1
|
Brodmerkel MN, Thiede L, De Santis E, Uetrecht C, Caleman C, Marklund EG. Collision induced unfolding and molecular dynamics simulations of norovirus capsid dimers reveal strain-specific stability profiles. Phys Chem Chem Phys 2024; 26:13094-13105. [PMID: 38628116 DOI: 10.1039/d3cp06344e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Collision induced unfolding (CIU) is a method used with ion mobility mass spectrometry to examine protein structures and their stability. Such experiments yield information about higher order protein structures, yet are unable to provide details about the underlying processes. That information can however be provided using molecular dynamics simulations. Here, we investigate the gas-phase unfolding of norovirus capsid dimers from the Norwalk and Kawasaki strains by employing molecular dynamics simulations over a range of temperatures, representing different levels of activation, together with CIU experiments. The dimers have highly similar structures, but their CIU reveals different stability that can be explained by the different dynamics that arises in response to the activation seen in the simulations, including a part of the sequence with previously observed strain-specific dynamics in solution. Our findings show how similar protein variants can be examined using mass spectrometric techniques in conjunction with atomistic molecular dynamics simulations to reveal differences in stability as well as differences in how and where unfolding takes place upon activation.
Collapse
Affiliation(s)
- Maxim N Brodmerkel
- Department of Chemistry - BMC, Uppsala University, 75123 Uppsala, Sweden.
| | - Lars Thiede
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Leibniz Institute of Virology (LIV), Notkestrasse 85, 22607 Hamburg, Germany
- Institute of Chemistry and Metabolomics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Emiliano De Santis
- Department of Chemistry - BMC, Uppsala University, 75123 Uppsala, Sweden.
- Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
| | - Charlotte Uetrecht
- CSSB Centre for Structural Systems Biology, Deutsches Elektronen-Synchrotron DESY, Leibniz Institute of Virology (LIV), Notkestrasse 85, 22607 Hamburg, Germany
- Institute of Chemistry and Metabolomics, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Carl Caleman
- Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Erik G Marklund
- Department of Chemistry - BMC, Uppsala University, 75123 Uppsala, Sweden.
| |
Collapse
|
2
|
Wollter A, De Santis E, Ekeberg T, Marklund EG, Caleman C. Enhanced EMC-Advantages of partially known orientations in x-ray single particle imaging. J Chem Phys 2024; 160:114108. [PMID: 38506290 DOI: 10.1063/5.0188772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/28/2024] [Indexed: 03/21/2024] Open
Abstract
Single particle imaging of proteins in the gas phase with x-ray free-electron lasers holds great potential to study fast protein dynamics, but is currently limited by weak and noisy data. A further challenge is to discover the proteins' orientation as each protein is randomly oriented when exposed to x-rays. Algorithms such as the expand, maximize, and compress (EMC) exist that can solve the orientation problem and reconstruct the three-dimensional diffraction intensity space, given sufficient measurements. If information about orientation were known, for example, by using an electric field to orient the particles, the reconstruction would benefit and potentially reach better results. We used simulated diffraction experiments to test how the reconstructions from EMC improve with particles' orientation to a preferred axis. Our reconstructions converged to correct maps of the three-dimensional diffraction space with fewer measurements if biased orientation information was considered. Even for a moderate bias, there was still significant improvement. Biased orientations also substantially improved the results in the case of missing central information, in particular in the case of small datasets. The effects were even more significant when adding a background with 50% the strength of the averaged diffraction signal photons to the diffraction patterns, sometimes reducing the data requirement for convergence by a factor of 10. This demonstrates the usefulness of having biased orientation information in single particle imaging experiments, even for a weaker bias than what was previously known. This could be a key component in overcoming the problems with background noise that currently plague these experiments.
Collapse
Affiliation(s)
- August Wollter
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Husargatan 3, 75124 Uppsala, Sweden
| | - Emiliano De Santis
- Department of Chemistry-BMC, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Tomas Ekeberg
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Husargatan 3, 75124 Uppsala, Sweden
| | - Erik G Marklund
- Department of Chemistry-BMC, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Carl Caleman
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, DE-22607 Hamburg, Germany
| |
Collapse
|
3
|
Esser TK, Böhning J, Önür A, Chinthapalli DK, Eriksson L, Grabarics M, Fremdling P, Konijnenberg A, Makarov A, Botman A, Peter C, Benesch JLP, Robinson CV, Gault J, Baker L, Bharat TAM, Rauschenbach S. Cryo-EM of soft-landed β-galactosidase: Gas-phase and native structures are remarkably similar. SCIENCE ADVANCES 2024; 10:eadl4628. [PMID: 38354247 PMCID: PMC10866560 DOI: 10.1126/sciadv.adl4628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/11/2024] [Indexed: 02/16/2024]
Abstract
Native mass spectrometry (MS) has become widely accepted in structural biology, providing information on stoichiometry, interactions, homogeneity, and shape of protein complexes. Yet, the fundamental assumption that proteins inside the mass spectrometer retain a structure faithful to native proteins in solution remains a matter of intense debate. Here, we reveal the gas-phase structure of β-galactosidase using single-particle cryo-electron microscopy (cryo-EM) down to 2.6-Å resolution, enabled by soft landing of mass-selected protein complexes onto cold transmission electron microscopy (TEM) grids followed by in situ ice coating. We find that large parts of the secondary and tertiary structure are retained from the solution. Dehydration-driven subunit reorientation leads to consistent compaction in the gas phase. By providing a direct link between high-resolution imaging and the capability to handle and select protein complexes that behave problematically in conventional sample preparation, the approach has the potential to expand the scope of both native mass spectrometry and cryo-EM.
