51
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Dubey A, Takeuchi K, Reibarkh M, Arthanari H. The role of NMR in leveraging dynamics and entropy in drug design. JOURNAL OF BIOMOLECULAR NMR 2020; 74:479-498. [PMID: 32720098 PMCID: PMC7686249 DOI: 10.1007/s10858-020-00335-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/11/2020] [Indexed: 05/03/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy has contributed to structure-based drug development (SBDD) in a unique way compared to the other biophysical methods. The potency of a ligand binding to a protein is dictated by the binding free energy, which is an intricate interplay between entropy and enthalpy. In addition to providing the atomic resolution structural information, NMR can help to identify protein-ligand interactions that potentially contribute to the enthalpic component of the free energy. NMR can also illuminate dynamic aspects of the interaction, which correspond to the entropic term of the free energy. The ability of NMR to access both terms in the free energy equation stems from the suite of experiments developed to shed light on various aspects that contribute to both entropy and enthalpy, deepening our understanding of the biological function of macromolecules and assisting to target them in physiological conditions. Here we provide a brief account of the contribution of NMR to SBDD, highlighting hallmark examples and discussing the challenges that demand further method development. In the era of integrated biology, the unique ability of NMR to directly ascertain structural and dynamical aspects of macromolecule and monitor changes in these properties upon engaging a ligand can be combined with computational and other structural and biophysical methods to provide a more complete picture of the energetics of drug engagement with the target. Such efforts can be used to engineer better drugs.
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Affiliation(s)
- Abhinav Dubey
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Koh Takeuchi
- Cellular and Molecular Biotechnology Research Institute & Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, 135-0064, Japan.
| | - Mikhail Reibarkh
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ, 07065, USA
| | - Haribabu Arthanari
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA.
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52
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Agarwal PK, Bernard DN, Bafna K, Doucet N. Enzyme dynamics: Looking beyond a single structure. ChemCatChem 2020; 12:4704-4720. [PMID: 33897908 PMCID: PMC8064270 DOI: 10.1002/cctc.202000665] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Indexed: 12/23/2022]
Abstract
Conventional understanding of how enzymes function strongly emphasizes the role of structure. However, increasing evidence clearly indicates that enzymes do not remain fixed or operate exclusively in or close to their native structure. Different parts of the enzyme (from individual residues to full domains) undergo concerted motions on a wide range of time-scales, including that of the catalyzed reaction. Information obtained on these internal motions and conformational fluctuations has so far uncovered and explained many aspects of enzyme mechanisms, which could not have been understood from a single structure alone. Although there is wide interest in understanding enzyme dynamics and its role in catalysis, several challenges remain. In addition to technical difficulties, the vast majority of investigations are performed in dilute aqueous solutions, where conditions are significantly different than the cellular milieu where a large number of enzymes operate. In this review, we discuss recent developments, several challenges as well as opportunities related to this topic. The benefits of considering dynamics as an integral part of the enzyme function can also enable new means of biocatalysis, engineering enzymes for industrial and medicinal applications.
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Affiliation(s)
- Pratul K. Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, Oklahoma 74078
- Arium BioLabs, 2519 Caspian Drive, Knoxville, Tennessee 37932
| | - David N. Bernard
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada
| | - Khushboo Bafna
- Department of Chemistry and Chemical Biology, and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - Nicolas Doucet
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, Quebec, H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Structure, and Engineering, 1045 Avenue de la Médecine, Université Laval, Québec, QC, G1V 0A6, Canada
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53
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Xie T, Saleh T, Rossi P, Kalodimos CG. Conformational states dynamically populated by a kinase determine its function. Science 2020; 370:science.abc2754. [PMID: 33004676 DOI: 10.1126/science.abc2754] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/12/2020] [Indexed: 12/12/2022]
Abstract
Protein kinases intrinsically sample a number of conformational states with distinct catalytic and binding activities. We used nuclear magnetic resonance spectroscopy to describe in atomic-level detail how Abl kinase interconverts between an active and two discrete inactive structures. Extensive differences in key structural elements between the conformational states give rise to multiple intrinsic regulatory mechanisms. The findings explain how oncogenic mutants can counteract inhibitory mechanisms to constitutively activate the kinase. Energetic dissection revealed the contributions of the activation loop, the Asp-Phe-Gly (DFG) motif, the regulatory spine, and the gatekeeper residue to kinase regulation. Characterization of the transient conformation to which the drug imatinib binds enabled the elucidation of drug-resistance mechanisms. Structural insight into inactive states highlights how they can be leveraged for the design of selective inhibitors.
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Affiliation(s)
- Tao Xie
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Tamjeed Saleh
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Paolo Rossi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
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54
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Clay MC, Kalodimos CG. Adding Substituent Nonadditivity in Protein Allostery by NMR. Biophys J 2020; 119:1043-1044. [PMID: 32857961 DOI: 10.1016/j.bpj.2020.07.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 07/17/2020] [Accepted: 07/30/2020] [Indexed: 10/23/2022] Open
Affiliation(s)
- Mary C Clay
- Department of Structural Biology, St Jude Children's Research Hospital, Memphis, Tennessee
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55
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Tiwari VP, Vallurupalli P. A CEST NMR experiment to obtain glycine 1H α chemical shifts in 'invisible' minor states of proteins. JOURNAL OF BIOMOLECULAR NMR 2020; 74:443-455. [PMID: 32696193 DOI: 10.1007/s10858-020-00336-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/11/2020] [Indexed: 06/11/2023]
Abstract
Chemical exchange saturation transfer (CEST) experiments are routinely used to study protein conformational exchange between a 'visible' major state and 'invisible' minor states because they can detect minor states with lifetimes varying from ~ 3 to ~ 100 ms populated to just ~ 0.5%. Consequently several 1H, 15N and 13C CEST experiments have been developed to study exchange and obtain minor state chemical shifts at almost all backbone and sidechain sites in proteins. Conspicuously missing from this extensive set of CEST experiments is a 1H CEST experiment to study exchange at glycine (Gly) 1Hα sites as the existing 1H CEST experiments that have been designed to study dynamics in amide 1H-15N spin systems and methyl 13CH3 groups with three equivalent protons while suppressing 1H-1H NOE induced dips are not suitable for studying exchange in methylene 13CH2 groups with inequivalent protons. Here a Gly 1Hα CEST experiment to obtain the minor state Gly 1Hα chemical shifts is presented. The utility of this experiment is demonstrated on the L99A cavity mutant of T4 Lysozyme (T4L L99A) that undergoes conformational exchange between two compact conformers. The CEST derived minor state Gly 1Hα chemical shifts of T4L L99A are in agreement with those obtained previously using CPMG techniques. The experimental strategy presented here can also be used to obtain methylene proton minor state chemical shifts from protein sidechain and nucleic acid backbone sites.
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Affiliation(s)
- Ved Prakash Tiwari
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Pramodh Vallurupalli
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India.
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56
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Boulton S, Van K, VanSchouwen B, Augustine J, Akimoto M, Melacini G. Allosteric Mechanisms of Nonadditive Substituent Contributions to Protein-Ligand Binding. Biophys J 2020; 119:1135-1146. [PMID: 32882185 DOI: 10.1016/j.bpj.2020.07.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/30/2020] [Accepted: 07/06/2020] [Indexed: 02/07/2023] Open
Abstract
Quantifying chemical substituent contributions to ligand-binding free energies is challenging due to nonadditive effects. Protein allostery is a frequent cause of nonadditivity, but the underlying allosteric mechanisms often remain elusive. Here, we propose a general NMR-based approach to elucidate such mechanisms and we apply it to the HCN4 ion channel, whose cAMP-binding domain is an archetypal conformational switch. Using NMR, we show that nonadditivity arises not only from concerted conformational transitions, but also from conformer-specific effects, such as steric frustration. Our results explain how affinity-reducing functional groups may lead to affinity gains if combined. Surprisingly, our approach also reveals that nonadditivity depends markedly on the receptor conformation. It is negligible for the inhibited state but highly significant for the active state, opening new opportunities to tune potency and agonism of allosteric effectors.
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Affiliation(s)
- Stephen Boulton
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Katherine Van
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Bryan VanSchouwen
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada
| | - Jerry Augustine
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada
| | - Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada; Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada.
