1
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Chai Z, Li C. In-Cell 19F NMR of Proteins: Recent Progress and Future Opportunities. Chemistry 2024; 30:e202303988. [PMID: 38269421 DOI: 10.1002/chem.202303988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 01/26/2024]
Abstract
In vitro, 19F NMR methodology is preferably selected as a complementary and straightforward method for unveiling the conformations, dynamics, and interactions of biological molecules. Its effectiveness in vivo has seen continuous improvement, addressing challenges faced by conventional heteronuclear NMR experiments on structured proteins, such as severe line broadening, low signal-to-noise ratio, and background signals. Herein, we summarize the distinctive advantages of 19F NMR, along with recent progress in sample preparation and applications within the realm of in-cell NMR. Additionally, we offer insights into the future directions and prospects of this methodology based on our understanding.
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Affiliation(s)
- Zhaofei Chai
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, 430071, Wuhan, China
| | - Conggang Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, 430071, Wuhan, China
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2
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Alfano C, Fichou Y, Huber K, Weiss M, Spruijt E, Ebbinghaus S, De Luca G, Morando MA, Vetri V, Temussi PA, Pastore A. Molecular Crowding: The History and Development of a Scientific Paradigm. Chem Rev 2024; 124:3186-3219. [PMID: 38466779 PMCID: PMC10979406 DOI: 10.1021/acs.chemrev.3c00615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 02/13/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024]
Abstract
It is now generally accepted that macromolecules do not act in isolation but "live" in a crowded environment, that is, an environment populated by numerous different molecules. The field of molecular crowding has its origins in the far 80s but became accepted only by the end of the 90s. In the present issue, we discuss various aspects that are influenced by crowding and need to consider its effects. This Review is meant as an introduction to the theme and an analysis of the evolution of the crowding concept through time from colloidal and polymer physics to a more biological perspective. We introduce themes that will be more thoroughly treated in other Reviews of the present issue. In our intentions, each Review may stand by itself, but the complete collection has the aspiration to provide different but complementary perspectives to propose a more holistic view of molecular crowding.
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Affiliation(s)
- Caterina Alfano
- Structural
Biology and Biophysics Unit, Fondazione
Ri.MED, 90100 Palermo, Italy
| | - Yann Fichou
- CNRS,
Bordeaux INP, CBMN UMR 5248, IECB, University
of Bordeaux, F-33600 Pessac, France
| | - Klaus Huber
- Department
of Chemistry, University of Paderborn, 33098 Paderborn, Germany
| | - Matthias Weiss
- Experimental
Physics I, Physics of Living Matter, University
of Bayreuth, 95440 Bayreuth, Germany
| | - Evan Spruijt
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Simon Ebbinghaus
- Lehrstuhl
für Biophysikalische Chemie and Research Center Chemical Sciences
and Sustainability, Research Alliance Ruhr, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Giuseppe De Luca
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
| | | | - Valeria Vetri
- Dipartimento
di Fisica e Chimica − Emilio Segrè, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
| | | | - Annalisa Pastore
- King’s
College London, Denmark
Hill Campus, SE5 9RT London, United Kingdom
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3
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Liang Q, Zhang Y, Zhang H, Wu S, Gong W, Perrett S. Reversible Redox-Dependent Conformational Switch of the C-Terminal α-Helical Lid of Human Hsp70 Observed by In-Cell NMR. ACS Chem Biol 2023; 18:176-183. [PMID: 36524733 DOI: 10.1021/acschembio.2c00845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glutathionylation of human stress-inducible Hsp70 (hHsp70) under oxidative stress conditions has been suggested to act as an on/off switch of hHsp70 chaperone activity and thus transfer redox signals to hHsp70 clients through a change in conformation. The mechanism of this switch involves unfolding of the C-terminal α-helical lid, SBDα, upon glutathionylation, which then binds to and blocks the hHsp70 substrate-binding site. This process is reversible and redox-regulated and has been demonstrated for purified protein in solution. Here, we found that this redox-regulated reversible process also occurs in the cellular environment. Using Escherichia coli as a model system, in-cell NMR data clearly indicate that hHsp70 SBDα undergoes a conformational transition from ordered to disordered after diamide stimulation. The disordered SBDα could spontaneously recover back to the helix bundle conformation over time. This oxidative-stress induced process also occurred in cell lysate, with a similar unfolding rate as in cells, but the refolding rate was significantly slower in cell lysate. Increased temperature accelerates this process. Under heat stress alone, unfolding of the SBDα could not be detected in cells. Our in-cell NMR results provide direct support for the molecular switch model of hHsp70 redox regulation and also demonstrate the power of in-cell NMR for real-time study of protein structures during biological processes in living cells.
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Affiliation(s)
- Qihui Liang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yiying Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Si Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Weibin Gong
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Sarah Perrett
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
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4
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Xie Y, Gresham D, Holt L. Increased mesoscale diffusivity in response to acute glucose starvation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523352. [PMID: 36711511 PMCID: PMC9882054 DOI: 10.1101/2023.01.10.523352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Macromolecular crowding is an important parameter that impacts multiple biological processes. Passive microrheology using single particle tracking is a powerful means of studying macromolecular crowding. Here we monitored the diffusivity of self-assembling fluorescent nanoparticles (μNS) in response to acute glucose starvation. mRNP diffusivity was reduced upon glucose starvation as previously reported. In contrast, we observed increased diffusivity of μNS particles. Our results suggest that, upon glucose starvation, mRNP granule diffusivity may be reduced due to changes in physical interactions, while global crowding in the cytoplasm may be reduced.
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Affiliation(s)
- Ying Xie
- New York University, School of Medicine, Institute for Systems Genetics, New York, USA
- New York University, Center for Genomics and Systems Biology, Department of Biology, New York, USA
| | - David Gresham
- New York University, Center for Genomics and Systems Biology, Department of Biology, New York, USA
| | - Liam Holt
- New York University, School of Medicine, Institute for Systems Genetics, New York, USA
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5
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Xie Y, Gresham D, Holt LJ. Increased mesoscale diffusivity in response to acute glucose starvation. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000729. [PMID: 36908311 PMCID: PMC9996311 DOI: 10.17912/micropub.biology.000729] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/14/2023]
Abstract
Macromolecular crowding is an important property of cells that impacts multiple biological processes. Passive microrheology using single particle tracking is a powerful means of studying macromolecular crowding. Here we monitored the diffusivity of self-assembling fluorescent nanoparticles (μNS) and mRNPs ( GFA1 -PP7) in response to acute glucose starvation. mRNP diffusivity was reduced upon glucose starvation as previously reported. By contrast, we observed increased diffusivity of μNS particles. Our results suggest that, upon glucose starvation, mRNP granule diffusivity may be reduced due to increased physical interactions, whereas macromolecular crowding in the cytoplasm may be globally reduced.
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Affiliation(s)
- Ying Xie
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
- Department of Biology, New York University, New York, New York, United States
| | - David Gresham
- Department of Biology, New York University, New York, New York, United States
- Correspondence to: David Gresham (
)
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
- Correspondence to: Liam J Holt (
)
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6
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Pastore A, Temussi PA. Crowding revisited: Open questions and future perspectives. Trends Biochem Sci 2022; 47:1048-1058. [PMID: 35691783 DOI: 10.1016/j.tibs.2022.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 05/12/2022] [Accepted: 05/24/2022] [Indexed: 12/24/2022]
Abstract
Although biophysical studies have traditionally been performed in diluted solutions, it was pointed out in the late 1990s that the cellular milieu contains several other macromolecules, creating a condition of molecular crowding. How crowding affects protein stability is an important question heatedly discussed over the past 20 years. Theoretical estimations have suggested a 5-20°C effect of fold stabilisation. This estimate, however, is at variance with what has been verified experimentally that proposes only a limited increase of stability, opening the question whether some of the assumptions taken for granted should be reconsidered. The present review critically analyses the causes of this discrepancy and discusses the limitations and implications of the current concept of crowding.