Collapse
Affiliation(s)
- Tim K. Esser
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
- Thermo Fisher Scientific, 1 Boundary Park, Hemel Hempstead, Hertfordshire HP2 7GE, UK
| | - Jan Böhning
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Alpcan Önür
- Department of Chemistry, University of Konstanz, Konstanz 78457, Germany
| | - Dinesh K. Chinthapalli
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Lukas Eriksson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Marko Grabarics
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Paul Fremdling
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | | | - Alexander Makarov
- Thermo Fisher Scientific, Bremen 28199, Germany
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Aurelien Botman
- Thermo Fisher Scientific, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124, USA
| | - Christine Peter
- Department of Chemistry, University of Konstanz, Konstanz 78457, Germany
| | - Justin L. P. Benesch
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Carol V. Robinson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Joseph Gault
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Lindsay Baker
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Tanmay A. M. Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Stephan Rauschenbach
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| |
Collapse
|
4
|
Moore CC, Staroverov VN, Konermann L. Using Density Functional Theory for Testing the Robustness of Mobile-Proton Molecular Dynamics Simulations on Electrosprayed Ions: Structural Implications for Gaseous Proteins. J Phys Chem B 2023; 127:4061-4071. [PMID: 37116098 DOI: 10.1021/acs.jpcb.3c01581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Current experiments only provide low-resolution information on gaseous protein ions generated by electrospray ionization (ESI). Molecular dynamics (MD) simulations can yield complementary insights. Unfortunately, conventional MD does not capture the mobile nature of protons in gaseous proteins. Mobile-proton MD (MPMD) overcomes this limitation. Earlier MPMD data at 300 K indicated that protein ions generated by "native" ESI retain solution-like structures with a hydrophobic core and zwitterionic exterior [Bakhtiari, M.; Konermann, L. J. Phys. Chem. B 2019, 123, 1784-1796]. MPMD redistributes protons using electrostatic and proton affinity calculations. The robustness of this approach has never been scrutinized. Here, we close this gap by benchmarking MPMD against density functional theory (DFT) at the B3LYP/6-31G* level, which is well suited for predicting proton affinities. The computational cost of DFT necessitated the use of small peptides. The MPMD energetic ranking of proton configurations was found to be consistent with DFT single-point energies, implying that MPMD can reliably identify favorable protonation sites. Peptide MPMD runs converged to DFT-optimized structures only when applying 300-500 K temperature cycling, which was necessary to prevent trapping in local minima. Temperature cycling MPMD was then applied to gaseous protein ions. Native ubiquitin converted to slightly expanded structures with a zwitterionic core and a nonpolar exterior. Our data suggest that such inside-out protein structures are intrinsically preferred in the gas phase, and that they form in ESI experiments after moderate collisional excitation. This is in contrast to native ESI (with minimal collisional excitation, simulated by MPMD at 300 K), where kinetic trapping promotes the survival of solution-like structures. In summary, this work validates the MPMD approach for simulations on gaseous peptides and proteins.
Collapse
Affiliation(s)
- Conrad C Moore
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Viktor N Staroverov
- 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
| |
Collapse
|
5
|
Brodmerkel MN, De Santis E, Caleman C, Marklund EG. Rehydration Post-orientation: Investigating Field-Induced Structural Changes via Computational Rehydration. Protein J 2023:10.1007/s10930-023-10110-y. [PMID: 37031302 DOI: 10.1007/s10930-023-10110-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2023] [Indexed: 04/10/2023]
Abstract
Proteins can be oriented in the gas phase using strong electric fields, which brings advantages for structure determination using X-ray free electron lasers. Both the vacuum conditions and the electric-field exposure risk damaging the protein structures. Here, we employ molecular dynamics simulations to rehydrate and relax vacuum and electric-field exposed proteins in aqueous solution, which simulates a refinement of structure models derived from oriented gas-phase proteins. We find that the impact of the strong electric fields on the protein structures is of minor importance after rehydration, compared to that of vacuum exposure and ionization in electrospraying. The structures did not fully relax back to their native structure in solution on the simulated timescales of 200 ns, but they recover several features, including native-like intra-protein contacts, which suggests that the structures remain in a state from which the fully native structure is accessible. Our findings imply that the electric fields used in native mass spectrometry are well below a destructive level, and suggest that structures inferred from X-ray diffraction from gas-phase proteins are relevant for solution and in vivo conditions, at least after in silico rehydration.
Collapse
Affiliation(s)
- Maxim N Brodmerkel
- Department of Chemistry - BMC, Uppsala University, Box 576, 75123, Uppsala, Sweden
| | - Emiliano De Santis
- Department of Chemistry - BMC, Uppsala University, Box 576, 75123, Uppsala, Sweden
- Department of Physics and Astronomy, Uppsala University, 75120, Uppsala, Sweden
| | - Carl Caleman
- Department of Physics and Astronomy, Uppsala University, 75120, Uppsala, Sweden
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Erik G Marklund
- Department of Chemistry - BMC, Uppsala University, Box 576, 75123, Uppsala, Sweden.
| |
Collapse
|
6
|
Santambrogio C, Ponzini E, Grandori R. Native mass spectrometry for the investigation of protein structural (dis)order. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140828. [PMID: 35926718 DOI: 10.1016/j.bbapap.2022.140828] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/24/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
A central challenge in structural biology is represented by dynamic and heterogeneous systems, as typically represented by proteins in solution, with the extreme case of intrinsically disordered proteins (IDPs) [1-3]. These proteins lack a specific three-dimensional structure and have poorly organized secondary structure. For these reasons, they escape structural characterization by conventional biophysical methods. The investigation of these systems requires description of conformational ensembles, rather than of unique, defined structures or bundles of largely superimposable structures. Mass spectrometry (MS) has become a central tool in this field, offering a variety of complementary approaches to generate structural information on either folded or disordered proteins [4-6]. Two main categories of methods can be recognized. On one side, conformation-dependent reactions (such as cross-linking, covalent labeling, H/D exchange) are exploited to label molecules in solution, followed by the characterization of the labeling products by denaturing MS [7-11]. On the other side, non-denaturing ("native") MS can be used to directly explore the different conformational components in terms of geometry and structural compactness [12-16]. All these approaches have in common the capability to conjugate protein structure investigation with the peculiar analytical power of MS measurements, offering the possibility of assessing species distributions for folding and binding equilibria and the combination of both. These methods can be combined with characterization of noncovalent complexes [17, 18] and post-translational modifications [19-23]. This review focuses on the application of native MS to protein structure and dynamics investigation, with a general methodological section, followed by examples on specific proteins from our laboratory.