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57
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Karunanithy G, Reinstein J, Hansen DF. Multiquantum Chemical Exchange Saturation Transfer NMR to Quantify Symmetrical Exchange: Application to Rotational Dynamics of the Guanidinium Group in Arginine Side Chains. J Phys Chem Lett 2020; 11:5649-5654. [PMID: 32543198 PMCID: PMC7370295 DOI: 10.1021/acs.jpclett.0c01322] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Chemical exchange saturation transfer (CEST) NMR experiments have emerged as a powerful tool for characterizing dynamics in proteins. We show here that the CEST approach can be extended to systems with symmetrical exchange, where the NMR signals of all exchanging species are severely broadened. To achieve this, multiquantum CEST (MQ-CEST) is introduced, where the CEST pulse is applied to a longitudinal multispin order density element and the CEST profiles are encoded onto nonbroadened nuclei. The MQ-CEST approach is demonstrated on the restricted rotation of guanidinium groups in arginine residues within proteins. These groups and their dynamics are essential for many enzymes and for noncovalent interactions through the formation of hydrogen bonds, salt-bridges, and π-stacking interactions, and their rate of rotation is highly indicative of the extent of interactions formed. The MQ-CEST method is successfully applied to guanidinium groups in the 19 kDa L99A mutant of T4 lysozyme.
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Affiliation(s)
- Gogulan Karunanithy
- Institute
of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Jochen Reinstein
- Department
of Biomolecular Mechanisms, Max Planck Institute
for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
| | - D. Flemming Hansen
- Institute
of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
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58
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Rangadurai A, Shi H, Al-Hashimi HM. Extending the Sensitivity of CEST NMR Spectroscopy to Micro-to-Millisecond Dynamics in Nucleic Acids Using High-Power Radio-Frequency Fields. Angew Chem Int Ed Engl 2020; 59:11262-11266. [PMID: 32168407 PMCID: PMC7857695 DOI: 10.1002/anie.202000493] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/07/2020] [Indexed: 11/10/2022]
Abstract
Biomolecules undergo motions on the micro-to-millisecond timescale to adopt low-populated transient states that play important roles in folding, recognition, and catalysis. NMR techniques, such as Carr-Purcell-Meiboom-Gill (CPMG), chemical exchange saturation transfer (CEST), and R1ρ are the most commonly used methods for characterizing such transitions at atomic resolution under solution conditions. CPMG and CEST are most effective at characterizing motions on the millisecond timescale. While some implementations of the R1ρ experiment are more broadly sensitive to motions on the micro-to-millisecond timescale, they entail the use of selective irradiation schemes and inefficient 1D data acquisition methods. Herein, we show that high-power radio-frequency fields can be used in CEST experiments to extend the sensitivity to faster motions on the micro-to-millisecond timescale. Given the ease of implementing high-power fields in CEST, this should make it easier to characterize micro-to-millisecond dynamics in biomolecules.
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Affiliation(s)
- Atul Rangadurai
- Department of Biochemistry, Duke University, 229, Nanaline Duke Building, 307 Research Drive, Durham, NC, 27710, USA
| | - Honglue Shi
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
| | - Hashim M Al-Hashimi
- Department of Biochemistry, Duke University, 229, Nanaline Duke Building, 307 Research Drive, Durham, NC, 27710, USA
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
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59
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Rangadurai A, Shi H, Al‐Hashimi HM. Extending the Sensitivity of CEST NMR Spectroscopy to Micro‐to‐Millisecond Dynamics in Nucleic Acids Using High‐Power Radio‐Frequency Fields. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Atul Rangadurai
- Department of Biochemistry Duke University 229, Nanaline Duke Building, 307 Research Drive Durham NC 27710 USA
| | - Honglue Shi
- Department of Chemistry Duke University Durham NC 27708 USA
| | - Hashim M. Al‐Hashimi
- Department of Biochemistry Duke University 229, Nanaline Duke Building, 307 Research Drive Durham NC 27710 USA
- Department of Chemistry Duke University Durham NC 27708 USA
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60
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Nishizawa M, Walinda E, Morimoto D, Sugase K. Pinpoint analysis of a protein in slow exchange using F 1F 2-selective ZZ-exchange spectroscopy: assignment and kinetic analysis. JOURNAL OF BIOMOLECULAR NMR 2020; 74:205-211. [PMID: 32236785 DOI: 10.1007/s10858-020-00309-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
ZZ-exchange spectroscopy is widely used to study slow exchange processes in biomolecules, especially determination of exchange rates and assignment of minor peaks. However, if the exchange cross peaks overlap or the populations are skewed, kinetic analysis is hindered. In order to analyze slow exchange protein dynamics under such conditions, here we have developed a new method by combining ZZ-exchange and F1F2-selective NMR spectroscopy. We demonstrate the utility of this method by examining the monomer-dimer transition of the ubiquitin-associated domain of p62, successfully assigning the minor (monomeric) peaks and obtaining the exchange rates, which cannot be achieved by ZZ-exchange alone.
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Affiliation(s)
- Mayu Nishizawa
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-Ku, Kyoto, 615-8510, Japan
| | - Erik Walinda
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Sakyo-ku Yoshida Konoe-cho, Kyoto, 606-8501, Japan
| | - Daichi Morimoto
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-Ku, Kyoto, 615-8510, Japan
| | - Kenji Sugase
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-Ku, Kyoto, 615-8510, Japan.
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61
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Stoffel S, Zhang QW, Li DH, Smith BD, Peng JW. NMR Relaxation Dispersion Reveals Macrocycle Breathing Dynamics in a Cyclodextrin-based Rotaxane. J Am Chem Soc 2020; 142:7413-7424. [PMID: 32212648 DOI: 10.1021/jacs.9b12524] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A distinctive feature of mechanically interlocked molecules (MIMs) is the relative motion between the mechanically bonded components, and often it is the functional basis for artificial molecular machines and new functional materials. Optimization of machine or materials performance requires knowledge of the underlying atomic-level mechanisms that control the motion. The field of biomolecular NMR spectroscopy has developed a diverse set of pulse schemes that can characterize molecular dynamics over a broad time scale, but these techniques have not yet been used to characterize the motion within MIMs. This study reports the first observation of NMR relaxation dispersion related to MIM motion. The rotary (pirouette) motion of α-cyclodextrin (αCD) wheels was characterized in a complementary pair of rotaxanes with pirouetting switched ON or OFF. 13C and 1H NMR relaxation dispersion measurements reveal previously unknown exchange dynamics for the αCD wheels in the pirouette-ON rotaxane with a rate constant of 2200 s-1 at 298 K and an activation barrier of ΔF‡ = 43 ± 3 kJ/mol. The exchange dynamics disappear in the pirouette-OFF rotaxane, demonstrating their switchable nature. The 13C and 1H sites exhibiting relaxation dispersion suggest that the exchange involves "macrocycle breathing", in which the αCD wheel fluctuates between a contracted or expanded state, the latter enabling diffusive rotary motion about the axle. The substantial insight from these NMR relaxation dispersion methods suggests similar dynamic NMR methods can illuminate the fast time scale (microsecond to millisecond) mechanisms of intercomponent motion in a wide range of MIMs.
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Affiliation(s)
| | - Qi-Wei Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, Dongchuan Road 500, Shanghai 200241, China
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62
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Abstract
Structural biology often focuses primarily on three-dimensional structures of biological macromolecules, deposited in the Protein Data Bank (PDB). This resource is a remarkable entity for the world-wide scientific and medical communities, as well as the general public, as it is a growing translation into three-dimensional space of the vast information in genomic databases, e.g. GENBANK. There is, however, significantly more to understanding biological function than the three-dimensional coordinate space for ground-state structures of biomolecules. The vast array of biomolecules experiences natural dynamics, interconversion between multiple conformational states, and molecular recognition and allosteric events that play out on timescales ranging from picoseconds to seconds. This wide range of timescales demands ingenious and sophisticated experimental tools to sample and interpret these motions, thus enabling clearer insight into functional annotation of the PDB. NMR spectroscopy is unique in its ability to sample this range of timescales at atomic resolution and in physiologically relevant conditions using spin relaxation methods. The field is constantly expanding to provide new creative experiments, to yield more detailed coverage of timescales, and to broaden the power of interpretation and analysis methods. This review highlights the current state of the methodology and examines the extension of analysis tools for more complex experiments and dynamic models. The future for understanding protein dynamics is bright, and these extended tools bring greater compatibility with developments in computational molecular dynamics, all of which will further our understanding of biological molecular functions. These facets place NMR as a key component in integrated structural biology.
