1
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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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2
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Luchinat E, Cremonini M, Banci L. Radio Signals from Live Cells: The Coming of Age of In-Cell Solution NMR. Chem Rev 2022; 122:9267-9306. [PMID: 35061391 PMCID: PMC9136931 DOI: 10.1021/acs.chemrev.1c00790] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
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A detailed knowledge
of the complex processes that make cells and
organisms alive is fundamental in order to understand diseases and
to develop novel drugs and therapeutic treatments. To this aim, biological
macromolecules should ideally be characterized at atomic resolution
directly within the cellular environment. Among the existing structural
techniques, solution NMR stands out as the only one able to investigate
at high resolution the structure and dynamic behavior of macromolecules
directly in living cells. With the advent of more sensitive NMR hardware
and new biotechnological tools, modern in-cell NMR approaches have
been established since the early 2000s. At the coming of age of in-cell
NMR, we provide a detailed overview of its developments and applications
in the 20 years that followed its inception. We review the existing
approaches for cell sample preparation and isotopic labeling, the
application of in-cell NMR to important biological questions, and
the development of NMR bioreactor devices, which greatly increase
the lifetime of the cells allowing real-time monitoring of intracellular
metabolites and proteins. Finally, we share our thoughts on the future
perspectives of the in-cell NMR methodology.
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Affiliation(s)
- Enrico Luchinat
- Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum−Università di Bologna, Piazza Goidanich 60, 47521 Cesena, Italy
- Magnetic Resonance Center, Università degli Studi di Firenze, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Matteo Cremonini
- Magnetic Resonance Center, Università degli Studi di Firenze, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Lucia Banci
- Magnetic Resonance Center, Università degli Studi di Firenze, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
- Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy
- Dipartimento di Chimica, Università degli Studi di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
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3
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Cao R, Liu X, Liu Y, Zhai X, Cao T, Wang A, Qiu J. Applications of nuclear magnetic resonance spectroscopy to the evaluation of complex food constituents. Food Chem 2020; 342:128258. [PMID: 33508899 DOI: 10.1016/j.foodchem.2020.128258] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/10/2020] [Accepted: 09/27/2020] [Indexed: 11/18/2022]
Abstract
Due to a number of unparalleled advantages such as fastness, accuracy, intactness, nuclear magnetic resonance spectroscopy (NMR) has fulfilled a significant role in determining structures and dynamics of various physical, chemical and biological systems in the field of food analysis. This study introduced the principle of NMR, key NMR techniques such as 1H NMR, DOSY, NOESY, HSQC, etc., and the knowledge of NMR applications on the evaluation of complex food system, especially the interactions of food components. The reviewed research work provides sufficient evidence that NMR spectroscopy has been an invaluable tool and will play an increasingly important role in specific technical support for food assessment. In addition, NMR combined with various other technologies could give a complete picture of the mechanism of the performance of functional food compounds, which are vital for human health and influence the intrinsic food properties during processing, storage and transportation at the molecular level.
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Affiliation(s)
- Ruge Cao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China; State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Xinru Liu
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Yuqian Liu
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Xuqing Zhai
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Tianya Cao
- Institute of Food Science and Technology, Henan Agricultural University, Zhengzhou 450000, China
| | - Aili Wang
- Key laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), College of Pharmacy and Biological Engineering, Chengdu University, Chengdu 610106, China
| | - Ju Qiu
- Institute of Food and Nutrition Development, Ministry of Agriculture, Haidian, Beijing 100081, China.
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4
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Breindel L, Burz DS, Shekhtman A. Active metabolism unmasks functional protein-protein interactions in real time in-cell NMR. Commun Biol 2020; 3:249. [PMID: 32439966 PMCID: PMC7242440 DOI: 10.1038/s42003-020-0976-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/29/2020] [Indexed: 01/05/2023] Open
Abstract
Protein–protein interactions, PPIs, underlie most cellular processes, but many PPIs depend on a particular metabolic state that can only be observed in live, actively metabolizing cells. Real time in-cell NMR spectroscopy, RT-NMR, utilizes a bioreactor to maintain cells in an active metabolic state. Improvement in bioreactor technology maintains ATP levels at >95% for up to 24 hours, enabling protein overexpression and a previously undetected interaction between prokaryotic ubiquitin-like protein, Pup, and mycobacterial proteasomal ATPase, Mpa, to be detected. Singular value decomposition, SVD, of the NMR spectra collected over the course of Mpa overexpression easily identified the PPIs despite the large variation in background signals due to the highly active metabolome. Leonard Breindel et al. develop a real time in-cell NMR spectroscopy that utilizes a bioreactor to maintain cells metabolically active. This real time in-cell NMR spectroscopy enables the identification of protein–protein interactions that would not happen when cells don’t produce energy, suggesting the utility of this method.