Collapse
Affiliation(s)
- Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
| | - Erika Ponzini
- Materials Science Department, University of Milano-Bicocca, Via R. Cozzi 55, 20125 Milan, Italy; COMiB Research Center, University of Milano-Bicocca, Via R. Cozzi 55, 20125 Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
| |
Collapse
|
7
|
Turzo SMBA, Seffernick JT, Rolland AD, Donor MT, Heinze S, Prell JS, Wysocki VH, Lindert S. Protein shape sampled by ion mobility mass spectrometry consistently improves protein structure prediction. Nat Commun 2022; 13:4377. [PMID: 35902583 PMCID: PMC9334640 DOI: 10.1038/s41467-022-32075-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 07/14/2022] [Indexed: 11/09/2022] Open
Abstract
Ion mobility (IM) mass spectrometry provides structural information about protein shape and size in the form of an orientationally-averaged collision cross-section (CCSIM). While IM data have been used with various computational methods, they have not yet been utilized to predict monomeric protein structure from sequence. Here, we show that IM data can significantly improve protein structure determination using the modelling suite Rosetta. We develop the Rosetta Projection Approximation using Rough Circular Shapes (PARCS) algorithm that allows for fast and accurate prediction of CCSIM from structure. Following successful testing of the PARCS algorithm, we use an integrative modelling approach to utilize IM data for protein structure prediction. Additionally, we propose a confidence metric that identifies near native models in the absence of a known structure. The results of this study demonstrate the ability of IM data to consistently improve protein structure prediction. Collision cross sections (CCS) from ion mobility mass spectrometry provide information about protein shape and size. Here, the authors develop an algorithm to predict CCS and integrate experimental ion mobility data into Rosetta-based molecular modelling to predict protein structures from sequence.
Collapse
Affiliation(s)
- S M Bargeen Alam Turzo
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, Ohio State University, Columbus, OH, 43210, USA
| | - Justin T Seffernick
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, Ohio State University, Columbus, OH, 43210, USA
| | - Amber D Rolland
- Department of Chemistry and Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR, 97403, USA
| | - Micah T Donor
- Department of Chemistry and Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR, 97403, USA
| | - Sten Heinze
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, Ohio State University, Columbus, OH, 43210, USA
| | - James S Prell
- Department of Chemistry and Biochemistry and Materials Science Institute, University of Oregon, Eugene, OR, 97403, USA
| | - Vicki H Wysocki
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, Ohio State University, Columbus, OH, 43210, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, Ohio State University, Columbus, OH, 43210, USA.
| |
Collapse
|
8
|
Tomlinson L, Batchelor M, Sarsby J, Byrne DP, Brownridge PJ, Bayliss R, Eyers PA, Eyers CE. Exploring the Conformational Landscape and Stability of Aurora A Using Ion-Mobility Mass Spectrometry and Molecular Modeling. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:420-435. [PMID: 35099954 PMCID: PMC9007459 DOI: 10.1021/jasms.1c00271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/19/2022] [Accepted: 01/19/2022] [Indexed: 05/06/2023]
Abstract
Protein kinase inhibitors are highly effective in treating diseases driven by aberrant kinase signaling and as chemical tools to help dissect the cellular roles of kinase signaling complexes. Evaluating the effects of binding of small molecule inhibitors on kinase conformational dynamics can assist in understanding both inhibition and resistance mechanisms. Using gas-phase ion-mobility mass spectrometry (IM-MS), we characterize changes in the conformational landscape and stability of the protein kinase Aurora A (Aur A) driven by binding of the physiological activator TPX2 or small molecule inhibition. Aided by molecular modeling, we establish three major conformations, the relative abundances of which were dependent on the Aur A activation status: one highly populated compact conformer similar to that observed in most crystal structures, a second highly populated conformer possessing a more open structure infrequently found in crystal structures, and an additional low-abundance conformer not currently represented in the protein databank. Notably, inhibitor binding induces more compact configurations of Aur A, as adopted by the unbound enzyme, with both IM-MS and modeling revealing inhibitor-mediated stabilization of active Aur A.
Collapse
Affiliation(s)
- Lauren
J. Tomlinson
- Centre
for Proteome Research, Department of Biochemistry & Systems Biology,
Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
- Department
of Biochemistry & Systems Biology, Institute of Systems, Molecular
& Integrative Biology, University of
Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
| | - Matthew Batchelor
- Astbury
Centre for Structural Molecular Biology, School of Molecular and Cellular
Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Joscelyn Sarsby
- Centre
for Proteome Research, Department of Biochemistry & Systems Biology,
Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
| | - Dominic P. Byrne
- Department
of Biochemistry & Systems Biology, Institute of Systems, Molecular
& Integrative Biology, University of
Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
| | - Philip J. Brownridge
- Centre
for Proteome Research, Department of Biochemistry & Systems Biology,
Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
| | - Richard Bayliss
- Astbury
Centre for Structural Molecular Biology, School of Molecular and Cellular
Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K.
| | - Patrick A. Eyers
- Department
of Biochemistry & Systems Biology, Institute of Systems, Molecular
& Integrative Biology, University of
Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
| | - Claire E. Eyers
- Centre
for Proteome Research, Department of Biochemistry & Systems Biology,
Institute of Systems, Molecular & Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
- Department
of Biochemistry & Systems Biology, Institute of Systems, Molecular
& Integrative Biology, University of
Liverpool, Crown Street, Liverpool L69 7ZB, U.K.