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63
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Delhommel F, Gabel F, Sattler M. Current approaches for integrating solution NMR spectroscopy and small-angle scattering to study the structure and dynamics of biomolecular complexes. J Mol Biol 2020; 432:2890-2912. [DOI: 10.1016/j.jmb.2020.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/27/2020] [Accepted: 03/10/2020] [Indexed: 01/24/2023]
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64
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De Paula VS, Jude KM, Nerli S, Glassman CR, Garcia KC, Sgourakis NG. Interleukin-2 druggability is modulated by global conformational transitions controlled by a helical capping switch. Proc Natl Acad Sci U S A 2020; 117:7183-7192. [PMID: 32184322 PMCID: PMC7132253 DOI: 10.1073/pnas.2000419117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Interleukin-2 (IL-2) is a small α-helical cytokine that regulates immune cell homeostasis through its recruitment to a high-affinity heterotrimeric receptor complex (IL-2Rα/IL-2Rβ/γc). IL-2 has been shown to have therapeutic efficacy for immune diseases by preferentially expanding distinct T cell compartments, and several regulatory T cell (Treg)-biasing anti-IL-2 antibodies have been developed for combination therapies. The conformational plasticity of IL-2 plays an important role in its biological actions by modulating the strength of receptor and drug interactions. Through an NMR analysis of milliseconds-timescale dynamics of free mouse IL-2 (mIL-2), we identify a global transition to a sparse conformation which is regulated by an α-helical capping "switch" at the loop between the A and B helices (AB loop). Binding to either an anti-mouse IL-2 monoclonal antibody (mAb) or a small molecule inhibitor near the loop induces a measurable response at the core of the structure, while locking the switch to a single conformation through a designed point mutation leads to a global quenching of core dynamics accompanied by a pronounced effect in mAb binding. By elucidating key details of the long-range allosteric communication between the receptor binding surfaces and the core of the IL-2 structure, our results offer a direct blueprint for designing precision therapeutics targeting a continuum of conformational states.
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Affiliation(s)
- Viviane S De Paula
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064
| | - Kevin M Jude
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Santrupti Nerli
- Department of Computer Science, University of California, Santa Cruz, CA 95064
| | - Caleb R Glassman
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - K Christopher Garcia
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305;
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Nikolaos G Sgourakis
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, CA 95064;
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65
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Park SH, Lee JH. Dynamic G Protein-Coupled Receptor Signaling Probed by Solution NMR Spectroscopy. Biochemistry 2020; 59:1065-1080. [PMID: 32092261 DOI: 10.1021/acs.biochem.0c00032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for investigating various dynamic features of G protein-coupled receptor (GPCR) signaling. In this Perspective, we focus on NMR techniques to characterize ligand-dependent conformational dynamics of GPCRs as well as the interaction of GPCRs with their environment and ligands. We also describe circumstances under which each technique should be applied, their advantages and disadvantages, and how they can be combined with other strategies to deepen the understanding of GPCR signaling at the molecular level.
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Affiliation(s)
- Sho Hee Park
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Jung Ho Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
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66
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Alderson TR, Kay LE. Unveiling invisible protein states with NMR spectroscopy. Curr Opin Struct Biol 2020; 60:39-49. [DOI: 10.1016/j.sbi.2019.10.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/28/2019] [Indexed: 12/24/2022]
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67
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Gołowicz D, Kasprzak P, Orekhov V, Kazimierczuk K. Fast time-resolved NMR with non-uniform sampling. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 116:40-55. [PMID: 32130958 DOI: 10.1016/j.pnmrs.2019.09.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 06/10/2023]
Abstract
NMR spectroscopy is a versatile tool for studying time-dependent processes: chemical reactions, phase transitions or macromolecular structure changes. However, time-resolved NMR is usually based on the simplest among available techniques - one-dimensional spectra serving as "snapshots" of the studied process. One of the reasons is that multidimensional experiments are very time-expensive due to costly sampling of evolution time space. In this review we summarize efforts to alleviate the problem of limited applicability of multidimensional NMR in time-resolved studies. We focus on techniques based on sparse or non-uniform sampling (NUS), which lead to experimental time reduction by omitting a significant part of the data during measurement and reconstructing it mathematically, adopting certain assumptions about the spectrum. NUS spectra are faster to acquire than conventional ones and thus better suited to the role of "snapshots", but still suffer from non-stationarity of the signal i.e. amplitude and frequency variations within a dataset. We discuss in detail how these instabilities affect the spectra, and what are the optimal ways of sampling the non-stationary FID signal. Finally, we discuss related areas of NMR where serial experiments are exploited and how they can benefit from the same NUS-based approaches.
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Affiliation(s)
- Dariusz Gołowicz
- Centre of New Technologies, University of Warsaw, Banacha 2C, Warsaw 02-097, Poland; Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw 02-093, Poland.
| | - Paweł Kasprzak
- Centre of New Technologies, University of Warsaw, Banacha 2C, Warsaw 02-097, Poland; Department of Mathematical Methods in Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - Vladislav Orekhov
- Department of Chemistry & Molecular Biology, University of Gothenburg, Box 462, 405 30 Gothenburg, Sweden.
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68
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Kaur H, Grahl A, Hartmann JB, Hiller S. Sample Preparation and Technical Setup for NMR Spectroscopy with Integral Membrane Proteins. Methods Mol Biol 2020; 2127:373-396. [PMID: 32112334 DOI: 10.1007/978-1-0716-0373-4_24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
NMR spectroscopy is a method of choice to characterize structure, function, and dynamics of integral membrane proteins at atomic resolution. Here, we describe protocols for sample preparation and characterization by NMR spectroscopy of two integral membrane proteins with different architecture, the α-helical membrane protein MsbA and the β-barrel membrane protein BamA. The protocols describe recombinant expression in E. coli, protein refolding, purification, and reconstitution in suitable membrane mimetics, as well as key setup steps for basic NMR experiments. These include experiments on protein samples in the solid state under magic angle spinning (MAS) conditions and experiments on protein samples in aqueous solution. Since MsbA and BamA are typical examples of their respective architectural classes, the protocols presented here can also serve as a reference for other integral membrane proteins.
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Affiliation(s)
- Hundeep Kaur
- Biozentrum, University of Basel, Basel, Switzerland
| | - Anne Grahl
- Biozentrum, University of Basel, Basel, Switzerland
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69
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Zhao B, Baisden JT, Zhang Q. Probing excited conformational states of nucleic acids by nitrogen CEST NMR spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 310:106642. [PMID: 31785475 PMCID: PMC6934915 DOI: 10.1016/j.jmr.2019.106642] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 10/30/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
Characterizing low-populated and short-lived excited conformational states has become increasingly important for understanding mechanisms of RNA function. Interconversion between RNA ground and excited conformational states often involves base pairing rearrangements that lead to changes in the hydrogen-bond network. Here, we present two 15N chemical exchange saturation transfer (CEST) NMR experiments that utilize protonated and non-protonated nitrogens, which are key hydrogen-bond donors and acceptors, for characterizing excited conformational states in RNA. We demonstrated these approaches on the B. Cereus fluoride riboswitch, where 15N CEST profiles complement 13C CEST profiles in depicting a potential pathway for ligand-dependent allosteric regulation of the excited conformational state of the fluoride riboswitch.
