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Nash S, Vachet RW. Gas-Phase Unfolding of Protein Complexes Distinguishes Conformational Isomers. J Am Chem Soc 2022; 144:22128-22139. [PMID: 36414315 DOI: 10.1021/jacs.2c09573] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Proteins can adopt different conformational states that are important for their biological function and, in some cases, can be responsible for their dysfunction. The essential roles that proteins play in biological systems make distinguishing the structural differences between these conformational states both fundamentally and practically important. Here, we demonstrate that collision-induced unfolding (CIU), in combination with ion mobility-mass spectrometry (IM-MS) measurements, distinguish subtly different conformational states for protein complexes. Using the open and closed states of the β-lactoglobulin (βLG) dimer as a model, we show that these two conformational isomers unfold during collisional activation to generate distinct states that are readily separated by IM-MS. Extensive molecular modeling of the CIU process reproduces the distinct unfolding intermediates and identifies the molecular details that explain why the two conformational states unfold in distinct ways. Strikingly, the open conformational state forms new electrostatic interactions upon collisional heating, while the closed state does not. These newly formed electrostatic interactions involve residues on the loop differentially positioned in the two βLG conformational isomers, highlighting that gas-phase unfolding pathways reflect aspects of solution structure. This combination of experiment and theory provides a path forward for distinguishing subtly different conformational isomers for protein complexes via gas-phase unfolding experiments. Our results also have implications for understanding how protein complexes dissociate in the gas phase, indicating that current models need to be refined to explain protein complex dissociation.
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Affiliation(s)
- Stacey Nash
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Richard W Vachet
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.,Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003 United States
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2
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Lin Y, Gross ML. Mass Spectrometry-Based Structural Proteomics for Metal Ion/Protein Binding Studies. Biomolecules 2022; 12:135. [PMID: 35053283 PMCID: PMC8773722 DOI: 10.3390/biom12010135] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
Metal ions are critical for the biological and physiological functions of many proteins. Mass spectrometry (MS)-based structural proteomics is an ever-growing field that has been adopted to study protein and metal ion interactions. Native MS offers information on metal binding and its stoichiometry. Footprinting approaches coupled with MS, including hydrogen/deuterium exchange (HDX), "fast photochemical oxidation of proteins" (FPOP) and targeted amino-acid labeling, identify binding sites and regions undergoing conformational changes. MS-based titration methods, including "protein-ligand interactions by mass spectrometry, titration and HD exchange" (PLIMSTEX) and "ligand titration, fast photochemical oxidation of proteins and mass spectrometry" (LITPOMS), afford binding stoichiometry, binding affinity, and binding order. These MS-based structural proteomics approaches, their applications to answer questions regarding metal ion protein interactions, their limitations, and recent and potential improvements are discussed here. This review serves as a demonstration of the capabilities of these tools and as an introduction to wider applications to solve other questions.
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Affiliation(s)
- Yanchun Lin
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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3
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Dang H, Chen Z, Chen W, Luo X, Liu P, Wang L, Chen J, Tang X, Wang Z, Liang Y. The residues 4 to 6 at the N-terminus in particular modulate fibril propagation of β-microglobulin. Acta Biochim Biophys Sin (Shanghai) 2021; 54:187-198. [PMID: 35130623 PMCID: PMC9909321 DOI: 10.3724/abbs.2021017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The ΔN6 truncation is the main posttranslational modification of β-microglobulin (βM) found in dialysis-related amyloid. Investigation of the interaction of wild-type (WT) βM with N-terminally truncated variants is therefore of medical relevance. However, it is unclear which residues among the six residues at the N-terminus are crucial to the interactions and the modulation of amyloid fibril propagation of βM. We herein analyzed homo- and heterotypic seeding of amyloid fibrils of WT human βM and its N-terminally-truncated variants ΔN1 to ΔN6, lacking up to six residues at the N-terminus. At acidic pH 2.5, we produced amyloid fibrils from recombinant, WT βM and its six truncated variants, and found that ΔN6 βM fibrils exhibit a significantly lower conformational stability than WT βM fibrils. Importantly, under more physiological conditions (pH 6.2), we assembled amyloid fibrils only from recombinant, ΔN4, ΔN5, and ΔN6 βM but not from WT βM and its three truncated variants ΔN1 to ΔN3. Notably, the removal of the six, five or four residues at the N-terminus leads to enhanced fibril formation, and homo- and heterotypic seeding of ΔN6 fibrils strongly promotes amyloid fibril formation of WT βM and its six truncated variants, including at more physiological pH 6.2. Collectively, these results demonstrated that the residues 4 to 6 at the N-terminus particularly modulate amyloid fibril propagation of βM and the interactions of WT βM with N-terminally truncated variants, potentially indicating the direct relevance to the involvement of the protein's aggregation in dialysis-related amyloidosis.