| |
Collapse
|
9
|
Rolland AD, Biberic LS, Prell JS. Investigation of Charge-State-Dependent Compaction of Protein Ions with Native Ion Mobility-Mass Spectrometry and Theory. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:369-381. [PMID: 35073092 DOI: 10.1021/jasms.1c00351] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The precise relationship between native gas-phase protein ion structure, charge, desolvation, and activation remains elusive. Much evidence supports the Charge Residue Model for native protein ions formed by electrospray ionization, but scaling laws derived from it relate only to overall ion size. Closer examination of drift tube CCSs across individual native protein ion charge state distributions (CSDs) reveals deviations from global trends. To investigate whether this is due to structure variation across CSDs or contributions of long-range charge-dipole interactions, we performed in vacuo force field molecular dynamics (MD) simulations of multiple charge conformers of three proteins representing a variety of physical and structural features: β-lactoglobulin, concanavalin A, and glutamate dehydrogenase. Results from these simulated ions indicate subtle structure variation across their native CSDs, although effects of these structural differences and long-range charge-dependent interactions on CCS are small. The structure and CCS of smaller proteins may be more sensitive to charge due to their low surface-to-volume ratios and reduced capacity to compact. Secondary and higher order structure from condensed-phase structures is largely retained in these simulations, supporting the use of the term "native-like" to describe results from native ion mobility-mass spectrometry experiments, although, notably, the most compact structure can be the most different from the condensed-phase structure. Collapse of surface side chains to self-solvate through formation of new hydrogen bonds is a major feature of gas-phase compaction and likely occurs during the desolvation process. Results from these MD simulations provide new insight into the relationship of gas-phase protein ion structure, charge, and CCS.
Collapse
Affiliation(s)
- Amber D Rolland
- Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403-1253, United States
| | - Lejla S Biberic
- Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403-1253, United States
| | - James S Prell
- Department of Chemistry and Biochemistry, University of Oregon, 1253 University of Oregon, Eugene, Oregon 97403-1253, United States
- Materials Science Institute, University of Oregon, 1252 University of Oregon, Eugene, Oregon 97403-1252, United States
| |
Collapse
|
10
|
Abramsson ML, Sahin C, Hopper JTS, Branca RMM, Danielsson J, Xu M, Chandler SA, Österlund N, Ilag LL, Leppert A, Costeira-Paulo J, Lang L, Teilum K, Laganowsky A, Benesch JLP, Oliveberg M, Robinson CV, Marklund EG, Allison TM, Winther JR, Landreh M. Charge Engineering Reveals the Roles of Ionizable Side Chains in Electrospray Ionization Mass Spectrometry. JACS AU 2021; 1:2385-2393. [PMID: 34977906 PMCID: PMC8717373 DOI: 10.1021/jacsau.1c00458] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Indexed: 05/03/2023]
Abstract
In solution, the charge of a protein is intricately linked to its stability, but electrospray ionization distorts this connection, potentially limiting the ability of native mass spectrometry to inform about protein structure and dynamics. How the behavior of intact proteins in the gas phase depends on the presence and distribution of ionizable surface residues has been difficult to answer because multiple chargeable sites are present in virtually all proteins. Turning to protein engineering, we show that ionizable side chains are completely dispensable for charging under native conditions, but if present, they are preferential protonation sites. The absence of ionizable side chains results in identical charge state distributions under native-like and denaturing conditions, while coexisting conformers can be distinguished using ion mobility separation. An excess of ionizable side chains, on the other hand, effectively modulates protein ion stability. In fact, moving a single ionizable group can dramatically alter the gas-phase conformation of a protein ion. We conclude that although the sum of the charges is governed solely by Coulombic terms, their locations affect the stability of the protein in the gas phase.
Collapse
Affiliation(s)
- Mia L. Abramsson
- Department
of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Tomtebodavägen 23A, 171 65 Stockholm, Sweden
| | - Cagla Sahin
- Department
of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Tomtebodavägen 23A, 171 65 Stockholm, Sweden
- Linderstrøm-Lang
Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen, Denmark
| | - Jonathan T. S. Hopper
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Rui M. M. Branca
- Department
of Oncology-Pathology, Science for Life
Laboratory and Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Jens Danielsson
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Mingming Xu
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Shane A. Chandler
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Nicklas Österlund
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Leopold L. Ilag
- Department
of Material and Environmental Chemistry, Stockholm University, 106 91 Stockholm, Sweden
| | - Axel Leppert
- Department
of Biosciences and Nutrition, Karolinska
Institutet, Neo, 141 83 Huddinge, Sweden
| | - Joana Costeira-Paulo
- Department
of Chemistry−BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Lisa Lang
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Kaare Teilum
- Linderstrøm-Lang
Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen, Denmark
| | - Arthur Laganowsky
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Justin L. P. Benesch
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Mikael Oliveberg
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Carol V. Robinson
- Department
of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Erik G. Marklund
- Department
of Chemistry−BMC, Uppsala University, Box 576, 751 23 Uppsala, Sweden
| | - Timothy M. Allison
- Biomolecular
Interaction Centre, School of Physical and Chemical Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Jakob R. Winther
- Linderstrøm-Lang
Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen, Denmark
| | - Michael Landreh
- Department
of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Tomtebodavägen 23A, 171 65 Stockholm, Sweden
| |
Collapse
|
11
|
Donor MT, Wilson JW, Shepherd SO, Prell JS. Lipid Head Group Adduction to Soluble Proteins Follows Gas-Phase Basicity Predictions: Dissociation Barriers and Charge Abstraction. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2021; 469:116670. [PMID: 34421332 PMCID: PMC8372978 DOI: 10.1016/j.ijms.2021.116670] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Native mass spectrometry analysis of membrane proteins has yielded many useful insights in recent years with respect to membrane protein-lipid interactions, including identifying specific interactions and even measuring binding affinities based on observed abundances of lipid-bound ions after collision-induced dissociation (CID). However, the behavior of non-covalent complexes subjected to extensive CID can in principle be affected by numerous factors related to gas-phase chemistry, including gas-phase basicity (GB) and acidity, shared-proton bonds, and other factors. A recent report from our group showed that common lipids span a wide range of GB values. Notably, phosphatidylcholine (PC) and sphingomyelin lipids are more basic than arginine, suggesting they may strip charge upon dissociation in positive ion mode, while phosphoserine lipids are slightly less basic than arginine and may form especially strong shared-proton bonds. Here, we use CID to probe the strength of non-specific gas-phase interactions between lipid head groups and several soluble proteins, used to deliberately avoid possible physiological protein-lipid interactions. The strengths of the protein-head group interactions follow the trend predicted based solely on lipid and amino acid GBs: phosphoserine (PS) head group forms the strongest bonds with these proteins and out-competes the other head groups studied, while glycerophosphocholine (GPC) head groups form the weakest interactions and dissociate carrying away a positive charge. These results indicate that gas-phase thermochemistry can play an important role in determining which head groups remain bound to protein ions with native-like structures and charge states in positive ion mode upon extensive collisional activation.
