1
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Lebedenko OO, Salikov VA, Izmailov SA, Podkorytov IS, Skrynnikov NR. Using NMR diffusion data to validate MD models of disordered proteins: Test case of N-terminal tail of histone H4. Biophys J 2024; 123:80-100. [PMID: 37990496 PMCID: PMC10808029 DOI: 10.1016/j.bpj.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/28/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
MD simulations can provide uniquely detailed models of intrinsically disordered proteins (IDPs). However, these models need careful experimental validation. The coefficient of translational diffusion Dtr, measurable by pulsed field gradient NMR, offers a potentially useful piece of experimental information related to the compactness of the IDP's conformational ensemble. Here, we investigate, both experimentally and via the MD modeling, the translational diffusion of a 25-residue N-terminal fragment from histone H4 (N-H4). We found that the predicted values of Dtr, as obtained from mean-square displacement of the peptide in the MD simulations, are largely determined by the viscosity of the MD water (which has been reinvestigated as a part of our study). Beyond that, our analysis of the diffusion data indicates that MD simulations of N-H4 in the TIP4P-Ew water give rise to an overly compact conformational ensemble for this peptide. In contrast, TIP4P-D and OPC simulations produce the ensembles that are consistent with the experimental Dtr result. These observations are supported by the analyses of the 15N spin relaxation rates. We also tested a number of empirical methods to predict Dtr based on IDP's coordinates extracted from the MD snapshots. In particular, we show that the popular approach involving the program HYDROPRO can produce misleading results. This happens because HYDROPRO is not intended to predict the diffusion properties of highly flexible biopolymers such as IDPs. Likewise, recent empirical schemes that exploit the relationship between the small-angle x-ray scattering-informed conformational ensembles of IDPs and the respective experimental Dtr values also prove to be problematic. In this sense, the first-principle calculations of Dtr from the MD simulations, such as demonstrated in this work, should provide a useful benchmark for future efforts in this area.
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Affiliation(s)
- Olga O Lebedenko
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Vladislav A Salikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia; Department of Chemistry, Purdue University, West Lafayette, Indiana.
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2
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Sun W, Lebedenko OO, Salguero NG, Shannon MD, Zandian M, Poirier MG, Skrynnikov NR, Jaroniec CP. Conformational and Interaction Landscape of Histone H4 Tails in Nucleosomes Probed by Paramagnetic NMR Spectroscopy. J Am Chem Soc 2023; 145:25478-25485. [PMID: 37943892 PMCID: PMC10719895 DOI: 10.1021/jacs.3c10340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The fundamental repeat unit of chromatin, the nucleosome, consists of approximately 147 base pairs of double-stranded DNA and a histone protein octamer containing two copies each of histones H2A, H2B, H3, and H4. Each histone possesses a dynamically disordered N-terminal tail domain, and it is well-established that the tails of histones H3 and H4 play key roles in chromatin compaction and regulation. Here we investigate the conformational ensemble and interactions of the H4 tail in nucleosomes by means of solution NMR measurements of paramagnetic relaxation enhancements (PREs) in recombinant samples reconstituted with 15N-enriched H4 and nitroxide spin-label tagged H3. The experimental PREs, which report on the proximities of individual H4 tail residues to the different H3 spin-label sites, are interpreted by using microsecond time-scale molecular dynamics simulations of the nucleosome core particle. Collectively, these data enable improved localization of histone H4 tails in nucleosomes and support the notion that H4 tails engage in a fuzzy complex interaction with nucleosomal DNA.
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Affiliation(s)
- Wenjun Sun
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Olga O. Lebedenko
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Nicole Gonzalez Salguero
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Matthew D. Shannon
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Mohamad Zandian
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Michael G. Poirier
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
| | - Nikolai R. Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
- Department of Chemistry, Purdue University, West Lafayette 47907, United States
| | - Christopher P. Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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3
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Abyzov A, Mandelkow E, Zweckstetter M, Rezaei-Ghaleh N. Fast Motions Dominate Dynamics of Intrinsically Disordered Tau Protein at High Temperatures. Chemistry 2023; 29:e202203493. [PMID: 36579699 DOI: 10.1002/chem.202203493] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/17/2022] [Accepted: 12/21/2022] [Indexed: 12/30/2022]
Abstract
Reorientational dynamics of intrinsically disordered proteins (IDPs) contain multiple motions often clustered around three motional modes: ultrafast librational motions of amide groups, fast local backbone conformational fluctuations and slow chain segmental motions. This dynamic picture is mainly based on 15 N NMR relaxation studies of IDPs at relatively low temperatures where the amide-water proton exchange rates are sufficiently small. Less is known, however, about the dynamics of IDPs at more physiological temperatures. Here, we investigate protein dynamics in a 441-residue long IDP, tau protein, in the temperature range from 0-25 °C, using 15 N NMR relaxation rates and spectral density analysis. While at these temperatures relaxation rates are still better described in terms of amide group librational motions, local backbone dynamics and chain segmental motions, the temperature-dependent trend of spectral densities suggests that the timescales of fast backbone conformational fluctuations and slower chain segmental motions might become inseparable at higher temperatures. Our data demonstrate the remarkable dynamic plasticity of this prototypical IDP and highlight the need for dynamic studies of IDPs at multiple temperatures.
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Affiliation(s)
- Anton Abyzov
- Translational Structural Biology Group, German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, D-37075, Göttingen, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Venusberg-Campus 1, D-53127, Bonn, Germany
- Research Center CAESAR, Ludwig-Erhard-Allee 2, D-53175, Bonn, Germany
| | - Markus Zweckstetter
- Department of NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077, Göttingen, Germany
- Translational Structural Biology Group, German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, D-37075, Göttingen, Germany
| | - Nasrollah Rezaei-Ghaleh
- Institute of Physical Biology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, D-40225, Düsseldorf, Germany
- Institute of Biological Information Processing, IBI-7: Structural Biochemistry, Forschungszentrum Jülich, D-52428, Jülich, Germany
- Department of NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, D-37077, Göttingen, Germany
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4
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Yu L, Brüschweiler R. Quantitative prediction of ensemble dynamics, shapes and contact propensities of intrinsically disordered proteins. PLoS Comput Biol 2022; 18:e1010036. [PMID: 36084124 PMCID: PMC9491582 DOI: 10.1371/journal.pcbi.1010036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 09/21/2022] [Accepted: 08/03/2022] [Indexed: 12/29/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are highly dynamic systems that play an important role in cell signaling processes and their misfunction often causes human disease. Proper understanding of IDP function not only requires the realistic characterization of their three-dimensional conformational ensembles at atomic-level resolution but also of the time scales of interconversion between their conformational substates. Large sets of experimental data are often used in combination with molecular modeling to restrain or bias models to improve agreement with experiment. It is shown here for the N-terminal transactivation domain of p53 (p53TAD) and Pup, which are two IDPs that fold upon binding to their targets, how the latest advancements in molecular dynamics (MD) simulations methodology produces native conformational ensembles by combining replica exchange with series of microsecond MD simulations. They closely reproduce experimental data at the global conformational ensemble level, in terms of the distribution properties of the radius of gyration tensor, and at the local level, in terms of NMR properties including 15N spin relaxation, without the need for reweighting. Further inspection revealed that 10-20% of the individual MD trajectories display the formation of secondary structures not observed in the experimental NMR data. The IDP ensembles were analyzed by graph theory to identify dominant inter-residue contact clusters and characteristic amino-acid contact propensities. These findings indicate that modern MD force fields with residue-specific backbone potentials can produce highly realistic IDP ensembles sampling a hierarchy of nano- and picosecond time scales providing new insights into their biological function.
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Affiliation(s)
- Lei Yu
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Rafael Brüschweiler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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5
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He W, Li X, Xue H, Yang Y, Mencius J, Bai L, Zhang J, Xu J, Wu B, Xue Y, Quan S. Insights into the client protein release mechanism of the ATP-independent chaperone Spy. Nat Commun 2022; 13:2818. [PMID: 35595811 PMCID: PMC9122904 DOI: 10.1038/s41467-022-30499-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
Molecular chaperones play a central role in regulating protein homeostasis, and their active forms often contain intrinsically disordered regions (IDRs). However, how IDRs impact chaperone action remains poorly understood. Here, we discover that the disordered N terminus of the prototype chaperone Spy facilitates client release. With NMR spectroscopy and molecular dynamics simulations, we find that the N terminus can bind transiently to the client-binding cavity of Spy primarily through electrostatic interactions mediated by the N-terminal D26 residue. This intramolecular interaction results in a dynamic competition of the N terminus with the client for binding to Spy, which promotes client discharge. Our results reveal the mechanism by which Spy releases clients independent of energy input, thus enriching the current knowledge on how ATP-independent chaperones release their clients and highlighting the importance of synergy between IDRs and structural domains in regulating protein function.
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Affiliation(s)
- Wei He
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China
| | - Xinming Li
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100084, Beijing, China
| | - Hongjuan Xue
- National Facility for Protein Science in Shanghai, ZhangJiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Yuanyuan Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China
| | - Jun Mencius
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China
| | - Ling Bai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China
| | - Jiayin Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China
| | - Jianhe Xu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China
| | - Bin Wu
- National Facility for Protein Science in Shanghai, ZhangJiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China.
| | - Yi Xue
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Tsinghua University, 100084, Beijing, China.
| | - Shu Quan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai Collaborative Innovation Center for Biomanufacturing (SCICB), Shanghai, 200237, China. .,Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, East China University of Science and Technology, Shanghai, 200237, China.