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Affiliation(s)
- Bo Zhao
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jared T Baisden
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Qi Zhang
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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70
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Shi H, Liu B, Nussbaumer F, Rangadurai A, Kreutz C, Al-Hashimi HM. NMR Chemical Exchange Measurements Reveal That N6-Methyladenosine Slows RNA Annealing. J Am Chem Soc 2019; 141:19988-19993. [PMID: 31826614 DOI: 10.1021/jacs.9b10939] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N6-Methyladenosine (m6A) is an abundant epitranscriptomic modification that plays important roles in many aspects of RNA metabolism. While m6A is thought to mainly function by recruiting reader proteins to specific RNA sites, the modification can also reshape RNA-protein and RNA-RNA interactions by altering RNA structure mainly by destabilizing base pairing. Little is known about how m6A and other epitranscriptomic modifications might affect the kinetic rates of RNA folding and other conformational transitions that are also important for cellular activity. Here, we used NMR R1ρ relaxation dispersion and chemical exchange saturation transfer to noninvasively and site-specifically measure nucleic acid hybridization kinetics. The methodology was validated on two DNA duplexes and then applied to examine how a single m6A alters the hybridization kinetics in two RNA duplexes. The results show that m6A minimally impacts the rate constant for duplex dissociation, changing koff by ∼1-fold but significantly slows the rate of duplex annealing, decreasing kon by ∼7-fold. A reduction in the annealing rate was observed robustly for two different sequence contexts at different temperatures, both in the presence and absence of Mg2+. We propose that rotation of the N6-methyl group from the preferred syn conformation in the unpaired nucleotide to the energetically disfavored anti conformation required for Watson-Crick pairing is responsible for the reduced annealing rate. The results help explain why in mRNA m6A slows down tRNA selection and more generally suggest that m6A may exert cellular functions by reshaping the kinetics of RNA conformational transitions.
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Affiliation(s)
- Honglue Shi
- Department of Chemistry , Duke University , Durham , North Carolina 27710 , United States
| | - Bei Liu
- Department of Biochemistry , Duke University School of Medicine , Durham , North Carolina 27710 , United States
| | - Felix Nussbaumer
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI) , University of Innsbruck , 6020 Innsbruck , Austria
| | - Atul Rangadurai
- Department of Biochemistry , Duke University School of Medicine , Durham , North Carolina 27710 , United States
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI) , University of Innsbruck , 6020 Innsbruck , Austria
| | - Hashim M Al-Hashimi
- Department of Chemistry , Duke University , Durham , North Carolina 27710 , United States.,Department of Biochemistry , Duke University School of Medicine , Durham , North Carolina 27710 , United States
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71
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Marušič M, Schlagnitweit J, Petzold K. RNA Dynamics by NMR Spectroscopy. Chembiochem 2019; 20:2685-2710. [PMID: 30997719 PMCID: PMC6899578 DOI: 10.1002/cbic.201900072] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/12/2019] [Indexed: 12/22/2022]
Abstract
An ever-increasing number of functional RNAs require a mechanistic understanding. RNA function relies on changes in its structure, so-called dynamics. To reveal dynamic processes and higher energy structures, new NMR methods have been developed to elucidate these dynamics in RNA with atomic resolution. In this Review, we provide an introduction to dynamics novices and an overview of methods that access most dynamic timescales, from picoseconds to hours. Examples are provided as well as insight into theory, data acquisition and analysis for these different methods. Using this broad spectrum of methodology, unprecedented detail and invisible structures have been obtained and are reviewed here. RNA, though often more complicated and therefore neglected, also provides a great system to study structural changes, as these RNA structural changes are more easily defined-Lego like-than in proteins, hence the numerous revelations of RNA excited states.
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Affiliation(s)
- Maja Marušič
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
| | - Judith Schlagnitweit
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
| | - Katja Petzold
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
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72
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Yuwen T, Kay LE. Revisiting 1H N CPMG relaxation dispersion experiments: a simple modification can eliminate large artifacts. JOURNAL OF BIOMOLECULAR NMR 2019; 73:641-650. [PMID: 31646421 DOI: 10.1007/s10858-019-00276-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 09/06/2019] [Indexed: 05/25/2023]
Abstract
Carr-Purcell-Meiboom-Gill relaxation dispersion experiments are commonly used to probe biomolecular dynamics on the millisecond timescale. The simplest experiment involves using backbone 15N spins as probes of motion and pulse sequences are now available for providing accurate dispersion profiles in this case. In contrast, 1H-based experiments recorded on fully protonated samples are less common because of difficulties associated with homonuclear scalar couplings that can result in transfer of magnetization between coupled spins, leading to significant artifacts. Herein we examine a version of the 1HN CPMG experiment that has been used in our laboratory where a pair of CPMG pulse trains comprising non-selective, high power 1H refocusing pulses sandwich an amide selective pulse that serves to refocus scalar-coupled evolution by the end of the train. The origin of the artifacts in our original scheme is explained and a new, significantly improved sequence is presented. The utility of the new experiment is demonstrated by obtaining flat 1HN dispersion profiles in a protonated protein system that is not expected to undergo millisecond timescale dynamics, and subsequently by measuring profiles on a cavity mutant of T4 lysozyme that exchanges between a pair of distinct states, establishing that high quality data can be generated even for fully protonated samples.
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Affiliation(s)
- Tairan Yuwen
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Program in Molecular Medicine, Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
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73
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Bibow S. Opportunities and Challenges of Backbone, Sidechain, and RDC Experiments to Study Membrane Protein Dynamics in a Detergent-Free Lipid Environment Using Solution State NMR. Front Mol Biosci 2019; 6:103. [PMID: 31709261 PMCID: PMC6823230 DOI: 10.3389/fmolb.2019.00103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/19/2019] [Indexed: 12/22/2022] Open
Abstract
Whereas solution state NMR provided a wealth of information on the dynamics landscape of soluble proteins, only few studies have investigated membrane protein dynamics in a detergent-free lipid environment. Recent developments of smaller nanodiscs and other lipid-scaffolding polymers, such as styrene maleic acid (SMA), however, open new and promising avenues to explore the function-dynamics relationship of membrane proteins as well as between membrane proteins and their surrounding lipid environment. Favorably sized lipid-bilayer nanodiscs, established membrane protein reconstitution protocols and sophisticated solution NMR relaxation methods probing dynamics over a wide range of timescales will eventually reveal unprecedented lipid-membrane protein interdependencies that allow us to explain things we have not been able to explain so far. In particular, methyl group dynamics resulting from CEST, CPMG, ZZ exchange, and RDC experiments are expected to provide new and surprising insights due to their proximity to lipids, their applicability in large 100+ kDa assemblies and their simple labeling due to the availability of commercial precursors. This review summarizes the recent developments of membrane protein dynamics with a special focus on membrane protein dynamics in lipid-bilayer nanodiscs. Opportunities and challenges of backbone, side chain and RDC dynamics applied to membrane proteins are discussed. Solution-state NMR and lipid nanodiscs bear great potential to change our molecular understanding of lipid-membrane protein interactions.
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Affiliation(s)
- Stefan Bibow
- Biozentrum, University of Basel, Basel, Switzerland
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74
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Jameson G, Hansen AL, Li D, Bruschweiler-Li L, Brüschweiler R. Extreme Nonuniform Sampling for Protein NMR Dynamics Studies in Minimal Time. J Am Chem Soc 2019; 141:16829-16838. [PMID: 31560199 DOI: 10.1021/jacs.9b08032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
NMR spectroscopy is an extraordinarily rich source of quantitative dynamics of proteins in solution using spin relaxation or chemical exchange saturation transfer (CEST) experiments. However, 15N-CEST measurements require prolonged multidimensional, so-called pseudo-3D HSQC experiments where the pseudo dimension is a radio frequency offset Δω of a weak 15N saturation field. Nonuniform sampling (NUS) approaches have the potential to significantly speed up these measurements, but they also carry the risk of introducing serious artifacts and the systematic optimization of nonuniform sampling schedules has remained elusive. It is demonstrated here how this challenge can be addressed by using fitted cross-peaks of a reference 2D HSQC experiment as footprints, which are subsequently used to reconstruct cross-peak amplitudes of a pseudo-3D data set as a function of Δω by a linear least-squares fit. It is shown for protein Im7 how the approach can yield highly accurate CEST profiles based on an absolutely minimally sampled (AMS) data set allowing a speed-up of a factor 20-30. Spectrum-specific optimized nonuniform sampling (SONUS) schemes based on the Cramer-Rao lower bound metric were critical to achieve such a performance, revealing also more general properties of optimal sampling schedules. This is the first systematic exploration and optimization of NUS schedules for the dramatic speed-up of quantitative multidimensional NMR measurements that minimize unwanted errors.