Collapse
Affiliation(s)
- Micah T. Donor
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - Jesse W. Wilson
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - Samantha O. Shepherd
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
| | - James S. Prell
- Department of Chemistry and Biochemistry, 1253 University of Oregon, Eugene OR 97403-1253
- Materials Science Institute, University of Oregon, 1252 University of Oregon, Eugene, OR 97403-1252
| |
Collapse
|
12
|
Rinke G, Harnau L, Rauschenbach S. Material and Charge Transport of Large Organic Salt Clusters and Nanoparticles in Electrospray Ion Beam Deposition. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1648-1658. [PMID: 33656859 DOI: 10.1021/jasms.0c00311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Electrospray ion beam deposition (ES-IBD) or ion soft landing has been demonstrated as a technique suitable for processing nonvolatile molecules in vacuum under perfectly controlled conditions, an approach also desirable for the deposition of nanoparticles. Here, we present results from several approaches to generate, characterize, and deposit nanoparticle ion beams in vacuum for deposition. We focus on cluster ion beams generated by ESI of organic salt solutions. Small cluster ions of the salts appear in the mass spectra as defined peaks. In addition, we find nanoparticle-sized aggregates, appearing as a low intensity background at high m/z-ratio, and show by IBD experiments that these clusters carry the major amount of material in the ion beam. This transition from clusters to nanoparticles, and their successful deposition, shows that ES-IBD can in principle handle ion beams of very heavy and highly charged nanoparticles. In related experiments, however, we found the deposition of nanoparticles from dispersions to be of low reproducibility, due to the lack of control by mass spectrometry.
Collapse
Affiliation(s)
- Gordon Rinke
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, DE-70569 Stuttgart, Germany
| | - Ludger Harnau
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, DE-70569 Stuttgart, Germany
| | - Stephan Rauschenbach
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, DE-70569 Stuttgart, Germany
| |
Collapse
|
13
|
Spoel D, Zhang J, Zhang H. Quantitative predictions from molecular simulations using explicit or implicit interactions. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1560] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- David Spoel
- Uppsala Center for Computational Chemistry, Science for Life Laboratory, Department of Cell and Molecular Biology Uppsala University Uppsala Sweden
| | - Jin Zhang
- Department of Chemistry Southern University of Science and Technology Shenzhen China
| | - Haiyang Zhang
- Department of Biological Science and Engineering, School of Chemistry and Biological Engineering University of Science and Technology Beijing Beijing China
| |
Collapse
|
14
|
Caldwell BJ, Norris A, Zakharova E, Smith CE, Wheat CT, Choudhary D, Sotomayor M, Wysocki VH, Bell CE. Oligomeric complexes formed by Redβ single strand annealing protein in its different DNA bound states. Nucleic Acids Res 2021; 49:3441-3460. [PMID: 33693865 PMCID: PMC8034648 DOI: 10.1093/nar/gkab125] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 02/09/2021] [Accepted: 03/02/2021] [Indexed: 02/06/2023] Open
Abstract
Redβ is a single strand annealing protein from bacteriophage λ that binds loosely to ssDNA, not at all to pre-formed dsDNA, but tightly to a duplex intermediate of annealing. As viewed by electron microscopy, Redβ forms oligomeric rings on ssDNA substrate, and helical filaments on the annealed duplex intermediate. However, it is not clear if these are the functional forms of the protein in vivo. We have used size-exclusion chromatography coupled with multi-angle light scattering, analytical ultracentrifugation and native mass spectrometry (nMS) to characterize the size of the oligomers formed by Redβ in its different DNA-bound states. The nMS data, which resolve species with the highest resolution, reveal that Redβ forms an oligomer of 12 subunits in the absence of DNA, complexes ranging from 4 to 14 subunits on 38-mer ssDNA, and a much more distinct and stable complex of 11 subunits on 38-mer annealed duplex. We also measure the concentration of Redβ in cells active for recombination and find it to range from 7 to 27 μM. Collectively, these data provide new insights into the dynamic nature of the complex on ssDNA, and the more stable and defined complex on annealed duplex.
Collapse
Affiliation(s)
- Brian J Caldwell
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew Norris
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Ekaterina Zakharova
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA
| | - Christopher E Smith
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA
| | - Carter T Wheat
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA
| | - Deepanshu Choudhary
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Marcos Sotomayor
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Vicki H Wysocki
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Charles E Bell
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| |
Collapse
|
15
|
Konermann L, Aliyari E, Lee JH. Mobile Protons Limit the Stability of Salt Bridges in the Gas Phase: Implications for the Structures of Electrosprayed Protein Ions. J Phys Chem B 2021; 125:3803-3814. [PMID: 33848419 DOI: 10.1021/acs.jpcb.1c00944] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Electrosprayed protein ions can retain native-like conformations. The intramolecular contacts that stabilize these compact gas-phase structures remain poorly understood. Recent work has uncovered abundant salt bridges in electrosprayed proteins. Salt bridges are zwitterionic BH+/A- contacts. The low dielectric constant in the vacuum strengthens electrostatic interactions, suggesting that salt bridges could be a key contributor to the retention of compact protein structures. A problem with this assertion is that H+ are mobile, such that H+ transfer can convert salt bridges into neutral B0/HA0 contacts. This possible salt bridge annihilation puts into question the role of zwitterionic motifs in the gas phase, and it calls for a detailed analysis of BH+/A- versus B0/HA0 interactions. Here, we investigate this issue using molecular dynamics (MD) simulations and electrospray experiments. MD data for short model peptides revealed that salt bridges with static H+ have dissociation energies around 700 kJ mol-1. The corresponding B0/HA0 contacts are 1 order of magnitude weaker. When considering the effects of mobile H+, BH+/A- bond energies were found to be between these two extremes, confirming that H+ migration can significantly weaken salt bridges. Next, we examined the protein ubiquitin under collision-induced unfolding (CIU) conditions. CIU simulations were conducted using three different MD models: (i) Positive-only runs with static H+ did not allow for salt bridge formation and produced highly expanded CIU structures. (ii) Zwitterionic runs with static H+ resulted in abundant salt bridges, culminating in much more compact CIU structures. (iii) Mobile H+ simulations allowed for the dynamic formation/annihilation of salt bridges, generating CIU structures intermediate between scenarios (i) and (ii). Our results uncover that mobile H+ limit the stabilizing effects of salt bridges in the gas phase. Failure to consider the effects of mobile H+ in MD simulations will result in unrealistic outcomes under CIU conditions.