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6
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Camacho-Zarco AR, Schnapka V, Guseva S, Abyzov A, Adamski W, Milles S, Jensen MR, Zidek L, Salvi N, Blackledge M. NMR Provides Unique Insight into the Functional Dynamics and Interactions of Intrinsically Disordered Proteins. Chem Rev 2022; 122:9331-9356. [PMID: 35446534 PMCID: PMC9136928 DOI: 10.1021/acs.chemrev.1c01023] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
Intrinsically disordered
proteins are ubiquitous throughout all
known proteomes, playing essential roles in all aspects of cellular
and extracellular biochemistry. To understand their function, it is
necessary to determine their structural and dynamic behavior and to
describe the physical chemistry of their interaction trajectories.
Nuclear magnetic resonance is perfectly adapted to this task, providing
ensemble averaged structural and dynamic parameters that report on
each assigned resonance in the molecule, unveiling otherwise inaccessible
insight into the reaction kinetics and thermodynamics that are essential
for function. In this review, we describe recent applications of NMR-based
approaches to understanding the conformational energy landscape, the
nature and time scales of local and long-range dynamics and how they
depend on the environment, even in the cell. Finally, we illustrate
the ability of NMR to uncover the mechanistic basis of functional
disordered molecular assemblies that are important for human health.
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Affiliation(s)
| | - Vincent Schnapka
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Serafima Guseva
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Anton Abyzov
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Wiktor Adamski
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | - Sigrid Milles
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
| | | | - Lukas Zidek
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 82500 Brno, Czech Republic.,Central European Institute of Technology, Masaryk University, Kamenice 5, 82500 Brno, Czech Republic
| | - Nicola Salvi
- Université Grenoble Alpes, CEA, CNRS, IBS, 38000 Grenoble, France
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7
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Abyzov A, Blackledge M, Zweckstetter M. Conformational Dynamics of Intrinsically Disordered Proteins Regulate Biomolecular Condensate Chemistry. Chem Rev 2022; 122:6719-6748. [PMID: 35179885 PMCID: PMC8949871 DOI: 10.1021/acs.chemrev.1c00774] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Motions in biomolecules
are critical for biochemical reactions.
In cells, many biochemical reactions are executed inside of biomolecular
condensates formed by ultradynamic intrinsically disordered proteins.
A deep understanding of the conformational dynamics of intrinsically
disordered proteins in biomolecular condensates is therefore of utmost
importance but is complicated by diverse obstacles. Here we review
emerging data on the motions of intrinsically disordered proteins
inside of liquidlike condensates. We discuss how liquid–liquid
phase separation modulates internal motions across a wide range of
time and length scales. We further highlight the importance of intermolecular
interactions that not only drive liquid–liquid phase separation
but appear as key determinants for changes in biomolecular motions
and the aging of condensates in human diseases. The review provides
a framework for future studies to reveal the conformational dynamics
of intrinsically disordered proteins in the regulation of biomolecular
condensate chemistry.
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Affiliation(s)
- Anton Abyzov
- Translational Structural Biology Group, German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| | - Martin Blackledge
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 38044 Grenoble, France.,CEA, DSV, IBS, 38044 Grenoble, France.,CNRS, IBS, 38044 Grenoble, France
| | - Markus Zweckstetter
- Translational Structural Biology Group, German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany.,Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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8
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Das D, Arora L, Mukhopadhyay S. Fluorescence Depolarization Kinetics Captures Short-Range Backbone Dihedral Rotations and Long-Range Correlated Dynamics of an Intrinsically Disordered Protein. J Phys Chem B 2021; 125:9708-9718. [PMID: 34415768 DOI: 10.1021/acs.jpcb.1c04426] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intrinsically disordered proteins (IDPs) do not autonomously fold into well-defined three-dimensional structures and are best described as a heterogeneous ensemble of rapidly interconverting conformers. It is challenging to elucidate their complex dynamic signatures using a single technique. In this study, we employed sensitive fluorescence depolarization kinetics by following picosecond time-resolved fluorescence anisotropy decays to directly capture the essential dynamical features of intrinsically disordered α-synuclein (α-syn) site-specifically labeled with thiol-active fluorophores. By utilizing a long-lifetime (≥10 ns) anisotropic label, we were able to discern three distinct rotational components of α-syn. The subnanosecond component represents the local wobbling-in-cone motion of the fluorophore, whereas the slower (∼1.4 ns) component corresponds to the short-range backbone dynamics governed by collective torsional fluctuations in the Ramachandran Φ-Ψ dihedral space. This backbone dihedral rotational time scale is sensitive to the local chain stiffness and slows down in the presence of an adjacent proline residue. We also observed a small-amplitude (≤10%) slower rotational correlation time (6-10 ns) that represents the long-range correlated dynamics involving a much longer segment of the polypeptide chain. These intrinsic dynamic signatures of IDPs will provide critical mechanistic underpinnings in a mosaic of biophysical phenomena involving internal friction, allosteric interactions, and phase separation.
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9
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Virtanen SI, Kiirikki AM, Mikula KM, Iwaï H, Ollila OHS. Heterogeneous dynamics in partially disordered proteins. Phys Chem Chem Phys 2021; 22:21185-21196. [PMID: 32929427 DOI: 10.1039/d0cp03473h] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Importance of disordered protein regions is increasingly recognized in biology, but their characterization remains challenging due to the lack of suitable experimental and theoretical methods. NMR experiments can detect multiple timescale dynamics and structural details of disordered protein regions, but their detailed interpretation is often difficult. Here we combine protein backbone 15N spin relaxation data with molecular dynamics (MD) simulations to detect not only heterogeneous dynamics of large partially disordered proteins but also their conformational ensembles. We observed that the rotational dynamics of folded regions in partially disordered proteins is dominated by similar rigid body rotation as in globular proteins, thereby being largely independent of flexible disordered linkers. Disordered regions, on the other hand, exhibit complex rotational motions with multiple timescales below ∼30 ns which are difficult to detect from experimental data alone, but can be captured by MD simulations. Combining MD simulations and backbone 15N spin relaxation data, measured applying segmental isotopic labeling with salt-inducible split intein, we resolved the conformational ensemble and dynamics of partially disordered periplasmic domain of TonB protein from Helicobacter pylori containing 250 residues. To demonstrate the universality of our approach, it was applied also to the partially disordered region of chicken Engrailed 2. Our results pave the way in understanding how TonB transfers energy from inner membrane to the outer membrane receptors in Gram-negative bacteria, as well as the function of other proteins with disordered domains.
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Affiliation(s)
- Salla I Virtanen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - Anne M Kiirikki
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - Kornelia M Mikula
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - Hideo Iwaï
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - O H Samuli Ollila
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
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10
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Tesei G, Martins JM, Kunze MBA, Wang Y, Crehuet R, Lindorff-Larsen K. DEER-PREdict: Software for efficient calculation of spin-labeling EPR and NMR data from conformational ensembles. PLoS Comput Biol 2021; 17:e1008551. [PMID: 33481784 PMCID: PMC7857587 DOI: 10.1371/journal.pcbi.1008551] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 02/03/2021] [Accepted: 11/19/2020] [Indexed: 11/25/2022] Open
Abstract
Owing to their plasticity, intrinsically disordered and multidomain proteins require descriptions based on multiple conformations, thus calling for techniques and analysis tools that are capable of dealing with conformational ensembles rather than a single protein structure. Here, we introduce DEER-PREdict, a software program to predict Double Electron-Electron Resonance distance distributions as well as Paramagnetic Relaxation Enhancement rates from ensembles of protein conformations. DEER-PREdict uses an established rotamer library approach to describe the paramagnetic probes which are bound covalently to the protein.DEER-PREdict has been designed to operate efficiently on large conformational ensembles, such as those generated by molecular dynamics simulation, to facilitate the validation or refinement of molecular models as well as the interpretation of experimental data. The performance and accuracy of the software is demonstrated with experimentally characterized protein systems: HIV-1 protease, T4 Lysozyme and Acyl-CoA-binding protein. DEER-PREdict is open source (GPLv3) and available at github.com/KULL-Centre/DEERpredict and as a Python PyPI package pypi.org/project/DEERPREdict.
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Affiliation(s)
- Giulio Tesei
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - João M. Martins
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Micha B. A. Kunze
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Yong Wang
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ramon Crehuet
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- CSIC-Institute for Advanced Chemistry of Catalonia (IQAC), Barcelona, Spain
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory & the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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11
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Gomes GNW, Krzeminski M, Namini A, Martin EW, Mittag T, Head-Gordon T, Forman-Kay JD, Gradinaru CC. Conformational Ensembles of an Intrinsically Disordered Protein Consistent with NMR, SAXS, and Single-Molecule FRET. J Am Chem Soc 2020; 142:15697-15710. [PMID: 32840111 PMCID: PMC9987321 DOI: 10.1021/jacs.0c02088] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intrinsically disordered proteins (IDPs) have fluctuating heterogeneous conformations, which makes their structural characterization challenging. Although challenging, characterization of the conformational ensembles of IDPs is of great interest, since their conformational ensembles are the link between their sequences and functions. An accurate description of IDP conformational ensembles depends crucially on the amount and quality of the experimental data, how it is integrated, and if it supports a consistent structural picture. We used integrative modeling and validation to apply conformational restraints and assess agreement with the most common structural techniques for IDPs: Nuclear Magnetic Resonance (NMR) spectroscopy, Small-angle X-ray Scattering (SAXS), and single-molecule Förster Resonance Energy Transfer (smFRET). Agreement with such a diverse set of experimental data suggests that details of the generated ensembles can now be examined with a high degree of confidence. Using the disordered N-terminal region of the Sic1 protein as a test case, we examined relationships between average global polymeric descriptions and higher-moments of their distributions. To resolve apparent discrepancies between smFRET and SAXS inferences, we integrated SAXS data with NMR data and reserved the smFRET data for independent validation. Consistency with smFRET, which was not guaranteed a priori, indicates that, globally, the perturbative effects of NMR or smFRET labels on the Sic1 ensemble are minimal. Analysis of the ensembles revealed distinguishing features of Sic1, such as overall compactness and large end-to-end distance fluctuations, which are consistent with biophysical models of Sic1's ultrasensitive binding to its partner Cdc4. Our results underscore the importance of integrative modeling and validation in generating and drawing conclusions from IDP conformational ensembles.