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Affiliation(s)
- Leonard Breindel
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Ave, Albany, NY, 12222, USA
| | - David S Burz
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Ave, Albany, NY, 12222, USA
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, State University of New York, 1400 Washington Ave, Albany, NY, 12222, USA.
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5
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Brinson RG, Arbogast LW, Marino JP, Delaglio F. Best Practices in Utilization of 2D-NMR Spectral Data as the Input for Chemometric Analysis in Biopharmaceutical Applications. J Chem Inf Model 2020; 60:2339-2355. [DOI: 10.1021/acs.jcim.0c00081] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Robert G. Brinson
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, The University of Maryland, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - Luke W. Arbogast
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, The University of Maryland, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - John P. Marino
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, The University of Maryland, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - Frank Delaglio
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, The University of Maryland, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
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6
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Chung BT, Chen HY, Gordon J, Mammoli D, Sriram R, Autry AW, Le Page LM, Chaumeil MM, Shin P, Slater J, Tan CT, Suszczynski C, Chang S, Li Y, Bok RA, Ronen SM, Larson PEZ, Kurhanewicz J, Vigneron DB. First hyperpolarized [2- 13C]pyruvate MR studies of human brain metabolism. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 309:106617. [PMID: 31648132 PMCID: PMC6880930 DOI: 10.1016/j.jmr.2019.106617] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/04/2019] [Accepted: 10/06/2019] [Indexed: 05/04/2023]
Abstract
We developed methods for the preparation of hyperpolarized (HP) sterile [2-13C]pyruvate to test its feasibility in first-ever human NMR studies following FDA-IND & IRB approval. Spectral results using this MR stable-isotope imaging approach demonstrated the feasibility of investigating human cerebral energy metabolism by measuring the dynamic conversion of HP [2-13C]pyruvate to [2-13C]lactate and [5-13C]glutamate in the brain of four healthy volunteers. Metabolite kinetics, signal-to-noise (SNR) and area-under-curve (AUC) ratios, and calculated [2-13C]pyruvate to [2-13C]lactate conversion rates (kPL) were measured and showed similar but not identical inter-subject values. The kPL measurements were equivalent with prior human HP [1-13C]pyruvate measurements.
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Affiliation(s)
- Brian T Chung
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA; UCSF - UC Berkeley Graduate Program in Bioengineering, University of California, USA.
| | - Hsin-Yu Chen
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Jeremy Gordon
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Daniele Mammoli
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Renuka Sriram
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Adam W Autry
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Lydia M Le Page
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA; Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA 94158, USA
| | - Myriam M Chaumeil
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA; Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA 94158, USA
| | - Peter Shin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - James Slater
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Chou T Tan
- ISOTEC Stable Isotope Division, MilliporeSigma, Merck KGaA, Miamisburg, OH 45342, USA
| | - Chris Suszczynski
- ISOTEC Stable Isotope Division, MilliporeSigma, Merck KGaA, Miamisburg, OH 45342, USA
| | - Susan Chang
- Department of Medicine, University of California, San Francisco, CA 94158, USA
| | - Yan Li
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Robert A Bok
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Sabrina M Ronen
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Peder E Z Larson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA
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7
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Speer SL, Guseman AJ, Patteson JB, Ehrmann BM, Pielak GJ. Controlling and quantifying protein concentration in Escherichia coli. Protein Sci 2019; 28:1307-1311. [PMID: 31054180 DOI: 10.1002/pro.3637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 05/02/2019] [Indexed: 01/01/2023]
Abstract
The cellular environment is dynamic and complex, involving thousands of different macromolecules with total concentrations of hundreds of grams per liter. However, most biochemistry is conducted in dilute buffer where the concentration of macromolecules is less than 10 g/L. High concentrations of macromolecules affect protein stability, function, and protein complex formation, but to understand these phenomena fully we need to know the concentration of the test protein in cells. Here, we quantify the concentration of an overexpressed recombinant protein, a variant of the B1 domain of protein G, in Tuner (DE3)™ Escherichia coli cells as a function of inducer concentration. We find that the protein expression level is controllable, and expression saturates at over 2 mM upon induction with 0.4 mM isopropyl β-d-thiogalactoside. We discuss the results in terms of what can and cannot be learned from in-cell protein NMR studies in E. coli.
