) Using broad line polarizing agents to efficiently polarize 1H spins. (ii) Increasing the magnetic field to 6.7 T and above. (iii) Applying microwave frequency modulation. (iv) Applying (1)H-(13)C cross polarization. (v) Transferring hyperpolarized solution through a magnetic tunnel.
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Affiliation(s)
- Aurélien Bornet
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Batochime, CH-1015 Lausanne, Switzerland.
| | - Sami Jannin
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Batochime, CH-1015 Lausanne, Switzerland; Bruker BioSpin AG, Industriestrasse 26, 8117 Fällanden, Switzerland.
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15
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Bukharov MS, Shtyrlin VG, Mamin GV, Stapf S, Mattea C, Mukhtarov AS, Serov NY, Gilyazetdinov EM. Structure and Dynamics of Solvation Shells of Copper(II) Complexes with N,O-Containing Ligands. Inorg Chem 2015; 54:9777-84. [DOI: 10.1021/acs.inorgchem.5b01467] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mikhail S. Bukharov
- A.M. Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya St. 18, 420008, Kazan, Russian Federation
| | - Valery G. Shtyrlin
- A.M. Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya St. 18, 420008, Kazan, Russian Federation
| | - Georgy V. Mamin
- Institute of Physics, Kazan Federal University, Kremlevskaya St. 18, 420008 Kazan, Russian Federation
| | - Siegfried Stapf
- Fachgebiet Technische Physik II/Polymerphysik,
Institute of Physics, Technische Universität Ilmenau, P.O. Box 100 565, 98684 Ilmenau, Germany
| | - Carlos Mattea
- Fachgebiet Technische Physik II/Polymerphysik,
Institute of Physics, Technische Universität Ilmenau, P.O. Box 100 565, 98684 Ilmenau, Germany
| | - Anvar Sh. Mukhtarov
- A.M. Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya St. 18, 420008, Kazan, Russian Federation
| | - Nikita Yu. Serov
- A.M. Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya St. 18, 420008, Kazan, Russian Federation
| | - Edward M. Gilyazetdinov
- A.M. Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya St. 18, 420008, Kazan, Russian Federation
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16
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Franck JM, Ding Y, Stone K, Qin PZ, Han S. Anomalously Rapid Hydration Water Diffusion Dynamics Near DNA Surfaces. J Am Chem Soc 2015; 137:12013-23. [PMID: 26256693 PMCID: PMC4656248 DOI: 10.1021/jacs.5b05813] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The emerging Overhauser effect dynamic nuclear polarization (ODNP) technique measures the translational mobility of water within the vicinity (5-15 Å) of preselected sites. The work presented here expands the capabilities of the ODNP technique and illuminates an important, previously unseen, property of the translational diffusion dynamics of water at the surface of DNA duplexes. We attach nitroxide radicals (i.e., spin labels) to multiple phosphate backbone positions of DNA duplexes, allowing ODNP to measure the hydration dynamics at select positions along the DNA surface. With a novel approach to ODNP analysis, we isolate the contributions of water molecules at these sites that undergo free translational diffusion from water molecules that either loosely bind to or exchange protons with the DNA. The results reveal that a significant population of water in a localized volume adjacent to the DNA surface exhibits fast, bulk-like characteristics and moves unusually rapidly compared to water found in similar probe volumes near protein and membrane surfaces. Control studies show that the observation of these characteristics are upheld even when the DNA duplex is tethered to streptavidin or the mobility of the nitroxides is altered. This implies that, as compared to protein or lipid surfaces, it is an intrinsic feature of the DNA duplex surface that it interacts only weakly with a significant fraction of the surface hydration water network. The displacement of this translationally mobile water is energetically less costly than that of more strongly bound water by up to several kBT and thus can lower the activation barrier for interactions involving the DNA surface.
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Affiliation(s)
- John M. Franck
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
- National Biomedical Center for Advanced ESR Technology, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY
| | - Yuan Ding
- Department of Chemistry, University of Southern California, Los Angeles, CA
| | - Katherine Stone
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
- Pacira Pharmaceuticals, Inc, San Diego, CA
| | - Peter Z. Qin
- Department of Chemistry, University of Southern California, Los Angeles, CA
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA
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17
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Cheng CY, Olijve LLC, Kausik R, Han S. Cholesterol enhances surface water diffusion of phospholipid bilayers. J Chem Phys 2015; 141:22D513. [PMID: 25494784 DOI: 10.1063/1.4897539] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Elucidating the physical effect of cholesterol (Chol) on biological membranes is necessary towards rationalizing their structural and functional role in cell membranes. One of the debated questions is the role of hydration water in Chol-embedding lipid membranes, for which only little direct experimental data are available. Here, we study the hydration dynamics in a series of Chol-rich and depleted bilayer systems using an approach termed (1)H Overhauser dynamic nuclear polarization (ODNP) NMR relaxometry that enables the sensitive and selective determination of water diffusion within 5-10 Å of a nitroxide-based spin label, positioned off the surface of the polar headgroups or within the nonpolar core of lipid membranes. The Chol-rich membrane systems were prepared from mixtures of Chol, dipalmitoyl phosphatidylcholine and/or dioctadecyl phosphatidylcholine lipid that are known to form liquid-ordered, raft-like, domains. Our data reveal that the translational diffusion of local water on the surface and within the hydrocarbon volume of the bilayer is significantly altered, but in opposite directions: accelerated on the membrane surface and dramatically slowed in the bilayer interior with increasing Chol content. Electron paramagnetic resonance (EPR) lineshape analysis shows looser packing of lipid headgroups and concurrently tighter packing in the bilayer core with increasing Chol content, with the effects peaking at lipid compositions reported to form lipid rafts. The complementary capability of ODNP and EPR to site-specifically probe the hydration dynamics and lipid ordering in lipid membrane systems extends the current understanding of how Chol may regulate biological processes. One possible role of Chol is the facilitation of interactions between biological constituents and the lipid membrane through the weakening or disruption of strong hydrogen-bond networks of the surface hydration layers that otherwise exert stronger repulsive forces, as reflected in faster surface water diffusivity. Another is the concurrent tightening of lipid packing that reduces passive, possibly unwanted, diffusion of ions and water across the bilayer.