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Affiliation(s)
- Gregory-Neal W Gomes
- Department of Physics, University of Toronto, Toronto, Ontario M5G 1X8, Canada.,Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Mickaël Krzeminski
- Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Ashley Namini
- Department of Physics, University of Toronto, Toronto, Ontario M5G 1X8, Canada.,Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Erik W Martin
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, United States
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, United States
| | - Teresa Head-Gordon
- Departments of Chemistry, Bioengineering, Chemical and Biomolecular Engineering University of California, Berkeley, California 94720, United States
| | - Julie D Forman-Kay
- Molecular Medicine Program, Hospital for Sick Children, Toronto, Ontario M5S 1A8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Claudiu C Gradinaru
- Department of Physics, University of Toronto, Toronto, Ontario M5G 1X8, Canada.,Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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12
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Yu F, Wang C, Li Y, Ma H, Wang R, Liu Y, Suzuki N, Terashima C, Ohtani B, Ochiai T, Fujishima A, Zhang X. Enhanced Solar Photothermal Catalysis over Solution Plasma Activated TiO 2. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2000204. [PMID: 32832348 PMCID: PMC7435248 DOI: 10.1002/advs.202000204] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/25/2020] [Indexed: 05/22/2023]
Abstract
Colored wide-bandgap semiconductor oxides with abundant mid-gap states have long been regarded as promising visible light responsive photocatalysts. However, their catalytic activities are hampered by charge recombination at deep level defects, which constitutes the critical challenge to practical applications of these oxide photocatalysts. To address the challenge, a strategy is proposed here that includes creating shallow-level defects above the deep-level defects and thermal activating the migration of trapped electrons out of the deep-level defects via these shallow defects. A simple and scalable solution plasma processing (SPP) technique is developed to process the presynthesized yellow TiO2 with numerous oxygen vacancies (Ov), which incorporates hydrogen dopants into the TiO2 lattice and creates shallow-level defects above deep level of Ov, meanwhile retaining the original visible absorption of the colored TiO2. At elevated temperature, the SPP-treated TiO2 exhibits a 300 times higher conversion rate for CO2 reduction under solar light irradiation and a 7.5 times higher removal rate of acetaldehyde under UV light irradiation, suggesting the effectiveness of the proposed strategy to enhance the photoactivity of colored wide-bandgap oxides for energy and environmental applications.
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Affiliation(s)
- Fei Yu
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
| | - Changhua Wang
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
| | - Yingying Li
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
| | - He Ma
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
| | - Rui Wang
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
| | - Yichun Liu
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
| | - Norihiro Suzuki
- Photocatalysis International Research CenterResearch Institute for Science & TechnologyTokyo University of Science2641 YamazakiNodaChiba278‐8510Japan
| | - Chiaki Terashima
- Photocatalysis International Research CenterResearch Institute for Science & TechnologyTokyo University of Science2641 YamazakiNodaChiba278‐8510Japan
| | - Bunsho Ohtani
- Graduate School of Environmental ScienceHokkaido UniversitySapporo060‐0810Japan
| | - Tsuyoshi Ochiai
- Materials Analysis GroupKawasaki Technical Support DepartmentLocal Independent Administrative Agency Kanagawa Institute of industrial Science and Technology (KISTEC)Kanagawa213‐0012Japan
| | - Akira Fujishima
- Photocatalysis International Research CenterResearch Institute for Science & TechnologyTokyo University of Science2641 YamazakiNodaChiba278‐8510Japan
| | - Xintong Zhang
- Key Laboratory of UV‐Emitting Materials and Technology of Chinese Ministry of EducationNortheast Normal UniversityChangchun130024China
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13
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Zou Y, Yu L, Fang X, Zheng Y, Yang Y, Wang C. Position-coded multivalent peptide-peptide interactions revealed by tryptophan-scanning mutagenesis. J Pept Sci 2020; 26:e3273. [PMID: 32583616 DOI: 10.1002/psc.3273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/06/2020] [Accepted: 06/09/2020] [Indexed: 11/08/2022]
Abstract
We demonstrate in this contribution the evidence that significant cooperative binding effect can be identified for the amino acid sites that are determinant to the binding characteristics in peptide-peptide interactions. The analysis of tryptophan-scanning mutagenesis of the 14-mer peptide consisting only of glycine provides a mapping of position-dependent contributions to the binding energy. The pronounced tryptophan-associated peptide-peptide interactions are originated from the indole moieties with the main chains of 14-mer glycines containing N-H and CO moieties. Specifically, with the presence of two tryptophans as determinant amino acids, cooperative binding can be observed, which are dependent on relative positions of the two tryptophans with a "volcano"-like characteristics. An optimal separation of 6-10 amino acids between two adjacent binding sites can be identified to achieve maximal binding interactions.
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Affiliation(s)
- Yimin Zou
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology, Beijing, China.,Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, China
| | - Lanlan Yu
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology, Beijing, China.,State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Xiaocui Fang
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology, Beijing, China
| | - Yongfang Zheng
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology, Beijing, China.,Department of Chemistry, Tsinghua University, Beijing, China
| | - Yanlian Yang
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology, Beijing, China
| | - Chen Wang
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology, Beijing, China
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14
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Hicks A, Escobar CA, Cross TA, Zhou HX. Sequence-Dependent Correlated Segments in the Intrinsically Disordered Region of ChiZ. Biomolecules 2020; 10:biom10060946. [PMID: 32585849 PMCID: PMC7355643 DOI: 10.3390/biom10060946] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 12/12/2022] Open
Abstract
How sequences of intrinsically disordered proteins (IDPs) code for their conformational dynamics is poorly understood. Here, we combined NMR spectroscopy, small-angle X-ray scattering (SAXS), and molecular dynamics (MD) simulations to characterize the conformations and dynamics of ChiZ1-64. MD simulations, first validated by SAXS and secondary chemical shift data, found scant α-helices or β-strands but a considerable propensity for polyproline II (PPII) torsion angles. Importantly, several blocks of residues (e.g., 11–29) emerge as “correlated segments”, identified by their frequent formation of PPII stretches, salt bridges, cation-π interactions, and sidechain-backbone hydrogen bonds. NMR relaxation experiments showed non-uniform transverse relaxation rates (R2s) and nuclear Overhauser enhancements (NOEs) along the sequence (e.g., high R2s and NOEs for residues 11–14 and 23–28). MD simulations further revealed that the extent of segmental correlation is sequence-dependent; segments where internal interactions are more prevalent manifest elevated “collective” motions on the 5–10 ns timescale and suppressed local motions on the sub-ns timescale. Amide proton exchange rates provides corroboration, with residues in the most correlated segment exhibiting the highest protection factors. We propose the correlated segment as a defining feature for the conformations and dynamics of IDPs.
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Affiliation(s)
- Alan Hicks
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; (A.H.); (C.A.E.)
- Department of Physics, Florida State University, Tallahassee, FL 32306, USA
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Cristian A. Escobar
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; (A.H.); (C.A.E.)
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Timothy A. Cross
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA; (A.H.); (C.A.E.)
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
- Correspondence: (T.A.C.); (H.-X.Z.)
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
- Correspondence: (T.A.C.); (H.-X.Z.)
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15
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Izmailov SA, Rabdano SO, Hasanbasri Z, Podkorytov IS, Saxena S, Skrynnikov NR. Structural and dynamic origins of ESR lineshapes in spin-labeled GB1 domain: the insights from spin dynamics simulations based on long MD trajectories. Sci Rep 2020; 10:957. [PMID: 31969574 PMCID: PMC6976580 DOI: 10.1038/s41598-019-56750-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 12/06/2019] [Indexed: 12/04/2022] Open
Abstract
Site-directed spin labeling (SDSL) ESR is a valuable tool to probe protein systems that are not amenable to characterization by x-ray crystallography, NMR or EM. While general principles that govern the shape of SDSL ESR spectra are known, its precise relationship with protein structure and dynamics is still not fully understood. To address this problem, we designed seven variants of GB1 domain bearing R1 spin label and recorded the corresponding MD trajectories (combined length 180 μs). The MD data were subsequently used to calculate time evolution of the relevant spin density matrix and thus predict the ESR spectra. The simulated spectra proved to be in good agreement with the experiment. Further analysis confirmed that the spectral shape primarily reflects the degree of steric confinement of the R1 tag and, for the well-folded protein such as GB1, offers little information on local backbone dynamics. The rotameric preferences of R1 side chain are determined by the type of the secondary structure at the attachment site. The rotameric jumps involving dihedral angles χ1 and χ2 are sufficiently fast to directly influence the ESR lineshapes. However, the jumps involving multiple dihedral angles tend to occur in (anti)correlated manner, causing smaller-than-expected movements of the R1 proxyl ring. Of interest, ESR spectra of GB1 domain with solvent-exposed spin label can be accurately reproduced by means of Redfield theory. In particular, the asymmetric character of the spectra is attributable to Redfield-type cross-correlations. We envisage that the current MD-based, experimentally validated approach should lead to a more definitive, accurate picture of SDSL ESR experiments.
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Affiliation(s)
- Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russia
| | - Sevastyan O Rabdano
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russia
| | - Zikri Hasanbasri
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russia
| | - Sunil Saxena
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, 199034, Russia.
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA.
