1
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Illes-Toth E, Rempel DL, Gross ML. Exploration of Resveratrol as a Potent Modulator of α-Synuclein Fibril Formation. ACS Chem Neurosci 2024; 15:503-516. [PMID: 38194353 PMCID: PMC10922803 DOI: 10.1021/acschemneuro.3c00571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024] Open
Abstract
The molecular determinants of amyloid protein misfolding and aggregation are key for the development of therapeutic interventions in neurodegenerative disease. Although small synthetic molecules, bifunctional molecules, and natural products offer a potentially advantageous approach to therapeutics to remodel aggregation, their evaluation requires new platforms that are informed at the molecular level. To that end, we chose pulsed hydrogen/deuterium exchange mass spectrometry (HDX-MS) to discern the phenomena of aggregation modulation for a model system of alpha synuclein (αS) and resveratrol, an antiamyloid compound. We invoked, as a complement to HDX, advanced kinetic modeling described here to illuminate the details of aggregation and to determine the number of oligomeric populations by kinetically fitting the experimental data under conditions of limited proteolysis. The misfolding of αS is most evident within and nearby the nonamyloid-β component region, and resveratrol significantly remodels that aggregation. HDX distinguishes readily a less solvent-accessible, more structured oligomer that coexists with a solvent-accessible, more disordered oligomer during aggregation. A view of the misfolding emerges from time-dependent changes in the fractional species across the protein with or without resveratrol, while details were determined through kinetic modeling of the protected species. A detailed picture of the inhibitory action of resveratrol with time and regional specificity emerges, a picture that can be obtained for other inhibitors and amyloid proteins. Moreover, the model reveals that new states of aggregation are sampled, providing new insights on amyloid formation. The findings were corroborated by circular dichroism and transmission electron microscopy.
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Affiliation(s)
- Eva Illes-Toth
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| | - Don L Rempel
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
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2
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Kish M, Subramanian S, Smith V, Lethbridge N, Cole L, Vollmer F, Bond NJ, Phillips JJ. Allosteric Regulation of Glycogen Phosphorylase by Order/Disorder Transition of the 250' and 280s Loops. Biochemistry 2023; 62:1360-1368. [PMID: 36989206 PMCID: PMC10116597 DOI: 10.1021/acs.biochem.2c00671] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Allostery is a fundamental mechanism of protein activation, yet the precise dynamic changes that underlie functional regulation of allosteric enzymes, such as glycogen phosphorylase (GlyP), remain poorly understood. Despite being the first allosteric enzyme described, its structural regulation is still a challenging problem: the key regulatory loops of the GlyP active site (250' and 280s) are weakly stable and often missing density or have large b-factors in structural models. This led to the longstanding hypothesis that GlyP regulation is achieved through gating of the active site by (dis)order transitions, as first proposed by Barford and Johnson. However, testing this requires a quantitative measurement of weakly stable local structure which, to date, has been technically challenging in such a large protein. Hydrogen-deuterium-exchange mass spectrometry (HDX-MS) is a powerful tool for studying protein dynamics, and millisecond HDX-MS has the ability to measure site-localized stability differences in weakly stable structures, making it particularly valuable for investigating allosteric regulation in GlyP. Here, we used millisecond HDX-MS to measure the local structural perturbations of glycogen phosphorylase b (GlyPb), the phosphorylated active form (GlyPa), and the inhibited glucose-6 phosphate complex (GlyPb:G6P) at near-amino acid resolution. Our results support the Barford and Johnson hypothesis for GlyP regulation by providing insight into the dynamic changes of the key regulatory loops.
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Affiliation(s)
- Monika Kish
- Living Systems Institute, Department of Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, U.K
| | - Sivaraman Subramanian
- Living Systems Institute, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 6QD, U.K
| | | | | | - Lindsay Cole
- Applied Photophysics Ltd, Leatherhead, KT227BA, U.K
| | - Frank Vollmer
- Living Systems Institute, Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 6QD, U.K
| | - Nicholas J Bond
- Analytical Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, Milstein Building, Granta Park, Cambridge, CB21 6GH, U.K
| | - Jonathan J Phillips
- Living Systems Institute, Department of Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, U.K
- Alan Turing Institute, British Library, London, NW1 2DB, U.K
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3
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Kish M, Smith V, Lethbridge N, Cole L, Bond NJ, Phillips JJ. Online Fully Automated System for Hydrogen/Deuterium-Exchange Mass Spectrometry with Millisecond Time Resolution. Anal Chem 2023; 95:5000-5008. [PMID: 36896500 PMCID: PMC10034745 DOI: 10.1021/acs.analchem.2c05310] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Amide hydrogen/deuterium-exchange mass spectrometry (HDX-MS) is a powerful tool for analyzing the conformational dynamics of proteins in a solution. Current conventional methods have a measurement limit starting from several seconds and are solely reliant on the speed of manual pipetting or a liquid handling robot. Weakly protected regions of polypeptides, such as in short peptides, exposed loops and intrinsically disordered the protein exchange on the millisecond timescale. Typical HDX methods often cannot resolve the structural dynamics and stability in these cases. Numerous academic laboratories have demonstrated the considerable utility of acquiring HDX-MS data in the sub-second regimes. Here, we describe the development of a fully automated HDX-MS apparatus to resolve amide exchange on the millisecond timescale. Like conventional systems, this instrument boasts automated sample injection with software selection of labeling times, online flow mixing and quenching, while being fully integrated with a liquid chromatography-MS system for existing standard "bottom-up" workflows. HDX-MS's rapid exchange kinetics of several peptides demonstrate the repeatability, reproducibility, back-exchange, and mixing kinetics achieved with the system. Comparably, peptide coverage of 96.4% with 273 peptides was achieved, supporting the equivalence of the system to standard robotics. Additionally, time windows of 50 ms-300 s allowed full kinetic transitions to be observed for many amide groups; especially important are short time points (50-150 ms) for regions that are likely highly dynamic and solvent- exposed. We demonstrate that information on structural dynamics and stability can be measured for stretches of weakly stable polypeptides in small peptides and in local regions of a large enzyme, glycogen phosphorylase.
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Affiliation(s)
- Monika Kish
- Living Systems Institute, Department of Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, U.K
| | | | | | - Lindsay Cole
- Applied Photophysics Ltd, Leatherhead KT227BA, U.K
| | - Nicholas J Bond
- Analytical Sciences, Biopharmaceutical Development, BioPharmaceuticals R&D, AstraZeneca, Milstein Building, Granta Park, Cambridge CB21 6GH, U.K
| | - Jonathan J Phillips
- Living Systems Institute, Department of Biosciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, U.K
- Alan Turing Institute, British Library, London NW1 2DB, U.K
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4
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Developments in rapid hydrogen-deuterium exchange methods. Essays Biochem 2023; 67:165-174. [PMID: 36636941 DOI: 10.1042/ebc20220174] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 01/14/2023]
Abstract
Biological macromolecules, such as proteins, nucleic acids, and carbohydrates, contain heteroatom-bonded hydrogens that undergo exchange with solvent hydrogens on timescales ranging from microseconds to hours. In hydrogen-deuterium exchange mass spectrometry (HDX-MS), this exchange process is used to extract information about biomolecular structure and dynamics. This minireview focuses on millisecond timescale HDX-MS measurements, which, while less common than 'conventional' timescale (seconds to hours) HDX-MS, provide a unique window into weakly structured species, weak (or fast cycling) binding interactions, and subtle shifts in conformational dynamics. This includes intrinsically disordered proteins and regions (IDPs/IDRs) that are associated with cancer and amyloidotic neurodegenerative disease. For nucleic acids and carbohydrates, structures such as isomers, stems, and loops, can be elucidated and overall structural rigidity can be assessed. We will provide a brief overview of technical developments in rapid HDX followed by highlights of various applications, emphasising the importance of broadening the HDX timescale to improve throughput and to capture a wider range of function-relevant dynamic and structural shifts.
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5
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Tajoddin NN, Konermann L. Structural Dynamics of a Thermally Stressed Monoclonal Antibody Characterized by Temperature-Dependent H/D Exchange Mass Spectrometry. Anal Chem 2022; 94:15499-15509. [DOI: 10.1021/acs.analchem.2c03931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nastaran N. Tajoddin
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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6
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Safaric Tepes P, Segovia D, Jevtic S, Ramirez D, Lyons SK, Sordella R. Patient-derived xenografts and in vitro model show rationale for imatinib mesylate repurposing in HEY1-NCoA2-driven mesenchymal chondrosarcoma. J Transl Med 2022; 102:1038-1049. [PMID: 36775418 DOI: 10.1038/s41374-021-00704-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 01/17/2023] Open
Abstract
Mesenchymal chondrosarcoma (MCS) is a high-grade malignancy that represents 2-9% of chondrosarcomas and mostly affects children and young adults. HEY1-NCoA2 gene fusion is considered to be a driver of tumorigenesis and it has been identified in 80% of MCS tumors. The shortage of MCS samples and biological models creates a challenge for the development of effective therapeutic strategies to improve the low survival rate of MCS patients. Previous molecular studies using immunohistochemical staining of patient samples suggest that activation of PDGFR signaling could be involved in MCS tumorigenesis. This work presents the development of two independent in vitro and in vivo models of HEY1-NCoA2-driven MCS and their application in a drug repurposing strategy. The in vitro model was characterized by RNA sequencing at the single-cell level and successfully recapitulated relevant MCS features. Imatinib, as well as specific inhibitors of ABL and PDGFR, demonstrated a highly selective cytotoxic effect targeting the HEY1-NCoA2 fusion-driven cellular model. In addition, patient-derived xenograft (PDX) models of MCS harboring the HEY1-NCoA2 fusion were developed from a primary tumor and its distant metastasis. In concordance with in vitro observations, imatinib was able to significantly reduce tumor growth in MCS-PDX models. The conclusions of this study serve as preclinical results to revisit the clinical efficacy of imatinib in the treatment of HEY1-NCoA2-driven MCS.