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Affiliation(s)
- Chi-Yuan Cheng
- Department of Chemistry and Biochemistry and Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA
| | - Luuk L C Olijve
- Laboratory of Macromolecular and Organic Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Ravinath Kausik
- Department of Chemistry and Biochemistry and Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA
| | - Songi Han
- Department of Chemistry and Biochemistry and Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA
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18
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Protein MRI contrast agent with unprecedented metal selectivity and sensitivity for liver cancer imaging. Proc Natl Acad Sci U S A 2015; 112:6607-12. [PMID: 25971726 DOI: 10.1073/pnas.1423021112] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
With available MRI techniques, primary and metastatic liver cancers that are associated with high mortality rates and poor treatment responses are only diagnosed at late stages, due to the lack of highly sensitive contrast agents without Gd(3+) toxicity. We have developed a protein contrast agent (ProCA32) that exhibits high stability for Gd(3+) and a 10(11)-fold greater selectivity for Gd(3+) over Zn(2+) compared with existing contrast agents. ProCA32, modified from parvalbumin, possesses high relaxivities (r1/r2: 66.8 mmol(-1)⋅s(-1)/89.2 mmol(-1)⋅s(-1) per particle). Using T1- and T2-weighted, as well as T2/T1 ratio imaging, we have achieved, for the first time (to our knowledge), robust MRI detection of early liver metastases as small as ∼0.24 mm in diameter, much smaller than the current detection limit of 10-20 mm. Furthermore, ProCA32 exhibits appropriate in vivo preference for liver sinusoidal spaces and pharmacokinetics for high-quality imaging. ProCA32 will be invaluable for noninvasive early detection of primary and metastatic liver cancers as well as for monitoring treatment and guiding therapeutic interventions, including drug delivery.
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19
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Pravdivtsev AN, Yurkovskaya AV, Zimmermann H, Vieth HM, Ivanov KL. Magnetic field dependent long-lived spin states in amino acids and dipeptides. Phys Chem Chem Phys 2014; 16:7584-94. [PMID: 24634918 DOI: 10.1039/c3cp55197k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetic field dependence of long-lived spin states (LLSs) of the β-CH2 protons of aromatic amino acids was studied. LLSs are spin states, which are immune to dipolar relaxation, thus having lifetimes far exceeding the longitudinal relaxation times; the simplest example of an LLS is given by the singlet state of two coupled spins. LLSs were created by means of the photo-chemically induced dynamic nuclear polarization technique. The systems studied were amino acids, histidine and tyrosine, with different isotopomers. For labeled amino acids with the α-CH and aromatic protons substituted by deuterium at low fields the LLS lifetime, TLLS, for the β-CH2 protons was more than 40 times longer than the T1-relaxation time. Upon increasing the number of protons the ratio TLLS/T1 was reduced; however, even in the fully protonated amino acids it was about 10; that is, the long-lived mode was still preserved in the system. In addition, the effect of paramagnetic impurities on spin relaxation was studied; field dependencies of T1 and TLLS were measured. LLSs were also formed in tyrosine-containing dyads; a TLLS/T1 ratio of ∼7 was found, usable for extending the spin polarization lifetime in such systems.
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Affiliation(s)
- Andrey N Pravdivtsev
- International Tomography Center SB RAS, Institutskaya 3a, Novosibirsk, 630090, Russia.
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20
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Tritt-Goc J, Rachocki A, Bielejewski M. The solvent dynamics at pore surfaces in molecular gels studied by field-cycling magnetic resonance relaxometry. SOFT MATTER 2014; 10:7810-7818. [PMID: 25145831 DOI: 10.1039/c4sm01140f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The molecular dynamics of the solvent molecules at liquid-solid interfaces in low molecular mass gels and in bulk solvents have been identified and characterized with the aid of field-cycling NMR relaxometry. The gels are formed using ethylene glycol (EG) and 1,3-propanediol (PG) with different concentrations of 4,6,4',6'-O-terephthalylidene-bis(methyl α-D-glucopyranoside) (gelator 1). The spin-lattice relaxation times of bulk solvents measured in the function of Larmor frequency were analyzed assuming the intramolecular and intermolecular dipole-dipole interactions. For analysis of the relaxation data for confined solvents the two-phase fast-exchange model was assumed. It was found that in a low-frequency range a dominating NMR relaxation mechanism of solvent interacting with internal surfaces of pores in studied molecular gels is reorientation mediated by translational displacements (RMTD). This dynamic process allows us to explain a very long correlation time of the order of 10(-5) s calculated for confined EG molecules and an even longer one for PG. The RMTD contribution to the relaxation is described by power-law frequency dependence. In the 1/EG gels the exponent is equal to 0.5 for all gelator concentrations suggesting the equipartition of the diffusion modes with different wavelengths. In this gel the relaxation dispersion data were transformed to a susceptibility representation and a "master-like" curve was constructed. In the 1/PG gel the exponent varies in the function of gelator concentration. Different behavior of the relaxation dispersion shape is due to the relative sizes of the ordered (at surface) and bulk-like phase. In the 1/EG gel the surface layer of the ordered molecules is always much smaller than the dimensions of the gel cavities whereas it differs in the 1/PG gel as a consequence of the disruption of the PG aggregates due to the solvent-gelator interaction.
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Affiliation(s)
- Jadwiga Tritt-Goc
- Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland.