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16
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Adamski W, Salvi N, Maurin D, Magnat J, Milles S, Jensen MR, Abyzov A, Moreau CJ, Blackledge M. A Unified Description of Intrinsically Disordered Protein Dynamics under Physiological Conditions Using NMR Spectroscopy. J Am Chem Soc 2019; 141:17817-17829. [PMID: 31591893 DOI: 10.1021/jacs.9b09002] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Intrinsically disordered proteins (IDPs) are flexible biomolecules whose essential functions are defined by their dynamic nature. Nuclear magnetic resonance (NMR) spectroscopy is ideally suited to the investigation of this behavior at atomic resolution. NMR relaxation is increasingly used to detect conformational dynamics in free and bound forms of IDPs under conditions approaching physiological, although a general framework providing a quantitative interpretation of these exquisitely sensitive probes as a function of experimental conditions is still lacking. Here, measuring an extensive set of relaxation rates sampling multiple-time-scale dynamics over a broad range of crowding conditions, we develop and test an integrated analytical description that accurately portrays the motion of IDPs as a function of the intrinsic properties of the crowded molecular environment. In particular we observe a strong dependence of both short-range and long-range motional time scales of the protein on the friction of the solvent. This tight coupling between the dynamic behavior of the IDP and its environment allows us to develop analytical expressions for protein motions and NMR relaxation properties that can be accurately applied over a vast range of experimental conditions. This unified dynamic description provides new insight into the physical behavior of IDPs, extending our ability to quantitatively investigate their conformational dynamics under complex environmental conditions, and accurately predicting relaxation rates reporting on motions on time scales up to tens of nanoseconds, both in vitro and in cellulo.
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Affiliation(s)
- Wiktor Adamski
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Nicola Salvi
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Damien Maurin
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Justine Magnat
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Sigrid Milles
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Malene Ringkjøbing Jensen
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Anton Abyzov
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Christophe J Moreau
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
| | - Martin Blackledge
- Institut de Biologie Structurale , Université Grenoble Alpes-CEA-CNRS , 71, Avenue des Martyrs , Grenoble , France
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17
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Smith AA, Ernst M, Riniker S, Meier BH. Localized and Collective Motions in HET-s(218-289) Fibrils from Combined NMR Relaxation and MD Simulation. Angew Chem Int Ed Engl 2019; 58:9383-9388. [PMID: 31070275 PMCID: PMC6618077 DOI: 10.1002/anie.201901929] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/17/2019] [Indexed: 12/20/2022]
Abstract
Nuclear magnetic resonance (NMR) relaxation data and molecular dynamics (MD) simulations are combined to characterize the dynamics of the fungal prion HET-s(218-289) in its amyloid form. NMR data is analyzed with the dynamics detector method, which yields timescale-specific information. An analogous analysis is performed on MD trajectories. Because specific MD predictions can be verified as agreeing with the NMR data, MD was used for further interpretation of NMR results: for the different timescales, cross-correlation coefficients were derived to quantify the correlation of the motion between different residues. Short timescales are the result of very local motions, while longer timescales are found for longer-range correlated motion. Similar trends on ns- and μs-timescales suggest that μs motion in fibrils is the result of motion correlated over many fibril layers.
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Affiliation(s)
- Albert A. Smith
- Physical ChemistryETH ZurichVladimir-Prelog-Weg 28093ZurichSwitzerland
- Present address: Institut für Medizinische Physik und BiophysikUniversität LeipzigHärtelstraße 16–1804107LeipzigGermany
| | - Matthias Ernst
- Physical ChemistryETH ZurichVladimir-Prelog-Weg 28093ZurichSwitzerland
| | - Sereina Riniker
- Physical ChemistryETH ZurichVladimir-Prelog-Weg 28093ZurichSwitzerland
| | - Beat H. Meier
- Physical ChemistryETH ZurichVladimir-Prelog-Weg 28093ZurichSwitzerland
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18
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Smith AA, Ernst M, Riniker S, Meier BH. Localized and Collective Motions in HET‐s(218‐289) Fibrils from Combined NMR Relaxation and MD Simulation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201901929] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Albert A. Smith
- Physical ChemistryETH Zurich Vladimir-Prelog-Weg 2 8093 Zurich Switzerland
- Present address: Institut für Medizinische Physik und BiophysikUniversität Leipzig Härtelstraße 16–18 04107 Leipzig Germany
| | - Matthias Ernst
- Physical ChemistryETH Zurich Vladimir-Prelog-Weg 2 8093 Zurich Switzerland
| | - Sereina Riniker
- Physical ChemistryETH Zurich Vladimir-Prelog-Weg 2 8093 Zurich Switzerland
| | - Beat H. Meier
- Physical ChemistryETH Zurich Vladimir-Prelog-Weg 2 8093 Zurich Switzerland
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19
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Kämpf K, Izmailov SA, Rabdano SO, Groves AT, Podkorytov IS, Skrynnikov NR. What Drives 15N Spin Relaxation in Disordered Proteins? Combined NMR/MD Study of the H4 Histone Tail. Biophys J 2018; 115:2348-2367. [PMID: 30527335 DOI: 10.1016/j.bpj.2018.11.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/07/2018] [Accepted: 11/12/2018] [Indexed: 12/26/2022] Open
Abstract
Backbone (15N) NMR relaxation is one of the main sources of information on dynamics of disordered proteins. Yet, we do not know very well what drives 15N relaxation in such systems, i.e., how different forms of motion contribute to the measurable relaxation rates. To address this problem, we have investigated, both experimentally and via molecular dynamics simulations, the dynamics of a 26-residue peptide imitating the N-terminal portion of the histone protein H4. One part of the peptide was found to be fully flexible, whereas the other part features some transient structure (a hairpin stabilized by hydrogen bonds). The following motional modes proved relevant for 15N relaxation. 1) Sub-picosecond librations attenuate relaxation rates according to S2 ∼0.85-0.90. 2) Axial peptide-plane fluctuations along a stretch of the peptide chain contribute to relaxation-active dynamics on a fast timescale (from tens to hundreds of picoseconds). 3) φ/ψ backbone jumps contribute to relaxation-active dynamics on both fast (from tens to hundreds of picoseconds) and slow (from hundreds of picoseconds to a nanosecond) timescales. The major contribution is from polyproline II (PPII) ↔ β transitions in the Ramachandran space; in the case of glycine residues, the major contribution is from PPII ↔ (β) ↔ rPPII transitions, in which rPPII is the mirror-image (right-handed) version of the PPII geometry, whereas β geometry plays the role of an intermediate state. 4) Reorientational motion of certain (sufficiently long-lived) elements of transient structure, i.e., rotational tumbling, contributes to slow relaxation-active dynamics on ∼1-ns timescale (however, it is difficult to isolate this contribution). In conclusion, recent advances in the area of force-field development have made it possible to obtain viable Molecular Dynamics models of protein disorder. After careful validation against the experimental relaxation data, these models can provide a valuable insight into mechanistic origins of spin relaxation in disordered peptides and proteins.
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Affiliation(s)
- Kerstin Kämpf
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sevastyan O Rabdano
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Adam T Groves
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia; Department of Chemistry, Purdue University, West Lafayette, Indiana.
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20
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Hsu A, Ferrage F, Palmer AG. Analysis of NMR Spin-Relaxation Data Using an Inverse Gaussian Distribution Function. Biophys J 2018; 115:2301-2309. [PMID: 30503534 DOI: 10.1016/j.bpj.2018.10.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/28/2018] [Accepted: 10/24/2018] [Indexed: 02/08/2023] Open
Abstract
Spin relaxation in solution-state NMR spectroscopy is a powerful approach to explore the conformational dynamics of biological macromolecules. Probability distribution functions for overall or internal correlation times have been used previously to model spectral density functions central to spin-relaxation theory. Applications to biological macromolecules rely on transverse relaxation rate constants, and when studying nanosecond timescale motions, sampling at ultralow frequencies is often necessary. Consequently, appropriate distribution functions necessitate spectral density functions that are accurate and convergent as frequencies approach zero. In this work, the inverse Gaussian probability distribution function is derived from general properties of spectral density functions at low and high frequencies for macromolecules in solution, using the principle of maximal entropy. This normalized distribution function is first used to calculate the correlation function, followed by the spectral density function. The resulting model-free spectral density functions are finite at a frequency of zero and can be used to describe distributions of either overall or internal correlation times using the model-free ansatz. To validate the approach, 15N spin-relaxation data for the bZip transcription factor domain of the Saccharomyces cerevisiae protein GCN4, in the absence of cognate DNA, were analyzed using the inverse Gaussian probability distribution for intramolecular correlation times. The results extend previous models for the conformational dynamics of the intrinsically disordered, DNA-binding region of the bZip transcription factor domain.
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Affiliation(s)
- Andrew Hsu
- Department of Chemistry, Columbia University, New York, New York
| | - Fabien Ferrage
- Laboratoire des Biomolécules, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, Paris, France
| | - Arthur G Palmer
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York.