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Affiliation(s)
- Polona Safaric Tepes
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA.
- Faculty of Pharmacy, University of Ljubljana, Kongresni trg 12, 1000, Ljubljana, Slovenia.
| | - Danilo Segovia
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
- Graduate Program in Molecular and Cellular Biology, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY, 11794, USA
| | - Sania Jevtic
- Phytoform Labs Ltd., Lawes Open Innovation Hub, West Common, Harpenden, Hertfordshire, England, UK
| | - Daniel Ramirez
- Hospital for Special Surgery, Pathology and Laboratory Medicine, 535 E 70th St, New York, NY, 10021, USA
| | - Scott K Lyons
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
| | - Raffaella Sordella
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY, 11724, USA
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7
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Sipe SN, Jeanne Dit Fouque K, Garabedian A, Leng F, Fernandez-Lima F, Brodbelt JS. Exploring the Conformations and Binding Location of HMGA2·DNA Complexes Using Ion Mobility Spectrometry and 193 nm Ultraviolet Photodissociation Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1092-1102. [PMID: 35687872 PMCID: PMC9274541 DOI: 10.1021/jasms.2c00083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although it is widely accepted that protein function is largely dependent on its structure, intrinsically disordered proteins (IDPs) lack defined structure but are essential in proper cellular processes. Mammalian high mobility group proteins (HMGA) are one such example of IDPs that perform a number of crucial nuclear activities and have been highly studied due to their involvement in the proliferation of a variety of disease and cancers. Traditional structural characterization methods have had limited success in understanding HMGA proteins and their ability to coordinate to DNA. Ion mobility spectrometry and mass spectrometry provide insights into the diversity and heterogeneity of structures adopted by IDPs and are employed here to interrogate HMGA2 in its unbound states and bound to two DNA hairpins. The broad distribution of collision cross sections observed for the apo-protein are restricted when HMGA2 is bound to DNA, suggesting that increased protein organization is promoted in the holo-form. Ultraviolet photodissociation was utilized to probe the changes in structures for the compact and elongated structures of HMGA2 by analyzing backbone cleavage propensities and solvent accessibility based on charge-site analysis, which revealed a spectrum of conformational possibilities. Namely, preferential binding of the DNA hairpins with the second of three AT-hooks of HMGA2 is suggested based on the suppression of backbone fragmentation and distribution of DNA-containing protein fragments.
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Affiliation(s)
- Sarah N Sipe
- Department of Chemistry, University of Texas, Austin, Texas 78712 United States
| | - Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Alyssa Garabedian
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Fenfei Leng
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas, Austin, Texas 78712 United States
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8
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James EI, Murphree TA, Vorauer C, Engen JR, Guttman M. Advances in Hydrogen/Deuterium Exchange Mass Spectrometry and the Pursuit of Challenging Biological Systems. Chem Rev 2021; 122:7562-7623. [PMID: 34493042 PMCID: PMC9053315 DOI: 10.1021/acs.chemrev.1c00279] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Solution-phase hydrogen/deuterium
exchange (HDX) coupled to mass
spectrometry (MS) is a widespread tool for structural analysis across
academia and the biopharmaceutical industry. By monitoring the exchangeability
of backbone amide protons, HDX-MS can reveal information about higher-order
structure and dynamics throughout a protein, can track protein folding
pathways, map interaction sites, and assess conformational states
of protein samples. The combination of the versatility of the hydrogen/deuterium
exchange reaction with the sensitivity of mass spectrometry has enabled
the study of extremely challenging protein systems, some of which
cannot be suitably studied using other techniques. Improvements over
the past three decades have continually increased throughput, robustness,
and expanded the limits of what is feasible for HDX-MS investigations.
To provide an overview for researchers seeking to utilize and derive
the most from HDX-MS for protein structural analysis, we summarize
the fundamental principles, basic methodology, strengths and weaknesses,
and the established applications of HDX-MS while highlighting new
developments and applications.
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Affiliation(s)
- Ellie I James
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Taylor A Murphree
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Clint Vorauer
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - John R Engen
- Department of Chemistry & Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
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9
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Lento C, Wilson DJ. Subsecond Time-Resolved Mass Spectrometry in Dynamic Structural Biology. Chem Rev 2021; 122:7624-7646. [PMID: 34324314 DOI: 10.1021/acs.chemrev.1c00222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Life at the molecular level is a dynamic world, where the key players-proteins, oligonucleotides, lipids, and carbohydrates-are in a perpetual state of structural flux, shifting rapidly between local minima on their conformational free energy landscapes. The techniques of classical structural biology, X-ray crystallography, structural NMR, and cryo-electron microscopy (cryo-EM), while capable of extraordinary structural resolution, are innately ill-suited to characterize biomolecules in their dynamically active states. Subsecond time-resolved mass spectrometry (MS) provides a unique window into the dynamic world of biological macromolecules, offering the capacity to directly monitor biochemical processes and conformational shifts with a structural dimension provided by the electrospray charge-state distribution, ion mobility, covalent labeling, or hydrogen-deuterium exchange. Over the past two decades, this suite of techniques has provided important insights into the inherently dynamic processes that drive function and pathogenesis in biological macromolecules, including (mis)folding, complexation, aggregation, ligand binding, and enzyme catalysis, among others. This Review provides a comprehensive account of subsecond time-resolved MS and the advances it has enabled in dynamic structural biology, with an emphasis on insights into the dynamic drivers of protein function.
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Affiliation(s)
- Cristina Lento
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Derek J Wilson
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
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10
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Beveridge R, Calabrese AN. Structural Proteomics Methods to Interrogate the Conformations and Dynamics of Intrinsically Disordered Proteins. Front Chem 2021; 9:603639. [PMID: 33791275 PMCID: PMC8006314 DOI: 10.3389/fchem.2021.603639] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/19/2021] [Indexed: 12/21/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) and regions of intrinsic disorder (IDRs) are abundant in proteomes and are essential for many biological processes. Thus, they are often implicated in disease mechanisms, including neurodegeneration and cancer. The flexible nature of IDPs and IDRs provides many advantages, including (but not limited to) overcoming steric restrictions in binding, facilitating posttranslational modifications, and achieving high binding specificity with low affinity. IDPs adopt a heterogeneous structural ensemble, in contrast to typical folded proteins, making it challenging to interrogate their structure using conventional tools. Structural mass spectrometry (MS) methods are playing an increasingly important role in characterizing the structure and function of IDPs and IDRs, enabled by advances in the design of instrumentation and the development of new workflows, including in native MS, ion mobility MS, top-down MS, hydrogen-deuterium exchange MS, crosslinking MS, and covalent labeling. Here, we describe the advantages of these methods that make them ideal to study IDPs and highlight recent applications where these tools have underpinned new insights into IDP structure and function that would be difficult to elucidate using other methods.
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Affiliation(s)
- Rebecca Beveridge
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Antonio N. Calabrese
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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11
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Corless EI, Saad Imran SM, Watkins MB, Bacik JP, Mattice JR, Patterson A, Danyal K, Soffe M, Kitelinger R, Seefeldt LC, Origanti S, Bennett B, Bothner B, Ando N, Antony E. The flexible N-terminus of BchL autoinhibits activity through interaction with its [4Fe-4S] cluster and released upon ATP binding. J Biol Chem 2021; 296:100107. [PMID: 33219127 PMCID: PMC7948495 DOI: 10.1074/jbc.ra120.016278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/10/2020] [Accepted: 11/20/2020] [Indexed: 11/10/2022] Open
Abstract
A key step in bacteriochlorophyll biosynthesis is the reduction of protochlorophyllide to chlorophyllide, catalyzed by dark-operative protochlorophyllide oxidoreductase. Dark-operative protochlorophyllide oxidoreductase contains two [4Fe-4S]-containing component proteins (BchL and BchNB) that assemble upon ATP binding to BchL to coordinate electron transfer and protochlorophyllide reduction. But the precise nature of the ATP-induced conformational changes is poorly understood. We present a crystal structure of BchL in the nucleotide-free form where a conserved, flexible region in the N-terminus masks the [4Fe-4S] cluster at the docking interface between BchL and BchNB. Amino acid substitutions in this region produce a hyperactive enzyme complex, suggesting a role for the N-terminus in autoinhibition. Hydrogen-deuterium exchange mass spectrometry shows that ATP binding to BchL produces specific conformational changes leading to release of the flexible N-terminus from the docking interface. The release also promotes changes within the local environment surrounding the [4Fe-4S] cluster and promotes BchL-complex formation with BchNB. A key patch of amino acids, Asp-Phe-Asp (the 'DFD patch'), situated at the mouth of the BchL ATP-binding pocket promotes intersubunit cross stabilization of the two subunits. A linked BchL dimer with one defective ATP-binding site does not support protochlorophyllide reduction, illustrating nucleotide binding to both subunits as a prerequisite for the intersubunit cross stabilization. The masking of the [4Fe-4S] cluster by the flexible N-terminal region and the associated inhibition of the activity is a novel mechanism of regulation in metalloproteins. Such mechanisms are possibly an adaptation to the anaerobic nature of eubacterial cells with poor tolerance for oxygen.