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21
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Preslar AT, Parigi G, McClendon MT, Sefick SS, Moyer TJ, Haney CR, Waters EA, MacRenaris KW, Luchinat C, Stupp SI, Meade TJ. Gd(III)-labeled peptide nanofibers for reporting on biomaterial localization in vivo. ACS NANO 2014; 8:7325-32. [PMID: 24937195 PMCID: PMC4216205 DOI: 10.1021/nn502393u] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 06/17/2014] [Indexed: 05/23/2023]
Abstract
Bioactive supramolecular nanostructures are of great importance in regenerative medicine and the development of novel targeted therapies. In order to use supramolecular chemistry to design such nanostructures, it is extremely important to track their fate in vivo through the use of molecular imaging strategies. Peptide amphiphiles (PAs) are known to generate a wide array of supramolecular nanostructures, and there is extensive literature on their use in areas such as tissue regeneration and therapies for disease. We report here on a series of PA molecules based on the well-established β-sheet amino acid sequence V3A3 conjugated to macrocyclic Gd(III) labels for magnetic resonance imaging (MRI). These conjugates were shown to form cylindrical supramolecular assemblies using cryogenic transmission electron microscopy and small-angle X-ray scattering. Using nuclear magnetic relaxation dispersion analysis, we observed that thermal annealing of the nanostructures led to a decrease in water exchange lifetime (τm) of hundreds of nanoseconds only for molecules that self-assemble into nanofibers of high aspect ratio. We interpret this decrease to indicate more solvent exposure to the paramagnetic moiety on annealing, resulting in faster water exchange within angstroms of the macrocycle. We hypothesize that faster water exchange in the nanofiber-forming PAs arises from the dehydration and increase in packing density on annealing. Two of the self-assembling conjugates were selected for imaging PAs after intramuscular injections of the PA C16V3A3E3-NH2 in the tibialis anterior muscle of a murine model. Needle tracts were clearly discernible with MRI at 4 days postinjection. This work establishes Gd(III) macrocycle-conjugated peptide amphiphiles as effective tracking agents for peptide amphiphile materials in vivo over the timescale of days.
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Affiliation(s)
- Adam T. Preslar
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Mark T. McClendon
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Samantha S. Sefick
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Tyson J. Moyer
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Chad R. Haney
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Emily A. Waters
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Keith W. MacRenaris
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Samuel I. Stupp
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Address correspondence to ,
| | - Thomas J. Meade
- Departments of Chemistry, Materials Science and Engineering, and Institute for BioNanotechnology in Medicine, Chemical and Biological Engineering, Departments of Chemistry, Molecular Biosciences, Neurobiology and Radiology, and Center for Advanced Molecular Imaging, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Address correspondence to ,
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22
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Franck JM, Sokolovski M, Kessler N, Matalon E, Gordon-Grossman M, Han SI, Goldfarb D, Horovitz A. Probing water density and dynamics in the chaperonin GroEL cavity. J Am Chem Soc 2014; 136:9396-403. [PMID: 24888581 PMCID: PMC4091268 DOI: 10.1021/ja503501x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
ATP-dependent binding of the chaperonin
GroEL to its cofactor GroES
forms a cavity in which encapsulated substrate proteins can fold in
isolation from bulk solution. It has been suggested that folding in
the cavity may differ from that in bulk solution owing to steric confinement,
interactions with the cavity walls, and differences between the properties
of cavity-confined and bulk water. However, experimental data regarding
the cavity-confined water are lacking. Here, we report measurements
of water density and diffusion dynamics in the vicinity of a spin
label attached to a cysteine in the Tyr71 → Cys GroES mutant
obtained using two magnetic resonance techniques: electron-spin echo
envelope modulation and Overhauser dynamic nuclear polarization. Residue
71 in GroES is fully exposed to bulk water in free GroES and to confined
water within the cavity of the GroEL–GroES complex. Our data
show that water density and translational dynamics in the vicinity
of the label do not change upon complex formation, thus indicating
that bulk water-exposed and cavity-confined GroES surface water share
similar properties. Interestingly, the diffusion dynamics of water
near the GroES surface are found to be unusually fast relative to
other protein surfaces studied. The implications of these findings
for chaperonin-assisted folding mechanisms are discussed.
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Affiliation(s)
- John M Franck
- Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
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23
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Rachocki A, Tritt-Goc J. Novel application of NMR relaxometry in studies of diffusion in virgin rape oil. Food Chem 2014; 152:94-9. [DOI: 10.1016/j.foodchem.2013.11.112] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 10/09/2013] [Accepted: 11/20/2013] [Indexed: 01/22/2023]
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24
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Harris T, Szekely O, Frydman L. On the potential of hyperpolarized water in biomolecular NMR studies. J Phys Chem B 2014; 118:3281-90. [PMID: 24417324 PMCID: PMC5040483 DOI: 10.1021/jp4102916] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A main obstacle arising when using ex situ hyperpolarization to increase the sensitivity of biomolecular NMR is the fast relaxation that macromolecular spins undergo upon being transferred from the polarizer to the spectrometer, where their observation takes place. To cope with this limitation, the present study explores the use of hyperpolarized water as a means to enhance the sensitivity of nuclei in biomolecules. Methods to achieve proton polarizations in excess of 5% in water transferred into the NMR spectrometer were devised, as were methods enabling this polarization to last for up to 30 s. Upon dissolving amino acids and polypeptides sited at the spectrometer into such hyperpolarized water, a substantial enhancement of certain biomolecular amide and amine proton resonances was observed. This exchange-driven (1)H enhancement was further passed on to side-chain and to backbone nitrogens, owing to spontaneous one-bond Overhauser processes. (15)N signal enhancements >500 over 11.7 T thermal counterparts could thus be imparted in a kinetic process that enabled multiscan signal averaging. Besides potential bioanalytical uses, this approach opens interesting possibilities in the monitoring of dynamic biomolecular processes, including solvent accessibility and exchange process.