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Affiliation(s)
- Shannon L Speer
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, 27599
| | - Alex J Guseman
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, 27599
| | - Jon B Patteson
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, 27599
| | - Brandie M Ehrmann
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, 27599
| | - Gary J Pielak
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, 27599.,Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, 27599.,Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, 27599.,Integrative Program for Biological and Genome Sciences, University of North Carolina, Chapel Hill, North Carolina, 27599
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8
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The Inescapable Effects of Ribosomes on In-Cell NMR Spectroscopy and the Implications for Regulation of Biological Activity. Int J Mol Sci 2019; 20:ijms20061297. [PMID: 30875837 PMCID: PMC6471074 DOI: 10.3390/ijms20061297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/05/2019] [Accepted: 03/09/2019] [Indexed: 12/16/2022] Open
Abstract
The effects of RNA on in-cell NMR spectroscopy and ribosomes on the kinetic activity of several metabolic enzymes are reviewed. Quinary interactions between labelled target proteins and RNA broaden in-cell NMR spectra yielding apparent megadalton molecular weights in-cell. The in-cell spectra can be resolved by using cross relaxation-induced polarization transfer (CRINEPT), heteronuclear multiple quantum coherence (HMQC), transverse relaxation-optimized, NMR spectroscopy (TROSY). The effect is reproduced in vitro by using reconstituted total cellular RNA and purified ribosome preparations. Furthermore, ribosomal binding antibiotics alter protein quinary structure through protein-ribosome and protein-mRNA-ribosome interactions. The quinary interactions of Adenylate kinase, Thymidylate synthase and Dihydrofolate reductase alter kinetic properties of the enzymes. The results demonstrate that ribosomes may specifically contribute to the regulation of biological activity.
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9
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Abstract
In-cell NMR spectroscopy is a powerful tool to study protein structures and interactions under near physiological conditions in both prokaryotic and eukaryotic living cells. The low sensitivity and resolution of in-cell NMR spectra and limited lifetime of cells over the course of an in-cell experiment have presented major hurdles to wide acceptance of the technique, limiting it to a few select systems. These issues are addressed by introducing the use of the CRINEPT pulse sequence to increase the sensitivity and resolution of in-cell NMR spectra and the use of a bioreactor to maintain cell viability for up to 24h. Application of advanced pulse sequences and bioreactor during in-cell NMR experiments will facilitate the exploration of a wide range of biological processes.
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10
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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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11
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Sciolino N, Burz DS, Shekhtman A. In-Cell NMR Spectroscopy of Intrinsically Disordered Proteins. Proteomics 2019; 19:e1800055. [PMID: 30489014 DOI: 10.1002/pmic.201800055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/29/2018] [Indexed: 01/14/2023]
Abstract
This review summarizes the results of in-cell Nuclear Magnetic Resonance, NMR, spectroscopic investigations of the eukaryotic and prokaryotic intrinsically disordered proteins, IDPs: α-synuclein, prokaryotic ubiquitin-like protein, Pup, tubulin-related neuronal protein, Tau, phenylalanyl-glycyl-repeat-rich nucleoporins, FG Nups, and the negative regulator of flagellin synthesis, FlgM. The results show that the cellular behavior of IDPs may differ significantly from that observed in the test tube.