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Affiliation(s)
- Elliot I Corless
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA; Department of Biochemistry, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | | | - Maxwell B Watkins
- Department of Chemistry, Princeton University, Princeton, New Jersey, USA; Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - John-Paul Bacik
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Jenna R Mattice
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Angela Patterson
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Karamatullah Danyal
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, USA
| | - Mark Soffe
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, USA
| | - Robert Kitelinger
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Lance C Seefeldt
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, USA
| | - Sofia Origanti
- Department of Biology, Saint Louis University, St Louis, Missouri, USA
| | - Brian Bennett
- Department of Physics, Marquette University, Milwaukee, Wisconsin, USA
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Nozomi Ando
- Department of Chemistry, Princeton University, Princeton, New Jersey, USA; Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA.
| | - Edwin Antony
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA; Department of Biochemistry, Saint Louis University School of Medicine, St Louis, Missouri, USA.
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12
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Belorusova AY, Bourguet M, Hessmann S, Chalhoub S, Kieffer B, Cianférani S, Rochel N. Molecular determinants of MED1 interaction with the DNA bound VDR-RXR heterodimer. Nucleic Acids Res 2020; 48:11199-11213. [PMID: 32990725 PMCID: PMC7641746 DOI: 10.1093/nar/gkaa775] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/24/2020] [Accepted: 09/08/2020] [Indexed: 12/26/2022] Open
Abstract
The MED1 subunit of the Mediator complex is an essential coactivator of nuclear receptor-mediated transcriptional activation. While structural requirements for ligand-dependent binding of classical coactivator motifs of MED1 to numerous nuclear receptor ligand-binding domains have been fully elucidated, the recognition of the full-length or truncated coactivator by full nuclear receptor complexes remain unknown. Here we present structural details of the interaction between a large part of MED1 comprising its structured N-terminal and the flexible receptor-interacting domains and the mutual heterodimer of the vitamin D receptor (VDR) and the retinoid X receptor (RXR) bound to their cognate DNA response element. Using a combination of structural and biophysical methods we show that the ligand-dependent interaction between VDR and the second coactivator motif of MED1 is crucial for complex formation and we identify additional, previously unseen, interaction details. In particular, we identified RXR regions involved in the interaction with the structured N-terminal domain of MED1, as well as VDR regions outside the classical coactivator binding cleft affected by coactivator recruitment. These findings highlight important roles of each receptor within the heterodimer in selective recognition of MED1 and contribute to our understanding of the nuclear receptor-coregulator complexes.
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Affiliation(s)
- Anna Y Belorusova
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Maxime Bourguet
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, CNRS UMR 7178, IPHC, Strasbourg, France
| | - Steve Hessmann
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, CNRS UMR 7178, IPHC, Strasbourg, France
| | - Sandra Chalhoub
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Bruno Kieffer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique, Université de Strasbourg, CNRS UMR 7178, IPHC, Strasbourg, France
| | - Natacha Rochel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France.,Centre National de la Recherche Scientifique UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale U1258, Illkirch, France.,Université de Strasbourg, Illkirch, France
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13
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Mitra G. Emerging Role of Mass Spectrometry-Based Structural Proteomics in Elucidating Intrinsic Disorder in Proteins. Proteomics 2020; 21:e2000011. [PMID: 32959512 DOI: 10.1002/pmic.202000011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 06/30/2020] [Indexed: 12/14/2022]
Abstract
Inherent disorder is an integral part of all proteomes, represented as fully or partially unfolded proteins. The lack of order in intrinsically disordered proteins (IDPs) results in an incredibly flexible, floppy, and heterogeneous ensemble, contrary to the well-structured and unique organization of folded proteins. Despite such unusual demeanor, IDPs are crucial for numerous cellular processes and are increasingly being associated with disease-causing pathologies. These warrant more intensive investigation of this atypical class of protein. Traditional biophysical tools, however, fall short of analyzing IDPs, thus making their structure-function characterization challenging. Mass spectrometry (MS) in recent years has evolved as a valuable tool for elucidating the unusual conformational facets of IDPs. In this review, the features of advanced MS techniques such as Hydrogen-deuterium exchange (HDX)-MS, native MS, limited proteolysis (LiP)-MS, chemical cross-linking (XL)-MS, and Fast photochemical oxidation of proteins (FPOP)-MS are briefly discussed. Recent MS studies on IDPs and the unique advantages/shortfalls associated with the above methods while evaluating structural proteomics of IDPs, are illustrated. Eventually the future scope of the MS methods in further decoding the unexplored landscapes of IDPs is presented.
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Affiliation(s)
- Gopa Mitra
- Clinical Proteomics Unit, Division of Molecular Medicine, St. John's Research Institute, St John's Medical College, St. John's National Academy of Health Sciences, 100 Feet Road, Koramangala, Bangalore, Karnataka, 560034, India
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14
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Tajoddin NN, Konermann L. Analysis of Temperature-Dependent H/D Exchange Mass Spectrometry Experiments. Anal Chem 2020; 92:10058-10067. [DOI: 10.1021/acs.analchem.0c01828] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Nastaran N. Tajoddin
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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15
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Hodge EA, Benhaim MA, Lee KK. Bridging protein structure, dynamics, and function using hydrogen/deuterium-exchange mass spectrometry. Protein Sci 2020; 29:843-855. [PMID: 31721348 PMCID: PMC7096709 DOI: 10.1002/pro.3790] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022]
Abstract
Much of our understanding of protein structure and mechanistic function has been derived from static high-resolution structures. As structural biology has continued to evolve it has become clear that high-resolution structures alone are unable to fully capture the mechanistic basis for protein structure and function in solution. Recently Hydrogen/Deuterium-exchange Mass Spectrometry (HDX-MS) has developed into a powerful and versatile tool for structural biologists that provides novel insights into protein structure and function. HDX-MS enables direct monitoring of a protein's structural fluctuations and conformational changes under native conditions in solution even as it is carrying out its functions. In this review, we focus on the use of HDX-MS to monitor these dynamic changes in proteins. We examine how HDX-MS has been applied to study protein structure and function in systems ranging from large, complex assemblies to intrinsically disordered proteins, and we discuss its use in probing conformational changes during protein folding and catalytic function. STATEMENT FOR A BROAD AUDIENCE: The biophysical and structural characterization of proteins provides novel insight into their functionalities. Protein motions, ranging from small scale local fluctuations to larger concerted structural rearrangements, often determine protein function. Hydrogen/Deuterium-exchange Mass Spectrometry (HDX-MS) has proven a powerful biophysical tool capable of probing changes in protein structure and dynamic protein motions that are often invisible to most other techniques.
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Affiliation(s)
- Edgar A. Hodge
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWashington
| | - Mark A. Benhaim
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWashington
| | - Kelly K. Lee
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWashington
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16
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Schramm A, Bignon C, Brocca S, Grandori R, Santambrogio C, Longhi S. An arsenal of methods for the experimental characterization of intrinsically disordered proteins - How to choose and combine them? Arch Biochem Biophys 2019; 676:108055. [PMID: 31356778 DOI: 10.1016/j.abb.2019.07.020] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/16/2019] [Accepted: 07/24/2019] [Indexed: 12/12/2022]
Abstract
In this review, we detail the most common experimental approaches to assess and characterize protein intrinsic structural disorder, with the notable exception of NMR and EPR spectroscopy, two ideally suited approaches that will be described in depth in two other reviews within this special issue. We discuss the advantages, the limitations, as well as the caveats of the various methods. We also describe less common and more demanding approaches that enable achieving further insights into the conformational properties of IDPs. Finally, we present recent developments that have enabled assessment of structural disorder in living cells, and discuss the currently available methods to model IDPs as conformational ensembles.
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Affiliation(s)
- Antoine Schramm
- CNRS and Aix-Marseille Univ, Laboratoire Architecture et Fonction des Macromolecules Biologiques (AFMB), UMR 7257, Marseille, France
| | - Christophe Bignon
- CNRS and Aix-Marseille Univ, Laboratoire Architecture et Fonction des Macromolecules Biologiques (AFMB), UMR 7257, Marseille, France
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Sonia Longhi
- CNRS and Aix-Marseille Univ, Laboratoire Architecture et Fonction des Macromolecules Biologiques (AFMB), UMR 7257, Marseille, France.
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17
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Abstract
NMR spectroscopy has proven to be a key method for studying intrinsically disordered proteins (IDPs). Nonetheless, traditional NMR methods developed for solving structures of ordered protein complexes are insufficient for the full characterization of dynamic IDP complexes, where the energy landscape is broader and more rugged. Furthermore, due to their high sensitivity to environmental changes, NMR studies of IDP complexes must be conducted with extra care and the observed NMR parameters thoroughly evaluated to enable disentanglement of binding events from ensemble distribution changes. In this chapter, written for the non-NMR expert, we start out by outlining sample preparation for IDP complexes, guide through the recording and evaluation of diagnostic 1H,15N-HSQC spectra, and delineate more sophisticated NMR strategies to follow for the particular type of complex. The most relevant experiments are then described in terms of aims, needs, pitfalls, analysis, and expected outcomes, with references to recent examples.