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Affiliation(s)
- Talia Harris
- Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel
| | - Or Szekely
- Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel
| | - Lucio Frydman
- Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel
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25
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Bukharov MS, Shtyrlin VG, Mukhtarov AS, Mamin GV, Stapf S, Mattea C, Krutikov AA, Il'in AN, Serov NY. Study of structural and dynamic characteristics of copper(ii) amino acid complexes in solutions by combined EPR and NMR relaxation methods. Phys Chem Chem Phys 2014; 16:9411-21. [DOI: 10.1039/c4cp00255e] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Franck JM, Pavlova A, Scott JA, Han S. Quantitative cw Overhauser effect dynamic nuclear polarization for the analysis of local water dynamics. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 74:33-56. [PMID: 24083461 PMCID: PMC3798041 DOI: 10.1016/j.pnmrs.2013.06.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 01/10/2013] [Indexed: 05/03/2023]
Abstract
Liquid state Overhauser effect Dynamic Nuclear Polarization (ODNP) has experienced a recent resurgence of interest. The ODNP technique described here relies on the double resonance of electron spin resonance (ESR) at the most common, i.e. X-band (∼10GHz), frequency and ¹H nuclear magnetic resonance (NMR) at ∼15 MHz. It requires only a standard continuous wave (cw) ESR spectrometer with an NMR probe inserted or built into an X-band cavity. We focus on reviewing a new and powerful manifestation of ODNP as a high frequency NMR relaxometry tool that probes dipolar cross relaxation between the electron spins and the ¹H nuclear spins at X-band frequencies. This technique selectively measures the translational mobility of water within a volume extending 0.5-1.5 nm outward from a nitroxide radical spin probe that is attached to a targeted site of a macromolecule. It allows one to study the dynamics of water that hydrates or permeates the surface or interior of proteins, polymers, and lipid membrane vesicles. We begin by reviewing the recent advances that have helped develop ODNP into a tool for mapping the dynamic landscape of hydration water with sub-nanometer locality. In order to bind this work coherently together and to place it in the context of the extensive body of research in the field of NMR relaxometry, we then rephrase the analytical model and extend the description of the ODNP-derived NMR signal enhancements. This extended model highlights several aspects of ODNP data analysis, including the importance of considering all possible effects of microwave sample heating, the need to consider the error associated with various relaxation rates, and the unique ability of ODNP to probe the electron-¹H cross-relaxation process, which is uniquely sensitive to fast (tens of ps) dynamical processes. By implementing the relevant corrections in a stepwise fashion, this paper draws a consensus result from previous ODNP procedures and then shows how such data can be further corrected to yield clear and reproducible saturation of the NMR hyperpolarization process. Finally, drawing on these results, we broadly survey the previous ODNP dynamics literature. We find that the vast number of published, empirical hydration dynamics data can be reproducibly classified into regimes of surface, interfacial, vs. buried water dynamics.
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Affiliation(s)
- John M Franck
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
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27
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Hydration dynamics as an intrinsic ruler for refining protein structure at lipid membrane interfaces. Proc Natl Acad Sci U S A 2013; 110:16838-43. [PMID: 24082088 DOI: 10.1073/pnas.1307678110] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Knowing the topology and location of protein segments at water-membrane interfaces is critical for rationalizing their functions, but their characterization is challenging under physiological conditions. Here, we debut a unique spectroscopic approach by using the hydration dynamics gradient found across the phospholipid bilayer as an intrinsic ruler for determining the topology, immersion depth, and orientation of protein segments in lipid membranes, particularly at water-membrane interfaces. This is achieved through the site-specific quantification of translational diffusion of hydration water using an emerging tool, (1)H Overhauser dynamic nuclear polarization (ODNP)-enhanced NMR relaxometry. ODNP confirms that the membrane-bound region of α-synuclein (αS), an amyloid protein known to insert an amphipathic α-helix into negatively charged phospholipid membranes, forms an extended α-helix parallel to the membrane surface. We extend the current knowledge by showing that residues 90-96 of bound αS, which is a transition segment that links the α-helix and the C terminus, adopt a larger loop than an idealized α-helix. The unstructured C terminus gradually threads through the surface hydration layers of lipid membranes, with the beginning portion residing within 5-15 Å above the phosphate level, and only the very end of C terminus surveying bulk water. Remarkably, the intrinsic hydration dynamics gradient along the bilayer normal extends to 20-30 Å above the phosphate level, as demonstrated with a peripheral membrane protein, annexin B12. ODNP offers the opportunity to reveal previously unresolvable structure and location of protein segments well above the lipid phosphate, whose structure and dynamics critically contribute to the understanding of functional versatility of membrane proteins.
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28
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Keymeulen F, De Bernardin P, Dalla Cort A, Bartik K. Paramagnetic relaxation enhancement experiments: a valuable tool for the characterization of micellar nanodevices. J Phys Chem B 2013; 117:11654-9. [PMID: 24007395 DOI: 10.1021/jp4076367] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Micellar incorporation of hydrophobic molecular receptors is a promising strategy to obtain efficient nanodevices that work in water. In order to fully evaluate the potential of this approach, information on the localization and orientation of the receptor inside the micelle are necessary. Systematic studies undertaken on a uranyl-salophen receptor incorporated into CTABr and CTACl micelles show that nuclear magnetic resonance paramagnetic relaxation enhancement (NMR-PRE) experiments are particularly suitable to provide this type of information. The effect on the measurements of surfactant concentration, nature of the surfactant polar head, and ionic strength is also reported. Notably the normalization procedure applied to the obtained data can be considered of general application, thus enabling the comparison of information collected for different types of supramolecular micelle/receptor systems.
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Affiliation(s)
- Flore Keymeulen
- Engineering of Molecular NanoSystems, Université libre de Bruxelles , 50 avenue F.D. Roosevelt, B-1050 Brussels, Belgium
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29
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Meier R, Kruk D, Rössler EA. Intermolecular spin relaxation and translation diffusion in liquids and polymer melts: insight from field-cycling 1H NMR relaxometry. Chemphyschem 2013; 14:3071-81. [PMID: 23881836 DOI: 10.1002/cphc.201300257] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Indexed: 11/11/2022]
Abstract
With the advent of commercial field-cycling (FC) spectrometers, NMR relaxometry has gained new momentum as a method of investigating dynamics in liquids and polymers. The outcome of FC NMR experiments is spin-lattice relaxation time versus frequency (relaxation dispersion). In the case of protons, due to the intra- and intermolecular origin of dipolar interactions, the relaxation dispersion reflects rotational as well as translational dynamics. The latter shows a universal dispersion law at low frequencies, which allows determination of the diffusion coefficient D(T) in addition to the rotational correlation time τ(rot)(T), that is, FC (1)H NMR becomes an alternative to field-gradient NMR spectroscopy. Subdiffusive translation found in polymers can be accessed by singling out the intermolecular relaxation through isotope dilution experiments, and the mean square displacement can then be revealed as a function of time, thus complementing neutron scattering experiments. Likewise, information on reorientational dynamics is provided by the intramolecular relaxation. Assuming frequency-temperature superposition the corresponding correlation functions can be monitored up to eight decades in amplitude and time, which allows thorough testing of current polymer theories.