Collapse
Affiliation(s)
- Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Elnaz Aliyari
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Justin H Lee
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| |
Collapse
|
16
|
Bellamy‐Carter J, O'Grady L, Passmore M, Jenner M, Oldham NJ. Decoding Protein Gas‐Phase Stability with Alanine Scanning and Collision‐Induced Unfolding Ion Mobility Mass Spectrometry. ACTA ACUST UNITED AC 2020. [DOI: 10.1002/anse.202000019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Louisa O'Grady
- School of Chemistry University of Nottingham University Park Nottingham NG7 2RD UK
| | - Munro Passmore
- Department of Chemistry University of Warwick Coventry CV4 7AL UK
| | - Matthew Jenner
- Department of Chemistry University of Warwick Coventry CV4 7AL UK
- Warwick Integrative Synthetic Biology Centre University of Warwick Coventry CV4 7AL UK
| | - Neil J. Oldham
- School of Chemistry University of Nottingham University Park Nottingham NG7 2RD UK
| |
Collapse
|
17
|
Kohnke B, Kutzner C, Grubmüller H. A GPU-Accelerated Fast Multipole Method for GROMACS: Performance and Accuracy. J Chem Theory Comput 2020; 16:6938-6949. [PMID: 33084336 PMCID: PMC7660746 DOI: 10.1021/acs.jctc.0c00744] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An important and computationally demanding part of molecular dynamics simulations is the calculation of long-range electrostatic interactions. Today, the prevalent method to compute these interactions is particle mesh Ewald (PME). The PME implementation in the GROMACS molecular dynamics package is extremely fast on individual GPU nodes. However, for large scale multinode parallel simulations, PME becomes the main scaling bottleneck as it requires all-to-all communication between the nodes; as a consequence, the number of exchanged messages scales quadratically with the number of involved nodes in that communication step. To enable efficient and scalable biomolecular simulations on future exascale supercomputers, clearly a method with a better scaling property is required. The fast multipole method (FMM) is such a method. As a first step on the path to exascale, we have implemented a performance-optimized, highly efficient GPU FMM and integrated it into GROMACS as an alternative to PME. For a fair performance comparison between FMM and PME, we first assessed the accuracies of the methods for various sets of input parameters. With parameters yielding similar accuracies for both methods, we determined the performance of GROMACS with FMM and compared it to PME for exemplary benchmark systems. We found that FMM with a multipole order of 8 yields electrostatic forces that are as accurate as PME with standard parameters. Further, for typical mixed-precision simulation settings, FMM does not lead to an increased energy drift with multipole orders of 8 or larger. Whereas an ≈50 000 atom simulation system with our FMM reaches only about a third of the performance with PME, for systems with large dimensions and inhomogeneous particle distribution, e.g., aerosol systems with water droplets floating in a vacuum, FMM substantially outperforms PME already on a single node.
Collapse
Affiliation(s)
- Bartosz Kohnke
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Carsten Kutzner
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Helmut Grubmüller
- Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| |
Collapse
|
18
|
Mandl T, Östlin C, Dawod IE, Brodmerkel MN, Marklund EG, Martin AV, Timneanu N, Caleman C. Structural Heterogeneity in Single Particle Imaging Using X-ray Lasers. J Phys Chem Lett 2020; 11:6077-6083. [PMID: 32578996 PMCID: PMC7416308 DOI: 10.1021/acs.jpclett.0c01144] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 06/17/2020] [Indexed: 05/09/2023]
Abstract
One of the challenges facing single particle imaging with ultrafast X-ray pulses is the structural heterogeneity of the sample to be imaged. For the method to succeed with weakly scattering samples, the diffracted images from a large number of individual proteins need to be averaged. The more the individual proteins differ in structure, the lower the achievable resolution in the final reconstructed image. We use molecular dynamics to simulate two globular proteins in vacuum, fully desolvated as well as with two different solvation layers, at various temperatures. We calculate the diffraction patterns based on the simulations and evaluate the noise in the averaged patterns arising from the structural differences and the surrounding water. Our simulations show that the presence of a minimal water coverage with an average 3 Å thickness will stabilize the protein, reducing the noise associated with structural heterogeneity, whereas additional water will generate more background noise.