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Affiliation(s)
- Haibin Dang
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China
| | - Zhixian Chen
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China
| | - Wang Chen
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China
| | - Xudong Luo
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China
| | | | - Liqiang Wang
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China
| | - Jie Chen
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China
| | | | | | - Yi Liang
- Hubei Key Laboratory of Cell HomeostasisCollege of Life SciencesWuhan UniversityWuhan 430072China2.Wuhan University Shenzhen Research InstituteShenzhen 518057Chinaand 3.School of Civil EngineeringWuhan UniversityWuhan430072China,Correspondence address. Tel: +86-27-68754902; E-mail:
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4
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Loureiro RJS, Faísca PFN. The Early Phase of β2-Microglobulin Aggregation: Perspectives From Molecular Simulations. Front Mol Biosci 2020; 7:578433. [PMID: 33134317 PMCID: PMC7550760 DOI: 10.3389/fmolb.2020.578433] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/08/2020] [Indexed: 11/24/2022] Open
Abstract
Protein β2-microglobulin is the causing agent of two amyloidosis, dialysis related amyloidosis (DRA), affecting the bones and cartilages of individuals with chronic renal failure undergoing long-term hemodialysis, and a systemic amyloidosis, found in one French family, which impairs visceral organs. The protein’s small size and its biomedical significance attracted the attention of theoretical scientists, and there are now several studies addressing its aggregation mechanism in the context of molecular simulations. Here, we review the early phase of β2-microglobulin aggregation, by focusing on the identification and structural characterization of monomers with the ability to trigger aggregation, and initial small oligomers (dimers, tetramers, hexamers etc.) formed in the so-called nucleation phase. We focus our analysis on results from molecular simulations and integrate our views with those coming from in vitro experiments to provide a broader perspective of this interesting field of research. We also outline directions for future computer simulation studies.
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Affiliation(s)
- Rui J S Loureiro
- Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisboa, Lisbon, Portugal
| | - Patrícia F N Faísca
- Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, University of Lisboa, Lisbon, Portugal.,Department of Physics, Faculty of Sciences, University of Lisboa, Lisbon, Portugal
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Garcia AM, Giorgiutti C, El Khoury Y, Bauer V, Spiegelhalter C, Leize-Wagner E, Hellwig P, Potier N, Torbeev V. Aggregation and Amyloidogenicity of the Nuclear Coactivator Binding Domain of CREB-Binding Protein. Chemistry 2020; 26:9889-9899. [PMID: 32364648 DOI: 10.1002/chem.202001847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/30/2020] [Indexed: 12/28/2022]
Abstract
The nuclear coactivator binding domain (NCBD) of transcriptional co-regulator CREB-binding protein (CBP) is an example of conformationally malleable proteins that can bind to structurally unrelated protein targets and adopt distinct folds in the respective protein complexes. Here, we show that the folding landscape of NCBD contains an alternative pathway that results in protein aggregation and self-assembly into amyloid fibers. The initial steps of such protein misfolding are driven by intermolecular interactions of its N-terminal α-helix bringing multiple NCBD molecules into contact. These oligomers then undergo slow but progressive interconversion into β-sheet-containing aggregates. To reveal the concealed aggregation potential of NCBD we used a chemically synthesized mirror-image d-NCBD form. The addition of d-NCBD promoted self-assembly into amyloid precipitates presumably due to formation of thermodynamically more stable racemic β-sheet structures. The unexpected aggregation of NCBD needs to be taken into consideration given the multitude of protein-protein interactions and resulting biological functions mediated by CBP.