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Affiliation(s)
- Roman Meier
- Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany)
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30
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Cheng CY, Han S. Dynamic Nuclear Polarization Methods in Solids and Solutions to Explore Membrane Proteins and Membrane Systems. Annu Rev Phys Chem 2013; 64:507-32. [DOI: 10.1146/annurev-physchem-040412-110028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane proteins regulate vital cellular processes, including signaling, ion transport, and vesicular trafficking. Obtaining experimental access to their structures, conformational fluctuations, orientations, locations, and hydration in membrane environments, as well as the lipid membrane properties, is critical to understanding their functions. Dynamic nuclear polarization (DNP) of frozen solids can dramatically boost the sensitivity of current solid-state nuclear magnetic resonance tools to enhance access to membrane protein structures in native membrane environments. Overhauser DNP in the solution state can map out the local and site-specific hydration dynamics landscape of membrane proteins and lipid membranes, critically complementing the structural and dynamics information obtained by electron paramagnetic resonance spectroscopy. Here, we provide an overview of how DNP methods in solids and solutions can significantly increase our understanding of membrane protein structures, dynamics, functions, and hydration in complex biological membrane environments.
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Affiliation(s)
- Chi-Yuan Cheng
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106
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31
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Kruk D, Korpała A, Kubica A, Kowalewski J, Rössler EA, Moscicki J. 1H relaxation dispersion in solutions of nitroxide radicals: Influence of electron spin relaxation. J Chem Phys 2013; 138:124506. [DOI: 10.1063/1.4795006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Franck JM, Scott JA, Han S. Nonlinear scaling of surface water diffusion with bulk water viscosity of crowded solutions. J Am Chem Soc 2013; 135:4175-8. [PMID: 23347324 PMCID: PMC3785640 DOI: 10.1021/ja3112912] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The translational hydration dynamics within 0.5-1.5 nm of the surface of a DPPC liposome, a model biomacromolecular surface, is analyzed by the recently developed Overhauser dynamic nuclear polarization (ODNP) technique. We find that dramatic changes to the bulk solvent cause only weak changes in the surface hydration dynamics. Specifically, both a >10-fold increase in bulk viscosity and the restriction of diffusion by confinement on a multiple nm length-scale change the local translational diffusion coefficient of the surface water surrounding the lipid bilayer by <2.5-fold. By contrast, previous ODNP studies have shown that changes to the biomacromolecular surface induced by folding, binding, or aggregation can cause local hydration dynamics to vary by factors of up to 30. We suggest that the surface topology and chemistry at the ≤1.5 nm scale, rather than the characteristics of the solvent, nearly exclusively determine the macromolecule's surface hydration dynamics.
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Affiliation(s)
- John M. Franck
- Dept. of Chemistry and Biochemistry, University of California, Santa Barbara
| | - John A. Scott
- Dept. of Chemistry and Biochemistry, University of California, Santa Barbara
| | - Songi Han
- Dept. of Chemistry and Biochemistry, University of California, Santa Barbara
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33
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Kruk D, Korpała A, Kubica A, Meier R, Rössler EA, Moscicki J. Translational diffusion in paramagnetic liquids by 1H NMR relaxometry: nitroxide radicals in solution. J Chem Phys 2013; 138:024506. [PMID: 23320703 DOI: 10.1063/1.4772097] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
For nitroxide radicals in solution one can identify three frequency regimes in which (1)H spin-lattice relaxation rate of solvent molecules depend linearly on square root of the (1)H resonance frequency. Combining a recently developed theory of nuclear (proton) spin-lattice relaxation in solutions of nitroxide radicals [D. Kruk et al., J. Chem. Phys. 137, 044512 (2012)] with properties of the spectral density function associated with translational dynamics, relationships between the corresponding linear changes of the relaxation rate (for (14)N spin probes) and relative translational diffusion coefficient of the solvent and solute molecules have been derived (in analogy to (15)N spin probes [E. Belorizky et al., J. Phys. Chem. A 102, 3674 (1998)]). This method allows a simple and straightforward determination of diffusion coefficients in spin-labeled systems, by means of (1)H nuclear magnetic resonance (NMR) relaxometry. The approach has thoroughly been tested by applying to a large set of experimental data-(1)H spin-lattice relaxation dispersion results for solutions of different viscosity (decalin, glycerol, propylene glycol) of (14)N and (15)N spin probes. The experiments have been performed versus temperature (to cover a broad range of translational diffusion coefficients) using field cycling spectrometer which covers three decades in (1)H resonance frequency, 10 kHz-20 MHz. The limitations of NMR relaxometry caused by the time scale of the translational dynamics as well as electron spin relaxation have been discussed. It has been shown that for spin-labeled systems NMR relaxometry gives access to considerably faster diffusion processes than for diamagnetic systems.
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Affiliation(s)
- D Kruk
- Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Sloneczna 54, PL-10710 Olsztyn, Poland.
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Kruk D, Korpala A, Rössler E, Earle KA, Medycki W, Moscicki J. 1H NMR relaxation in glycerol solutions of nitroxide radicals: effects of translational and rotational dynamics. J Chem Phys 2012; 136:114504. [PMID: 22443774 DOI: 10.1063/1.3692603] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
(1)H spin-lattice relaxation rates in glycerol solutions of selected nitroxide radicals at temperatures between 200 K and 400 K were measured at 15 MHz and 25 MHz. The frequency and temperature conditions were chosen in such a way that the relaxation rates go through their maximum values and are affected by neither the electron spin relaxation nor the electron-nitrogen nucleus hyperfine coupling, so that the focus could be put on the mechanisms of motion. By comparison with (1)H spin-lattice relaxation results for pure glycerol, it has been demonstrated that the inter-molecular electron spin-proton spin dipole-dipole interactions are affected not only by relative translational motion of the solvent and solute molecules, but also by their rotational dynamics as the interacting spins are displaced from the molecular centers; the eccentricity effects are usually not taken into account. The (1)H relaxation data have been decomposed into translational and rotational contributions and their relative importance as a function of frequency and temperature discussed in detail. It has been demonstrated that neglecting the rotational effects on the inter-molecular interactions leads to non-realistic conclusions regarding the translational dynamics of the paramagnetic molecules.