Collapse
Affiliation(s)
- Thomas Mandl
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
- University
of Applied Sciences Technikum Wien, Höchstädtplatz 6, A-1200 Wien, Austria
| | - Christofer Östlin
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Ibrahim E. Dawod
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
- European
XFEL GmbH, Holzkoppel
4, DE-22869 Schenefeld, Germany
| | - Maxim N. Brodmerkel
- Department
of Chemistry—BMC, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Erik G. Marklund
- Department
of Chemistry—BMC, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Andrew V. Martin
- School
of Science, RMIT University, Melbourne, Victoria 3000, Australia
- ARC Centre
of Excellence for Advanced Molecular Imaging, Clayton, Victoria 3800, Australia
| | - Nicusor Timneanu
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Carl Caleman
- Department
of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
- Center
for Free-Electron Laser Science, Deutsches
Elektronen-Synchrotron, Notkestraße 85, DE-22607 Hamburg, Germany
| |
Collapse
|
19
|
Allison TM, Barran P, Cianférani S, Degiacomi MT, Gabelica V, Grandori R, Marklund EG, Menneteau T, Migas LG, Politis A, Sharon M, Sobott F, Thalassinos K, Benesch JLP. Computational Strategies and Challenges for Using Native Ion Mobility Mass Spectrometry in Biophysics and Structural Biology. Anal Chem 2020; 92:10872-10880. [DOI: 10.1021/acs.analchem.9b05791] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Timothy M. Allison
- School of Physical and Chemical Sciences, Biomolecular Interaction Centre, University of Canterbury, Christchurch 8140, New Zealand
| | - Perdita Barran
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester M1 7DN, United Kingdom
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), Université de Strasbourg, CNRS, IPHC UMR 7178, 67000 Strasbourg, France
| | - Matteo T. Degiacomi
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, United Kingdom
| | - Valérie Gabelica
- University of Bordeaux, INSERM and CNRS, ARNA Laboratory, IECB site, 2 Rue Robert Escarpit, 33600 Pessac, France
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126, Milan, Italy
| | - Erik G. Marklund
- Department of Chemistry - BMC, Uppsala University, Box 576, 75123, Uppsala, Sweden
| | - Thomas Menneteau
- Division of Biosciences, Institute of Structural and Molecular Biology, University College of London, Gower Street, London WC1E 6BT, United Kingdom
| | - Lukasz G. Migas
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester M1 7DN, United Kingdom
| | - Argyris Politis
- Department of Chemistry, King’s College London, 7 Trinity Street, London SE1 1DB, United Kingdom
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Frank Sobott
- Biomolecular & Analytical Mass Spectrometry, Department of Chemistry, University of Antwerp, 2020 Antwerp, Belgium
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Konstantinos Thalassinos
- Department of Chemistry, King’s College London, 7 Trinity Street, London SE1 1DB, United Kingdom
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, Malet Street, London WC1E 7HX, United Kingdom
| | - Justin L. P. Benesch
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, South Parks Road, Oxford OX1 3TA, United Kingdom
| |
Collapse
|
20
|
Vimer S, Ben-Nissan G, Morgenstern D, Kumar-Deshmukh F, Polkinghorn C, Quintyn RS, Vasil’ev YV, Beckman JS, Elad N, Wysocki VH, Sharon M. Comparative Structural Analysis of 20S Proteasome Ortholog Protein Complexes by Native Mass Spectrometry. ACS CENTRAL SCIENCE 2020; 6:573-588. [PMID: 32342007 PMCID: PMC7181328 DOI: 10.1021/acscentsci.0c00080] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Indexed: 05/06/2023]
Abstract
Ortholog protein complexes are responsible for equivalent functions in different organisms. However, during evolution, each organism adapts to meet its physiological needs and the environmental challenges imposed by its niche. This selection pressure leads to structural diversity in protein complexes, which are often difficult to specify, especially in the absence of high-resolution structures. Here, we describe a multilevel experimental approach based on native mass spectrometry (MS) tools for elucidating the structural preservation and variations among highly related protein complexes. The 20S proteasome, an essential protein degradation machinery, served as our model system, wherein we examined five complexes isolated from different organisms. We show that throughout evolution, from the Thermoplasma acidophilum archaeal prokaryotic complex to the eukaryotic 20S proteasomes in yeast (Saccharomyces cerevisiae) and mammals (rat - Rattus norvegicus, rabbit - Oryctolagus cuniculus and human - HEK293 cells), the proteasome increased both in size and stability. Native MS structural signatures of the rat and rabbit 20S proteasomes, which heretofore lacked high-resolution, three-dimensional structures, highly resembled that of the human complex. Using cryoelectron microscopy single-particle analysis, we were able to obtain a high-resolution structure of the rat 20S proteasome, allowing us to validate the MS-based results. Our study also revealed that the yeast complex, and not those in mammals, was the largest in size and displayed the greatest degree of kinetic stability. Moreover, we also identified a new proteoform of the PSMA7 subunit that resides within the rat and rabbit complexes, which to our knowledge have not been previously described. Altogether, our strategy enables elucidation of the unique structural properties of protein complexes that are highly similar to one another, a framework that is valid not only to ortholog protein complexes, but also for other highly related protein assemblies.
Collapse
Affiliation(s)
- Shay Vimer
- Department
of Biomolecular Sciences, Weizmann Institute
of Science, Rehovot, Israel
| | - Gili Ben-Nissan
- Department
of Biomolecular Sciences, Weizmann Institute
of Science, Rehovot, Israel
| | - David Morgenstern
- Israel
Structural Proteomics Center, Weizmann Institute
of Science, Rehovot, Israel
| | | | - Caley Polkinghorn
- Department
of Biomolecular Sciences, Weizmann Institute
of Science, Rehovot, Israel
| | - Royston S. Quintyn
- Department
of Chemistry and Biochemistry and Resource for Native Mass Spectrometry
Guided Structural Biology, Ohio State University, Columbus, Ohio 43210, United States
| | - Yury V. Vasil’ev
- e-MSion
Inc., 2121 NE Jack London
Drive, Corvallis, Oregon 97330, United States
| | - Joseph S. Beckman
- e-MSion
Inc., 2121 NE Jack London
Drive, Corvallis, Oregon 97330, United States
- Linus
Pauling Institute and the Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Nadav Elad
- Department
of Chemical Research Support, Weizmann Institute
of Science, Rehovot, Israel
| | - Vicki H. Wysocki
- Department
of Chemistry and Biochemistry and Resource for Native Mass Spectrometry
Guided Structural Biology, Ohio State University, Columbus, Ohio 43210, United States
| | - Michal Sharon
- Department
of Biomolecular Sciences, Weizmann Institute
of Science, Rehovot, Israel
| |
Collapse
|
21
|
Sever AIM, Konermann L. Gas Phase Protein Folding Triggered by Proton Stripping Generates Inside-Out Structures: A Molecular Dynamics Simulation Study. J Phys Chem B 2020; 124:3667-3677. [DOI: 10.1021/acs.jpcb.0c01934] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Alexander I. M. Sever
- 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
| |
Collapse
|
22
|
McAlary L, Harrison JA, Aquilina JA, Fitzgerald SP, Kelso C, Benesch JL, Yerbury JJ. Trajectory Taken by Dimeric Cu/Zn Superoxide Dismutase through the Protein Unfolding and Dissociation Landscape Is Modulated by Salt Bridge Formation. Anal Chem 2019; 92:1702-1711. [DOI: 10.1021/acs.analchem.9b01699] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Luke McAlary
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Julian A. Harrison
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - J. Andrew Aquilina
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | | | - Celine Kelso
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Justin L.P. Benesch
- Department of Chemistry, Physical and Theoretical Chemistry Department, University of Oxford, Oxford OX1 3QZ, U.K
| | - Justin J. Yerbury
- Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia
- Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia
| |
Collapse
|
23
|
Rolland AD, Prell JS. Computational Insights into Compaction of Gas-Phase Protein and Protein Complex Ions in Native Ion Mobility-Mass Spectrometry. Trends Analyt Chem 2019; 116:282-291. [PMID: 31983791 PMCID: PMC6979403 DOI: 10.1016/j.trac.2019.04.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Native ion mobility-mass spectrometry (IM-MS) is a rapidly growing field for studying the composition and structure of biomolecules and biomolecular complexes using gas-phase methods. Typically, ions are formed in native IM-MS using gentle nanoelectrospray ionization conditions, which in many cases can preserve condensed-phase stoichiometry. Although much evidence shows that large-scale condensed-phase structure, such as quaternary structure and topology, can also be preserved, it is less clear to what extent smaller-scale structure is preserved in native IM-MS. This review surveys computational and experimental efforts aimed at characterizing compaction and structural rearrangements of protein and protein complex ions upon transfer to the gas phase. A brief summary of gas-phase compaction results from molecular dynamics simulations using multiple common force fields and a wide variety of protein ions is presented and compared to literature IM-MS data.