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21
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Kooshapur H, Schwieters CD, Tjandra N. Conformational Ensemble of Disordered Proteins Probed by Solvent Paramagnetic Relaxation Enhancement (sPRE). Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201807365] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Hamed Kooshapur
- Laboratory of Structural Biophysics, National Heart, Lung and Blood Institute; National Institutes of Health; Bethesda MD 20892 USA
| | - Charles D. Schwieters
- Office of Intramural Research; Center for Information Technology; National Institutes of Health; Bethesda MD 20892 USA
| | - Nico Tjandra
- Laboratory of Structural Biophysics, National Heart, Lung and Blood Institute; National Institutes of Health; Bethesda MD 20892 USA
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22
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Kooshapur H, Schwieters CD, Tjandra N. Conformational Ensemble of Disordered Proteins Probed by Solvent Paramagnetic Relaxation Enhancement (sPRE). Angew Chem Int Ed Engl 2018; 57:13519-13522. [PMID: 30125451 DOI: 10.1002/anie.201807365] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/27/2018] [Indexed: 01/05/2023]
Abstract
Characterization of the conformational ensemble of disordered proteins is highly important for understanding protein folding and aggregation mechanisms, but remains a computational and experimental challenge owing to the dynamic nature of these proteins. New observables that can provide unique insights into transient residual structures in disordered proteins are needed. Here using denatured ubiquitin as a model system, NMR solvent paramagnetic relaxation enhancement (sPRE) measurements provide an accurate and highly sensitive probe for detecting low populations of residual structure in a disordered protein. Furthermore, a new ensemble calculation approach based on sPRE restraints in conjunction with residual dipolar couplings (RDCs) and small-angle X-ray scattering (SAXS) is used to define the conformational ensemble of disordered proteins at atomic resolution. The approach presented should be applicable to a wide range of dynamic macromolecules.
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Affiliation(s)
- Hamed Kooshapur
- Laboratory of Structural Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Charles D Schwieters
- Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Nico Tjandra
- Laboratory of Structural Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
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23
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Studying backbone torsional dynamics of intrinsically disordered proteins using fluorescence depolarization kinetics. J Biosci 2018. [DOI: 10.1007/s12038-018-9766-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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24
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Takahashi S, Yoshida A, Oikawa H. Hypothesis: structural heterogeneity of the unfolded proteins originating from the coupling of the local clusters and the long-range distance distribution. Biophys Rev 2018; 10:363-373. [PMID: 29446056 DOI: 10.1007/s12551-018-0405-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 02/05/2018] [Indexed: 01/22/2023] Open
Abstract
We propose a hypothesis that explains two apparently contradicting observations for the heterogeneity of the unfolded proteins. First, the line confocal method of the single-molecule Förster resonance energy transfer (sm-FRET) spectroscopy revealed that the unfolded proteins possess broad peaks in the FRET efficiency plot, implying the significant heterogeneity that lasts longer than milliseconds. Second, the fluorescence correlation method demonstrated that the unfolded proteins fluctuate in the time scale shorter than 100 ns. To formulate the hypothesis, we first summarize the recent consensus for the structure and dynamics of the unfolded proteins. We next discuss the conventional method of the sm-FRET spectroscopy and its limitations for the analysis of the unfolded proteins, followed by the advantages of the line confocal method that revealed the heterogeneity. Finally, we propose that the structural heterogeneity formed by the local clustering of hydrophobic residues modulates the distribution of the long-range distance between the labeled chromophores, resulting in the broadening of the peak in the FRET efficiency plot. A clustering of hydrophobic residues around the chromophore might further contribute to the broadening. The proposed clusters are important for the understanding of protein folding mechanism.
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Affiliation(s)
- Satoshi Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan. .,Department of Chemistry, Graduate school of Science, Tohoku University, Aramaki 6-3, Aoba-ku, Sendai, 980-8578, Japan.
| | - Aya Yoshida
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan.,Department of Chemistry, Graduate school of Science, Tohoku University, Aramaki 6-3, Aoba-ku, Sendai, 980-8578, Japan
| | - Hiroyuki Oikawa
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan.,Department of Chemistry, Graduate school of Science, Tohoku University, Aramaki 6-3, Aoba-ku, Sendai, 980-8578, Japan
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25
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Sasmal S, Lincoff J, Head-Gordon T. Effect of a Paramagnetic Spin Label on the Intrinsically Disordered Peptide Ensemble of Amyloid-β. Biophys J 2017; 113:1002-1011. [PMID: 28877484 DOI: 10.1016/j.bpj.2017.06.067] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/16/2017] [Accepted: 06/30/2017] [Indexed: 10/18/2022] Open
Abstract
Paramagnetic relaxation enhancement is an NMR technique that has yielded important insight into the structure of folded proteins, although the perturbation introduced by the large spin probe might be thought to diminish its usefulness when applied to characterizing the structural ensembles of intrinsically disordered proteins (IDPs). We compare the computationally generated structural ensembles of the IDP amyloid-β42 (Aβ42) to an alternative sequence in which a nitroxide spin label attached to cysteine has been introduced at its N-terminus. Based on this internally consistent computational comparison, we find that the spin label does not perturb the signature population of the β-hairpin formed by residues 16-21 and 29-36 that is dominant in the Aβ42 reference ensemble. However, the presence of the tag induces a strong population shift in a subset of the original Aβ42 structural sub-populations, including a sevenfold enhancement of the β-hairpin formed by residues 27-31 and 33-38. Through back-calculation of NMR observables from the computational structural ensembles, we show that the structural differences between the labeled and unlabeled peptide would be evident in local residual dipolar couplings, and possibly differences in homonuclear 1H-1H nuclear Overhauser effects (NOEs) and heteronuclear 1H-15N NOEs if the paramagnetic contribution to the longitudinal relaxation does not suppress the NOE intensities in the real experiment. This work shows that molecular simulation provides a complementary approach to resolving the potential structural perturbations introduced by reporter tags that can aid in the interpretation of paramagnetic relaxation enhancement, double electron-electron resonance, and fluorescence resonance energy transfer experiments applied to IDPs.
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Affiliation(s)
- Sukanya Sasmal
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California
| | - James Lincoff
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California
| | - Teresa Head-Gordon
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California; Department of Chemistry, University of California, Berkeley, Berkeley, California; Department of Bioengineering, University of California, Berkeley, Berkeley, California; Pitzer Center for Theoretical Chemistry, University of California, Berkeley, Berkeley, California.
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26
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Salvi N, Abyzov A, Blackledge M. Atomic resolution conformational dynamics of intrinsically disordered proteins from NMR spin relaxation. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:43-60. [PMID: 29157493 DOI: 10.1016/j.pnmrs.2017.06.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 05/08/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful experimental approaches for investigating the conformational behaviour of intrinsically disordered proteins (IDPs). IDPs represent a significant fraction of all proteomes, and, despite their importance for understanding fundamental biological processes, the molecular basis of their activity still remains largely unknown. The functional mechanisms exploited by IDPs in their interactions with other biomolecules are defined by their intrinsic dynamic modes and associated timescales, justifying the considerable interest over recent years in the development of technologies adapted to measure and describe this behaviour. NMR spin relaxation delivers information-rich, site-specific data reporting on conformational fluctuations occurring throughout the molecule. Here we review recent progress in the use of 15N relaxation to identify local backbone dynamics and long-range chain-like motions in unfolded proteins.
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Affiliation(s)
- Nicola Salvi
- Institut de Biologie Structurale (IBS), CEA, CNRS, University Grenoble Alpes, Grenoble 38044, France
| | - Anton Abyzov
- Institut de Biologie Structurale (IBS), CEA, CNRS, University Grenoble Alpes, Grenoble 38044, France
| | - Martin Blackledge
- Institut de Biologie Structurale (IBS), CEA, CNRS, University Grenoble Alpes, Grenoble 38044, France.
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27
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Jain N, Narang D, Bhasne K, Dalal V, Arya S, Bhattacharya M, Mukhopadhyay S. Direct Observation of the Intrinsic Backbone Torsional Mobility of Disordered Proteins. Biophys J 2017; 111:768-774. [PMID: 27558720 DOI: 10.1016/j.bpj.2016.07.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 07/14/2016] [Accepted: 07/20/2016] [Indexed: 12/20/2022] Open
Abstract
The fundamental backbone dynamics of unfolded proteins arising due to intrinsic ϕ-ψ dihedral angle fluctuations dictate the course of protein folding, binding, assembly, and function. These internal fluctuations are also critical for protein misfolding associated with a range of human diseases. However, direct observation and unambiguous assignment of this inherent dynamics in chemically denatured proteins is extremely challenging due to various experimental limitations. To directly map the backbone torsional mobility in the ϕ-ψ dihedral angle space, we used a model intrinsically disordered protein, namely, α-synuclein, that adopts an expanded state under native conditions. We took advantage of nonoccurrence of tryptophan in α-synuclein and created a number of single-tryptophan variants encompassing the entire polypeptide chain. We then utilized highly sensitive picosecond time-resolved fluorescence depolarization measurements that allowed us to discern the site-specific torsional relaxation at a low protein concentration under physiological conditions. For all the locations, the depolarization kinetics exhibited two well-separated rotational-correlation-time components. The shorter, subnanosecond component arises due to the local mobility of the indole side chain, whereas the longer rotational-correlation-time component (1.37 ± 0.15 ns), independent of global tumbling, represents a characteristic timescale for short-range conformational exchange in the ϕ-ψ dihedral space. This correlation time represents an intrinsic timescale for torsional relaxation and is independent of position, which is expected for an extended polypeptide chain having little or no propensity to form persistent structures. We were also able to capture this intrinsic timescale at the N-terminal unstructured domain of the prion protein. Our estimated timescale of the segmental mobility is similar to that of unfolded proteins studied by nuclear magnetic resonance in conjunction with molecular dynamics simulations. Our results have broader implications for a diverse range of functionally and pathologically important intrinsically disordered proteins and disordered regions.
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Affiliation(s)
- Neha Jain
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India
| | - Dominic Narang
- Centre for Protein Science, Design, and Engineering, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India
| | - Karishma Bhasne
- Centre for Protein Science, Design, and Engineering, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India
| | - Vijit Dalal
- Centre for Protein Science, Design, and Engineering, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India
| | - Shruti Arya
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India
| | - Mily Bhattacharya
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design, and Engineering, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER), Mohali, Knowledge City, S.A.S. Nagar, Mohali, Punjab, India.