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Affiliation(s)
- Gregory Jameson
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States.,Biophysics Graduate Program , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Alexandar L Hansen
- Campus Chemical Instrument Center , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Dawei Li
- Campus Chemical Instrument Center , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Lei Bruschweiler-Li
- Campus Chemical Instrument Center , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Rafael Brüschweiler
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States.,Biophysics Graduate Program , The Ohio State University , Columbus , Ohio 43210 , United States.,Campus Chemical Instrument Center , The Ohio State University , Columbus , Ohio 43210 , United States.,Department of Biological Chemistry and Pharmacology , The Ohio State University , Columbus , Ohio 43210 , United States
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75
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Arthanari H, Takeuchi K, Dubey A, Wagner G. Emerging solution NMR methods to illuminate the structural and dynamic properties of proteins. Curr Opin Struct Biol 2019; 58:294-304. [PMID: 31327528 PMCID: PMC6778509 DOI: 10.1016/j.sbi.2019.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 06/03/2019] [Accepted: 06/10/2019] [Indexed: 12/20/2022]
Abstract
The first recognition of protein breathing was more than 50 years ago. Today, we are able to detect the multitude of interaction modes, structural polymorphisms, and binding-induced changes in protein structure that direct function. Solution-state NMR spectroscopy has proved to be a powerful technique, not only to obtain high-resolution structures of proteins, but also to provide unique insights into the functional dynamics of proteins. Here, we summarize recent technical landmarks in solution NMR that have enabled characterization of key biological macromolecular systems. These methods have been fundamental to atomic resolution structure determination and quantitative analysis of dynamics over a wide range of time scales by NMR. The ability of NMR to detect lowly populated protein conformations and transiently formed complexes plays a critical role in its ability to elucidate functionally important structural features of proteins and their dynamics.
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Affiliation(s)
- Haribabu Arthanari
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, United States; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, United States.
| | - Koh Takeuchi
- Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology, 135-0064 Tokyo, Japan.
| | - Abhinav Dubey
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, United States; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, United States
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, United States.
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76
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Vallurupalli P, Tiwari VP, Ghosh S. A Double-Resonance CEST Experiment To Study Multistate Protein Conformational Exchange: An Application to Protein Folding. J Phys Chem Lett 2019; 10:3051-3056. [PMID: 31081645 DOI: 10.1021/acs.jpclett.9b00985] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Despite the importance of protein dynamics to function, studying exchange between multiple conformational states remains a challenge because sparsely populated states are invisible to conventional techniques. CEST NMR experiments can detect minor states with lifetimes between 5 and 200 ms populated to a level of just ∼1%. However, CEST often cannot provide the exchange mechanism for processes involving three or more states, leaving the role of the detected minor states unknown. Here a double-resonance CEST experiment to determine the kinetics of multistate exchange is presented. The approach that involves irradiating resonances from two minor states simultaneously is used to study the exchange of T4 lysozyme (T4L) between the dominant native state and two minor states, the unfolded state and a second minor state (B), each populated to only ∼4%. Regular CEST does not provide the folding mechanism, but double-resonance CEST clearly shows that T4L can fold directly without going through B.
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Affiliation(s)
- Pramodh Vallurupalli
- TIFR Centre for Interdisciplinary Sciences , Tata Institute of Fundamental Research Hyderabad , 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District , Hyderabad , Telangana 500107 , India
| | - Ved Prakash Tiwari
- TIFR Centre for Interdisciplinary Sciences , Tata Institute of Fundamental Research Hyderabad , 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District , Hyderabad , Telangana 500107 , India
| | - Shamasree Ghosh
- TIFR Centre for Interdisciplinary Sciences , Tata Institute of Fundamental Research Hyderabad , 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District , Hyderabad , Telangana 500107 , India
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77
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Abstract
Biological molecules are often highly dynamic, and this flexibility can be critical for function. The large range of sampled timescales and the fact that many of the conformers that are continually explored are only transiently formed and sparsely populated challenge current biophysical approaches. Solution nuclear magnetic resonance (NMR) spectroscopy has emerged as a powerful method for characterizing biomolecular dynamics in detail, even in cases where excursions involve short-lived states. Here, we briefly review a number of NMR experiments for studies of biomolecular dynamics on the microsecond-to-second timescale and focus on applications to protein and nucleic acid systems that clearly illustrate the functional relevance of motion in both health and disease.
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Affiliation(s)
- Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Lewis E. Kay
- Departments of Molecular Genetics, Biochemistry, and Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Program in Molecular Medicine, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
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78
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Zhang H, Keane SC. Advances that facilitate the study of large RNA structure and dynamics by nuclear magnetic resonance spectroscopy. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1541. [PMID: 31025514 PMCID: PMC7169810 DOI: 10.1002/wrna.1541] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/18/2019] [Accepted: 04/02/2019] [Indexed: 12/22/2022]
Abstract
The characterization of functional yet nonprotein coding (nc) RNAs has expanded the role of RNA in the cell from a passive player in the central dogma of molecular biology to an active regulator of gene expression. The misregulation of ncRNA function has been linked with a variety of diseases and disorders ranging from cancers to neurodegeneration. However, a detailed molecular understanding of how ncRNAs function has been limited; due, in part, to the difficulties associated with obtaining high-resolution structures of large RNAs. Tertiary structure determination of RNA as a whole is hampered by various technical challenges, all of which are exacerbated as the size of the RNA increases. Namely, RNAs tend to be highly flexible and dynamic molecules, which are difficult to crystallize. Biomolecular nuclear magnetic resonance (NMR) spectroscopy offers a viable alternative to determining the structure of large RNA molecules that do not readily crystallize, but is itself hindered by some technical limitations. Recently, a series of advancements have allowed the biomolecular NMR field to overcome, at least in part, some of these limitations. These advances include improvements in sample preparation strategies as well as methodological improvements. Together, these innovations pave the way for the study of ever larger RNA molecules that have important biological function. This article is categorized under: RNA Structure and Dynamics > RNA Structure, Dynamics, and Chemistry Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Huaqun Zhang
- Biophysics Program, University of Michigan, Ann Arbor, Michigan
| | - Sarah C Keane
- Biophysics Program, University of Michigan, Ann Arbor, Michigan.,Department of Chemistry, University of Michigan, Ann Arbor, Michigan
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79
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Hu W, Wang H, Hou Y, Hao Y, Liu D. Trimethylsilyl reporter groups for NMR studies of conformational changes in G protein-coupled receptors. FEBS Lett 2019; 593:1113-1121. [PMID: 30953343 DOI: 10.1002/1873-3468.13382] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/04/2019] [Accepted: 03/26/2019] [Indexed: 12/22/2022]
Abstract
Large membrane proteins such as G protein-coupled receptors (GPCRs) are difficult for NMR study due to severe signal overlaps and unfavorable relaxation properties. We used a trimethylsilyl (TMS) group as a reporter group for 1 H NMR study of conformational changes in proteins, utilizing high-intensity 1 H NMR signals near 0 p.p.m. The β2 -adrenergic receptor was labeled with TMS groups at two cysteines located at the cytoplasmic ends of helices VI and VII. Binding of various ligands led to changes in 1 H NMR signals, which manifested that helix VI is sensitive to G protein-specific activation, whereas helix VII is sensitive to β-arrestin-specific activation. Thus, the TMS group is a useful reporter group in NMR for studying conformational changes in membrane proteins such as GPCRs.
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Affiliation(s)
- Wanhui Hu
- iHuman Institute, ShanghaiTech University, China
| | - Huixia Wang
- iHuman Institute, ShanghaiTech University, China.,Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yaguang Hou
- iHuman Institute, ShanghaiTech University, China.,Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yimei Hao
- iHuman Institute, ShanghaiTech University, China.,Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
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80
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Tiwari VP, Pandit S, Vallurupalli P. Exchangeable deuterons introduce artifacts in amide 15N CEST experiments used to study protein conformational exchange. JOURNAL OF BIOMOLECULAR NMR 2019; 73:43-48. [PMID: 30661150 DOI: 10.1007/s10858-018-00223-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 12/27/2018] [Indexed: 06/09/2023]
Abstract
Protein molecules sample different conformations in solution and characterizing these conformations is crucial to understanding protein function. 15N CEST experiments are now routinely used to study slow conformational exchange of protein molecules between a 'visible' major state and 'invisible' minor states. These experiments have also been adapted to measure the solvent exchange rates of amide protons by exploiting the one bond deuterium isotope effect on the amide 15N chemical shifts. However at moderately high temperatures (~ 50 °C) that are sometimes required to populate protein minor conformers to levels (~ 1%) that can be detected by CEST experiments solvent H/D exchange can lead to 'dips' in low B115N CEST profiles that can be wrongly assigned to the conformational exchange process being characterized. This is demonstrated in the case of ~ 18 kDa T4 Lysozyme (T4L) at 50 °C and the ~ 11 kDa E. coli hibernation promoting factor (HPF) at 52 °C. This problem is trivially solved by eliminating the exchangeable deuterons in the solvent by using either an external D2O lock or by using a small amount (~ 1-3%) of a molecule like d6-DMSO that does not contain exchangeable deuterons to lock the spectrometer.