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18
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Hung PJ, Johnson B, Chen BR, Byrum AK, Bredemeyer AL, Yewdell WT, Johnson TE, Lee BJ, Deivasigamani S, Hindi I, Amatya P, Gross ML, Paull TT, Pisapia DJ, Chaudhuri J, Petrini JJH, Mosammaparast N, Amarasinghe GK, Zha S, Tyler JK, Sleckman BP. MRI Is a DNA Damage Response Adaptor during Classical Non-homologous End Joining. Mol Cell 2018; 71:332-342.e8. [PMID: 30017584 PMCID: PMC6083883 DOI: 10.1016/j.molcel.2018.06.018] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/20/2018] [Accepted: 06/07/2018] [Indexed: 11/15/2022]
Abstract
The modulator of retrovirus infection (MRI or CYREN) is a 30-kDa protein with a conserved N-terminal Ku-binding motif (KBM) and a C-terminal XLF-like motif (XLM). We show that MRI is intrinsically disordered and interacts with many DNA damage response (DDR) proteins, including the kinases ataxia telangiectasia mutated (ATM) and DNA-PKcs and the classical non-homologous end joining (cNHEJ) factors Ku70, Ku80, XRCC4, XLF, PAXX, and XRCC4. MRI forms large multimeric complexes that depend on its N and C termini and localizes to DNA double-strand breaks (DSBs), where it promotes the retention of DDR factors. Mice deficient in MRI and XLF exhibit embryonic lethality at a stage similar to those deficient in the core cNHEJ factors XRCC4 or DNA ligase IV. Moreover, MRI is required for cNHEJ-mediated DSB repair in XLF-deficient lymphocytes. We propose that MRI is an adaptor that, through multivalent interactions, increases the avidity of DDR factors to DSB-associated chromatin to promote cNHEJ.
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Affiliation(s)
- Putzer J Hung
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Britney Johnson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Bo-Ruei Chen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Andrea K Byrum
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrea L Bredemeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - William T Yewdell
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Tanya E Johnson
- The Department of Molecular Biosciences and the Howard Hughes Medical Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - Brian J Lee
- Institute for Cancer Genetics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Shruthi Deivasigamani
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Issa Hindi
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Parmeshwar Amatya
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael L Gross
- Department of Chemistry, Washington University, One Brookings Drive, St. Louis, MO 63130, USA
| | - Tanya T Paull
- The Department of Molecular Biosciences and the Howard Hughes Medical Institute, The University of Texas at Austin, Austin, TX 78712, USA
| | - David J Pisapia
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - John J H Petrini
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Nima Mosammaparast
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Shan Zha
- Institute for Cancer Genetics, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Jessica K Tyler
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Barry P Sleckman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, USA.
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19
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Xiao K, Zhao Y, Choi M, Liu H, Blanc A, Qian J, Cahill TJ, Li X, Xiao Y, Clark LJ, Li S. Revealing the architecture of protein complexes by an orthogonal approach combining HDXMS, CXMS, and disulfide trapping. Nat Protoc 2018; 13:1403-1428. [PMID: 29844522 DOI: 10.1038/nprot.2018.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Many cellular functions necessitate structural assemblies of two or more associated proteins. The structural characterization of protein complexes using standard methods, such as X-ray crystallography, is challenging. Herein, we describe an orthogonal approach using hydrogen-deuterium-exchange mass spectrometry (HDXMS), cross-linking mass spectrometry (CXMS), and disulfide trapping to map interactions within protein complexes. HDXMS measures changes in solvent accessibility and hydrogen bonding upon complex formation; a decrease in HDX rate could account for newly formed intermolecular or intramolecular interactions. To distinguish between inter- and intramolecular interactions, we use a CXMS method to determine the position of direct interface regions by trapping intermolecular residues in close proximity to various cross-linkers (e.g., disuccinimidyl adipate (DSA)) of different lengths and reactive groups. Both MS-based experiments are performed on high-resolution mass spectrometers (e.g., an Orbitrap Elite hybrid mass spectrometer). The physiological relevance of the interactions identified through HDXMS and CXMS is investigated by transiently co-expressing cysteine mutant pairs, one mutant on each protein at the discovered interfaces, in an appropriate cell line, such as HEK293. Disulfide-trapped protein complexes are formed within cells spontaneously or are facilitated by addition of oxidation reagents such as H2O2 or diamide. Western blotting analysis, in the presence and absence of reducing reagents, is used to determine whether the disulfide bonds are formed in the proposed complex interface in physiologically relevant milieus. The procedure described here requires 1-2 months. We demonstrate this approach using the β2-adrenergic receptor-β-arrestin1 complex as the model system.
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Affiliation(s)
- Kunhong Xiao
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Vascular Medicine Institute, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Biomedical Mass Spectrometry Center, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yang Zhao
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Minjung Choi
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Hongda Liu
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Adi Blanc
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Jiang Qian
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Thomas J Cahill
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | - Xue Li
- Department of Chemistry, Michigan State University, East Lansing, Michigan, USA
| | - Yunfang Xiao
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lisa J Clark
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sheng Li
- Department of Chemistry, University of California at San Diego, La Jolla, California, USA
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20
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Fast CS, Vahidi S, Konermann L. Changes in Enzyme Structural Dynamics Studied by Hydrogen Exchange-Mass Spectrometry: Ligand Binding Effects or Catalytically Relevant Motions? Anal Chem 2017; 89:13326-13333. [DOI: 10.1021/acs.analchem.7b03506] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Courtney S. Fast
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Siavash Vahidi
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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21
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Trabjerg E, Kartberg F, Christensen S, Rand KD. Conformational characterization of nerve growth factor-β reveals that its regulatory pro-part domain stabilizes three loop regions in its mature part. J Biol Chem 2017; 292:16665-16676. [PMID: 28798232 DOI: 10.1074/jbc.m117.803320] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/07/2017] [Indexed: 11/06/2022] Open
Abstract
Nerve growth factor-β (NGF) is essential for the correct development of the nervous system. NGF exists in both a mature form and a pro-form (proNGF). The two forms have opposing effects on neurons: NGF induces proliferation, whereas proNGF induces apoptosis via binding to a receptor complex of the common neurotrophin receptor (p75NTR) and sortilin. The overexpression of both proNGF and sortilin has been associated with several neurodegenerative diseases. Insights into the conformational differences between proNGF and NGF are central to a better understanding of the opposing mechanisms of action of NGF and proNGF on neurons. However, whereas the structure of NGF has been determined by X-ray crystallography, the structural details for proNGF remain elusive. Here, using a sensitive MS-based analytical method to measure the hydrogen/deuterium exchange of proteins in solution, we analyzed the conformational properties of proNGF and NGF. We detected the presence of a localized higher-order structure motif in the pro-part of proNGF. Furthermore, by comparing the hydrogen/deuterium exchange in the mature part of NGF and proNGF, we found that the presence of the pro-part in proNGF causes a structural stabilization of three loop regions in the mature part, possibly through a direct molecular interaction. Moreover, using tandem MS analyses, we identified two N-linked and two O-linked glycosylations in the pro-part of proNGF. These results advance our knowledge of the conformational properties of proNGF and NGF and help provide a rationale for the diverse biological effects of NGF and proNGF at the molecular level.