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Affiliation(s)
- Ana Maria Garcia
- ISIS (Institut de Science et d'Ingénierie Supramoléculaires) and, icFRC (International Center for Frontier Research in Chemistry), University of Strasbourg, CNRS-UMR 7006, 8 allée Gaspard Monge, 67083, Strasbourg, France
| | - Christophe Giorgiutti
- Laboratory of Mass-Spectrometry of Interactions and Systems, University of Strasbourg, CNRS-UMR 7140, 1 rue Blaise Pascal, 67070, Strasbourg, France
| | - Youssef El Khoury
- Laboratory of Bioelectrochemistry and Spectroscopy, University of Strasbourg, CNRS-UMR 7140, 1 rue Blaise Pascal, 67070, Strasbourg, France
| | - Valentin Bauer
- ISIS (Institut de Science et d'Ingénierie Supramoléculaires) and, icFRC (International Center for Frontier Research in Chemistry), University of Strasbourg, CNRS-UMR 7006, 8 allée Gaspard Monge, 67083, Strasbourg, France
| | - Coralie Spiegelhalter
- Imaging Center, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM-U964, University of Strasbourg, CNRS-UMR 7104, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Emmanuelle Leize-Wagner
- Laboratory of Mass-Spectrometry of Interactions and Systems, University of Strasbourg, CNRS-UMR 7140, 1 rue Blaise Pascal, 67070, Strasbourg, France
| | - Petra Hellwig
- Laboratory of Bioelectrochemistry and Spectroscopy, University of Strasbourg, CNRS-UMR 7140, 1 rue Blaise Pascal, 67070, Strasbourg, France
- Institute for Advanced Study, USIAS University of Strasbourg, 5 allée du Général Rouvillois, 67083, Strasbourg, France
| | - Noelle Potier
- Laboratory of Mass-Spectrometry of Interactions and Systems, University of Strasbourg, CNRS-UMR 7140, 1 rue Blaise Pascal, 67070, Strasbourg, France
| | - Vladimir Torbeev
- ISIS (Institut de Science et d'Ingénierie Supramoléculaires) and, icFRC (International Center for Frontier Research in Chemistry), University of Strasbourg, CNRS-UMR 7006, 8 allée Gaspard Monge, 67083, Strasbourg, France
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6
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Marcinko TM, Drews T, Liu T, Vachet RW. Epigallocatechin-3-gallate Inhibits Cu(II)-Induced β-2-Microglobulin Amyloid Formation by Binding to the Edge of Its β-Sheets. Biochemistry 2020; 59:1093-1103. [PMID: 32100530 DOI: 10.1021/acs.biochem.0c00043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epigallocatechin-3-gallate (EGCG) is a catechin found in green tea that can inhibit the amyloid formation of a wide variety of proteins. EGCG's ability to prevent or redirect the amyloid formation of so many proteins may reflect a common mechanism of action, and thus, greater molecular-level insight into how it exerts its effect could have broad implications. Here, we investigate the molecular details of EGCG's inhibition of the protein β-2-microglobulin (β2m), which forms amyloids in patients undergoing long-term dialysis treatment. Using size-exclusion chromatography and a collection of mass spectrometry-based techniques, we find that EGCG prevents Cu(II)-induced β2m amyloid formation by diverting the normal progression of preamyloid oligomers toward the formation of spherical, redissolvable aggregates. EGCG exerts its effect by binding with a micromolar affinity (Kd ≈ 5 μM) to the β2m monomer on the edge of two β-sheets near the N-terminus. This interaction destabilizes the preamyloid dimer and prevents the formation of a tetramer species previously shown to be essential for Cu(II)-induced β2m amyloid formation. EGCG's binding at the edge of the β-sheets in β2m is consistent with a previous hypothesis that EGCG generally prevents amyloid formation by binding cross-β-sheet aggregation intermediates.
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Affiliation(s)
- Tyler M Marcinko
- Department of Chemistry, University of Massachusetts-Amherst, 374 Lederle Graduate Research Tower A, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Thomas Drews
- Department of Chemistry, University of Massachusetts-Amherst, 374 Lederle Graduate Research Tower A, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Tianying Liu
- Department of Chemistry, University of Massachusetts-Amherst, 374 Lederle Graduate Research Tower A, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Richard W Vachet
- Department of Chemistry, University of Massachusetts-Amherst, 374 Lederle Graduate Research Tower A, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
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