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Affiliation(s)
- Ved Prakash Tiwari
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Subhendu Pandit
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India
| | - Pramodh Vallurupalli
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, Telangana, 500107, India.
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81
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Abstract
GEST NMR provides dynamic information on host–guest systems. It allows signal amplification of low concentrated complexes, detection of intermolecular interactions and quantification of guest exchange rates.
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Affiliation(s)
- Liat Avram
- Faculty of Chemistry
- Weizmann Institute of Science
- 7610001 Rehovot
- Israel
| | - Amnon Bar-Shir
- Faculty of Chemistry
- Weizmann Institute of Science
- 7610001 Rehovot
- Israel
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82
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Abstract
The phenomenon of chemical or conformational exchange in NMR spectroscopy has enabled detailed characterization of time-dependent aspects of biomolecular function, including folding, molecular recognition, allostery, and catalysis, on timescales from microsecond to second. Importantly, NMR methods based on a variety of spin relaxation parameters have been developed that provide quantitative information on interconversion kinetics, thermodynamic properties, and structural features of molecular states populated to a fraction of a percent at equilibrium and otherwise unobservable by other NMR approaches. The ongoing development of more sophisticated experimental techniques and the necessity to apply these methods to larger and more complex molecular systems engenders a corresponding need for theoretical advances describing such techniques and facilitating data analysis in applications. This review surveys current aspects of the theory of chemical exchange, as utilized in ZZ-exchange; Hahn and Carr-Purcell-Meiboom-Gill (CPMG) spin-echo; and R1ρ, chemical exchange saturation transfer (CEST), and dark state saturation transfer (DEST) spin-locking experiments. The review emphasizes theoretical results for kinetic topologies with more than two interconverting states, both to obtain compact analytical forms suitable for data analysis and to establish conditions for distinguishability between alternative kinetic schemes.
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Affiliation(s)
- Arthur G Palmer
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States.
| | - Hans Koss
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
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83
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Abstract
NMR spectroscopy has proven to be a key method for studying intrinsically disordered proteins (IDPs). Nonetheless, traditional NMR methods developed for solving structures of ordered protein complexes are insufficient for the full characterization of dynamic IDP complexes, where the energy landscape is broader and more rugged. Furthermore, due to their high sensitivity to environmental changes, NMR studies of IDP complexes must be conducted with extra care and the observed NMR parameters thoroughly evaluated to enable disentanglement of binding events from ensemble distribution changes. In this chapter, written for the non-NMR expert, we start out by outlining sample preparation for IDP complexes, guide through the recording and evaluation of diagnostic 1H,15N-HSQC spectra, and delineate more sophisticated NMR strategies to follow for the particular type of complex. The most relevant experiments are then described in terms of aims, needs, pitfalls, analysis, and expected outcomes, with references to recent examples.
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84
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Schneider R, Blackledge M, Jensen MR. Elucidating binding mechanisms and dynamics of intrinsically disordered protein complexes using NMR spectroscopy. Curr Opin Struct Biol 2018; 54:10-18. [PMID: 30316104 DOI: 10.1016/j.sbi.2018.09.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 01/10/2023]
Abstract
Advances in characterizing complexes of intrinsically disordered proteins (IDPs) have led to the discovery of a remarkably diverse interaction landscape that includes folding-upon-binding, highly dynamic complexes, multivalent interactions as well as regulatory switches controlled by post-translational modifications. Nuclear magnetic resonance (NMR) spectroscopy has in recent years made significant contributions to this field by describing the binding mechanisms and mapping conformational dynamics on multiple time scales. Importantly, this progress has been associated with specific methodological developments in NMR, for example in exchange techniques, allowing challenging biological systems to be studied at atomic resolution. In general, the level of dynamics observed in IDP complexes does not correlate with binding affinities, demonstrating the intricate relationship between conformational dynamics and IDP regulatory function.
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Affiliation(s)
- Robert Schneider
- Univ. Lille, CNRS, UMR 8576 - Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France
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85
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Bibow S, Hiller S. A guide to quantifying membrane protein dynamics in lipids and other native-like environments by solution-state NMR spectroscopy. FEBS J 2018; 286:1610-1623. [PMID: 30133960 DOI: 10.1111/febs.14639] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 07/04/2018] [Accepted: 08/20/2018] [Indexed: 02/06/2023]
Abstract
Recent biochemical and technical developments permit residue-specific solution NMR measurements of membrane protein (MP) dynamics in lipidic and chaperone-bound environments. This is possible by combinations of improved sample preparations with suitable NMR relaxation experiments to correlate protein function to backbone dynamics on timescales from picoseconds to seconds, even for large MP-lipid assemblies above 100 kDa in molecular mass. Here, we introduce the basic concepts of different NMR relaxation experiments, individually sensitive to specific timescales. We discuss the general limitations of detergent environments and highlight the importance for native-like environments when studying MPs. We then review three practical studies of fast- and slow-timescale MP dynamics in lipid environments, as well as in a natively unfolded, chaperone-bound state. These examples illustrate the new avenues solution NMR spectroscopy is taking to investigate MP dynamics in native-like environments with atomic resolution.
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86
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Yuwen T, Bah A, Brady JP, Ferrage F, Bouvignies G, Kay LE. Measuring Solvent Hydrogen Exchange Rates by Multifrequency Excitation 15N CEST: Application to Protein Phase Separation. J Phys Chem B 2018; 122:11206-11217. [DOI: 10.1021/acs.jpcb.8b06820] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Alaji Bah
- Hospital for Sick Children, Program in Molecular Medicine, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | | | - Fabien Ferrage
- Laboratoire des Biomolécules, LBM, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Guillaume Bouvignies
- Laboratoire des Biomolécules, LBM, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
| | - Lewis E. Kay
- Hospital for Sick Children, Program in Molecular Medicine, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
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87
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Resolving biomolecular motion and interactions by R2 and R1ρ relaxation dispersion NMR. Methods 2018; 148:28-38. [DOI: 10.1016/j.ymeth.2018.04.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/18/2018] [Accepted: 04/20/2018] [Indexed: 12/16/2022] Open
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88
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Niu X, Ding J, Zhang W, Li Q, Hu Y, Jin C. Residue selective 15N CEST and CPMG experiments for studies of millisecond timescale protein dynamics. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 293:47-55. [PMID: 29890486 DOI: 10.1016/j.jmr.2018.05.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/27/2018] [Accepted: 05/30/2018] [Indexed: 06/08/2023]
Abstract
Proteins are intrinsically dynamic molecules and undergo exchanges among multiple conformations to perform biological functions. The CPMG relaxation dispersion and CEST experiments are two important solution NMR techniques for characterizing the conformational exchange processes on the millisecond timescale. Traditional pseudo 3D 15N CEST and CPMG experiments have certain limitations in their applications. For example, both experiments have low sensitivity for broadened resonances, and the process of optimizing sample conditions and experimental parameters are often time consuming. To overcome these limitations, we herein present a new set of residue selective 15N CEST and CPMG pulse sequences by employing the Hartmann-Hahn cross-polarization transfer of magnetization in both 1D and 2D schemes. Combined with frequency labeling in the indirect dimension using only a small number of increments, the pulse sequences in the 2D scheme can be applied on resonances in overlapped regions of the 1H-15N HSQC spectrum. The pulse sequences were further applied on several proteins, demonstrating their advantages over the traditional CEST and CPMG experiments under specific circumstances.