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Affiliation(s)
- Esben Trabjerg
- From the Department of Pharmacy, University of Copenhagen, 2100 Copenhagen E, Denmark and.,the Department of Biologics, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Fredrik Kartberg
- the Department of Biologics, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Søren Christensen
- the Department of Biologics, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark
| | - Kasper D Rand
- From the Department of Pharmacy, University of Copenhagen, 2100 Copenhagen E, Denmark and
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22
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Al-Naqshabandi MA, Weis DD. Quantifying Protection in Disordered Proteins Using Millisecond Hydrogen Exchange-Mass Spectrometry and Peptic Reference Peptides. Biochemistry 2017; 56:4064-4072. [DOI: 10.1021/acs.biochem.6b01312] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
| | - David D. Weis
- Department
of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
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23
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Zhu S, Khatun R, Lento C, Sheng Y, Wilson DJ. Enhanced Binding Affinity via Destabilization of the Unbound State: A Millisecond Hydrogen–Deuterium Exchange Study of the Interaction between p53 and a Pleckstrin Homology Domain. Biochemistry 2017; 56:4127-4133. [DOI: 10.1021/acs.biochem.7b00193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shaolong Zhu
- Department
of Chemistry, York University, Toronto, Ontario, Canada M3J 1P3
| | - Rahima Khatun
- Department
of Biology, York University, Toronto, Ontario, Canada M3J 1P3
| | - Cristina Lento
- Department
of Chemistry, York University, Toronto, Ontario, Canada M3J 1P3
| | - Yi Sheng
- Department
of Biology, York University, Toronto, Ontario, Canada M3J 1P3
| | - Derek J. Wilson
- Department
of Chemistry, York University, Toronto, Ontario, Canada M3J 1P3
- Centre
for Research in Mass Spectrometry, York University, Toronto, Ontario, Canada M3J 1P3
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24
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Sardis MF, Tsirigotaki A, Chatzi KE, Portaliou AG, Gouridis G, Karamanou S, Economou A. Preprotein Conformational Dynamics Drive Bivalent Translocase Docking and Secretion. Structure 2017. [DOI: 10.1016/j.str.2017.05.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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25
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Rusinga FI, Weis DD. Soft interactions and volume exclusion by polymeric crowders can stabilize or destabilize transient structure in disordered proteins depending on polymer concentration. Proteins 2017; 85:1468-1479. [PMID: 28425679 DOI: 10.1002/prot.25307] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/07/2017] [Accepted: 04/17/2017] [Indexed: 01/19/2023]
Abstract
The effects of macromolecular crowding on the transient structure of intrinsically disordered proteins is not well-understood. Crowding by biological molecules inside cells could modulate transient structure and alter IDP function. Volume exclusion theory and observations of structured proteins suggest that IDP transient structure would be stabilized by macromolecular crowding. Amide hydrogen exchange (HX) of IDPs in highly concentrated polymer solutions would provide valuable insights into IDP transient structure under crowded conditions. Here, we have used mass spectrometry to measure HX by a transiently helical random coil domain of the activator of thyroid and retinoid receptor (ACTR) in solutions containing 300 g L-1 and 400 g L-1 of Ficoll, a synthetic polysaccharide, using a recently-developed strong cation exchange-based cleanup method [Rusinga, et al., Anal Chem 2017;89:1275-1282]. Transiently helical regions of ACTR exchanged faster in 300 g L-1 Ficoll than in dilute buffer. In contrast, one transient helix exchanged more slowly in 400 g L-1 Ficoll. Nonspecific interactions destabilize ACTR helicity in 300 g L-1 Ficoll because ACTR engages with the Ficoll polymer mesh. In contrast, 400 g L-1 Ficoll is a semi-dilute solution where ACTR cannot engage the Ficoll mesh. At this higher concentration, volume exclusion stabilizes ACTR helicity because ACTR is compacted in interstitial spaces between Ficoll molecules. Our results suggest that the interplay between nonspecific interactions and volume exclusion in different cellular compartments could modulate IDP function by altering the stability of IDP transient structures. Proteins 2017; 85:1468-1479. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Farai I Rusinga
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas, USA
| | - David D Weis
- Department of Chemistry and R. N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas, USA
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26
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Brown KA, Wilson DJ. Bottom-up hydrogen deuterium exchange mass spectrometry: data analysis and interpretation. Analyst 2017; 142:2874-2886. [DOI: 10.1039/c7an00662d] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A tutorial review on the fundamentals of HDX-MS with an emphasis on data analysis and interpretation.
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Affiliation(s)
- Kerene A. Brown
- Department of Chemistry
- York University
- Toronto
- Canada
- Center for Research in Mass Spectrometry
| | - Derek J. Wilson
- Department of Chemistry
- York University
- Toronto
- Canada
- Center for Research in Mass Spectrometry
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27
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Sheff JG, Hepburn M, Yu Y, Lees-Miller SP, Schriemer DC. Nanospray HX-MS configuration for structural interrogation of large protein systems. Analyst 2017; 142:904-910. [DOI: 10.1039/c6an02707e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An in-source column chiller supports nanoHX-MS workflows for analyzing proteins from cellular extracts.
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Affiliation(s)
- Joey G. Sheff
- Department of Chemistry
- University of Calgary
- Calgary
- Canada
| | - Morgan Hepburn
- Department of Biochemistry and Molecular Biology
- University of Calgary
- Calgary
- Canada
| | - Yaping Yu
- Department of Biochemistry and Molecular Biology
- University of Calgary
- Calgary
- Canada
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology
- University of Calgary
- Calgary
- Canada
| | - David C. Schriemer
- Department of Chemistry
- University of Calgary
- Calgary
- Canada
- Department of Biochemistry and Molecular Biology
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28
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Rusinga FI, Weis DD. Automated Strong Cation-Exchange Cleanup To Remove Macromolecular Crowding Agents for Protein Hydrogen Exchange Mass Spectrometry. Anal Chem 2016; 89:1275-1282. [PMID: 27936623 DOI: 10.1021/acs.analchem.6b04057] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Measuring amide hydrogen exchange (HX) of intrinsically disordered proteins (IDPs) in solutions containing high concentrations of macromolecular crowding agents would give new insights into the structure and dynamics of these proteins under crowded conditions. High concentrations of artificial crowders, required to simulate cellular crowding, introduce overwhelming interferences to mass spectrometry (MS) analysis. We have developed a fully automated, dual-stage online cleanup that uses strong cation-exchange (SCX) followed by reversed-phase desalting to remove Ficoll, a synthetic polymer, for HX-MS analysis of proteins under crowded conditions. We tested the efficiency of our method by measuring the HX-MS signal intensities of myoglobin peptides from crowded samples containing 300 g L-1 Ficoll and from uncrowded samples. Although there was loss of abundance relative to uncrowded myoglobin analyzed using conventional HX-MS, 97% coverage of the myoglobin sequence was still obtained. Control HX-MS experiments using unstructured peptides labeled at pD 4.0 under crowded and uncrowded conditions confirmed that Ficoll does not alter chemical exchange and that the same extent of HX is achieved in uncrowded solutions as in solutions containing 300 g L-1 of predeuterated Ficoll. We validated our method by measuring HX of CBP, the intrinsically disordered nuclear coactivator binding domain of CREB binding protein (UniProt CBP_MOUSE P45481 ), residues 2059-2117, at pD 6.5 under crowded and uncrowded conditions. Ficoll induced both protection and deprotection from HX in different regions of CBP, with the greatest deprotection occurring at the edges of helices. These results are consistent with previous observation of IDPs under the influence of synthetic polymers.
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Affiliation(s)
- Farai I Rusinga
- Department of Chemistry and the Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas , Lawrence, Kansas 66045, United States
| | - David D Weis
- Department of Chemistry and the Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas , Lawrence, Kansas 66045, United States
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29
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Keppel TR, Sarpong K, Murray EM, Monsey J, Zhu J, Bose R. Biophysical Evidence for Intrinsic Disorder in the C-terminal Tails of the Epidermal Growth Factor Receptor (EGFR) and HER3 Receptor Tyrosine Kinases. J Biol Chem 2016; 292:597-610. [PMID: 27872189 DOI: 10.1074/jbc.m116.747485] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/15/2016] [Indexed: 12/21/2022] Open
Abstract
The epidermal growth factor receptor (EGFR)/ErbB family of receptor tyrosine kinases includes oncogenes important in the progression of breast and other cancers, and they are targets for many drug development strategies. Each member of the ErbB family possesses a unique, structurally uncharacterized C-terminal tail that plays an important role in autophosphorylation and signal propagation. To determine whether these C-terminal tails are intrinsically disordered regions, we conducted a battery of biophysical experiments on the EGFR and HER3 tails. Using hydrogen/deuterium exchange mass spectrometry, we measured the conformational dynamics of intracellular half constructs and compared the tails with the ordered kinase domains. The C-terminal tails demonstrate more rapid deuterium exchange behavior when compared with the kinase domains. Next, we expressed and purified EGFR and HER3 tail-only constructs. Results from circular dichroism spectroscopy, size exclusion chromatography with multiangle light scattering, dynamic light scattering, analytical ultracentrifugation, and small angle X-ray scattering each provide evidence that the EGFR and HER3 C-terminal tails are intrinsically disordered with extended, non-globular structure in solution. The intrinsic disorder and extended conformation of these tails may be important for their function by increasing the capture radius and reducing the thermodynamic barriers for binding of downstream signaling proteins.
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Affiliation(s)
| | | | | | | | - Jian Zhu
- Hematology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Ron Bose
- From the Divisions of Oncology and
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30
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Mansouri AL, Grese LN, Rowe EL, Pino JC, Chennubhotla SC, Ramanathan A, O'Neill HM, Berthelier V, Stanley CB. Folding propensity of intrinsically disordered proteins by osmotic stress. MOLECULAR BIOSYSTEMS 2016; 12:3695-3701. [PMID: 27752679 PMCID: PMC5363718 DOI: 10.1039/c6mb00512h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Proteins imparted with intrinsic disorder conduct a range of essential cellular functions. To better understand the folding and hydration properties of intrinsically disordered proteins (IDPs), we used osmotic stress to induce conformational changes in nuclear co-activator binding domain (NCBD) and activator for thyroid hormone and retinoid receptor (ACTR) separate from their mutual binding. Osmotic stress was applied by the addition of small and polymeric osmolytes, where we discovered that water contributions to NCBD folding always exceeded those for ACTR. Both NCBD and ACTR were found to gain α-helical structure with increasing osmotic stress, consistent with their folding upon NCBD/ACTR complex formation. Using small-angle neutron scattering (SANS), we further characterized NCBD structural changes with the osmolyte ethylene glycol. Here a large reduction in overall size initially occurred before substantial secondary structural change. By focusing on folding propensity, and linked hydration changes, we uncover new insights that may be important for how IDP folding contributes to binding.