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Affiliation(s)
- Annalisa Pastore
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London, SE5 9RT, UK.
| | - Piero Andrea Temussi
- UK Dementia Research Institute at the Maurice Wohl Institute of King's College London, London, SE5 9RT, UK.
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7
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Theillet FX, Luchinat E. In-cell NMR: Why and how? PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 132-133:1-112. [PMID: 36496255 DOI: 10.1016/j.pnmrs.2022.04.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 06/17/2023]
Abstract
NMR spectroscopy has been applied to cells and tissues analysis since its beginnings, as early as 1950. We have attempted to gather here in a didactic fashion the broad diversity of data and ideas that emerged from NMR investigations on living cells. Covering a large proportion of the periodic table, NMR spectroscopy permits scrutiny of a great variety of atomic nuclei in all living organisms non-invasively. It has thus provided quantitative information on cellular atoms and their chemical environment, dynamics, or interactions. We will show that NMR studies have generated valuable knowledge on a vast array of cellular molecules and events, from water, salts, metabolites, cell walls, proteins, nucleic acids, drugs and drug targets, to pH, redox equilibria and chemical reactions. The characterization of such a multitude of objects at the atomic scale has thus shaped our mental representation of cellular life at multiple levels, together with major techniques like mass-spectrometry or microscopies. NMR studies on cells has accompanied the developments of MRI and metabolomics, and various subfields have flourished, coined with appealing names: fluxomics, foodomics, MRI and MRS (i.e. imaging and localized spectroscopy of living tissues, respectively), whole-cell NMR, on-cell ligand-based NMR, systems NMR, cellular structural biology, in-cell NMR… All these have not grown separately, but rather by reinforcing each other like a braided trunk. Hence, we try here to provide an analytical account of a large ensemble of intricately linked approaches, whose integration has been and will be key to their success. We present extensive overviews, firstly on the various types of information provided by NMR in a cellular environment (the "why", oriented towards a broad readership), and secondly on the employed NMR techniques and setups (the "how", where we discuss the past, current and future methods). Each subsection is constructed as a historical anthology, showing how the intrinsic properties of NMR spectroscopy and its developments structured the accessible knowledge on cellular phenomena. Using this systematic approach, we sought i) to make this review accessible to the broadest audience and ii) to highlight some early techniques that may find renewed interest. Finally, we present a brief discussion on what may be potential and desirable developments in the context of integrative studies in biology.
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Affiliation(s)
- Francois-Xavier Theillet
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
| | - Enrico Luchinat
- Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum - Università di Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; CERM - Magnetic Resonance Center, and Neurofarba Department, Università degli Studi di Firenze, 50019 Sesto Fiorentino, Italy
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8
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Navo CD, Oroz P, Mazo N, Blanco M, Peregrina JM, Jiménez-Osés G. Stereoselective α-Deuteration of Serine, Cysteine, Selenocysteine, and 2,3-Diaminopropanoic Acid Derivatives. Org Lett 2022; 24:6810-6815. [PMID: 36082943 DOI: 10.1021/acs.orglett.2c02715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Efficient methodologies for synthesizing enantiopure α-deuterated derivatives of serine, cysteine, selenocysteine, and 2,3-diaminopropanoic acid have been developed. H/D exchange was achieved by deprotonation of a chiral bicyclic serine equivalent followed by selective deuteration. Additionally, diastereoselective additions of thiols, selenols, and amines to a chiral bicyclic dehydroalanine in deuterated alcohols allowed site-selective deuteration at the Cα atom of cysteine, selenocysteine, and 2,3-diaminopropanoic acid derivatives. A deuterated analogue of carbocysteine, a drug for the treatment of bronchiectasis, was synthesized.
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Affiliation(s)
- Claudio D Navo
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain
| | - Paula Oroz
- Departamento de Química, Centro de Investigación en Síntesis Química, Universidad de La Rioja, 26006 Logroño, La Rioja, Spain
| | - Nuria Mazo
- Departamento de Química, Centro de Investigación en Síntesis Química, Universidad de La Rioja, 26006 Logroño, La Rioja, Spain
| | - Marina Blanco
- Departamento de Química, Centro de Investigación en Síntesis Química, Universidad de La Rioja, 26006 Logroño, La Rioja, Spain
| | - Jesús M Peregrina
- Departamento de Química, Centro de Investigación en Síntesis Química, Universidad de La Rioja, 26006 Logroño, La Rioja, Spain
| | - Gonzalo Jiménez-Osés
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain.,Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
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9
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Irukuvajjula SS, Reddy JG, Vadrevu R. Crowding by Poly(ethylene glycol) Destabilizes Chemotaxis Protein Y (CheY). Biochemistry 2022; 61:1431-1443. [PMID: 35796609 DOI: 10.1021/acs.biochem.2c00030] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The prevailing understanding of various aspects of biochemical processes, including folding, stability, intermolecular interactions, and the binding of metals, substrates, and inhibitors, is derived from studies carried out under dilute and homogeneous conditions devoid of a crowding-related environment. The effect of crowding-induced modulation on the structure and stability of native and magnesium-dependent Chemotaxis Y (CheY), a bacterial signaling protein, was probed in the presence and absence of poly(ethylene glycol) (PEG). A combined analysis from circular dichroism, intrinsic and extrinsic fluorescence, and tryptophan fluorescence lifetime changes indicates that PEG perturbs the structure but leaves the thermal stability largely unchanged. Intriguingly, while the stability of the protein is enhanced in the presence of magnesium under dilute buffer conditions, PEG-induced crowding leads to reduced thermal stability in the presence of magnesium. Nuclear magnetic resonance (NMR) chemical shift perturbations and resonance broadening for a subset of residues indicate that PEG interacts specifically with a subset of hydrophilic and hydrophobic residues found predominantly in α helices, β strands, and in the vicinity of the metal-binding region. Thus, PEG prompted conformational perturbation, presumably provides a different situation for magnesium interaction, thereby perturbing the magnesium-prompted stability. In summary, our results highlight the dominance of enthalpic contributions between PEG and CheY via both hydrophilic and hydrophobic interactions, which can subtly affect the conformation, modulating the metal-protein interaction and stability, implying that in the context of cellular situation, structure, stability, and magnesium binding thermodynamics of CheY may be different from those measured in dilute solution.
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Affiliation(s)
- Shivkumar Sharma Irukuvajjula
- Department of Biological Sciences, Birla Institute of Technology & Science─Pilani, Hyderabad Campus, Jawahar Nagar, Shamirpet, Hyderabad 500078, India
| | - Jithender G Reddy
- NMR Division, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Ministry of Science and Technology, Uppal Road, Tarnaka, Hyderabad 500007, India
| | - Ramakrishna Vadrevu
- Department of Biological Sciences, Birla Institute of Technology & Science─Pilani, Hyderabad Campus, Jawahar Nagar, Shamirpet, Hyderabad 500078, India
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10
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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: 44] [Impact Index Per Article: 22.0] [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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11
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Gopi S, Naganathan AN. Non-specific DNA-driven quinary interactions promote structural transitions in proteins. Phys Chem Chem Phys 2020; 22:12671-12677. [PMID: 32458879 DOI: 10.1039/d0cp01758b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The nature and distribution of charged residues on the surface of proteins play a vital role in determining the binding affinity, selectivity and kinetics of association to ligands. When it comes to DNA-binding domains (DBDs), these functional features manifest as anisotropic distribution of positively charged residues on the protein surface driven by the requirement to bind DNA, a highly negatively charged polymer. In this work, we compare the thermodynamic behavior of nine different proteins belonging to three families - LacR, engrailed and Brk - some of which are disordered in solution in the absence of DNA. Combining detailed electrostatic calculations and statistical mechanical modeling of folding landscapes at different distances and relative orientations with respect to DNA, we show that non-specific electrostatic interactions between the protein and DNA can promote structural transitions in DBDs. Such quinary interactions that are strictly agnostic to the DNA sequence induce varied behaviors including folding of disordered domains, partial unfolding of ordered proteins and (de-)population of intermediate states. Our work highlights that the folding landscape of proteins can be tuned as a function of distance from DNA and hints at possible reasons for DBDs exhibiting complex kinetic-thermodynamic behaviors in the absence of DNA.