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Affiliation(s)
- D Kruk
- Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Sloneczna 54, PL-10710 Olsztyn, Poland.
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Kruk D, Korpała A, Kowalewski J, Rössler EA, Moscicki J. 1H relaxation dispersion in solutions of nitroxide radicals: Effects of hyperfine interactions with 14N and 15N nuclei. J Chem Phys 2012; 137:044512. [DOI: 10.1063/1.4736854] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Walton JW, Carr R, Evans NH, Funk AM, Kenwright AM, Parker D, Yufit DS, Botta M, De Pinto S, Wong KL. Isostructural Series of Nine-Coordinate Chiral Lanthanide Complexes Based on Triazacyclononane. Inorg Chem 2012; 51:8042-56. [DOI: 10.1021/ic300147p] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James W. Walton
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - Rachel Carr
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - Nicholas H. Evans
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - Alexander M. Funk
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - Alan M. Kenwright
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - David Parker
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - Dmitry S. Yufit
- Department of Chemistry, Durham University, South Road, Durham
DH1 3LE, U.K
| | - Mauro Botta
- Dipartimento di
Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, “Amedeo Avogadro”
Viale Teresa Michel 11, 15121 Alessandria, Italy
| | - Sara De Pinto
- Dipartimento di
Scienze e Innovazione Tecnologica, Università del Piemonte Orientale, “Amedeo Avogadro”
Viale Teresa Michel 11, 15121 Alessandria, Italy
| | - Ka-Leung Wong
- Department of Chemistry, Hong Kong Baptist University, Kowloon
Tong, Hong Kong
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37
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Fries PH. Model-free nuclear magnetic resonance study of intermolecular free energy landscapes in liquids with paramagnetic Ln3+ spotlights: Theory and application to Arg-Gly-Asp. J Chem Phys 2012; 136:044504. [DOI: 10.1063/1.3671990] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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38
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Türke MT, Parigi G, Luchinat C, Bennati M. Overhauser DNP with15N labelled Frémy's salt at 0.35 Tesla. Phys Chem Chem Phys 2012; 14:502-10. [DOI: 10.1039/c1cp22332a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Miéville P, Jannin S, Bodenhausen G. Relaxometry of insensitive nuclei: optimizing dissolution dynamic nuclear polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 210:137-40. [PMID: 21393034 DOI: 10.1016/j.jmr.2011.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/03/2011] [Accepted: 02/06/2011] [Indexed: 05/15/2023]
Abstract
We report measurements of spin-lattice relaxation of carbon-13 as a function of the magnetic field ('relaxometry') in view of optimizing dissolution-DNP. The sample is temporarily lifted into the stray field above a high-resolution magnet using a simple and inexpensive 'shuttle'. The signals of arbitrary molecules can be observed at high field with high-resolution and sensitivity. During the dissolution process and subsequent 'voyage' from the polarizer to the NMR magnet, relaxation is accelerated by paramagnetic polarizing agents, but it can be quenched by using scavengers.
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Affiliation(s)
- Pascal Miéville
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, Lausanne, Switzerland
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40
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Armstrong BD, Choi J, López C, Wesener DA, Hubbell W, Cavagnero S, Han S. Site-specific hydration dynamics in the nonpolar core of a molten globule by dynamic nuclear polarization of water. J Am Chem Soc 2011; 133:5987-95. [PMID: 21443207 PMCID: PMC3095581 DOI: 10.1021/ja111515s] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Water-protein interactions play a direct role in protein folding. The chain collapse that accompanies protein folding involves extrusion of water from the nonpolar core. For many proteins, including apomyoglobin (apoMb), hydrophobic interactions drive an initial collapse to an intermediate state before folding to the final structure. However, the debate continues as to whether the core of the collapsed intermediate state is hydrated and, if so, what the dynamic nature of this water is. A key challenge is that protein hydration dynamics is significantly heterogeneous, yet suitable experimental techniques for measuring hydration dynamics with site-specificity are lacking. Here, we introduce Overhauser dynamic nuclear polarization at 0.35 T via site-specific nitroxide spin labels as a unique tool to probe internal and surface protein hydration dynamics with site-specific resolution in the molten globular, native, and unfolded protein states. The (1)H NMR signal enhancement of water carries information about the local dynamics of the solvent within ∼10 Å of a spin label. EPR is used synergistically to gain insights on local polarity and mobility of the spin-labeled protein. Several buried and solvent-exposed sites of apoMb are examined, each bearing a covalently bound nitroxide spin label. We find that the nonpoloar core of the apoMb molten globule is hydrated with water bearing significant translational dynamics, only 4-6-fold slower than that of bulk water. The hydration dynamics of the native state is heterogeneous, while the acid-unfolded state bears fast-diffusing hydration water. This study provides a high-resolution glimpse at the folding-dependent nature of protein hydration dynamics.