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Affiliation(s)
- Amanda L Mansouri
- Department of Medicine, Graduate School of Medicine, University of Tennessee, Health Science Center, Knoxville, TN, USA
| | - Laura N Grese
- Department of Medicine, Graduate School of Medicine, University of Tennessee, Health Science Center, Knoxville, TN, USA and Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - Erica L Rowe
- Department of Medicine, Graduate School of Medicine, University of Tennessee, Health Science Center, Knoxville, TN, USA and Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - James C Pino
- Health Data Sciences Institute, Computational Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - S Chakra Chennubhotla
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Arvind Ramanathan
- Health Data Sciences Institute, Computational Science and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Hugh M O'Neill
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - Valerie Berthelier
- Department of Medicine, Graduate School of Medicine, University of Tennessee, Health Science Center, Knoxville, TN, USA
| | - Christopher B Stanley
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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31
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Killoran RC, Sowole MA, Halim MA, Konermann L, Choy WY. Conformational characterization of the intrinsically disordered protein Chibby: Interplay between structural elements in target recognition. Protein Sci 2016; 25:1420-9. [PMID: 27082063 DOI: 10.1002/pro.2936] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 04/09/2016] [Accepted: 04/11/2016] [Indexed: 11/12/2022]
Abstract
The protein Chibby (Cby) is an antagonist of the Wnt signaling pathway, where it inhibits the binding between the transcriptional coactivator β-catenin and the Tcf/Lef transcription factors. The 126 residue Cby is partially disordered; its N-terminal half is unstructured while its C-terminal half comprises a coiled-coil domain. Previous structural analyses of Cby using NMR spectroscopy suffered from severe line broadening for residues within the protein's C-terminal half, hindering detailed characterization of the coiled-coil domain. Here, we use hydrogen/deuterium exchange-mass spectrometry (HDX-MS) to examine Cby's C-terminal half. Results reveal that Cby is divided into three structural elements: a disordered N-terminal half, a coiled-coil domain, and a C-terminal unstructured extension consisting of the last ∼ 25 residues (which we term C-terminal extension). A series of truncation constructs were designed to assess the roles of individual structural elements in protein stability and Cby binding to TC-1, a positive regulator of the Wnt signaling pathway. CD and NMR data show that Cby maintains coiled-coil structure upon deletion of either disordered region. NMR and ITC binding experiments between Cby and TC-1 illustrate that the interaction is retained upon deletion of either Cby's N-terminal half or its C-terminal extension. Intriguingly, Cby's C-terminal half alone binds to TC-1 with significantly greater affinity compared to full-length Cby, implying that target binding of the coiled-coil domain is affected by the flanking disordered regions.
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Affiliation(s)
- Ryan C Killoran
- Department of Biochemistry, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Modupeola A Sowole
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Mohammad A Halim
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Lars Konermann
- Department of Biochemistry, The University of Western Ontario, London, Ontario, N6A 5C1, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Wing-Yiu Choy
- Department of Biochemistry, The University of Western Ontario, London, Ontario, N6A 5C1, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
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32
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Maaty WS, Weis DD. Label-Free, In-Solution Screening of Peptide Libraries for Binding to Protein Targets Using Hydrogen Exchange Mass Spectrometry. J Am Chem Soc 2016; 138:1335-43. [PMID: 26741284 DOI: 10.1021/jacs.5b11742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is considerable interest in the discovery of peptide ligands that bind to protein targets. Discovery of such ligands is usually approached by screening large peptide libraries. However, the individual peptides must be tethered to a tag that preserves their individual identities (e.g., phage display or one-bead one-compound). To overcome this limitation, we have developed a method for screening libraries of label-free peptides for binding to a protein target in solution as a single batch. The screening is based on decreased amide hydrogen exchange by peptides that bind to the target. Hydrogen exchange is measured by mass spectrometry. We demonstrate the approach using a peptide library derived from the Escherichia coli proteome that contained 6664 identifiable features. The library was spiked separately with a peptide spanning the calmodulin binding domain of endothelial nitric oxide synthase (eNOS, 494-513) and a peptide spanning the N-terminal 20 residues of bovine ribonuclease A (S peptide). Human calmodulin and bovine ribonuclease S (RNase S) were screened against the library. Using a novel data analysis workflow, we identified the eNOS peptide as the only calmodulin binding peptide and S peptide as the only ribonuclease S binding peptide in the library.
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Affiliation(s)
- Walid S Maaty
- Department of Nucleic Acid and Protein Structure, Agricultural Genetic Engineering Research Institute, Agricultural Research Center , Giza 12619, Egypt
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33
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Zhang J, Kitova EN, Li J, Eugenio L, Ng K, Klassen JS. Localizing Carbohydrate Binding Sites in Proteins Using Hydrogen/Deuterium Exchange Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:83-90. [PMID: 26423923 DOI: 10.1007/s13361-015-1263-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 08/24/2015] [Accepted: 08/31/2015] [Indexed: 06/05/2023]
Abstract
The application of hydrogen/deuterium exchange mass spectrometry (HDX-MS) to localize ligand binding sites in carbohydrate-binding proteins is described. Proteins from three bacterial toxins, the B subunit homopentamers of Cholera toxin and Shiga toxin type 1 and a fragment of Clostridium difficile toxin A, and their interactions with native carbohydrate receptors, GM1 pentasaccharides (β-Gal-(1→3)-β-GalNAc-(1→4)[α-Neu5Ac-(2→3)]-β-Gal-(1→4)-Glc), Pk trisaccharide (α-Gal-(1→4)-β-Gal-(1→4)-Glc) and CD-grease (α-Gal-(1→3)-β-Gal-(1→4)-β-GlcNAcO(CH2)8CO2CH3), respectively, served as model systems for this study. Comparison of the differences in deuterium uptake for peptic peptides produced in the absence and presence of ligand revealed regions of the proteins that are protected against deuterium exchange upon ligand binding. Notably, protected regions generally coincide with the carbohydrate binding sites identified by X-ray crystallography. However, ligand binding can also result in increased deuterium exchange in other parts of the protein, presumably through allosteric effects. Overall, the results of this study suggest that HDX-MS can serve as a useful tool for localizing the ligand binding sites in carbohydrate-binding proteins. However, a detailed interpretation of the changes in deuterium exchange upon ligand binding can be challenging because of the presence of ligand-induced changes in protein structure and dynamics.
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Affiliation(s)
- Jingjing Zhang
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
- Alberta Glycomics Centre, Edmonton, Alberta, Canada
| | - Elena N Kitova
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
- Alberta Glycomics Centre, Edmonton, Alberta, Canada
| | - Jun Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
- Alberta Glycomics Centre, Edmonton, Alberta, Canada
| | - Luiz Eugenio
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Alberta Glycomics Centre, Edmonton, Alberta, Canada
| | - Kenneth Ng
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Alberta Glycomics Centre, Edmonton, Alberta, Canada
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
- Alberta Glycomics Centre, Edmonton, Alberta, Canada.
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34
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Donohoe GC, Arndt JR, Valentine SJ. Online deuterium hydrogen exchange and protein digestion coupled with ion mobility spectrometry and tandem mass spectrometry. Anal Chem 2015; 87:5247-54. [PMID: 25893550 DOI: 10.1021/acs.analchem.5b00277] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Online deuterium hydrogen exchange (DHX) and pepsin digestion (PD) is demonstrated using drift tube ion mobility spectrometry (DTIMS) coupled with linear ion trap (LTQ) mass spectrometry (MS) with electron transfer dissociation (ETD) capabilities. DHX of deuterated ubiquitin, followed by subsequent quenching and digestion, is performed within ∼60 s, yielding 100% peptide sequence coverage. The high reproducibility of the IMS separation allows spectral feature matching between two-dimensional IMS-MS datasets (undeuterated and deuterated) without the need for dataset alignment. Extracted ion drift time distributions (XIDTDs) of deuterated peptic peptides are mobility-matched to corresponding XIDTDs of undeuterated peptic peptides that were identified using collision-induced dissociation (CID). Matching XIDTDs allows a straightforward identification and deuterium retention evaluation for labeled peptides. Aside from the mobility separation, the ion trapping capabilities of the LTQ, combined with ETD, are demonstrated to provide single-residue resolution. Deuterium retention for the c- series ions across residues M(1)-L(15) and N(25)-R(42) are in good agreement with the known secondary structural elements within ubiquitin.
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Affiliation(s)
- Gregory C Donohoe
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - James R Arndt
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Stephen J Valentine
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
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35
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McAllister RG, Konermann L. Challenges in the Interpretation of Protein H/D Exchange Data: A Molecular Dynamics Simulation Perspective. Biochemistry 2015; 54:2683-92. [DOI: 10.1021/acs.biochem.5b00215] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert G. McAllister
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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36
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Keppel TR, Weis DD. Mapping residual structure in intrinsically disordered proteins at residue resolution using millisecond hydrogen/deuterium exchange and residue averaging. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:547-554. [PMID: 25481641 DOI: 10.1007/s13361-014-1033-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/16/2014] [Accepted: 10/16/2014] [Indexed: 06/04/2023]
Abstract
Measurement of residual structure in intrinsically disordered proteins can provide insights into the mechanisms by which such proteins undergo coupled binding and folding. The present work describes an approach to measure residual structure in disordered proteins using millisecond hydrogen/deuterium (H/D) exchange in a conventional bottom-up peptide-based workflow. We used the exchange mid-point, relative to a totally deuterated control, to quantify the rate of H/D exchange in each peptide. A weighted residue-by-residue average of these midpoints was used to map the extent of residual structure at near single-residue resolution. We validated this approach both by simulating a disordered protein and experimentally using the p300 binding domain of ACTR, a model disordered protein already well-characterized by other approaches. Secondary structure elements mapped in the present work are in good agreement with prior nuclear magnetic resonance measurements. The new approach was somewhat limited by a loss of spatial resolution and subject to artifacts because of heterogeneities in intrinsic exchange. Approaches to correct these limitations are discussed.