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28
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Olsson S, Noé F. Mechanistic Models of Chemical Exchange Induced Relaxation in Protein NMR. J Am Chem Soc 2016; 139:200-210. [DOI: 10.1021/jacs.6b09460] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Simon Olsson
- Computational Molecular
Biology,
FB Mathematik und Informatik, Freie Universität Berlin, Berlin 14195, Germany
| | - Frank Noé
- Computational Molecular
Biology,
FB Mathematik und Informatik, Freie Universität Berlin, Berlin 14195, Germany
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29
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Salvi N, Abyzov A, Blackledge M. Multi-Timescale Dynamics in Intrinsically Disordered Proteins from NMR Relaxation and Molecular Simulation. J Phys Chem Lett 2016; 7:2483-9. [PMID: 27300592 DOI: 10.1021/acs.jpclett.6b00885] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Intrinsically disordered proteins (IDPs) access highly diverse ensembles of conformations in their functional states. Although this conformational plasticity is essential to their function, little is known about the dynamics underlying interconversion between accessible states. Nuclear magnetic resonance (NMR) relaxation rates contain a wealth of information about the time scales and amplitudes of motion in IDPs, but the highly dynamic nature of IDPs complicates their interpretation. We present a novel framework in which a series of molecular dynamics (MD) simulations are used in combination with experimental (15)N relaxation measurements to characterize the ensemble of dynamic processes contributing to the observed rates. By accounting for the distinct dynamic averaging present in the different conformational states sampled by the equilibrium ensemble, we are able to accurately describe both dynamic time scales and local and global conformational sampling. The method is robust, systematically improving agreement with independent experimental relaxation data, irrespective of the actively targeted rates, and suggesting interdependence of motions occurring on time scales varying over 3 orders of magnitude.
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Affiliation(s)
- Nicola Salvi
- Institut de Biologie Structurale, CEA, CNRS, University Grenoble Alpes , Grenoble 38044, France
| | - Anton Abyzov
- Institut de Biologie Structurale, CEA, CNRS, University Grenoble Alpes , Grenoble 38044, France
| | - Martin Blackledge
- Institut de Biologie Structurale, CEA, CNRS, University Grenoble Alpes , Grenoble 38044, France
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30
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Khan SN, Charlier C, Augustyniak R, Salvi N, Déjean V, Bodenhausen G, Lequin O, Pelupessy P, Ferrage F. Distribution of Pico- and Nanosecond Motions in Disordered Proteins from Nuclear Spin Relaxation. Biophys J 2016; 109:988-99. [PMID: 26331256 PMCID: PMC4564687 DOI: 10.1016/j.bpj.2015.06.069] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/15/2015] [Accepted: 06/23/2015] [Indexed: 11/30/2022] Open
Abstract
Intrinsically disordered proteins and intrinsically disordered regions (IDRs) are ubiquitous in the eukaryotic proteome. The description and understanding of their conformational properties require the development of new experimental, computational, and theoretical approaches. Here, we use nuclear spin relaxation to investigate the distribution of timescales of motions in an IDR from picoseconds to nanoseconds. Nitrogen-15 relaxation rates have been measured at five magnetic fields, ranging from 9.4 to 23.5 T (400-1000 MHz for protons). This exceptional wealth of data allowed us to map the spectral density function for the motions of backbone NH pairs in the partially disordered transcription factor Engrailed at 11 different frequencies. We introduce an approach called interpretation of motions by a projection onto an array of correlation times (IMPACT), which focuses on an array of six correlation times with intervals that are equidistant on a logarithmic scale between 21 ps and 21 ns. The distribution of motions in Engrailed varies smoothly along the protein sequence and is multimodal for most residues, with a prevalence of motions around 1 ns in the IDR. We show that IMPACT often provides better quantitative agreement with experimental data than conventional model-free or extended model-free analyses with two or three correlation times. We introduce a graphical representation that offers a convenient platform for a qualitative discussion of dynamics. Even when relaxation data are only acquired at three magnetic fields that are readily accessible, the IMPACT analysis gives a satisfactory characterization of spectral density functions, thus opening the way to a broad use of this approach.
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Affiliation(s)
- Shahid N Khan
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Cyril Charlier
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Rafal Augustyniak
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Nicola Salvi
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne, BCH, Lausanne, Switzerland
| | - Victoire Déjean
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Geoffrey Bodenhausen
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France; Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne, BCH, Lausanne, Switzerland
| | - Olivier Lequin
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Philippe Pelupessy
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France
| | - Fabien Ferrage
- Département de Chimie, École Normale Supérieure-PSL Research University, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, LBM, Paris, France; Centre National de la Recherche Scientifique, UMR 7203 LBM, Paris, France.
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31
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Yuwen T, Xue Y, Skrynnikov NR. Role of Electrostatic Interactions in Binding of Peptides and Intrinsically Disordered Proteins to Their Folded Targets: 2. The Model of Encounter Complex Involving the Double Mutant of the c-Crk N-SH3 Domain and Peptide Sos. Biochemistry 2016; 55:1784-800. [PMID: 26910732 DOI: 10.1021/acs.biochem.5b01283] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tairan Yuwen
- Department
of Chemistry, Purdue University, West Lafayette Indiana 47907, United States
| | - Yi Xue
- Department
of Chemistry, Purdue University, West Lafayette Indiana 47907, United States
| | - Nikolai R. Skrynnikov
- Department
of Chemistry, Purdue University, West Lafayette Indiana 47907, United States
- Laboratory
of Biomolecular NMR, St. Petersburg State University, St. Petersburg 199034, Russia
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32
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Csizmok V, Follis AV, Kriwacki RW, Forman-Kay JD. Dynamic Protein Interaction Networks and New Structural Paradigms in Signaling. Chem Rev 2016; 116:6424-62. [PMID: 26922996 DOI: 10.1021/acs.chemrev.5b00548] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Understanding signaling and other complex biological processes requires elucidating the critical roles of intrinsically disordered proteins (IDPs) and regions (IDRs), which represent ∼30% of the proteome and enable unique regulatory mechanisms. In this review, we describe the structural heterogeneity of disordered proteins that underpins these mechanisms and the latest progress in obtaining structural descriptions of conformational ensembles of disordered proteins that are needed for linking structure and dynamics to function. We describe the diverse interactions of IDPs that can have unusual characteristics such as "ultrasensitivity" and "regulated folding and unfolding". We also summarize the mounting data showing that large-scale assembly and protein phase separation occurs within a variety of signaling complexes and cellular structures. In addition, we discuss efforts to therapeutically target disordered proteins with small molecules. Overall, we interpret the remodeling of disordered state ensembles due to binding and post-translational modifications within an expanded framework for allostery that provides significant insights into how disordered proteins transmit biological information.
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Affiliation(s)
- Veronika Csizmok
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada
| | - Ariele Viacava Follis
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States
| | - Richard W Kriwacki
- Department of Structural Biology, St. Jude Children's Research Hospital , Memphis, Tennessee 38105, United States.,Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center , Memphis, Tennessee 38163, United States
| | - Julie D Forman-Kay
- Molecular Structure & Function, The Hospital for Sick Children , Toronto, ON M5G 0A4, Canada.,Department of Biochemistry, University of Toronto , Toronto, ON M5S 1A8, Canada
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33
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Gill ML, Byrd RA, Palmer AG. Dynamics of GCN4 facilitate DNA interaction: a model-free analysis of an intrinsically disordered region. Phys Chem Chem Phys 2016; 18:5839-49. [PMID: 26661739 PMCID: PMC4894059 DOI: 10.1039/c5cp06197k] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Intrinsically disordered proteins (IDPs) and proteins with intrinsically disordered regions (IDRs) are known to play important roles in regulatory and signaling pathways. A critical aspect of these functions is the ability of IDP/IDRs to form highly specific complexes with target molecules. However, elucidation of the contributions of conformational dynamics to function has been limited by challenges associated with structural heterogeneity of IDP/IDRs. Using NMR spin relaxation parameters ((15)N R1, (15)N R2, and {(1)H}-(15)N heteronuclear NOE) collected at four static magnetic fields ranging from 14.1 to 21.1 T, we have analyzed the backbone dynamics of the basic leucine-zipper (bZip) domain of the Saccharomyces cerevisiae transcription factor GCN4, whose DNA binding domain is intrinsically disordered in the absence of DNA substrate. We demonstrate that the extended model-free analysis can be applied to proteins with IDRs such as apo GCN4 and that these results significantly extend previous NMR studies of GCN4 dynamics performed using a single static magnetic field of 11.74 T [Bracken, et al., J. Mol. Biol., 1999, 285, 2133-2146] and correlate well with molecular dynamics simulations [Robustelli, et al., J. Chem. Theory Comput., 2013, 9, 5190-5200]. In contrast to the earlier work, data at multiple static fields allows the time scales of internal dynamics of GCN4 to be reliably quantified. Large amplitude dynamic fluctuations in the DNA-binding region have correlation times (τs ≈ 1.4-2.5 ns) consistent with a two-step mechanism in which partially ordered bZip conformations of GCN4 form initial encounter complexes with DNA and then rapidly rearrange to the high affinity state with fully formed basic region recognition helices.