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Affiliation(s)
- Brandon D. Armstrong
- Department of Physics, University of California-Santa Barbara, Santa Barbara, CA. 93106-9530
| | - Jennifer Choi
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI. 53706
| | - Carlos López
- Department of Chemistry and Biochemistry and the Jules Stein Eye Institute, University of California-Los Angeles, CA. 90095-7008
| | - Darryl A. Wesener
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI. 53706
| | - Wayne Hubbell
- Department of Chemistry and Biochemistry and the Jules Stein Eye Institute, University of California-Los Angeles, CA. 90095-7008
| | - Silvia Cavagnero
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI. 53706
| | - Songi Han
- Department of Chemistry and Biochemistry and Materials Research Laboratory, University of California-Santa Barbara, 93106-9510
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41
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Mastarone DJ, Harrison VS, Eckermann AL, Parigi G, Luchinat C, Meade TJ. A modular system for the synthesis of multiplexed magnetic resonance probes. J Am Chem Soc 2011; 133:5329-37. [PMID: 21413801 PMCID: PMC3086647 DOI: 10.1021/ja1099616] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have developed a modular architecture for preparing high-relaxivity multiplexed probes utilizing click chemistry. Our system incorporates azide bearing Gd(III) chelates and a trialkyne scaffold with a functional group for subsequent modification. In optimizing the relaxivity of this new complex, we undertook a study of the linker length between a chelate and the scaffold to determine its effect on relaxivity. The results show a strong dependence on flexibility between the individual chelates and the scaffold with decreasing linker length leading to significant increases in relaxivity. Nuclear magnetic resonance dispersion (NMRD) spectra were obtained to confirm a 10-fold increase in the rotational correlation time from 0.049 to 0.60 ns at 310 K. We have additionally obtained a crystal structure demonstrating that modification with an azide does not impact the coordination of the lanthanide. The resulting multinuclear center has a 500% increase in per Gd (or ionic) relaxivity at 1.41 T versus small molecule contrast agents and a 170% increase in relaxivity at 9.4 T.
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Affiliation(s)
- Daniel J. Mastarone
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Victoria S.R. Harrison
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Amanda L. Eckermann
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
| | - Giacomo Parigi
- CERM and Department of Chemistry, University of Florence, Florence, Italy
| | - Claudio Luchinat
- CERM and Department of Chemistry, University of Florence, Florence, Italy
| | - Thomas J. Meade
- Department of Chemistry, Molecular Biosciences, Neurobiology and Physiology, and Radiology, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113
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42
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Kimmich R, Stapf S, Seitter RO, Callaghan P, Khozina E. Molecular Dynamics of Monomer, Oligomer, and Polymer Liquids in Porous Media: A Field-Cycling Nmr Relaxometry and NMR Field-Gradient Diffusometry Study. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-366-189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTThe molecular dynamics of fluids in porous media has been studied using field-cycling NMR relaxometry and NMR field-gradient diffusometry. The frequency dependences of the 1H and 2H spin-lattice relaxation times T1 of various liquids in porous glass reveal weak and strong adsorption behaviour depending on the polarity of the adsorbates. Correlation times eight orders of magnitude longer than in bulk have been observed. The T1 dispersion moreover reflects geometrical details of the matrix in a length scale three orders of magnitude longer than the adsorbate molecules. The mean-square displacements of adsorbate molecules on the surface are only one order of magnitude less than in bulk. The global diffusivity is reduced by tortuosity and porosity effects. The observed phenomena may be explained by bulk-mediated surface diffusion, i.e., Lévy walks. The dynamics of polymer chains much longer than the pore size is characteristicly different from that in bulk melts. There is evidence that the reptation mechanism explains at least a part of the phenomena observed for the porous matrix in contrast to findings with bulk polymer melts.
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Diakova G, Goddard Y, Korb JP, Bryant RG. Water-proton-spin-lattice-relaxation dispersion of paramagnetic protein solutions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:195-203. [PMID: 21134772 PMCID: PMC3026090 DOI: 10.1016/j.jmr.2010.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 09/29/2010] [Accepted: 11/03/2010] [Indexed: 05/23/2023]
Abstract
The paramagnetic contributions to water-proton-spin-lattice relaxation rate constants in protein systems spin-labeled with nitroxide radicals were re-examined. As noted by others, the strength of the dipolar coupling between water protons and the protein-bound nitroxide radical often appears to be larger than physically reasonable when the relaxation is assumed to be controlled by 3-dimensional diffusive processes in the vicinity of the spin label. We examine the effects of the surface in biasing the diffusive exploration of the radical region and derive a relaxation model that incorporates 2-dimensional dynamics at the interfacial layer. However, we find that the local 2-dimensional dynamics changes the shape of the relaxation dispersion profile but does not necessarily reproduce the low-field relaxation efficiency found by experiment. We examine the contributions of long-range dipolar couplings between the paramagnetic center and protein-bound-water molecules and find that the contributions from these several long range couplings may be competitive with translational contributions because the correlation time for global rotation of the protein is approximately 1000 times longer than that for the diffusive motion of water at the interfacial region. As a result the electron-proton dipolar coupling to rare protein-bound-water-molecule protons may be significant for protein systems that accommodate long-lived-water molecules. Although the estimate of local diffusion coefficients is not seriously compromised because it derives from the Larmor frequency dependence, these several contributions confound efforts to fit relaxation data quantitatively with unique models.
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Affiliation(s)
| | | | - Jean-Pierre Korb
- Physique de la Matière Condensée, Ecole Polytechnique, CNRS, 91128, Palaiseau, France
| | - Robert G. Bryant
- Chemistry Department University of Virginia Charlottesville, VA, USA
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van Bentum PJM, van der Heijden GHA, Villanueva-Garibay JA, Kentgens APM. Quantitative analysis of high field liquid state dynamic nuclear polarization. Phys Chem Chem Phys 2011; 13:17831-40. [DOI: 10.1039/c1cp22002k] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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45
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Espinosa-Marzal RM, Scherer GW. Advances in understanding damage by salt crystallization. Acc Chem Res 2010; 43:897-905. [PMID: 20214404 DOI: 10.1021/ar9002224] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The single most important cause of the deterioration of monuments in the Mediterranean basin, and elsewhere around the world, is the crystallization of salt within the pores of the stone. Considerable advances have been made in recent years in elucidating the fundamental mechanisms responsible for salt damage. As a result, new methods of treatment are being proposed that offer the possibility of attacking the cause of the problem, rather than simply treating the symptoms. In this Account, we review the thermodynamics and kinetics of crystallization, then examine how a range of technological innovations have been applied experimentally to further the current understanding of in-pore crystallization. We close with a discussion of how computer modeling now provides particularly valuable insight, including quantitative estimates of both the interaction forces between the mineral and the crystal and the stresses induced in the material. Analyzing the kinetics and thermodynamics of crystal growth within the pores of a stone requires sensitive tools used in combination. For example, calorimetry quantifies the amount of salt that precipitates in the pores of a stone during cooling, and dilatometric measurements on a companion sample reveal the stress exerted by the salt. Synchrotron X-rays can penetrate the stone and identify the metastable phases that often appear in the first stages of crystallization. Atomic force microscopy and environmental scanning electron microscopy permit study of the nanometric liquid film that typically lies between salt and stone; this film controls the magnitude of the pressure exerted and the kinetics of relaxation of the stress. These experimental advances provide validation for increasingly advanced simulations, using continuum models of reactive transport on a macroscopic scale and molecular dynamics on the atomic scale. Because of the fundamental understanding of the damage mechanisms that is beginning to emerge, it is possible to devise methods for protecting monuments and sculptures. For example, chemical modification of the stone can alter the repulsive forces that stabilize the liquid film between the salt and mineral surfaces, thereby reducing the stress that the salt can generate. Alternatively, molecules can be introduced into the pores of the stone that inhibit the nucleation or growth of salt crystals. Many challenges remain, however, particularly in understanding the complex interactions between salts, the role of metastable phases, the mechanism of crack initiation and growth, and the role of biofilms.