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Affiliation(s)
- Theodore R Keppel
- Department of Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS, 66045, USA
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37
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Zhu S, Shala A, Bezginov A, Sljoka A, Audette G, Wilson DJ. Hyperphosphorylation of intrinsically disordered tau protein induces an amyloidogenic shift in its conformational ensemble. PLoS One 2015; 10:e0120416. [PMID: 25767879 PMCID: PMC4359001 DOI: 10.1371/journal.pone.0120416] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/22/2015] [Indexed: 11/19/2022] Open
Abstract
Tau is an intrinsically disordered protein (IDP) whose primary physiological role is to stabilize microtubules in neuronal axons at all stages of development. In Alzheimer's and other tauopathies, tau forms intracellular insoluble amyloid aggregates known as neurofibrillary tangles, a process that appears in many cases to be preceded by hyperphosphorylation of tau monomers. Understanding the shift in conformational bias induced by hyperphosphorylation is key to elucidating the structural factors that drive tau pathology, however, as an IDP, tau is not amenable to conventional structural characterization. In this work, we employ a straightforward technique based on Time-Resolved ElectroSpray Ionization Mass Spectrometry (TRESI-MS) and Hydrogen/Deuterium Exchange (HDX) to provide a detailed picture of residual structure in tau, and the shifts in conformational bias induced by hyperphosphorylation. By comparing the native and hyperphosphorylated ensembles, we are able to define specific conformational biases that can easily be rationalized as enhancing amyloidogenic propensity. Representative structures for the native and hyperphosphorylated tau ensembles were generated by refinement of a broad sample of conformations generated by low-computational complexity modeling, based on agreement with the TRESI-HDX profiles.
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Affiliation(s)
- Shaolong Zhu
- Chemistry Department, York University, Toronto, ON, Canada
| | - Agnesa Shala
- Chemistry Department, York University, Toronto, ON, Canada
| | - Alexandr Bezginov
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Adnan Sljoka
- Department of Physics, Ryerson University, Toronto, ON, Canada
| | - Gerald Audette
- Chemistry Department, York University, Toronto, ON, Canada
| | - Derek J. Wilson
- Chemistry Department, York University, Toronto, ON, Canada
- Center for Research in Mass Spectrometry, Faculty of Science, York University, Toronto, ON, Canada
- * E-mail:
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38
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Sowole MA, Innes BT, Amunugama M, Litchfield DW, Brandl CJ, Shilton BH, Konermann L. Noncovalent binding of a cyclic peptide inhibitor to the peptidyl-prolyl isomerase Pin1, explored by hydrogen exchange mass spectrometry. CAN J CHEM 2015. [DOI: 10.1139/cjc-2014-0230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pin1 is a peptidyl-prolyl isomerase (PPIase) that plays a central role in eukaryotic cell cycle regulation, making this protein an interesting target for cancer therapy. Pin1 exhibits high specificity for substrates where proline is preceded by phosphoserine or phosphothreonine. The protein comprises an N-terminal WW (tryptophan–tryptophan) domain and a C-terminal PPIase domain. The cyclic peptide [CRYPEVEIC] (square brackets are used to denote the cyclic structure) represents a lead compound for a new class of nonphosphorylated Pin1 inhibitors. Unfortunately, it has not been possible thus far to characterize the Pin1–[CRYPEVEIC] complex by X-ray crystallography. Thus, the exact binding mode remains unknown. The current work employs hydrogen/deuterium exchange mass spectrometry for gaining insights into the Pin1–[CRYPEVEIC] interactions. The WW domain shows extensive conformational dynamics, both in the presence and in the absence of ligand. In contrast, profound changes in deuteration kinetics are observed in the PPIase domain after the addition of [CRYPEVEIC]. The secondary structure elements β2, α3, and α4 exhibit markedly reduced deuteration, consistent with their postulated involvement in ligand binding. Unexpectedly, [CRYPEVEIC] destabilizes the range of residues 61–86, a segment that comprises basic side chains that normally interact with the substrate phosphate. This destabilization is likely caused by steric clashes with Y3 or E5 of the inhibitor. Ligand-induced destabilization has previously been reported for a few other proteins, but effects of this type are not very common. Our findings suggest that future crystallization trials on Pin1 variants deleted for residues in the 61–86 range might provide a path towards high-resolution X-ray structures of Pin1 bound to cyclic peptide inhibitors.
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Affiliation(s)
- Modupeola A. Sowole
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - Brendan T. Innes
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Mahasilu Amunugama
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - David W. Litchfield
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Christopher J. Brandl
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Brian H. Shilton
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON N6A 5C1, Canada
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39
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Beveridge R, Covill S, Pacholarz KJ, Kalapothakis JMD, MacPhee CE, Barran PE. A Mass-Spectrometry-Based Framework To Define the Extent of Disorder in Proteins. Anal Chem 2014; 86:10979-91. [DOI: 10.1021/ac5027435] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rebecca Beveridge
- Manchester
Institute of Biotechnology, Michael Barber Centre for Collaborative
Mass Spectrometry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Sam Covill
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
| | - Kamila J. Pacholarz
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
| | - Jason M. D. Kalapothakis
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
- School
of Physics and Astronomy, University of Edinburgh, James Clerk
Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - Cait E. MacPhee
- School
of Physics and Astronomy, University of Edinburgh, James Clerk
Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - Perdita E. Barran
- Manchester
Institute of Biotechnology, Michael Barber Centre for Collaborative
Mass Spectrometry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
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40
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Harvey SR, Porrini M, Konijnenberg A, Clarke DJ, Tyler RC, Langridge-Smith PRR, MacPhee CE, Volkman BF, Barran PE. Dissecting the Dynamic Conformations of the Metamorphic Protein Lymphotactin. J Phys Chem B 2014; 118:12348-59. [DOI: 10.1021/jp504997k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
| | - Massimiliano Porrini
- Institut Européen de Chimie et Biologie (IECB), CNRS UMR 5248 Chimie et Biologie des Membranes et des Nano-objets (CBMN), 33607 Pessac Cedex, France
| | | | | | - Robert C. Tyler
- Department
of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | | | | | - Brian F. Volkman
- Department
of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Perdita E. Barran
- School
of Chemistry,
Manchester Institute of Biotechnology, University of Manchester, Manchester M1 7DN, United Kingdom
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41
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Rodriguez AD, Dunn SD, Konermann L. ATP-induced dimerization of the F0F1 ε subunit from Bacillus PS3: a hydrogen exchange-mass spectrometry study. Biochemistry 2014; 53:4072-80. [PMID: 24870150 DOI: 10.1021/bi5004684] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
F0F1 ATP synthase harnesses a transmembrane electrochemical gradient for the production of ATP. When operated in reverse, this multiprotein complex catalyzes ATP hydrolysis. In bacteria, the ε subunit is involved in regulating this ATPase activity. Also, ε is essential for coupling ATP hydrolysis (or synthesis) to proton translocation. The ε subunit consists of a β sandwich and two C-terminal helices, α1 and α2. The protein can switch from a compact fold to an alternate conformation where α1 and α2 are separated, resulting in an extended structure. ε from the thermophile Bacillus PS3 (Tε) binds ATP with high affinity such that this protein may function as an intracellular ATP level sensor. ATP binding to isolated Tε triggers a major conformational transition. Earlier data were interpreted in terms of an ATP + Tεextended → ATP·Tεcompact transition that may mimic aspects of the regulatory switching within F0F1 (Yagi et al. (2007) Proc. Natl. Acad. Sci. U.S.A., 104, 11233–11238). In this work, we employ complementary biophysical techniques for examining the ATP-induced conformational switching of isolated Tε. CD spectroscopy confirmed the occurrence of a large-scale conformational transition upon ATP binding, consistent with the formation of stable helical structure. Hydrogen/deuterium exchange (HDX) mass spectrometry revealed that this transition is accompanied by a pronounced stabilization in the vicinity of the ATP-binding pocket. Surprisingly, dramatic stabilization is also seen in the β8−β9 region, which is remote from the site of ATP interaction. Analytical ultracentrifugation uncovered a previously unrecognized feature of Tε: a high propensity to undergo dimerization in the presence of ATP. Comparison with existing crystallography data strongly suggests that the unexpected β8−β9 HDX protection is due to newly formed protein–protein contacts. Hence, ATP binding to isolated Tε proceeds according to 2ATP + 2Tεextended → (ATP·Tεcompact)2. Implications of this dimerization propensity for the possible role of Tε as an antibiotic target are discussed.
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42
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Sowole MA, Konermann L. Effects of Protein–Ligand Interactions on Hydrogen/Deuterium Exchange Kinetics: Canonical and Noncanonical Scenarios. Anal Chem 2014; 86:6715-22. [DOI: 10.1021/ac501849n] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Modupeola A. Sowole
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department
of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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43
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Beveridge R, Chappuis Q, Macphee C, Barran P. Mass spectrometry methods for intrinsically disordered proteins. Analyst 2014; 138:32-42. [PMID: 23108160 DOI: 10.1039/c2an35665a] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the last ten years mass spectrometry has emerged as a powerful biophysical technique capable of providing unique insights into the structure and dynamics of proteins. Part of this explosion in use involves investigations of the most recently 'discovered' subset of proteins: the so-called 'Intrinsically Disordered' or 'Natively Unstructured' proteins. A key advantage of the use of mass spectrometry to study intrinsically disordered proteins (IDPs) is its ability to test biophysical assertions made about why they differ from structured proteins. For example, from the charge state distribution presented by a protein following nano-electrospray (n-ESI) it is possible to infer the range of conformations present in solution and hence the extent of disorder; n-ESI is highly sensitive to the degree of folding at the moment of transfer from the liquid to the gas phase. The combination of mass spectrometry with ion mobility (IM-MS) provides rotationally averaged collision cross-sections of molecular ions which can be correlated with conformation; this too can be applied to IDPs. Another feature which can be monitored by IM-MS is the tendency of disordered proteins to form amyloid fibrils, the protein aggregates involved in the onset of neurodegenerative diseases such as Parkinson's and Alzheimer's. IM-MS provides a useful insight into events that occur during the early stages of aggregation including delineating the structure of the monomer, identifying oligomer distributions, and revealing mechanistic details of the aggregation process. Here we will review the use of MS and IM-MS to study IDPs using examples from our own and other laboratories.