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Affiliation(s)
- Xiaogang Niu
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, China; College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
| | - Jienv Ding
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, China; College of Life Sciences, Peking University, Beijing, China
| | - Wenbo Zhang
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, China; College of Life Sciences, Peking University, Beijing, China
| | - Qianwen Li
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, China; College of Life Sciences, Peking University, Beijing, China
| | - Yunfei Hu
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, China; College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Changwen Jin
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, China; College of Chemistry and Molecular Engineering, Peking University, Beijing, China; College of Life Sciences, Peking University, Beijing, China.
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89
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Yuwen T, Bouvignies G, Kay LE. Exploring methods to expedite the recording of CEST datasets using selective pulse excitation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 292:1-7. [PMID: 29753980 DOI: 10.1016/j.jmr.2018.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 04/23/2018] [Accepted: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Chemical Exchange Saturation Transfer (CEST) has emerged as a powerful tool for studies of biomolecular conformational exchange involving the interconversion between a major, visible conformer and one or more minor, invisible states. Applications typically entail recording a large number of 2D datasets, each of which differs in the position of a weak radio frequency field, so as to generate a CEST profile for each nucleus from which the chemical shifts of spins in the invisible state(s) are obtained. Here we compare a number of band-selective CEST schemes for speeding up the process using either DANTE or cosine-modulated excitation approaches. We show that while both are essentially identical for applications such as 15N CEST, in cases where the probed spins are dipolar or scalar coupled to other like spins there can be advantages for the cosine-excitation scheme.
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Affiliation(s)
- Tairan Yuwen
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| | - Guillaume Bouvignies
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Hospital for Sick Children, Program in Molecular Medicine, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
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90
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Knox R, Lento C, Wilson DJ. Mapping Conformational Dynamics to Individual Steps in the TEM-1 β-Lactamase Catalytic Mechanism. J Mol Biol 2018; 430:3311-3322. [PMID: 29964048 DOI: 10.1016/j.jmb.2018.06.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/14/2018] [Accepted: 06/22/2018] [Indexed: 10/28/2022]
Abstract
Conformational dynamics are increasingly recognized as being essential for enzyme function. However, there is virtually no direct experimental evidence to support the notion that individual dynamic modes are required for specific catalytic processes, apart from the initial step of substrate binding. In this work, we use a unique approach based on millisecond hydrogen-deuterium exchange mass spectrometry to identify dynamic modes linked to individual catalytic processes in the antibiotic resistance enzyme TEM-1 β-lactamase. Using a "good" substrate (ampicillin), a poorly hydrolyzed substrate (cephalexin) and a covalent inhibitor (clavulanate), we are able to isolate dynamic modes that are specifically linked to substrate binding, productive lactam ring hydrolysis and deacylation. These discoveries are ultimately translated into specific targets for allosteric TEM-1 inhibitor development.
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Affiliation(s)
- Ruth Knox
- Department of Chemistry, York University, Toronto, Canada M3J 1P3
| | - Cristina Lento
- Department of Chemistry, York University, Toronto, Canada M3J 1P3
| | - Derek J Wilson
- Department of Chemistry, York University, Toronto, Canada M3J 1P3; Center for Research in Mass Spectrometry, York University, Toronto, Canada M3J 1P3.
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91
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Chatterjee SD, Ubbink M, van Ingen H. Removal of slow-pulsing artifacts in in-phase 15N relaxation dispersion experiments using broadband 1H decoupling. JOURNAL OF BIOMOLECULAR NMR 2018; 71:69-77. [PMID: 29860650 PMCID: PMC6061081 DOI: 10.1007/s10858-018-0193-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/31/2018] [Indexed: 06/08/2023]
Abstract
Understanding of the molecular mechanisms of protein function requires detailed insight into the conformational landscape accessible to the protein. Conformational changes can be crucial for biological processes, such as ligand binding, protein folding, and catalysis. NMR spectroscopy is exquisitely sensitive to such dynamic changes in protein conformations. In particular, Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments are a powerful tool to investigate protein dynamics on a millisecond time scale. CPMG experiments that probe the chemical shift modulation of 15N in-phase magnetization are particularly attractive, due to their high sensitivity. These experiments require high power 1H decoupling during the CPMG period to keep the 15N magnetization in-phase. Recently, an improved version of the in-phase 15N-CPMG experiment was introduced, offering greater ease of use by employing a single 1H decoupling power for all CPMG pulsing rates. In these experiments however, incomplete decoupling of off-resonance amide 1H spins introduces an artefactual dispersion of relaxation rates, the so-called slow-pulsing artifact. Here, we analyze the slow-pulsing artifact in detail and demonstrate that it can be suppressed through the use of composite pulse decoupling (CPD). We report the performances of various CPD schemes and show that CPD decoupling based on the 90x-240y-90x element results in high-quality dispersion curves free of artifacts, even for amides with high 1H offset.
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Affiliation(s)
- Soumya Deep Chatterjee
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, P.O Box 9502, 2300 RA, Leiden, The Netherlands
| | - Marcellus Ubbink
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, P.O Box 9502, 2300 RA, Leiden, The Netherlands
| | - Hugo van Ingen
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, P.O Box 9502, 2300 RA, Leiden, The Netherlands.
- NMR Group, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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92
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Yuwen T, Kay LE, Bouvignies G. Dramatic Decrease in CEST Measurement Times Using Multi‐Site Excitation. Chemphyschem 2018; 19:1707-1710. [DOI: 10.1002/cphc.201800249] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Tairan Yuwen
- Departments of Molecular Genetics, Biochemistry and ChemistryUniversity of Toronto Toronto, Ontario M5S 1A8 Canada
| | - Lewis E. Kay
- Departments of Molecular Genetics, Biochemistry and ChemistryUniversity of Toronto Toronto, Ontario M5S 1A8 Canada
- Hospital for Sick ChildrenProgram in Molecular Medicine 555 University Avenue Toronto, Ontario M5G 1X8 Canada
| | - Guillaume Bouvignies
- Laboratoire des biomolécules, LBM, Département de chimie, École normale supérieure, PSL UniversitySorbonne Université, CNRS 75005 Paris France
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93
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Wu Q, Fenton BA, Wojtaszek JL, Zhou P. Probing the excited-state chemical shifts and exchange parameters by nitrogen-decoupled amide proton chemical exchange saturation transfer (HN dec-CEST). Chem Commun (Camb) 2018; 53:8541-8544. [PMID: 28707688 DOI: 10.1039/c7cc05021f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
CEST-NMR spectroscopy is a powerful tool for probing the conformational dynamics of macromolecules. We present a HNdec-CEST experiment that simplifies the relaxation matrix, reduces fitting parameters, and enhances signal resolution. Importantly, fitting of HNdec-CEST profiles enables robust extraction of exchange rates as well as excited-state chemical shifts and populations.
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Affiliation(s)
- Qinglin Wu
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
| | - Benjamin A Fenton
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
| | - Jessica L Wojtaszek
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
| | - Pei Zhou
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
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94
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Effects of maturation on the conformational free-energy landscape of SOD1. Proc Natl Acad Sci U S A 2018; 115:E2546-E2555. [PMID: 29483249 DOI: 10.1073/pnas.1721022115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating fatal syndrome characterized by very rapid degeneration of motor neurons. A leading hypothesis is that ALS is caused by toxic protein misfolding and aggregation, as also occurs in many other neurodegenerative disorders, such as prion, Alzheimer's, Parkinson's, and Huntington's diseases. A prominent cause of familial ALS is mutations in the protein superoxide dismutase (SOD1), which promote the formation of misfolded SOD1 conformers that are prone to aberrant interactions both with each other and with other cellular components. We have shown previously that immature SOD1, lacking bound Cu and Zn metal ions and the intrasubunit disulfide bond (apoSOD12SH), has a rugged free-energy surface (FES) and exchanges with four other conformations (excited states) that have millisecond lifetimes and sparse populations on the order of a few percent. Here, we examine further states of SOD1 along its maturation pathway, as well as those off-pathway resulting from metal loss that have been observed in proteinaceous inclusions. Metallation and disulfide bond formation lead to structural transformations including local ordering of the electrostatic loop and native dimerization that are observed in rare conformers of apoSOD12SH; thus, SOD1 maturation may occur via a population-switch mechanism whereby posttranslational modifications select for preexisting structures on the FES. Metallation and oxidation of SOD1 stabilize the native, mature conformation and decrease the number of detected excited conformational states, suggesting that it is the immature forms of the protein that contribute to misfolded conformations in vivo rather than the highly stable enzymatically active dimer.