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Affiliation(s)
- Rosa M. Espinosa-Marzal
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey
- Empa, Swiss Federal Laboratories of Materials Science and Technology, Duebendorf 8600, Switzerland
| | - George W. Scherer
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey
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46
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Glass DC, Krishnan M, Nutt DR, Smith JC. Temperature Dependence of Protein Dynamics Simulated with Three Different Water Models. J Chem Theory Comput 2010. [DOI: 10.1021/ct9006508] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dennis C. Glass
- University of Tennessee/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Marimuthu Krishnan
- University of Tennessee/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
| | - David R. Nutt
- University of Tennessee/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Jeremy C. Smith
- University of Tennessee/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, and Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
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Diakova G, Goddard YA, Korb JP, Bryant RG. Water and backbone dynamics in a hydrated protein. Biophys J 2010; 98:138-46. [PMID: 20085726 PMCID: PMC2800973 DOI: 10.1016/j.bpj.2009.09.054] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 09/24/2009] [Accepted: 09/28/2009] [Indexed: 11/26/2022] Open
Abstract
Rotational immobilization of proteins permits characterization of the internal peptide and water molecule dynamics by magnetic relaxation dispersion spectroscopy. Using different experimental approaches, we have extended measurements of the magnetic field dependence of the proton-spin-lattice-relaxation rate by one decade from 0.01 to 300 MHz for (1)H and showed that the underlying dynamics driving the protein (1)H spin-lattice relaxation is preserved over 4.5 decades in frequency. This extension is critical to understanding the role of (1)H(2)O in the total proton-spin-relaxation process. The fact that the protein-proton-relaxation-dispersion profile is a power law in frequency with constant coefficient and exponent over nearly 5 decades indicates that the characteristics of the native protein structural fluctuations that cause proton nuclear spin-lattice relaxation are remarkably constant over this wide frequency and length-scale interval. Comparison of protein-proton-spin-lattice-relaxation rate constants in protein gels equilibrated with (2)H(2)O rather than (1)H(2)O shows that water protons make an important contribution to the total spin-lattice relaxation in the middle of this frequency range for hydrated proteins because of water molecule dynamics in the time range of tens of ns. This water contribution is with the motion of relatively rare, long-lived, and perhaps buried water molecules constrained by the confinement. The presence of water molecule reorientational dynamics in the tens of ns range that are sufficient to affect the spin-lattice relaxation driven by (1)H dipole-dipole fluctuations should make the local dielectric properties in the protein frequency dependent in a regime relevant to catalytically important kinetic barriers to conformational rearrangements.
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Affiliation(s)
- Galina Diakova
- Chemistry Department, University of Virginia, Charlottesville, Virginia
| | - Yanina A. Goddard
- Chemistry Department, University of Virginia, Charlottesville, Virginia
| | - Jean-Pierre Korb
- Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Palaiseau, France
| | - Robert G. Bryant
- Chemistry Department, University of Virginia, Charlottesville, Virginia
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48
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Magnetic resonance water proton relaxation in protein solutions and tissue: T(1rho) dispersion characterization. PLoS One 2010; 5:e8565. [PMID: 20052404 PMCID: PMC2797329 DOI: 10.1371/journal.pone.0008565] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Accepted: 11/29/2009] [Indexed: 11/19/2022] Open
Abstract
Background Image contrast in clinical MRI is often determined by differences in tissue water proton relaxation behavior. However, many aspects of water proton relaxation in complex biological media, such as protein solutions and tissue are not well understood, perhaps due to the limited empirical data. Principal Findings Water proton T1, T2, and T1ρ of protein solutions and tissue were measured systematically under multiple conditions. Crosslinking or aggregation of protein decreased T2 and T1ρ, but did not change high-field T1. T1ρ dispersion profiles were similar for crosslinked protein solutions, myocardial tissue, and cartilage, and exhibited power law behavior with T1ρ(0) values that closely approximated T2. The T1ρ dispersion of mobile protein solutions was flat above 5 kHz, but showed a steep curve below 5 kHz that was sensitive to changes in pH. The T1ρ dispersion of crosslinked BSA and cartilage in DMSO solvent closely resembled that of water solvent above 5 kHz but showed decreased dispersion below 5 kHz. Conclusions Proton exchange is a minor pathway for tissue T1 and T1ρ relaxation above 5 kHz. Potential models for relaxation are discussed, however the same molecular mechanism appears to be responsible across 5 decades of frequencies from T1ρ to T1.
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49
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Belotti M, Martinelli A, Gianferri R, Brosio E. A proton NMR relaxation study of water dynamics in bovine serum albumin nanoparticles. Phys Chem Chem Phys 2010; 12:516-22. [DOI: 10.1039/b911433e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bennati M, Luchinat C, Parigi G, Türke MT. Water 1H relaxation dispersion analysis on a nitroxide radical provides information on the maximal signal enhancement in Overhauser dynamic nuclear polarization experiments. Phys Chem Chem Phys 2010; 12:5902-10. [DOI: 10.1039/c002304n] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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