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Affiliation(s)
- Soundhararajan Gopi
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India.
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12
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Addabbo RM, Dalphin MD, Mecha MF, Liu Y, Staikos A, Guzman-Luna V, Cavagnero S. Complementary Role of Co- and Post-Translational Events in De Novo Protein Biogenesis. J Phys Chem B 2020; 124:6488-6507. [DOI: 10.1021/acs.jpcb.0c03039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Rayna M. Addabbo
- Biophysics Graduate Degree Program, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Matthew D. Dalphin
- Biophysics Graduate Degree Program, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Miranda F. Mecha
- Biophysics Graduate Degree Program, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Yue Liu
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Alexios Staikos
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Valeria Guzman-Luna
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Silvia Cavagnero
- Biophysics Graduate Degree Program, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
- Department of Chemistry, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
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13
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Hu Y, Li C, He L, Jin C, Liu M. Mechanisms of Chaperones as Active Assistant/Protector for Proteins: Insights from NMR Studies. CHINESE J CHEM 2020. [DOI: 10.1002/cjoc.201900441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yunfei Hu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Conggang Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Lichun He
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Changwen Jin
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, College of Life Sciences, Peking University Beijing 100871 China
| | - Maili Liu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan National Laboratory for OptoelectronicsNational Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences (CAS) Wuhan Hubei 430071 China
- University of Chinese Academy of Sciences Beijing 100049 China
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14
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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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15
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Abstract
Copper is a redox-active transition metal ion required for the function of many essential human proteins. For biosynthesis of proteins coordinating copper, the metal may bind before, during or after folding of the polypeptide. If the metal binds to unfolded or partially folded structures of the protein, such coordination may modulate the folding reaction. The molecular understanding of how copper is incorporated into proteins requires descriptions of chemical, thermodynamic, kinetic and structural parameters involved in the formation of protein-metal complexes. Because free copper ions are toxic, living systems have elaborate copper-transport systems that include particular proteins that facilitate efficient and specific delivery of copper ions to target proteins. Therefore, these pathways become an integral part of copper protein folding in vivo. This review summarizes biophysical-molecular in vitro work assessing the role of copper in folding and stability of copper-binding proteins as well as protein-protein copper exchange reactions between human copper transport proteins. We also describe some recent findings about the participation of copper ions and copper proteins in protein misfolding and aggregation reactions in vitro.
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16
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Siegal G, Selenko P. Cells, drugs and NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 306:202-212. [PMID: 31358370 DOI: 10.1016/j.jmr.2019.07.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 06/08/2019] [Accepted: 07/08/2019] [Indexed: 05/18/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a versatile tool for investigating cellular structures and their compositions. While in vivo and whole-cell NMR have a long tradition in cell-based approaches, high-resolution in-cell NMR spectroscopy is a new addition to these methods. In recent years, technological advancements in multiple areas provided converging benefits for cellular MR applications, especially in terms of robustness, reproducibility and physiological relevance. Here, we review the use of cellular NMR methods for drug discovery purposes in academia and industry. Specifically, we discuss how developments in NMR technologies such as miniaturized bioreactors and flow-probe perfusion systems have helped to consolidate NMR's role in cell-based drug discovery efforts.
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Affiliation(s)
- Gregg Siegal
- ZoBio B.V., BioPartner 2 Building, J.H. Oortweg 19, 2333 Leiden, the Netherlands
| | - Philipp Selenko
- Department of Biological Regulation, Weizmann Institute of Science, 234 Herzl Street, 761000 Rehovot, Israel.
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17
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Dalaloyan A, Martorana A, Barak Y, Gataulin D, Reuveny E, Howe A, Elbaum M, Albeck S, Unger T, Frydman V, Abdelkader EH, Otting G, Goldfarb D. Tracking Conformational Changes in Calmodulin in vitro, in Cell Extract, and in Cells by Electron Paramagnetic Resonance Distance Measurements. Chemphyschem 2019; 20:1860-1868. [PMID: 31054266 DOI: 10.1002/cphc.201900341] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Indexed: 12/12/2022]
Abstract
It is an open question whether the conformations of proteins sampled in dilute solutions are the same as in the cellular environment. Here we address this question by double electron-electron resonance (DEER) distance measurements with Gd(III) spin labels to probe the conformations of calmodulin (CaM) in vitro, in cell extract, and in human HeLa cells. Using the CaM mutants N53C/T110C and T34C/T117C labeled with maleimide-DOTA-Gd(III) in the N- and C-terminal domains, we observed broad and varied interdomain distance distributions. The in vitro distance distributions of apo-CaM and holo-CaM in the presence and absence of the IQ target peptide can be described by combinations of closed, open, and collapsed conformations. In cell extract, apo- and holo-CaM bind to target proteins in a similar way as apo- and holo-CaM bind to IQ peptide in vitro. In HeLa cells, however, in the presence or absence of elevated in-cell Ca2+ levels CaM unexpectedly produced more open conformations and very broad distance distributions indicative of many different interactions with in-cell components. These results show-case the importance of in-cell analyses of protein structures.
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Affiliation(s)
| | | | | | | | | | - Andrew Howe
- Department of Chemical and Biological Physics
| | | | - Shira Albeck
- Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot, Israel
| | - Tamar Unger
- Department of Life Sciences Core Facilities, The Weizmann Institute of Science, Rehovot, Israel
| | | | - Elwy H Abdelkader
- Research School of Chemistry, Australian National University, Canberra, Australia
| | - Gottfried Otting
- Research School of Chemistry, Australian National University, Canberra, Australia
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18
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Tanaka T, Ikeya T, Kamoshida H, Suemoto Y, Mishima M, Shirakawa M, Güntert P, Ito Y. High‐Resolution Protein 3D Structure Determination in Living Eukaryotic Cells. Angew Chem Int Ed Engl 2019; 58:7284-7288. [DOI: 10.1002/anie.201900840] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/20/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Takashi Tanaka
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Teppei Ikeya
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Hajime Kamoshida
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Yusuke Suemoto
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Masaki Mishima
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Masahiro Shirakawa
- Department of Molecular EngineeringGraduate School of EngineeringKyoto University Nishikyo-ku Kyoto 615-8510 Japan
| | - Peter Güntert
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic ResonanceGoethe University Frankfurt 60438 Frankfurt am Main Germany
- Laboratory of Physical ChemistryETH Zürich 8093 Zürich Switzerland
| | - Yutaka Ito
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
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19
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Tanaka T, Ikeya T, Kamoshida H, Suemoto Y, Mishima M, Shirakawa M, Güntert P, Ito Y. High‐Resolution Protein 3D Structure Determination in Living Eukaryotic Cells. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900840] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Takashi Tanaka
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Teppei Ikeya
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Hajime Kamoshida
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Yusuke Suemoto
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Masaki Mishima
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
| | - Masahiro Shirakawa
- Department of Molecular EngineeringGraduate School of EngineeringKyoto University Nishikyo-ku Kyoto 615-8510 Japan
| | - Peter Güntert
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic ResonanceGoethe University Frankfurt 60438 Frankfurt am Main Germany
- Laboratory of Physical ChemistryETH Zürich 8093 Zürich Switzerland
| | - Yutaka Ito
- Department of ChemistryGraduate School of ScienceTokyo Metropolitan University 1-1 Minami-Osawa, Hachioji Tokyo 192-0397 Japan
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20
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21
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Breindel L, Burz DS, Shekhtman A. Interaction proteomics by using in-cell NMR spectroscopy. J Proteomics 2019; 191:202-211. [PMID: 29427760 PMCID: PMC6082733 DOI: 10.1016/j.jprot.2018.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/31/2018] [Accepted: 02/04/2018] [Indexed: 12/17/2022]
Abstract
A synopsis of in-cell NMR spectroscopic approaches to study interaction proteomics in prokaryotic and eukaryotic cells is presented. We describe the use of in-cell NMR spectroscopy to resolve high resolution protein structures, discuss methodologies for determining and analyzing high and low affinity protein-target structural interactions, including intrinsically disordered proteins, and detail important functional interactions that result from these interactions. SIGNIFICANCE: The ultimate goal of structural and biochemical research is to understand how macromolecular interactions give rise to and regulate biological activity in living cells. The challenge is formidable due to the complexity that arises not only from the number of proteins (genes) expressed by the organism, but also from the combinatorial interactions between them. Despite ongoing efforts to decipher the complex nature of protein interactions, new methods for structurally characterizing protein complexes are needed to fully understand molecular networks. With the onset of in-cell NMR spectroscopy, molecular structures and interactions can be studied under physiological conditions shedding light on the structural underpinning of biological activity.