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95
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Sekhar A, Velyvis A, Zoltsman G, Rosenzweig R, Bouvignies G, Kay LE. Conserved conformational selection mechanism of Hsp70 chaperone-substrate interactions. eLife 2018; 7:32764. [PMID: 29460778 PMCID: PMC5819949 DOI: 10.7554/elife.32764] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 12/27/2017] [Indexed: 12/17/2022] Open
Abstract
Molecular recognition is integral to biological function and frequently involves preferred binding of a molecule to one of several exchanging ligand conformations in solution. In such a process the bound structure can be selected from the ensemble of interconverting ligands a priori (conformational selection, CS) or may form once the ligand is bound (induced fit, IF). Here we focus on the ubiquitous and conserved Hsp70 chaperone which oversees the integrity of the cellular proteome through its ATP-dependent interaction with client proteins. We directly quantify the flux along CS and IF pathways using solution NMR spectroscopy that exploits a methyl TROSY effect and selective isotope-labeling methodologies. Our measurements establish that both bacterial and human Hsp70 chaperones interact with clients by selecting the unfolded state from a pre-existing array of interconverting structures, suggesting a conserved mode of client recognition among Hsp70s and highlighting the importance of molecular dynamics in this recognition event. Proteins are the workhorses of a cell and are involved in almost all biological processes. Newly made proteins need to ‘fold’ into precise three-dimensional shapes in order to carry out their roles. However, proteins sometimes fold incorrectly or unfold. These protein forms are not able to work effectively and in some cases may even cause diseases. Chaperone proteins help other proteins to fold correctly and are found in living organisms ranging in complexity from bacteria to humans. There are many different types of chaperones that play different roles inside cells. One, called Hsp70, binds to proteins that are incorrectly folded to help them to mature into their correct structures. However, it was not clear whether Hsp70 can also associate with the mature, correctly folded form of the proteins. A technique called Nuclear Magnetic Resonance (NMR) spectroscopy can distinguish between mature, unfolded and chaperone-bound forms of the same protein. Sekhar et al. therefore used NMR to investigate which forms of a protein Hsp70 binds to. This revealed that both the bacterial and human versions of the Hsp70 chaperone interact only with unfolded proteins. The results presented by Sekhar et al. also explain why Hsp70 does not disrupt the routine workings of the cell: because it does not bind to mature forms of proteins. These observations extend our understanding of how chaperones assist in folding proteins, and fit into a broader research theme exploring how proteins recognize one another. It will now be interesting to see whether the same mechanism holds for more complex forms of proteins, such as aggregates, or larger protein structures with regions of both folded and unfolded elements.
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Affiliation(s)
- Ashok Sekhar
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Algirdas Velyvis
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Guy Zoltsman
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Rina Rosenzweig
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Guillaume Bouvignies
- Laboratoire des Biomolécules, Département de chimie, École normale supérieure, UPMC Univ. Paris 06, CNRS, PSL Research University, Paris, France.,Sorbonne Universités, UPMC Univ. Paris 06, École normale supérieure, CNRS, Laboratoire des Biomolécules, Paris, France
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, Canada.,Department of Chemistry, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada.,Hospital for Sick Children, Program in Molecular Medicine, University Avenue, Toronto, Canada
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96
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Deshmukh L, Tugarinov V, Appella DH, Clore GM. Targeting a Dark Excited State of HIV-1 Nucleocapsid by Antiretroviral Thioesters Revealed by NMR Spectroscopy. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201713172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lalit Deshmukh
- Laboratory of Chemical Physics; National Institute of Diabetes and Digestive and Kidney Diseases; Bethesda MD 20892-0520 USA
- Present address: Department of Chemistry and Biochemistry; University of California, San Diego; La Jolla CA 92093 USA
| | - Vitali Tugarinov
- Laboratory of Chemical Physics; National Institute of Diabetes and Digestive and Kidney Diseases; Bethesda MD 20892-0520 USA
| | - Daniel H. Appella
- Laboratory of Bioorganic Chemistry; National Institute of Diabetes and Digestive and Kidney Diseases; Bethesda MD 20892-0830 USA
| | - G. Marius Clore
- Laboratory of Chemical Physics; National Institute of Diabetes and Digestive and Kidney Diseases; Bethesda MD 20892-0520 USA
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97
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Deshmukh L, Tugarinov V, Appella DH, Clore GM. Targeting a Dark Excited State of HIV-1 Nucleocapsid by Antiretroviral Thioesters Revealed by NMR Spectroscopy. Angew Chem Int Ed Engl 2018; 57:2687-2691. [PMID: 29345807 DOI: 10.1002/anie.201713172] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Indexed: 12/22/2022]
Abstract
HIV-1 nucleocapsid (NCp7) is a two Cys2 HisCys zinc knuckle (N-Zn and C-Zn) protein that plays a key role in viral replication. NCp7 conformational dynamics is characterized by NMR relaxation dispersion and chemical exchange saturation transfer measurements. While the N-Zn knuckle is conformationally stable, the C-Zn knuckle interconverts on the millisecond timescale between the major state, in which the zinc is coordinated by three cysteines and a histidine, and two folded minor species (with populations around 1 %) in which one of the coordination bonds (Cys413-Sγ-Zn or His421-Nϵ2-Zn) is hydrolyzed. These findings explain why antiretroviral thioesters specifically disrupt the C-Zn knuckle by initial acylation of Cys413, and show that transient, sparsely-populated ("dark"), excited states of proteins can present effective targets for rational drug design.
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Affiliation(s)
- Lalit Deshmukh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892-0520, USA.,Present address: Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Vitali Tugarinov
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892-0520, USA
| | - Daniel H Appella
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892-0830, USA
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892-0520, USA
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98
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Yuwen T, Kay LE. A new class of CEST experiment based on selecting different magnetization components at the start and end of the CEST relaxation element: an application to 1H CEST. JOURNAL OF BIOMOLECULAR NMR 2018; 70:93-102. [PMID: 29352366 DOI: 10.1007/s10858-017-0161-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/22/2017] [Indexed: 06/07/2023]
Abstract
Chemical exchange saturation transfer (CEST) experiments are becoming increasingly popular for investigating biomolecular exchange dynamics with rates on the order of approximately 50-500 s-1 and a rich toolkit of different methods has emerged over the past few years. Typically, experiments are based on the evolution of longitudinal magnetization, or in some cases two-spin order, during a fixed CEST relaxation delay, with the same class of magnetization prepared at the start and selected at end of the CEST period. Here we present a pair of TROSY-based pulse schemes for recording amide and methyl 1H CEST profiles where longitudinal magnetization at the start evolves to produce two-spin order that is then selected at the completion of the CEST element. This selection process subtracts out contributions from 1H-1H cross-relaxation on the fly that would otherwise complicate analysis of the data. It also obviates the need to record spin-state selective CEST profiles as an alternative to eliminating NOE effects, leading to significant improvements in sensitivity. The utility of the approach is demonstrated on a sample of a cavity mutant of T4 lysozyme that undergoes chemical exchange between conformations where the cavity is free and occupied.
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Affiliation(s)
- Tairan Yuwen
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Lewis E Kay
- Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada.
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99
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Yuwen T, Brady JP, Kay LE. Probing Conformational Exchange in Weakly Interacting, Slowly Exchanging Protein Systems via Off-Resonance R1ρ Experiments: Application to Studies of Protein Phase Separation. J Am Chem Soc 2018; 140:2115-2126. [DOI: 10.1021/jacs.7b09576] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Tairan Yuwen
- Departments
of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Jacob P. Brady
- Departments
of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Lewis E. Kay
- Departments
of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
- Hospital for Sick Children, Program in Molecular Medicine, Toronto, Ontario, Canada M5G 1X8
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100
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Current Solution NMR Techniques for Structure-Function Studies of Proteins and RNA Molecules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1105:43-58. [DOI: 10.1007/978-981-13-2200-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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