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Affiliation(s)
- Nicholas Sciolino
- 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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12
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Applications of In-Cell NMR in Structural Biology and Drug Discovery. Int J Mol Sci 2019; 20:ijms20010139. [PMID: 30609728 PMCID: PMC6337603 DOI: 10.3390/ijms20010139] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/24/2018] [Accepted: 12/29/2018] [Indexed: 01/23/2023] Open
Abstract
In-cell nuclear magnetic resonance (NMR) is a method to provide the structural information of a target at an atomic level under physiological conditions and a full view of the conformational changes of a protein caused by ligand binding, post-translational modifications or protein⁻protein interactions in living cells. Previous in-cell NMR studies have focused on proteins that were overexpressed in bacterial cells and isotopically labeled proteins injected into oocytes of Xenopus laevis or delivered into human cells. Applications of in-cell NMR in probing protein modifications, conformational changes and ligand bindings have been carried out in mammalian cells by monitoring isotopically labeled proteins overexpressed in living cells. The available protocols and successful examples encourage wide applications of this technique in different fields such as drug discovery. Despite the challenges in this method, progress has been made in recent years. In this review, applications of in-cell NMR are summarized. The successful applications of this method in mammalian and bacterial cells make it feasible to play important roles in drug discovery, especially in the step of target engagement.
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DeMott CM, Girardin R, Cobbert J, Reverdatto S, Burz DS, McDonough K, Shekhtman A. Potent Inhibitors of Mycobacterium tuberculosis Growth Identified by Using in-Cell NMR-based Screening. ACS Chem Biol 2018; 13:733-741. [PMID: 29359908 DOI: 10.1021/acschembio.7b00879] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In-cell NMR spectroscopy was used to screen for drugs that disrupt the interaction between prokaryotic ubiquitin like protein, Pup, and mycobacterial proteasome ATPase, Mpa. This interaction is critical for Mycobacterium tuberculosis resistance against nitric oxide (NO) stress; interruption of this process was proposed as a mechanism to control latent infection. Three compounds isolated from the NCI Diversity set III library rescued the physiological proteasome substrate from degradation suggesting that the proteasome degradation pathway was selectively targeted. Two of the compounds bind to Mpa with sub-micromolar to nanomolar affinity, and all three exhibit potency toward mycobacteria comparable to antibiotics currently available on the market, inhibiting growth in the low micromolar range.
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Affiliation(s)
- Christopher M. DeMott
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Roxie Girardin
- Wadsworth Center, New York Department of Health, Albany, New York 12208, United States
| | - Jacqueline Cobbert
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Sergey Reverdatto
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - David S. Burz
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Kathleen McDonough
- Wadsworth Center, New York Department of Health, Albany, New York 12208, United States
- Department of Biomedical Sciences, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222, United States
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14
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Breindel L, DeMott C, Burz DS, Shekhtman A. Real-Time In-Cell Nuclear Magnetic Resonance: Ribosome-Targeted Antibiotics Modulate Quinary Protein Interactions. Biochemistry 2018; 57:540-546. [PMID: 29266932 DOI: 10.1021/acs.biochem.7b00938] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
How ribosome antibiotics affect a wide range of biochemical pathways is not well understood; changes in RNA-mediated protein quinary interactions and consequent activity inside the crowded cytosol may provide one possible mechanism. We developed real-time (RT) in-cell nuclear magnetic resonance (NMR) spectroscopy to monitor temporal changes in protein quinary structure, for ≥24 h, in response to external and internal stimuli. RT in-cell NMR consists of a bioreactor containing gel-encapsulated cells inside a 5 mm NMR tube, a gravity siphon for continuous exchange of medium, and a horizontal drip irrigation system to supply nutrients to the cells during the experiment. We showed that adding antibiotics that bind to the small ribosomal subunit results in more extensive quinary interactions between thioredoxin and mRNA. The results substantiate the idea that RNA-mediated modulation of quinary protein interactions may provide the physical basis for ribosome inhibition and other regulatory pathways.