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Affiliation(s)
- Leonard Breindel
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA
| | - David S Burz
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.
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22
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Röder K, Joseph JA, Husic BE, Wales DJ. Energy Landscapes for Proteins: From Single Funnels to Multifunctional Systems. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201800175] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Konstantin Röder
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| | - Jerelle A. Joseph
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| | - Brooke E. Husic
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
| | - David J. Wales
- Department of ChemistryUniversity of CambridgeLensfield Road CB2 1EW Cambridge UK
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23
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Bortolini C, Kartanas T, Copic D, Condado Morales I, Zhang Y, Challa PK, Peter Q, Jávorfi T, Hussain R, Dong M, Siligardi G, Knowles TPJ, Charmet J. Resolving protein mixtures using microfluidic diffusional sizing combined with synchrotron radiation circular dichroism. LAB ON A CHIP 2018; 19:50-58. [PMID: 30515508 DOI: 10.1039/c8lc00757h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Circular dichroism spectroscopy has become a powerful tool to characterise proteins and other biomolecules. For heterogeneous samples such as those present for interacting proteins, typically only average spectroscopic features can be resolved. Here we overcome this limitation by using free-flow microfluidic size separation in-line with synchrotron radiation circular dichroism to resolve the secondary structure of each component of a model protein mixture containing monomers and fibrils. To enable this objective, we have integrated far-UV compatible measurement chambers into PDMS-based microfluidic devices. Two architectures are proposed so as to accommodate for a wide range of concentrations. The approach, which can be used in combination with other bulk measurement techniques, paves the way to the study of complex mixtures such as the ones associated with protein misfolding and aggregation diseases including Alzheimer's and Parkinson's diseases.
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Affiliation(s)
- Christian Bortolini
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB3 0FF, UK
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24
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Guseman AJ, Speer SL, Perez Goncalves GM, Pielak GJ. Surface Charge Modulates Protein-Protein Interactions in Physiologically Relevant Environments. Biochemistry 2018; 57:1681-1684. [PMID: 29473738 PMCID: PMC5977980 DOI: 10.1021/acs.biochem.8b00061] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein-protein interactions are fundamental to biology yet are rarely studied under physiologically relevant conditions where the concentration of macromolecules can exceed 300 g/L. These high concentrations cause cosolute-complex contacts that are absent in dilute buffer. Understanding such interactions is important because they organize the cellular interior. We used 19F nuclear magnetic resonance, the dimer-forming A34F variant of the model protein GB1, and the cosolutes bovine serum albumin (BSA) and lysozyme to assess the effects of repulsive and attractive charge-charge dimer-cosolute interactions on dimer stability. The interactions were also manipulated via charge-change variants and by changing the pH. Charge-charge repulsions between BSA and GB1 stabilize the dimer, and the effects of lysozyme indicate a role for attractive interactions. The data show that chemical interactions can regulate the strength of protein-protein interactions under physiologically relevant crowded conditions and suggest a mechanism for tuning the equilibrium thermodynamics of protein-protein interactions in cells.
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Affiliation(s)
- Alex J. Guseman
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Shannon L. Speer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Gerardo M. Perez Goncalves
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Gary J. Pielak
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Integrative Program for Biological and Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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25
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Chen JL, Zhao Y, Gong YJ, Pan BB, Wang X, Su XC. Stable and rigid DTPA-like paramagnetic tags suitable for in vitro and in situ protein NMR analysis. JOURNAL OF BIOMOLECULAR NMR 2018; 70:77-92. [PMID: 29224182 DOI: 10.1007/s10858-017-0160-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/05/2017] [Indexed: 06/07/2023]
Abstract
Organic synthesis of a ligand with high binding affinities for paramagnetic lanthanide ions is an effective way of generating paramagnetic effects on proteins. These paramagnetic effects manifested in high-resolution NMR spectroscopy are valuable dynamic and structural restraints of proteins and protein-ligand complexes. A paramagnetic tag generally contains a metal chelating moiety and a reactive group for protein modification. Herein we report two new DTPA-like tags, 4PS-PyDTTA and 4PS-6M-PyDTTA that can be site-specifically attached to a protein with a stable thioether bond. Both protein-tag adducts form stable lanthanide complexes, of which the binding affinities and paramagnetic tensors are tunable with respect to the 6-methyl group in pyridine. Paramagnetic relaxation enhancement (PRE) effects of Gd(III) complex on protein-tag adducts were evaluated in comparison with pseudocontact shift (PCS), and the results indicated that both 4PS-PyDTTA and 4PS-6M-PyDTTA tags are rigid and present high-quality PREs that are crucially important in elucidation of the dynamics and interactions of proteins and protein-ligand complexes. We also show that these two tags are suitable for in-situ protein NMR analysis.
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Affiliation(s)
- Jia-Liang Chen
- State Key Laboratory of Elemento-Organic Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Yu Zhao
- State Key Laboratory of Elemento-Organic Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Yan-Jun Gong
- State Key Laboratory of Elemento-Organic Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Bin-Bin Pan
- State Key Laboratory of Elemento-Organic Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xiao Wang
- State Key Laboratory of Elemento-Organic Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Xun-Cheng Su
- State Key Laboratory of Elemento-Organic Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), College of Chemistry, Nankai University, Tianjin, 300071, China.
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26
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Davis CM, Gruebele M, Sukenik S. How does solvation in the cell affect protein folding and binding? Curr Opin Struct Biol 2018; 48:23-29. [PMID: 29035742 DOI: 10.1016/j.sbi.2017.09.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 12/21/2022]
Abstract
The cellular environment is highly diverse and capable of rapid changes in solute composition and concentrations. Decades of protein studies have highlighted their sensitivity to solute environment, yet these studies were rarely performed in situ. Recently, new techniques capable of monitoring proteins in their natural context within a live cell have emerged. A recurring theme of these investigations is the importance of the often-neglected cellular solvation environment to protein function. An emerging consensus is that protein processes in the cell are affected by a combination of steric and non-steric interactions with this solution. Here we explain how protein surface area and volume changes control these two interaction types, and give recent examples that highlight how even mild environmental changes can alter cellular processes.
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Affiliation(s)
- Caitlin M Davis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Martin Gruebele
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Shahar Sukenik
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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27
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Pan BB, Yang F, Ye Y, Wu Q, Li C, Huber T, Su XC. 3D structure determination of a protein in living cells using paramagnetic NMR spectroscopy. Chem Commun (Camb) 2018; 52:10237-40. [PMID: 27470136 DOI: 10.1039/c6cc05490k] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Determining the three-dimensional structure of a protein in living cells remains particularly challenging. We demonstrated that the integration of site-specific tagging proteins and GPS-Rosetta calculations provides a fast and effective way of determining the structures of proteins in living cells, and in principle the interactions and dynamics of protein-ligand complexes.