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Affiliation(s)
- Rebecca Beveridge
- School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland
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Konermann L, Rodriguez AD, Sowole MA. Type 1 and Type 2 scenarios in hydrogen exchange mass spectrometry studies on protein–ligand complexes. Analyst 2014; 139:6078-87. [DOI: 10.1039/c4an01307g] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Ligand binding to a protein can elicit a wide range of responses when studied by HDX mass spectrometry.
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Affiliation(s)
- Lars Konermann
- Department of Chemistry
- The University of Western Ontario
- London, Canada
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Konermann L, Vahidi S, Sowole MA. Mass Spectrometry Methods for Studying Structure and Dynamics of Biological Macromolecules. Anal Chem 2013; 86:213-32. [DOI: 10.1021/ac4039306] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| | - Siavash Vahidi
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| | - Modupeola A. Sowole
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
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Ganguly D, Zhang W, Chen J. Electrostatically accelerated encounter and folding for facile recognition of intrinsically disordered proteins. PLoS Comput Biol 2013; 9:e1003363. [PMID: 24278008 PMCID: PMC3836701 DOI: 10.1371/journal.pcbi.1003363] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 10/10/2013] [Indexed: 11/18/2022] Open
Abstract
Achieving facile specific recognition is essential for intrinsically disordered proteins (IDPs) that are involved in cellular signaling and regulation. Consideration of the physical time scales of protein folding and diffusion-limited protein-protein encounter has suggested that the frequent requirement of protein folding for specific IDP recognition could lead to kinetic bottlenecks. How IDPs overcome such potential kinetic bottlenecks to viably function in signaling and regulation in general is poorly understood. Our recent computational and experimental study of cell-cycle regulator p27 (Ganguly et al., J. Mol. Biol. (2012)) demonstrated that long-range electrostatic forces exerted on enriched charges of IDPs could accelerate protein-protein encounter via "electrostatic steering" and at the same time promote "folding-competent" encounter topologies to enhance the efficiency of IDP folding upon encounter. Here, we further investigated the coupled binding and folding mechanisms and the roles of electrostatic forces in the formation of three IDP complexes with more complex folded topologies. The surface electrostatic potentials of these complexes lack prominent features like those observed for the p27/Cdk2/cyclin A complex to directly suggest the ability of electrostatic forces to facilitate folding upon encounter. Nonetheless, similar electrostatically accelerated encounter and folding mechanisms were consistently predicted for all three complexes using topology-based coarse-grained simulations. Together with our previous analysis of charge distributions in known IDP complexes, our results support a prevalent role of electrostatic interactions in promoting efficient coupled binding and folding for facile specific recognition. These results also suggest that there is likely a co-evolution of IDP folded topology, charge characteristics, and coupled binding and folding mechanisms, driven at least partially by the need to achieve fast association kinetics for cellular signaling and regulation.
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Affiliation(s)
- Debabani Ganguly
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas, United States of America
| | - Weihong Zhang
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas, United States of America
| | - Jianhan Chen
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
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Vahidi S, Stocks BB, Konermann L. Partially Disordered Proteins Studied by Ion Mobility-Mass Spectrometry: Implications for the Preservation of Solution Phase Structure in the Gas Phase. Anal Chem 2013; 85:10471-8. [DOI: 10.1021/ac402490r] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Siavash Vahidi
- Departments
of Chemistry
and Biochemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Bradley B. Stocks
- Departments
of Chemistry
and Biochemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Lars Konermann
- Departments
of Chemistry
and Biochemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
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Goswami D, Devarakonda S, Chalmers MJ, Pascal BD, Spiegelman BM, Griffin PR. Time window expansion for HDX analysis of an intrinsically disordered protein. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:1584-92. [PMID: 23884631 PMCID: PMC3773365 DOI: 10.1007/s13361-013-0669-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 05/07/2013] [Accepted: 05/08/2013] [Indexed: 05/16/2023]
Abstract
Application of typical HDX methods to examine intrinsically disordered proteins (IDP), proteins that are natively unstructured and highly dynamic at physiological pH, is limited because of the rapid exchange of unprotected amide hydrogens with solvent. The exchange rates of these fast exchanging amides are usually faster than the shortest time scale (10 s) employed in typical automated HDX-MS experiments. Considering the functional importance of IDPs and their association with many diseases, it is valuable to develop methods that allow the study of solution dynamics of these proteins as well as the ability to probe the interaction of IDPs with their wide range of binding partners. Here, we report the application of time window expansion to the millisecond range by altering the on-exchange pH of the HDX experiment to study a well-characterized IDP; the activation domain of the nuclear receptor coactivator, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). This method enabled mapping the regions of PGC-1α that are stabilized upon binding the ligand binding domain (LBD) of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ). We further demonstrate the method's applicability to other binding partners of the IDP PGC-1α and pave the way for characterizing many other biologically important ID proteins.
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Affiliation(s)
- Devrishi Goswami
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL, 33458, USA
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Sowole MA, Alexopoulos JA, Cheng YQ, Ortega J, Konermann L. Activation of ClpP protease by ADEP antibiotics: insights from hydrogen exchange mass spectrometry. J Mol Biol 2013; 425:4508-19. [PMID: 23948506 DOI: 10.1016/j.jmb.2013.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/27/2013] [Accepted: 08/06/2013] [Indexed: 10/26/2022]
Abstract
The bacterial protease ClpP consists of 14 subunits that assemble into two stacked heptameric rings. The central degradation chamber can be accessed via axial pores. In free ClpP, these pores are obstructed by the N-terminal regions of the seven subunits at either end of the barrel. Acyldepsipeptides (ADEPs) are antibacterial compounds that bind in hydrophobic clefts surrounding the pore region, causing the pores to open up. The ensuing uncontrolled degradation of intracellular proteins is responsible for the antibiotic activity of ADEPs. Recently published X-ray structures yielded conflicting models regarding the conformation adopted by the N-terminal regions in the open state. Here, we use hydrogen/deuterium exchange (HDX) mass spectrometry to obtain complementary insights into the ClpP behavior with and without ADEP1. Ligand binding causes rigidification of the equatorial belt, accompanied by destabilization in the vicinity of the binding clefts. The N-terminal regions undergo rapid deuteration with only minor changes after ADEP1 binding, revealing a lack of stable H-bonding. Our data point to a mechanism where the pore opening mechanism is mediated primarily by changes in the packing of N-terminal nonpolar side chains. We propose that a "hydrophobic plug" causes pore blockage in ligand-free ClpP. ADEP1 binding provides new hydrophobic anchor points that nonpolar N-terminal residues can interact with. In this way, ADEP1 triggers the transition to an open conformation, where nonpolar moieties are clustered around the rim of the pore. This proposed mechanism helps reconcile the conflicting models that had been put forward earlier.
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Affiliation(s)
- Modupeola A Sowole
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
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Marsh JJ, Guan HS, Li S, Chiles PG, Tran D, Morris TA. Structural insights into fibrinogen dynamics using amide hydrogen/deuterium exchange mass spectrometry. Biochemistry 2013; 52:5491-502. [PMID: 23875785 DOI: 10.1021/bi4007995] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We determined the amide hydrogen/deuterium exchange profile of native human fibrinogen under physiologic conditions. After optimization of the quench and proteolysis conditions, more than 1,200 peptides were identified by mass spectrometry, spanning more than 90% of the constituent Aα, Bβ, and γ chain amino acid sequences. The compact central and distal globular regions of fibrinogen were well protected from deuterium exchange, with the exception of the unfolded amino-terminal segments of the Aα and Bβ chains extending from the central region, and the short γ chain "tail" extending from each distal globular region. The triple-helical coiled-coil regions, which bridge the central region to each distal region, were also well protected with the exception of a moderately fast-exchanging area in the middle of each coiled-coil adjacent to the γ chain carbohydrate attachment site. These dynamic regions appear to provide flexibility to the fibrinogen molecule. The γ chain "out loop" contained within each coiled-coil also exchanged rapidly. The αC domain (Aα 392-610) exchanged rapidly, with the exception of a short segment sandwiched between a conserved disulfide linkage in the N-terminal αC subdomain. This latter finding is consistent with a mostly disordered structure for the αC domain in native fibrinogen. Analysis of the dysfibrinogen Bβ 235 Pro/Leu, which exhibits abnormal fibrin structure, revealed enhanced deuterium exchange surrounding the Pro/Leu substitution site as well as in the vicinity of the high affinity calcium binding site and the A knob polymerization pocket within the γC domain. The implication of these changes with respect to fibrin structure is discussed.
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Affiliation(s)
- James J Marsh
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093, USA.
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