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Affiliation(s)
- Leonard Breindel
- Department of Chemistry, University at Albany, State University of New York , 1400 Washington Avenue, Albany, New York 12222, United States
| | - Christopher DeMott
- Department of Chemistry, University at Albany, State University of New York , 1400 Washington Avenue, Albany, New York 12222, United States
| | - David S Burz
- Department of Chemistry, University at Albany, State University of New York , 1400 Washington Avenue, Albany, New York 12222, United States
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, State University of New York , 1400 Washington Avenue, Albany, New York 12222, United States
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15
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Affinities and Comparisons of Enzyme States by Principal Component Analysis of NMR Spectra, Automated using TREND Software. Methods Enzymol 2018; 607:217-240. [DOI: 10.1016/bs.mie.2018.05.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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16
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Burz DS, DeMott CM, Aldousary A, Dansereau S, Shekhtman A. Quantitative Determination of Interacting Protein Surfaces in Prokaryotes and Eukaryotes by Using In-Cell NMR Spectroscopy. Methods Mol Biol 2018; 1688:423-444. [PMID: 29151221 DOI: 10.1007/978-1-4939-7386-6_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This paper describes three protocols for identifying interacting surfaces on 15N-labeled target proteins of known structure by using in-cell NMR spectroscopy. The first protocol describes how to identify protein quinary structure interaction surfaces in prokaryotes by using cross-relaxation-induced polarization transfer, CRIPT, based in-cell NMR. The second protocol describes how to introduce labeled protein into eukaryotic (HeLa) cells via electroporation for CRIPT-based in-cell studies. The third protocol describes how to quantitatively map protein interacting surfaces by utilizing singular value decomposition, SVD, analysis of STructural INTeractions by in-cell NMR, STINT-NMR, data.
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Affiliation(s)
- David S Burz
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, CH 122, Albany, NY, 12222, USA
| | - Christopher M DeMott
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, CH 122, Albany, NY, 12222, USA
| | - Asma Aldousary
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, CH 122, Albany, NY, 12222, USA
| | - Stephen Dansereau
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, CH 122, Albany, NY, 12222, USA
| | - Alexander Shekhtman
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, CH 122, Albany, NY, 12222, USA.
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17
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Xu J, Van Doren SR. Tracking Equilibrium and Nonequilibrium Shifts in Data with TREND. Biophys J 2017; 112:224-233. [PMID: 28122211 DOI: 10.1016/j.bpj.2016.12.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 11/21/2016] [Accepted: 12/09/2016] [Indexed: 11/16/2022] Open
Abstract
Principal component analysis (PCA) discovers patterns in multivariate data that include spectra, microscopy, and other biophysical measurements. Direct application of PCA to crowded spectra, images, and movies (without selecting peaks or features) was shown recently to identify their equilibrium or temporal changes. To enable the community to utilize these capabilities with a wide range of measurements, we have developed multiplatform software named TREND to Track Equilibrium and Nonequilibrium population shifts among two-dimensional Data frames. TREND can also carry this out by independent component analysis. We highlight a few examples of finding concurrent processes. TREND extracts dual phases of binding to two sites directly from the NMR spectra of the titrations. In a cardiac movie from magnetic resonance imaging, TREND resolves principal components (PCs) representing breathing and the cardiac cycle. TREND can also reconstruct the series of measurements from selected PCs, as illustrated for a biphasic, NMR-detected titration and the cardiac MRI movie. Fidelity of reconstruction of series of NMR spectra or images requires more PCs than needed to plot the largest population shifts. TREND reads spectra from many spectroscopies in the most common formats (JCAMP-DX and NMR) and multiple movie formats. The TREND package thus provides convenient tools to resolve the processes recorded by diverse biophysical methods.
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Affiliation(s)
- Jia Xu
- Department of Biochemistry, University of Missouri, Columbia, Missouri
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18
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Li C, Zhao J, Cheng K, Ge Y, Wu Q, Ye Y, Xu G, Zhang Z, Zheng W, Zhang X, Zhou X, Pielak G, Liu M. Magnetic Resonance Spectroscopy as a Tool for Assessing Macromolecular Structure and Function in Living Cells. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2017; 10:157-182. [PMID: 28301750 DOI: 10.1146/annurev-anchem-061516-045237] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Investigating the structure, modification, interaction, and function of biomolecules in their native cellular environment leads to physiologically relevant knowledge about their mechanisms, which will benefit drug discovery and design. In recent years, nuclear and electron magnetic resonance (NMR) spectroscopy has emerged as a useful tool for elucidating the structure and function of biomacromolecules, including proteins, nucleic acids, and carbohydrates in living cells at atomic resolution. In this review, we summarize the progress and future of in-cell NMR as it is applied to proteins, nucleic acids, and carbohydrates.