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Affiliation(s)
- Bin-Bin Pan
- State Key Laboratory and Research Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China.
| | - Feng Yang
- State Key Laboratory and Research Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China.
| | - Yansheng Ye
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Qiong Wu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Conggang Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Thomas Huber
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
| | - Xun-Cheng Su
- State Key Laboratory and Research Institute of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin 300071, China.
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28
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Solution structure and interaction with copper in vitro and in living cells of the first BIR domain of XIAP. Sci Rep 2017; 7:16630. [PMID: 29192194 PMCID: PMC5709467 DOI: 10.1038/s41598-017-16723-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 11/16/2017] [Indexed: 12/20/2022] Open
Abstract
The X-chromosome linked inhibitor of apoptosis (XIAP) is a multidomain metalloprotein involved in caspase inhibition and in copper homeostasis. It contains three zinc-binding baculoviral IAP repeats (BIR) domains, which are responsible for caspase interaction. Recently, it has been suggested that the BIR domains can bind copper, however high resolution data on such interaction is missing. Here we characterize by NMR the structural properties of BIR1 in solution, and the effects of its interaction with copper both in vitro and in physiological environments. BIR1 is dimeric in solution, consistent with the X-ray structure. Cysteine 12, located in the unfolded N-terminal region, has a remarkably low redox potential, and is prone to oxidation even in reducing physiological environments. Interaction of BIR1 with copper(II) results in the oxidation of cysteine 12, with the formation of either an intermolecular disulfide bond between two BIR1 molecules or a mixed disulfide bond with glutathione, whereas the zinc binding site is not affected by the interaction.
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29
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Rydzik AM, Warminski M, Sikorski PJ, Baranowski MR, Walczak S, Kowalska J, Zuberek J, Lukaszewicz M, Nowak E, W Claridge TD, Darzynkiewicz E, Nowotny M, Jemielity J. mRNA cap analogues substituted in the tetraphosphate chain with CX2: identification of O-to-CCl2 as the first bridging modification that confers resistance to decapping without impairing translation. Nucleic Acids Res 2017; 45:8661-8675. [PMID: 28666355 PMCID: PMC5587727 DOI: 10.1093/nar/gkx569] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 06/20/2017] [Indexed: 12/20/2022] Open
Abstract
Analogues of the mRNA 5'-cap are useful tools for studying mRNA translation and degradation, with emerging potential applications in novel therapeutic interventions including gene therapy. We report the synthesis of novel mono- and dinucleotide cap analogues containing dihalogenmethylenebisphosphonate moiety (i.e. one of the bridging O atom substituted with CCl2 or CF2) and their properties in the context of cellular translational and decapping machineries, compared to phosphate-unmodified and previously reported CH2-substituted caps. The analogues were bound tightly to eukaryotic translation initiation factor 4E (eIF4E), with CCl2-substituted analogues having the highest affinity. When incorporated into mRNA, the CCl2-substituted dinucleotide most efficiently promoted cap-dependent translation. Moreover, the CCl2-analogues were potent inhibitors of translation in rabbit reticulocyte lysate. The crystal structure of eIF4E in complex with the CCl2-analogue revealed a significantly different ligand conformation compared to that of the unmodified cap analogue, which likely contributes to the improved binding. Both CCl2- and CF2- analogues showed lower susceptibility to hydrolysis by the decapping scavenger enzyme (DcpS) and, when incorporated into RNA, conferred stability against major cellular decapping enzyme (Dcp2) to transcripts. Furthermore, the use of difluoromethylene cap analogues was exemplified by the development of 19F NMR assays for DcpS activity and eIF4E binding.
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Affiliation(s)
- Anna M Rydzik
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland.,Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Marcin Warminski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Pawel J Sikorski
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Marek R Baranowski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Sylwia Walczak
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland.,College of Inter-Faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Joanna Kowalska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Joanna Zuberek
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Maciej Lukaszewicz
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Elzbieta Nowak
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 4 Ksiecia Trojdena Street, 02-109 Warsaw, Poland
| | - Timothy D W Claridge
- Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Edward Darzynkiewicz
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Zwirki i Wigury 93, 02-089 Warsaw, Poland.,Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 4 Ksiecia Trojdena Street, 02-109 Warsaw, Poland
| | - Jacek Jemielity
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
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30
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Abstract
In vitro, computational, and theoretical studies of protein folding have converged to paint a rich and complex energy landscape. This landscape is sensitively modulated by environmental conditions and subject to evolutionary pressure on protein function. Of these environments, none is more complex than the cell itself, where proteins function in the cytosol, in membranes, and in different compartments. A wide variety of kinetic and thermodynamics experiments, ranging from single-molecule studies to jump kinetics and from nuclear magnetic resonance to imaging on the microscope, have elucidated how protein energy landscapes facilitate folding and how they are subject to evolutionary constraints and environmental perturbation. Here we review some recent developments in the field and refer the reader to some original work and additional reviews that cover this broad topic in protein science.
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Affiliation(s)
- Martin Gruebele
- Center for Biophysics and Quantitative Biology, University of Illinois, Urbana, Illinois 61801; , .,Department of Chemistry, University of Illinois, Urbana, Illinois 61801; .,Department of Physics, University of Illinois, Urbana, Illinois 61801
| | - Kapil Dave
- Center for Biophysics and Quantitative Biology, University of Illinois, Urbana, Illinois 61801; ,
| | - Shahar Sukenik
- Department of Chemistry, University of Illinois, Urbana, Illinois 61801;
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31
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Uversky VN. Intrinsic disorder here, there, and everywhere, and nowhere to escape from it. Cell Mol Life Sci 2017; 74:3065-3067. [PMID: 28589440 PMCID: PMC11107637 DOI: 10.1007/s00018-017-2554-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 06/01/2017] [Indexed: 11/28/2022]
Abstract
The concept of protein intrinsic disorder persistently penetrates into all areas of modern protein science. It cannot be ignored anymore, and cannot be shrugged off, as it represents a vital feature (or, more correctly, a broad spectrum of important features), which, when added to and mixed with features arising from the well established protein structure-function paradigm, complete the picture of a functioning protein. The field of protein intrinsic disorder is very dynamic and fast developing. This Multi-Author Review represents a snapshot of this field by introducing some recent advances. Articles assembled in this Multi-Author Review introduce some of the new aspects of intrinsic disorder, outline some fascinating ideas related to the intrinsically disordered proteins, their structure, and functionality, and show challenges related to the analysis of proteins carrying intrinsic disorder.
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Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd. MDC07, Tampa, FL, 33612, USA.
- Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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32
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Feig M, Yu I, Wang PH, Nawrocki G, Sugita Y. Crowding in Cellular Environments at an Atomistic Level from Computer Simulations. J Phys Chem B 2017; 121:8009-8025. [PMID: 28666087 PMCID: PMC5582368 DOI: 10.1021/acs.jpcb.7b03570] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
![]()
The
effects of crowding in biological environments on biomolecular
structure, dynamics, and function remain not well understood. Computer
simulations of atomistic models of concentrated peptide and protein
systems at different levels of complexity are beginning to provide
new insights. Crowding, weak interactions with other macromolecules
and metabolites, and altered solvent properties within cellular environments
appear to remodel the energy landscape of peptides and proteins in
significant ways including the possibility of native state destabilization.
Crowding is also seen to affect dynamic properties, both conformational
dynamics and diffusional properties of macromolecules. Recent simulations
that address these questions are reviewed here and discussed in the
context of relevant experiments.