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Affiliation(s)
- Michelle L Gill
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA. and Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - R Andrew Byrd
- Structural Biophysics Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Arthur G Palmer
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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34
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Hough LE, Dutta K, Sparks S, Temel DB, Kamal A, Tetenbaum-Novatt J, Rout MP, Cowburn D. The molecular mechanism of nuclear transport revealed by atomic-scale measurements. eLife 2015; 4. [PMID: 26371551 PMCID: PMC4621360 DOI: 10.7554/elife.10027] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/07/2015] [Indexed: 12/29/2022] Open
Abstract
Nuclear pore complexes (NPCs) form a selective filter that allows the rapid passage of transport factors (TFs) and their cargoes across the nuclear envelope, while blocking the passage of other macromolecules. Intrinsically disordered proteins (IDPs) containing phenylalanyl-glycyl (FG)-rich repeats line the pore and interact with TFs. However, the reason that transport can be both fast and specific remains undetermined, through lack of atomic-scale information on the behavior of FGs and their interaction with TFs. We used nuclear magnetic resonance spectroscopy to address these issues. We show that FG repeats are highly dynamic IDPs, stabilized by the cellular environment. Fast transport of TFs is supported because the rapid motion of FG motifs allows them to exchange on and off TFs extremely quickly through transient interactions. Because TFs uniquely carry multiple pockets for FG repeats, only they can form the many frequent interactions needed for specific passage between FG repeats to cross the NPC. DOI:http://dx.doi.org/10.7554/eLife.10027.001 Eukaryotic cells have a nucleus that contains most of the organism's genetic material. Two layers of membrane form an envelope around the nucleus and protect its contents from the rest of the cell's interior. However, this protective barrier must also allow certain proteins and nucleic acids(collectively called ‘cargo’) to move in and out of the nucleus. Cargo molecules can pass through channel-like structures called nuclear pore complexes, which are embedded in the nuclear envelope. However, transport across this barrier is highly selective. While small molecules can pass freely through nuclear pore complexes, larger cargo can only be transported when they are bound to so-called transport factors. The nuclear pore complex is a large structure made up of more than 30 different proteins called nucleoporins. Like all proteins, nucleoporins are built from amino acids. Many nucleoporins contain repeating units of two amino acids, namely phenylalanine (which is often referred to as ‘F’) and glycine (or ‘G’). These ‘FG nucleoporins’ are found on the inside of the nuclear pore complex and interact with transport factors to allow them to transit across the nuclear envelope. Several models have been put forward to explain how FG nucleoporins block the passage of most molecules. But it was unclear from these models how these nucleoporins could do this while simultaneously allowing the selective and fast transport of nuclear transport receptors. There was also a major lack of experimental data that probed the behavior of FG nucleoporins in detail. Hough, Dutta et al. have now used a technique called nuclear magnetic resonance spectroscopy (or NMR for short) to address this issue. NMR can be used to analyze the structure of proteins and how they interact with other molecules. This analysis revealed that FG nucleoporins never adopt an ordered three-dimensional shape, even briefly; instead they remain unfolded or disordered, moving constantly. Nevertheless, and unlike many other unfolded proteins, FG nucleoporins do not aggregate into clumps. This is because they are constantly changing and continuously interacting with other molecules present inside the cell, which prevents them from aggregating. Hough, Dutta et al. also observed that the repeating units in the FG nucleoporins engaged briefly with a large number of sites or pockets present on the transport factors. These FG repeats can bind and then release the transport factors at unusually high speeds, which enables the transport factors to move quickly through the nuclear pore complex. This transit is specific because only transport factors have a high capacity for interacting with the FG repeats. These findings provide an explanation for how the nuclear pore complex achieves fast and selective transport. Further work is needed to see whether certain FG nucleoporins specifically interact with a particular type of transport factor, to provide preferred transport routes through the nuclear pore complex. DOI:http://dx.doi.org/10.7554/eLife.10027.002
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Affiliation(s)
| | - Kaushik Dutta
- New York Structural Biology Center, New York, United States
| | - Samuel Sparks
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, United States
| | - Deniz B Temel
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, United States
| | - Alia Kamal
- The Rockefeller University, New York, United States
| | | | | | - David Cowburn
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, United States
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35
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Relating sequence encoded information to form and function of intrinsically disordered proteins. Curr Opin Struct Biol 2015; 32:102-12. [PMID: 25863585 DOI: 10.1016/j.sbi.2015.03.008] [Citation(s) in RCA: 275] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/13/2015] [Accepted: 03/16/2015] [Indexed: 11/23/2022]
Abstract
Intrinsically disordered proteins (IDPs) showcase the importance of conformational plasticity and heterogeneity in protein function. We summarize recent advances that connect information encoded in IDP sequences to their conformational properties and functions. We focus on insights obtained through a combination of atomistic simulations and biophysical measurements that are synthesized into a coherent framework using polymer physics theories.
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36
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Parigi G, Rezaei-Ghaleh N, Giachetti A, Becker S, Fernandez C, Blackledge M, Griesinger C, Zweckstetter M, Luchinat C. Long-range correlated dynamics in intrinsically disordered proteins. J Am Chem Soc 2014; 136:16201-9. [PMID: 25331250 DOI: 10.1021/ja506820r] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Intrinsically disordered proteins (IDPs) are involved in a wide variety of physiological and pathological processes and are best described by ensembles of rapidly interconverting conformers. Using fast field cycling relaxation measurements we here show that the IDP α-synuclein as well as a variety of other IDPs undergoes slow reorientations at time scales comparable to folded proteins. The slow motions are not perturbed by mutations in α-synuclein, which are related to genetic forms of Parkinson's disease, and do not depend on secondary and tertiary structural propensities. Ensemble-based hydrodynamic calculations suggest that the time scale of the underlying correlated motion is largely determined by hydrodynamic coupling between locally rigid segments. Our study indicates that long-range correlated dynamics are an intrinsic property of IDPs and offers a general physical mechanism of correlated motions in highly flexible biomolecular systems.
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Affiliation(s)
- Giacomo Parigi
- Department of Chemistry "Ugo Schiff" and CERM, University of Florence , via Sacconi 6, 50019 Sesto Fiorentino, Italy
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37
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Jensen MR, Zweckstetter M, Huang JR, Blackledge M. Exploring free-energy landscapes of intrinsically disordered proteins at atomic resolution using NMR spectroscopy. Chem Rev 2014; 114:6632-60. [PMID: 24725176 DOI: 10.1021/cr400688u] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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38
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Yuwen T, Skrynnikov NR. Proton-decoupled CPMG: a better experiment for measuring (15)N R2 relaxation in disordered proteins. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 241:155-169. [PMID: 24120537 DOI: 10.1016/j.jmr.2013.08.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 06/02/2023]
Abstract
(15)N R2 relaxation is one of the most informative experiments for characterization of intrinsically disordered proteins (IDPs). Small changes in nitrogen R2 rates are often used to determine how IDPs respond to various biologically relevant perturbations such as point mutations, posttranslational modifications and weak ligand interactions. However collecting high-quality (15)N relaxation data can be difficult. Of necessity, the samples of IDPs are often prepared with low protein concentration and the measurement time can be limited because of rapid sample degradation. Furthermore, due to hardware limitations standard experiments such as (15)N spin-lock and CPMG can sample the relaxation decay only to ca. 150ms. This is much shorter than (15)N T2 times in disordered proteins at or near physiological temperature. As a result, the sampling of relaxation decay profiles in these experiments is suboptimal, which further lowers the precision of the measurements. Here we report a new implementation of the proton-decoupled (PD) CPMG experiment which allows one to sample (15)N R2 relaxation decay up to ca. 0.5-1s. The new experiment has been validated through comparison with the well-established spin-lock measurement. Using dilute samples of denatured ubiquitin, we have demonstrated that PD-CPMG produces up to 3-fold improvement in the precision of the data. It is expected that for intrinsically disordered proteins the gains may be even more substantial. We have also shown that this sequence has a number of favorable properties: (i) the spectra are recorded with narrow linewidth in nitrogen dimension; (ii) (15)N offset correction is small and easy to calculate; (iii) the experiment is immune to various spurious effects arising from solvent exchange; (iv) the results are stable with respect to pulse miscalibration and rf field inhomogeneity; (v) with minimal change, the pulse sequence can also be used to measure R2 relaxation of (15)N(ε) spins in arginine side chains. We anticipate that the new experiment will be a valuable addition to the NMR toolbox for studies of IDPs.
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Affiliation(s)
- Tairan Yuwen
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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Wunderlich C, Huber RG, Spitzer R, Liedl KR, Kloiber K, Kreutz C. A novel paramagnetic relaxation enhancement tag for nucleic acids: a tool to study structure and dynamics of RNA. ACS Chem Biol 2013; 8:2697-706. [PMID: 24053726 PMCID: PMC3870906 DOI: 10.1021/cb400589q] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/20/2013] [Indexed: 01/10/2023]
Abstract
In this work, we present a novel 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) radical phosphoramidite building block, which can be attached to the 5'-terminus of nucleic acids. To investigate the paramagnetic relaxation enhancement (PRE) emanating from this radical center, we incorporated the TEMPO label into various types of RNAs. We measured proton PREs for selectively (13)C-isotope labeled nucleotides to derive long-range distance restraints in a short 15 nucleotide stem-loop model system, underscoring the potential of the 5'-TEMPO tag to determine long-range distance restraints for solution structure determination. We subsequently applied the distance-dependent relaxation enhancement induced by the nitroxide radical to discern two folding states in a bistable RNA. Finally, we investigated the fast conformational sampling of the HIV-1 TAR RNA, a paradigm for structural flexibility in nucleic acids. With PRE NMR in combination with molecular dynamics simulations, the structural plasticity of this RNA was analyzed in the absence and presence of the ligand L-argininamide.