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Affiliation(s)
- 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, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Jiajing Zhao
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Kai Cheng
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Yuwei Ge
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, 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, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, 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, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Guohua Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Zeting Zhang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Wenwen Zheng
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Xu Zhang
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Xin Zhou
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
| | - Gary Pielak
- Department of Chemistry, Department of Biochemistry and Biophysics, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Maili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China; ,
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19
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Towards understanding cellular structure biology: In-cell NMR. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:547-557. [PMID: 28257994 DOI: 10.1016/j.bbapap.2017.02.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 02/22/2017] [Accepted: 02/27/2017] [Indexed: 12/20/2022]
Abstract
To watch biological macromolecules perform their functions inside the living cells is the dream of any biologists. In-cell nuclear magnetic resonance is a branch of biomolecular NMR spectroscopy that can be used to observe the structures, interactions and dynamics of these molecules in the living cells at atomic level. In principle, in-cell NMR can be applied to different cellular systems to achieve biologically relevant structural and functional information. In this review, we summarize the existing approaches in this field and discuss its applications in protein interactions, folding, stability and post-translational modifications. We hope this review will emphasize the effectiveness of in-cell NMR for studies of intricate biological processes and for structural analysis in cellular environments.
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20
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Abstract
Evidence is presented that binding isotherms, simple or biphasic, can be extracted directly from noninterpreted, complex 2D NMR spectra using principal component analysis (PCA) to reveal the largest trend(s) across the series. This approach renders peak picking unnecessary for tracking population changes. In 1:1 binding, the first principal component captures the binding isotherm from NMR-detected titrations in fast, slow, and even intermediate and mixed exchange regimes, as illustrated for phospholigand associations with proteins. Although the sigmoidal shifts and line broadening of intermediate exchange distorts binding isotherms constructed conventionally, applying PCA directly to these spectra along with Pareto scaling overcomes the distortion. Applying PCA to time-domain NMR data also yields binding isotherms from titrations in fast or slow exchange. The algorithm readily extracts from magnetic resonance imaging movie time courses such as breathing and heart rate in chest imaging. Similarly, two-step binding processes detected by NMR are easily captured by principal components 1 and 2. PCA obviates the customary focus on specific peaks or regions of images. Applying it directly to a series of complex data will easily delineate binding isotherms, equilibrium shifts, and time courses of reactions or fluctuations.
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Affiliation(s)
- Jia Xu
- Department of Biochemistry, University of Missouri , 117 Schweitzer Hall, Columbia, Missouri 65211, United States
| | - Steven R Van Doren
- Department of Biochemistry, University of Missouri , 117 Schweitzer Hall, Columbia, Missouri 65211, United States
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21
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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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22
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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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23
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Boulton S, Melacini G. Advances in NMR Methods To Map Allosteric Sites: From Models to Translation. Chem Rev 2016; 116:6267-304. [PMID: 27111288 DOI: 10.1021/acs.chemrev.5b00718] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The last five years have witnessed major developments in the understanding of the allosteric phenomenon, broadly defined as coupling between remote molecular sites. Such advances have been driven not only by new theoretical models and pharmacological applications of allostery, but also by progress in the experimental approaches designed to map allosteric sites and transitions. Among these techniques, NMR spectroscopy has played a major role given its unique near-atomic resolution and sensitivity to the dynamics that underlie allosteric couplings. Here, we highlight recent progress in the NMR methods tailored to investigate allostery with the goal of offering an overview of which NMR approaches are best suited for which allosterically relevant questions. The picture of the allosteric "NMR toolbox" is provided starting from one of the simplest models of allostery (i.e., the four-state thermodynamic cycle) and continuing to more complex multistate mechanisms. We also review how such an "NMR toolbox" has assisted the elucidation of the allosteric molecular basis for disease-related mutations and the discovery of novel leads for allosteric drugs. From this overview, it is clear that NMR plays a central role not only in experimentally validating transformative theories of allostery, but also in tapping the full translational potential of allosteric systems.