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Affiliation(s)
- Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan, United States.,Quantitative Biology Center, RIKEN , Kobe, Japan
| | - Isseki Yu
- Theoretical Molecular Science Laboratory, RIKEN , Wako, Japan.,iTHES Research Group, RIKEN , Wako, Japan
| | - Po-Hung Wang
- Theoretical Molecular Science Laboratory, RIKEN , Wako, Japan
| | - Grzegorz Nawrocki
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan, United States
| | - Yuji Sugita
- Quantitative Biology Center, RIKEN , Kobe, Japan.,Theoretical Molecular Science Laboratory, RIKEN , Wako, Japan.,iTHES Research Group, RIKEN , Wako, Japan.,Advanced Institute for Computational Science, RIKEN , Kobe, Japan
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33
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Minton AP. Explicit Incorporation of Hard and Soft Protein-Protein Interactions into Models for Crowding Effects in Protein Mixtures. 2. Effects of Varying Hard and Soft Interactions upon Prototypical Chemical Equilibria. J Phys Chem B 2017; 121:5515-5522. [PMID: 28505444 DOI: 10.1021/acs.jpcb.7b02378] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Previously derived approximate analytical relations for the activity coefficient of each solute in a mixture of up to three spherical solutes in a highly nonideal solution interacting via square well potentials of mean force (Hoppe, T.; Minton, A. P. J Phys Chem B. 2016, 120, 11866-11872) were used to explore the effect of heterogeneity in volume occupancy and intermolecular interactions upon prototypical schemes representing solubility, partitioning, conformational isomerization, and self-association in crowded solutions. Results generally indicate that all of the equilibria explored are exquisitely sensitive to variations in both volume occupancy and intermolecular interaction and have important implications for the design and execution of more detailed simulations of complex media.
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Affiliation(s)
- Allen P Minton
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, United States Department of Health and Human Welfare , Bethesda, Maryland United States
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34
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Physicochemical code for quinary protein interactions in Escherichia coli. Proc Natl Acad Sci U S A 2017; 114:E4556-E4563. [PMID: 28536196 DOI: 10.1073/pnas.1621227114] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
How proteins sense and navigate the cellular interior to find their functional partners remains poorly understood. An intriguing aspect of this search is that it relies on diffusive encounters with the crowded cellular background, made up of protein surfaces that are largely nonconserved. The question is then if/how this protein search is amenable to selection and biological control. To shed light on this issue, we examined the motions of three evolutionary divergent proteins in the Escherichia coli cytoplasm by in-cell NMR. The results show that the diffusive in-cell motions, after all, follow simplistic physical-chemical rules: The proteins reveal a common dependence on (i) net charge density, (ii) surface hydrophobicity, and (iii) the electric dipole moment. The bacterial protein is here biased to move relatively freely in the bacterial interior, whereas the human counterparts more easily stick. Even so, the in-cell motions respond predictably to surface mutation, allowing us to tune and intermix the protein's behavior at will. The findings show how evolution can swiftly optimize the diffuse background of protein encounter complexes by just single-point mutations, and provide a rational framework for adjusting the cytoplasmic motions of individual proteins, e.g., for rescuing poor in-cell NMR signals and for optimizing protein therapeutics.
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35
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Alfano C, Sanfelice D, Martin SR, Pastore A, Temussi PA. An optimized strategy to measure protein stability highlights differences between cold and hot unfolded states. Nat Commun 2017; 8:15428. [PMID: 28516908 PMCID: PMC5454340 DOI: 10.1038/ncomms15428] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 03/27/2017] [Indexed: 11/09/2022] Open
Abstract
Macromolecular crowding ought to stabilize folded forms of proteins, through an excluded volume effect. This explanation has been questioned and observed effects attributed to weak interactions with other cell components. Here we show conclusively that protein stability is affected by volume exclusion and that the effect is more pronounced when the crowder's size is closer to that of the protein under study. Accurate evaluation of the volume exclusion effect is made possible by the choice of yeast frataxin, a protein that undergoes cold denaturation above zero degrees, because the unfolded form at low temperature is more expanded than the corresponding one at high temperature. To achieve optimum sensitivity to changes in stability we introduce an empirical parameter derived from the stability curve. The large effect of PEG 20 on cold denaturation can be explained by a change in water activity, according to Privalov's interpretation of cold denaturation.
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Affiliation(s)
- Caterina Alfano
- Department of Basic and Clinical Neurosciences, King's College London, London SE5 9RX, UK
| | - Domenico Sanfelice
- Department of Basic and Clinical Neurosciences, King's College London, London SE5 9RX, UK
| | - Stephen R. Martin
- Structural Biology Science Technology Platform, The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Annalisa Pastore
- Department of Basic and Clinical Neurosciences, King's College London, London SE5 9RX, UK
- Department of Molecular Medicine, University of Pavia, Pavia 27100, Italy
| | - Piero Andrea Temussi
- Department of Basic and Clinical Neurosciences, King's College London, London SE5 9RX, UK
- Dipartimento di Scienze Chimiche, Universita' di Napoli Federico II, Napoli 80126, Italy
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36
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Gibbs EB, Cook EC, Showalter SA. Application of NMR to studies of intrinsically disordered proteins. Arch Biochem Biophys 2017; 628:57-70. [PMID: 28502465 DOI: 10.1016/j.abb.2017.05.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 12/20/2022]
Abstract
The prevalence of intrinsically disordered protein regions, particularly in eukaryotic proteins, and their clear functional advantages for signaling and gene regulation have created an imperative for high-resolution structural and mechanistic studies. NMR spectroscopy has played a central role in enhancing not only our understanding of the intrinsically disordered native state, but also how that state contributes to biological function. While pathological functions associated with protein aggregation are well established, it has recently become clear that disordered regions also mediate functionally advantageous assembly into high-order structures that promote the formation of membrane-less sub-cellular compartments and even hydrogels. Across the range of functional assembly states accessed by disordered regions, post-translational modifications and regulatory macromolecular interactions, which can also be investigated by NMR spectroscopy, feature prominently. Here we will explore the many ways in which NMR has advanced our understanding of the physical-chemical phase space occupied by disordered protein regions and provide prospectus for the future role of NMR in this emerging and exciting field.
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Affiliation(s)
- Eric B Gibbs
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Erik C Cook
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Scott A Showalter
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA; Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
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37
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Pastore A, Temussi PA. The Emperor's new clothes: Myths and truths of in-cell NMR. Arch Biochem Biophys 2017; 628:114-122. [PMID: 28259514 DOI: 10.1016/j.abb.2017.02.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 02/24/2017] [Accepted: 02/27/2017] [Indexed: 11/25/2022]
Abstract
In-cell NMR is a technique developed to study the structure and dynamical behavior of biological macromolecules in their natural environment, circumventing all isolation and purification steps. In principle, the potentialities of the technique are enormous, not only for the possibility of bypassing all purification steps but, even more importantly, for the wealth of information that can be gained from directly monitoring interactions among biological macromolecules in a natural cell. Here, we review critically the promises, successes and limits of this technique as it stands now. Interestingly, many of the problems of NMR in bacterial cells stem from the artificially high concentration of the protein under study whose overexpression is anyway necessary to select it from the background. This has, as a consequence, that when overexpressed, most globular proteins, do not show an NMR spectrum, limiting the applicability of the technique to intrinsically unfolded or specifically behaving proteins. The outlook for in-cell NMR of eukaryotic cells is more promising and is possibly the most attracting aspect for the future.
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Affiliation(s)
- Annalisa Pastore
- The Wohl Institute, King's College London, 5 Cutcombe Rd, London SE5 9RT, UK; University of Pavia, Department of Molecular Medicine, Pavia, Italy.
| | - Piero Andrea Temussi
- The Wohl Institute, King's College London, 5 Cutcombe Rd, London SE5 9RT, UK; University of Naples "Federico II", Department of Chemical Sciences, Naples, Italy
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38
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Hoppe T, Minton AP. Incorporation of Hard and Soft Protein-Protein Interactions into Models for Crowding Effects in Binary and Ternary Protein Mixtures. Comparison of Approximate Analytical Solutions with Numerical Simulation. J Phys Chem B 2016; 120:11866-11872. [PMID: 27779417 DOI: 10.1021/acs.jpcb.6b07736] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to better understand how nonspecific interactions between solutes can modulate specific biochemical reactions taking place in complex media, we introduce a simplified model aimed at elucidating general principles. In this model, solutions containing two or three species of interacting globular proteins are modeled as a fluid of spherical particles interacting through square well potentials that qualitatively capture both steric hard core repulsion and longer-ranged attraction or repulsion. The excess chemical potential, or free energy of solvation, of each particle species is calculated as a function of species concentrations, particle radii, and square well interaction range and depth. The results of analytical models incorporating two-body and three-body interactions are compared with the estimates of free energy obtained via Widom insertion into simulated equilibrium square-well fluids. The analytical models agree well with results of numeric simulations carried out for a variety of model parameters and fluid compositions up to a total particle volume fraction of ca. 0.2.