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Affiliation(s)
- Christoph
H. Wunderlich
- Institute
of Organic Chemistry and Center for Molecular Biosciences Innsbruck
(CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Roland G. Huber
- Institute
of General, Inorganic and Theoretical Chemistry and Center for Molecular
Biosciences Innsbruck (CMBI), University
of Innsbruck, Innrain
80/82, 6020 Innsbruck, Austria
| | - Romana Spitzer
- Institute
of Organic Chemistry and Center for Molecular Biosciences Innsbruck
(CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Klaus R. Liedl
- Institute
of General, Inorganic and Theoretical Chemistry and Center for Molecular
Biosciences Innsbruck (CMBI), University
of Innsbruck, Innrain
80/82, 6020 Innsbruck, Austria
| | - Karin Kloiber
- Institute
of Organic Chemistry and Center for Molecular Biosciences Innsbruck
(CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Christoph Kreutz
- Institute
of Organic Chemistry and Center for Molecular Biosciences Innsbruck
(CMBI), University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
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Ganoth A, Tsfadia Y, Wiener R. Ubiquitin: Molecular modeling and simulations. J Mol Graph Model 2013; 46:29-40. [DOI: 10.1016/j.jmgm.2013.09.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/09/2013] [Accepted: 09/10/2013] [Indexed: 01/18/2023]
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Naganathan AN, Orozco M. The Conformational Landscape of an Intrinsically Disordered DNA-Binding Domain of a Transcription Regulator. J Phys Chem B 2013; 117:13842-50. [DOI: 10.1021/jp408350v] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Athi N. Naganathan
- Department
of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India
| | - Modesto Orozco
- IRB-BSC
Joint Research Program in Computational Biology, Institute for Research in Biomedicine (IRB Barcelona), 08028 Barcelona, Spain
- Department
of Biochemistry and Molecular Biology, University of Barcelona, 08028 Barcelona, Spain
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Xu L, Wang X, Wang X. Characterization of the internal dynamics and conformational space of zinc-bound amyloid β peptides by replica-exchange molecular dynamics simulations. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:575-86. [DOI: 10.1007/s00249-013-0906-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/07/2013] [Accepted: 04/12/2013] [Indexed: 12/26/2022]
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Jensen MR, Ruigrok RWH, Blackledge M. Describing intrinsically disordered proteins at atomic resolution by NMR. Curr Opin Struct Biol 2013; 23:426-35. [PMID: 23545493 DOI: 10.1016/j.sbi.2013.02.007] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/20/2013] [Accepted: 02/20/2013] [Indexed: 11/27/2022]
Abstract
There is growing interest in the development of physical methods to study the conformational behaviour and biological activity of intrinsically disordered proteins (IDPs). In this review recent advances in the elucidation of quantitative descriptions of disordered proteins from nuclear magnetic resonance spectroscopy are presented. Ensemble approaches are particularly well adapted to map the conformational energy landscape sampled by the protein at atomic resolution. Significant advances in development of calibrated approaches to the statistical representation of the conformational behaviour of IDPs are presented, as well as applications to some biologically important systems where disorder plays a crucial role.
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Affiliation(s)
- Malene Ringkjøbing Jensen
- Protein Dynamics and Flexibility, Institut de Biologie Structurale Jean-Pierre Ebel, CEA, CNRS, UJF UMR 5075, 41 rue Jules Horowitz, 38027 Grenoble, France
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Residual dipolar couplings measured in unfolded proteins are sensitive to amino-acid-specific geometries as well as local conformational sampling. Biochem Soc Trans 2013; 40:989-94. [PMID: 22988852 DOI: 10.1042/bst20120187] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Many functional proteins do not have well defined folded structures. In recent years, both experimental and computational approaches have been developed to study the conformational behaviour of this type of protein. It has been shown previously that experimental RDCs (residual dipolar couplings) can be used to study the backbone sampling of disordered proteins in some detail. In these studies, the backbone structure was modelled using a common geometry for all amino acids. In the present paper, we demonstrate that experimental RDCs are also sensitive to the specific geometry of each amino acid as defined by energy-minimized internal co-ordinates. We have modified the FM (flexible-Meccano) algorithm that constructs conformational ensembles on the basis of a statistical coil model, to account for these differences. The modified algorithm inherits the advantages of the FM algorithm to efficiently sample the potential energy landscape for coil conformations. The specific geometries incorporated in the new algorithm result in a better reproduction of experimental RDCs and are generally applicable for further studies to characterize the conformational properties of intrinsically disordered proteins. In addition, the internal-co-ordinate-based algorithm is an order of magnitude more efficient, and facilitates side-chain construction, surface osmolyte simulation, spin-label distribution sampling and proline cis/trans isomer simulation.
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Abstract
Inside cells, the concentration of macromolecules can reach up to 400 g/L. In such crowded environments, proteins are expected to behave differently than in vitro. It has been shown that the stability and the folding rate of a globular protein can be altered by the excluded volume effect produced by a high density of macromolecules. However, macromolecular crowding effects on intrinsically disordered proteins (IDPs) are less explored. These proteins can be extremely dynamic and potentially sample a wide ensemble of conformations under non-denaturing conditions. The dynamic properties of IDPs are intimately related to the timescale of conformational exchange within the ensemble, which govern target recognition and how these proteins function. In this work, we investigated the macromolecular crowding effects on the dynamics of several IDPs by measuring the NMR spin relaxation parameters of three disordered proteins (ProTα, TC1, and α-synuclein) with different extents of residual structures. To aid the interpretation of experimental results, we also performed an MD simulation of ProTα. Based on the MD analysis, a simple model to correlate the observed changes in relaxation rates to the alteration in protein motions under crowding conditions was proposed. Our results show that 1) IDPs remain at least partially disordered despite the presence of high concentration of other macromolecules, 2) the crowded environment has differential effects on the conformational propensity of distinct regions of an IDP, which may lead to selective stabilization of certain target-binding motifs, and 3) the segmental motions of IDPs on the nanosecond timescale are retained under crowded conditions. These findings strongly suggest that IDPs function as dynamic structural ensembles in cellular environments.
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Kleinjung J, Fraternali F. Urea-Water Solvation Forces on Prion Structures. J Chem Theory Comput 2012; 8:3977-3984. [PMID: 23066353 PMCID: PMC3466777 DOI: 10.1021/ct300264w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Indexed: 01/28/2023]
Abstract
Solvation forces are crucial determinants in the equilibrium between the folded and unfolded state of proteins. Particularly interesting are the solvent forces of denaturing solvent mixtures on folded and misfolded states of proteins involved in neurodegeneration. The C-terminal globular domain of the ovine prion protein (1UW3) and its analogue H2H3 in the α-rich and β-rich conformation were used as model structures to study the solvation forces in 4 M aqueous urea using molecular dynamics. The model structures display very different secondary structures and solvent exposures. Most protein atoms favor interactions with urea over interactions with water. The force difference between protein-urea and protein-water interactions correlates with hydrophobicity; i.e., urea interacts preferentially with hydrophobic atoms, in agreement with results from solvent transfer experiments. Solvent Shannon entropy maps illustrate the mobility gradient of the urea-water mixture from the first solvation shell to the bulk. Single urea molecules replace water in the first solvation shell preferably at locations of relatively high solvent entropy.
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Affiliation(s)
- Jens Kleinjung
- Division of Mathematical Biology,
MRC National Institute for Medical Research, The Ridgeway, Mill Hill,
London NW7 1AA, United Kingdom
| | - Franca Fraternali
- Randall Division of Cell and
Molecular Biophysics, King’s College London, New Hunt’s
House, London SE1 1UL, United Kingdom
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Chen J. Towards the physical basis of how intrinsic disorder mediates protein function. Arch Biochem Biophys 2012; 524:123-31. [PMID: 22579883 DOI: 10.1016/j.abb.2012.04.024] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 04/28/2012] [Accepted: 04/30/2012] [Indexed: 02/06/2023]
Abstract
Intrinsically disordered proteins (IDPs) are an important class of functional proteins that is highly prevalent in biology and has broad association with human diseases. In contrast to structured proteins, free IDPs exist as heterogeneous and dynamical conformational ensembles under physiological conditions. Many concepts have been discussed on how such intrinsic disorder may provide crucial functional advantages, particularly in cellular signaling and regulation. Establishing the physical basis of these proposed phenomena requires not only detailed characterization of the disordered conformational ensembles, but also mechanistic understanding of the roles of various ensemble properties in IDP interaction and regulation. Here, we review the experimental and computational approaches that may be integrated to address many important challenges of establishing a "structural" basis of IDP function, and discuss some of the key emerging ideas on how the conformational ensembles of IDPs may mediate function, especially in coupled binding and folding interactions.
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Affiliation(s)
- Jianhan Chen
- Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA.
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Huang JR, Gabel F, Jensen MR, Grzesiek S, Blackledge M. Sequence-specific mapping of the interaction between urea and unfolded ubiquitin from ensemble analysis of NMR and small angle scattering data. J Am Chem Soc 2012; 134:4429-36. [PMID: 22309138 DOI: 10.1021/ja2118688] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The molecular details of how urea interacts with, and eventually denatures proteins, remain largely unknown. In this study we have used extensive experimental NMR data, in combination with statistical coil ensemble modeling and small-angle scattering, to analyze the conformational behavior of the protein ubiquitin in the presence of urea. In order to develop an atomic resolution understanding of the denatured state, conformational ensembles of full-atom descriptions of unfolded proteins, including side chain conformations derived from rotamer libraries, are combined with random sampling of explicit urea molecules in interaction with the protein. Using this description of the conformational equilibrium, we demonstrate that the direct-binding model of urea to the protein backbone is compatible with available experimental data. We find that, in the presence of 8 M urea, between 30 and 40% of the backbone peptide groups bind a urea molecule, independently reproducing results from a model-free analysis of small-angle neutron and X-ray scattering data. Crucially, this analysis also provides sequence specific details of the interaction between urea and the protein backbone. The pattern of urea-binding along the amino-acid sequence reveals a higher level of binding in the central part of the protein, a trend which resembles independent results derived from chemical shift mapping of the urea-protein interaction. Together these results substantiate the direct-binding model and provide a framework for studying the physical basis of interactions between proteins and solvent molecules.
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Affiliation(s)
- Jie-rong Huang
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, 41 Rue Jules Horowitz, Grenoble 38027, France
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