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Affiliation(s)
- Stephen Boulton
- Department of Chemistry and Chemical Biology Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main St. W., Hamilton L8S 4M1, Canada
| | - Giuseppe Melacini
- Department of Chemistry and Chemical Biology Department of Biochemistry and Biomedical Sciences, McMaster University , 1280 Main St. W., Hamilton L8S 4M1, Canada
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24
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Cobbert JD, DeMott C, Majumder S, Smith EA, Reverdatto S, Burz DS, McDonough KA, Shekhtman A. Caught in action: selecting peptide aptamers against intrinsically disordered proteins in live cells. Sci Rep 2015; 5:9402. [PMID: 25801767 PMCID: PMC4371151 DOI: 10.1038/srep09402] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 03/03/2015] [Indexed: 11/29/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) or unstructured segments within proteins play an important role in cellular physiology and pathology. Low cellular concentration, multiple binding partners, frequent post-translational modifications and the presence of multiple conformations make it difficult to characterize IDP interactions in intact cells. We used peptide aptamers selected by using the yeast-two-hybrid scheme and in-cell NMR to identify high affinity binders to transiently structured IDP and unstructured segments at atomic resolution. Since both the selection and characterization of peptide aptamers take place inside the cell, only physiologically relevant conformations of IDPs are targeted. The method is validated by using peptide aptamers selected against the prokaryotic ubiquitin-like protein, Pup, of the mycobacterium proteasome. The selected aptamers bind to distinct sites on Pup and have vastly different effects on rescuing mycobacterial proteasome substrate and on the survival of the Bacille-Calmette-Guèrin, BCG, strain of M. bovis. This technology can be applied to study the elusive action of IDPs under near physiological conditions.
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Affiliation(s)
| | | | | | - Eric A Smith
- Wadsworth Center, NY State Department of Health, Albany, NY
| | | | - David S Burz
- Department of Chemistry, University at Albany, Albany, NY
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25
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A tool set to map allosteric networks through the NMR chemical shift covariance analysis. Sci Rep 2014; 4:7306. [PMID: 25482377 PMCID: PMC4258684 DOI: 10.1038/srep07306] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 11/07/2014] [Indexed: 11/30/2022] Open
Abstract
Allostery is an essential regulatory mechanism of biological function. Allosteric sites are also pharmacologically relevant as they are often targeted with higher selectivity than orthosteric sites. However, a comprehensive map of allosteric sites poses experimental challenges because allostery is driven not only by structural changes, but also by modulations in dynamics that typically remain elusive to classical structure determination methods. An avenue to overcome these challenges is provided by the NMR chemical shift covariance analysis (CHESCA), as chemical shifts are exquisitely sensitive to redistributions in dynamic conformational ensembles. Here, we propose a set of complementary CHESCA algorithms designed to reliably detect allosteric networks with minimal occurrences of false positives or negatives. The proposed CHESCA toolset was tested for two allosteric proteins (PKA and EPAC) and is expected to complement traditional comparative structural analyses in the comprehensive identification of functionally relevant allosteric sites, including those in otherwise elusive partially unstructured regions.
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26
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Smith AE, Zhang Z, Pielak GJ, Li C. NMR studies of protein folding and binding in cells and cell-like environments. Curr Opin Struct Biol 2014; 30:7-16. [PMID: 25479354 DOI: 10.1016/j.sbi.2014.10.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 10/20/2014] [Accepted: 10/24/2014] [Indexed: 11/18/2022]
Abstract
Proteins function in cells where the concentration of macromolecules can exceed 300g/L. The ways in which this crowded environment affects the physical properties of proteins remain poorly understood. We summarize recent NMR-based studies of protein folding and binding conducted in cells and in vitro under crowded conditions. Many of the observations can be understood in terms of interactions between proteins and the rest of the intracellular environment (i.e. quinary interactions). Nevertheless, NMR studies of folding and binding in cells and cell-like environments remain in their infancy. The frontier involves investigations of larger proteins and further efforts in higher eukaryotic cells.
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Affiliation(s)
- Austin E Smith
- Department of Chemistry, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599-3290, USA
| | - Zeting Zhang
- 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, PR China
| | - Gary J Pielak
- Department of Chemistry, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599-3290, USA; Department of Biochemistry and Biophysics, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599-3290, USA.
| | - 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, PR China.
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