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Affiliation(s)
- Travis Hoppe
- Laboratory of Chemical Physics and ‡Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, United States Public Health Service , Bethesda, Maryland 20892, United States
| | - Allen P Minton
- Laboratory of Chemical Physics and ‡Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, United States Public Health Service , Bethesda, Maryland 20892, United States
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39
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Li D, Zhang Y, He Y, Zhang C, Wang J, Xiong Y, Zhang L, Liu Y, Shi P, Tian C. Protein-protein interaction analysis in crude bacterial lysates using combinational method of 19F site-specific incorporation and 19F NMR. Protein Cell 2016; 8:149-154. [PMID: 27785779 PMCID: PMC5291773 DOI: 10.1007/s13238-016-0336-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Dong Li
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Yanan Zhang
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Yao He
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Chengwei Zhang
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Jiefei Wang
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Ying Xiong
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Longhua Zhang
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Yangzhong Liu
- School of Chemistry, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Pan Shi
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China.
| | - Changlin Tian
- Hefei National Laboratory for Physical Science at the Microscale & School of Life Science, University of Science and Technology of China, Hefei, 230026, Anhui, China.
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40
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Qin S, Zhou HX. Protein folding, binding, and droplet formation in cell-like conditions. Curr Opin Struct Biol 2016; 43:28-37. [PMID: 27771543 DOI: 10.1016/j.sbi.2016.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/07/2016] [Indexed: 10/20/2022]
Abstract
The many bystander macromolecules in the crowded cellular environments present both steric repulsion and weak attraction to proteins undergoing folding or binding and hence impact the thermodynamic and kinetic properties of these processes. The weak but nonrandom binding with bystander macromolecules may facilitate subcellular localization and biological function. Weak binding also leads to the emergence of a protein-rich droplet phase, which has been implicated in regulating a variety of cellular functions. All these important problems can now be addressed by realistic modeling of intermolecular interactions. Configurational sampling of concentrated protein solutions is an ongoing challenge.
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Affiliation(s)
- Sanbo Qin
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Huan-Xiang Zhou
- Department of Physics and Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA.
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41
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Rivas G, Minton AP. Macromolecular Crowding In Vitro, In Vivo, and In Between. Trends Biochem Sci 2016; 41:970-981. [PMID: 27669651 DOI: 10.1016/j.tibs.2016.08.013] [Citation(s) in RCA: 306] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/18/2016] [Accepted: 08/22/2016] [Indexed: 10/21/2022]
Abstract
Biochemical processes take place in heterogeneous and highly volume-occupied or crowded environments that can considerably influence the reactivity and distribution of participating macromolecules. We summarize here the thermodynamic consequences of excluded-volume and long-range nonspecific intermolecular interactions for macromolecular reactions in volume-occupied media. In addition, we summarize and compare the information content of studies of crowding in vitro and in vivo. We emphasize the importance of characterizing the behavior not only of labeled tracer macromolecules but also the composition and behavior of unlabeled macromolecules in the immediate vicinity of the tracer. Finally, we propose strategies for extending quantitative analyses of crowding in simple model systems to increasingly complex media up to and including intact cells.
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Affiliation(s)
- Germán Rivas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Allen P Minton
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
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42
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The Differential Response of Proteins to Macromolecular Crowding. PLoS Comput Biol 2016; 12:e1005040. [PMID: 27471851 PMCID: PMC4966950 DOI: 10.1371/journal.pcbi.1005040] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/27/2016] [Indexed: 12/02/2022] Open
Abstract
The habitat in which proteins exert their function contains up to 400 g/L of macromolecules, most of which are proteins. The repercussions of this dense environment on protein behavior are often overlooked or addressed using synthetic agents such as poly(ethylene glycol), whose ability to mimic protein crowders has not been demonstrated. Here we performed a comprehensive atomistic molecular dynamic analysis of the effect of protein crowders on the structure and dynamics of three proteins, namely an intrinsically disordered protein (ACTR), a molten globule conformation (NCBD), and a one-fold structure (IRF-3) protein. We found that crowding does not stabilize the native compact structure, and, in fact, often prevents structural collapse. Poly(ethylene glycol) PEG500 failed to reproduce many aspects of the physiologically-relevant protein crowders, thus indicating its unsuitability to mimic the cell interior. Instead, the impact of protein crowding on the structure and dynamics of a protein depends on its degree of disorder and results from two competing effects: the excluded volume, which favors compact states, and quinary interactions, which favor extended conformers. Such a viscous environment slows down protein flexibility and restricts the conformational landscape, often biasing it towards bioactive conformations but hindering biologically relevant protein-protein contacts. Overall, the protein crowders used here act as unspecific chaperons that modulate the protein conformational space, thus having relevant consequences for disordered proteins. Most in vitro and in silico biophysical experiments generally study proteins in an isolated environment, overlooking that their natural environment—the cell cytoplasm—is a solution that is highly populated by proteins. To address this knowledge gap, here we explored how a crowded environment alters the conformational sampling of three proteins, each with a different degree of disorder and flexibility. We simulated a crowded system composed by the three proteins and reaching a cell-like concentration and compared the protein behavior observed with that induced by PEG500, a synthetic crowding agent. Despite some similarities between the environments, protein crowders showed a number of characteristics that raise concerns about the use of diluted solutions or synthetic agents when studying protein behavior.
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43
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Kadumuri RV, Gullipalli J, Subramanian S, Jaipuria G, Atreya HS, Vadrevu R. Crowding interactions perturb structure and stability by destabilizing the stable core of the α-subunit of tryptophan synthase. FEBS Lett 2016; 590:2096-105. [PMID: 27311646 DOI: 10.1002/1873-3468.12259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/06/2016] [Accepted: 06/13/2016] [Indexed: 11/12/2022]
Abstract
The consequences of crowding derived from relatively small and intrinsically disordered proteins are not clear yet. We report the effect of ficoll-70 on the structure and stability of native and partially folded states of the 29 kDa alpha subunit of tryptophan synthase (αTS). Overall, combining the changes in the circular dichroism and fluorescence spectra, in conjunction with the gradual loss of cooperativity under urea denaturation in the presence of increasing amounts of ficoll, it may be concluded that the crowding agent perturbs not only the native state but also the partially folded state of αTS. Importantly, NMR data indicate that ficoll interacts with the residues that constitute the stable core of the protein thus shedding light on the origin of the observed perturbation.
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Affiliation(s)
- Rajashekar Varma Kadumuri
- Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India
| | - Jagadeesh Gullipalli
- Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India
| | - SriVidya Subramanian
- Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India
| | - Garima Jaipuria
- NMR Research Centre, Indian Institute of Science, Bangalore, India
| | | | - Ramakrishna Vadrevu
- Department of Biological Sciences, Birla Institute of Technology & Science-Pilani, Hyderabad Campus, Hyderabad, India
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44
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Wei G, Xi W, Nussinov R, Ma B. Protein Ensembles: How Does Nature Harness Thermodynamic Fluctuations for Life? The Diverse Functional Roles of Conformational Ensembles in the Cell. Chem Rev 2016; 116:6516-51. [PMID: 26807783 PMCID: PMC6407618 DOI: 10.1021/acs.chemrev.5b00562] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
All soluble proteins populate conformational ensembles that together constitute the native state. Their fluctuations in water are intrinsic thermodynamic phenomena, and the distributions of the states on the energy landscape are determined by statistical thermodynamics; however, they are optimized to perform their biological functions. In this review we briefly describe advances in free energy landscape studies of protein conformational ensembles. Experimental (nuclear magnetic resonance, small-angle X-ray scattering, single-molecule spectroscopy, and cryo-electron microscopy) and computational (replica-exchange molecular dynamics, metadynamics, and Markov state models) approaches have made great progress in recent years. These address the challenging characterization of the highly flexible and heterogeneous protein ensembles. We focus on structural aspects of protein conformational distributions, from collective motions of single- and multi-domain proteins, intrinsically disordered proteins, to multiprotein complexes. Importantly, we highlight recent studies that illustrate functional adjustment of protein conformational ensembles in the crowded cellular environment. We center on the role of the ensemble in recognition of small- and macro-molecules (protein and RNA/DNA) and emphasize emerging concepts of protein dynamics in enzyme catalysis. Overall, protein ensembles link fundamental physicochemical principles and protein behavior and the cellular network and its regulation.
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Affiliation(s)
- Guanghong Wei
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Wenhui Xi
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, USA
- Sackler Inst. of Molecular Medicine Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, USA
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45
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Lopez J, Schneider R, Cantrelle FX, Huvent I, Lippens G. Studying Intrinsically Disordered Proteins under True In Vivo Conditions by Combined Cross-Polarization and Carbonyl-Detection NMR Spectroscopy. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601850] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Juan Lopez
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
- Departamento de Ciencias-Quimica; Pontificia Universidad Catolica del Peru; Av. Universitaria 1801 Lima 32 Peru
| | - Robert Schneider
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
| | - Francois-Xavier Cantrelle
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
| | - Isabelle Huvent
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
| | - Guy Lippens
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés; Université de Toulouse; CNRS; INRA; INSA Toulouse; 135 Avenue de Rangueil 31077 Toulouse France
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Lopez J, Schneider R, Cantrelle FX, Huvent I, Lippens G. Studying Intrinsically Disordered Proteins under True In Vivo Conditions by Combined Cross-Polarization and Carbonyl-Detection NMR Spectroscopy. Angew Chem Int Ed Engl 2016; 55:7418-22. [DOI: 10.1002/anie.201601850] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 03/28/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Juan Lopez
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
- Departamento de Ciencias-Quimica; Pontificia Universidad Catolica del Peru; Av. Universitaria 1801 Lima 32 Peru
| | - Robert Schneider
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
| | - Francois-Xavier Cantrelle
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
| | - Isabelle Huvent
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
| | - Guy Lippens
- Université de Lille; CNRS; UMR 8576, UGSF-Unité de Glycobiologie Structurale et Fonctionnelle; 59000 Lille France
- Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés; Université de Toulouse; CNRS; INRA; INSA Toulouse; 135 Avenue de Rangueil 31077 Toulouse France
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Fuccio C, Luchinat E, Barbieri L, Neri S, Fragai M. Algal autolysate medium to label proteins for NMR in mammalian cells. JOURNAL OF BIOMOLECULAR NMR 2016; 64:275-280. [PMID: 27106902 DOI: 10.1007/s10858-016-0026-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/22/2016] [Indexed: 06/05/2023]
Abstract
In-cell NMR provides structural and functional information on proteins directly inside living cells. At present, the high costs of the labeled media for mammalian cells represent a limiting factor for the development of this methodology. Here we report a protocol to prepare a homemade growth medium from Spirulina platensis autolysate, suitable to express uniformly labeled proteins inside mammalian cells at a reduced cost-per-sample. The human proteins SOD1 and Mia40 were overexpressed in human cells grown in (15)N-enriched S. platensis algal-derived medium, and high quality in-cell NMR spectra were obtained.
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Affiliation(s)
- Carmelo Fuccio
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Enrico Luchinat
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
- Department of Biomedical, Clinical and Experimental Sciences, University of Florence, Viale Morgagni 50, 50134, Florence, Italy
| | - Letizia Barbieri
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
- Giotto Biotech S.R.L., Via Madonna del Piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Sara Neri
- Giotto Biotech S.R.L., Via Madonna del Piano 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Marco Fragai
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy.
- Department of Chemistry "Ugo Schiff", University of Florence, Via della Lastruccia 3, 50019, Sesto Fiorentino, Florence, Italy.
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48
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Sequential protein expression and selective labeling for in-cell NMR in human cells. Biochim Biophys Acta Gen Subj 2016; 1860:527-33. [DOI: 10.1016/j.bbagen.2015.12.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 11/23/2022]
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49
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Direct structural evidence of protein redox regulation obtained by in-cell NMR. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:198-204. [PMID: 26589182 DOI: 10.1016/j.bbamcr.2015.11.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/04/2015] [Accepted: 11/07/2015] [Indexed: 12/30/2022]
Abstract
The redox properties of cellular environments are critical to many functional processes, and are strictly controlled in all living organisms. The glutathione-glutathione disulfide (GSH-GSSG) couple is the most abundant intracellular redox couple. A GSH redox potential can be calculated for each cellular compartment, which reflects the redox properties of that environment. This redox potential is often used to predict the redox state of a disulfide-containing protein, based on thermodynamic considerations. However, thiol-disulfide exchange reactions are often catalyzed by specific partners, and the distribution of the redox states of a protein may not correspond to the thermodynamic equilibrium with the GSH pool. Ideally, the protein redox state should be measured directly, bypassing the need to extrapolate from the GSH. Here, by in-cell NMR, we directly observe the redox state of three human proteins, Cox17, Mia40 and SOD1, in the cytoplasm of human and bacterial cells. We compare the observed distributions of redox states with those predicted by the GSH redox potential, and our results partially agree with the predictions. Discrepancies likely arise from the fact that the redox state of SOD1 is controlled by a specific partner, its copper chaperone (CCS), in a pathway which is not linked to the GSH redox potential. In principle, in-cell NMR allows determining whether redox proteins are at the equilibrium with GSH, or they are kinetically regulated. Such approach does not need assumptions on the redox potential of the environment, and provides a way to characterize each redox-regulating pathway separately.
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Tyrrell J, Weeks KM, Pielak GJ. Challenge of mimicking the influences of the cellular environment on RNA structure by PEG-induced macromolecular crowding. Biochemistry 2015; 54:6447-53. [PMID: 26430778 DOI: 10.1021/acs.biochem.5b00767] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There are large differences between the cellular environment and the conditions widely used to study RNA in vitro. SHAPE RNA structure probing in Escherichia coli cells has shown that the cellular environment stabilizes both long-range and local tertiary interactions in the adenine riboswitch aptamer domain. Synthetic crowding agents are widely used to understand the forces that stabilize RNA structure and in efforts to recapitulate the cellular environment under simplified experimental conditions. Here, we studied the structure and ligand binding ability of the adenine riboswitch in the presence of the macromolecular crowding agent, polyethylene glycol (PEG). Ethylene glycol and low-molecular mass PEGs destabilized RNA structure and caused the riboswitch to sample secondary structures different from those observed in simple buffered solutions or in cells. In the presence of larger PEGs, longer-range loop-loop interactions were more similar to those in cells than in buffer alone, consistent with prior work showing that larger PEGs stabilize compact RNA states. Ligand affinity was weakened by low-molecular mass PEGs but increased with high-molecular mass PEGs, indicating that PEG cosolvents exert complex chemical and steric effects on RNA structure. Regardless of polymer size, however, nucleotide-resolution structural characteristics observed in cells were not recapitulated in PEG solutions. Our results reveal that the cellular environment is difficult to recapitulate in vitro; mimicking the cellular state will likely require a combination of crowding agents and other chemical species.
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Affiliation(s)
- Jillian Tyrrell
- Department of Chemistry, ‡Department of Biochemistry and Biophysics, and §Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States
| | - Kevin M Weeks
- Department of Chemistry, ‡Department of Biochemistry and Biophysics, and §Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States
| | - Gary J Pielak
- Department of Chemistry, ‡Department of Biochemistry and Biophysics, and §Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States
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