Collapse
Affiliation(s)
- Amber D. Rolland
- Department of Chemistry and Biochemistry, 1253 University
of Oregon, Eugene, OR, USA, 97403-1253
| | - James S. Prell
- Department of Chemistry and Biochemistry, 1253 University
of Oregon, Eugene, OR, USA, 97403-1253
- Materials Science Institute, 1252 University of Oregon,
Eugene, OR, USA 97403-1252
| |
Collapse
|
24
|
Marklund EG, Benesch JL. Weighing-up protein dynamics: the combination of native mass spectrometry and molecular dynamics simulations. Curr Opin Struct Biol 2019; 54:50-58. [PMID: 30743182 DOI: 10.1016/j.sbi.2018.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/22/2018] [Accepted: 12/27/2018] [Indexed: 12/21/2022]
Abstract
Structural dynamics underpin biological function at the molecular level, yet many biophysical and structural biology approaches give only a static or averaged view of proteins. Native mass spectrometry yields spectra of the many states and interactions in the structural ensemble, but its spatial resolution is limited. Conversely, molecular dynamics simulations are innately high-resolution, but have a limited capacity for exploring all structural possibilities. The two techniques hence differ fundamentally in the information they provide, returning data that reflect different length scales and time scales, making them natural bedfellows. Here we discuss how the combination of native mass spectrometry with molecular dynamics simulations is enabling unprecedented insights into a range of biological questions by interrogating the motions of proteins, their assemblies, and interactions.
Collapse
Affiliation(s)
- Erik G Marklund
- Department of Chemistry - BMC, Uppsala University, Box 576, 75 123, Uppsala, Sweden.
| | - Justin Lp Benesch
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, United Kingdom.
| |
Collapse
|
25
|
Ion Mobility in Structural Biology. ADVANCES IN ION MOBILITY-MASS SPECTROMETRY: FUNDAMENTALS, INSTRUMENTATION AND APPLICATIONS 2019. [DOI: 10.1016/bs.coac.2018.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
26
|
Li H, Nguyen HH, Ogorzalek Loo RR, Campuzano IDG, Loo JA. An integrated native mass spectrometry and top-down proteomics method that connects sequence to structure and function of macromolecular complexes. Nat Chem 2018; 10:139-148. [PMID: 29359744 PMCID: PMC5784781 DOI: 10.1038/nchem.2908] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 11/06/2017] [Indexed: 12/23/2022]
Abstract
Mass spectrometry (MS) has become a crucial technique for the analysis of protein complexes. Native MS has traditionally examined protein subunit arrangements, while proteomics MS has focused on sequence identification. These two techniques are usually performed separately without taking advantage of the synergies between them. Here we describe the development of an integrated native MS and top-down proteomics method using Fourier-transform ion cyclotron resonance (FTICR) to analyse macromolecular protein complexes in a single experiment. We address previous concerns of employing FTICR MS to measure large macromolecular complexes by demonstrating the detection of complexes up to 1.8 MDa, and we demonstrate the efficacy of this technique for direct acquirement of sequence to higher-order structural information with several large complexes. We then summarize the unique functionalities of different activation/dissociation techniques. The platform expands the ability of MS to integrate proteomics and structural biology to provide insights into protein structure, function and regulation.
Collapse
Affiliation(s)
- Huilin Li
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Hong Hanh Nguyen
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
| | - Rachel R Ogorzalek Loo
- Department of Chemistry and Biochemistry, UCLA/DOE Institute of Genomics and Proteomics, and UCLA Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
| | - Iain D G Campuzano
- Discovery Analytical Sciences, Amgen, Thousand Oaks, California 91320, USA
| | - Joseph A Loo
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA.,Department of Chemistry and Biochemistry, UCLA/DOE Institute of Genomics and Proteomics, and UCLA Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
27
|
Montenegro FA, Cantero JR, Barrera NP. Combining Mass Spectrometry and X-Ray Crystallography for Analyzing Native-Like Membrane Protein Lipid Complexes. Front Physiol 2017; 8:892. [PMID: 29170643 PMCID: PMC5684187 DOI: 10.3389/fphys.2017.00892] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/24/2017] [Indexed: 01/22/2023] Open
Abstract
Membrane proteins represent a challenging family of macromolecules, particularly related to the methodology aimed at characterizing their three-dimensional structure. This is mostly due to their amphipathic nature as well as requirements of ligand bindings to stabilize or control their function. Recently, Mass Spectrometry (MS) has become an important tool to identify the overall stoichiometry of native-like membrane proteins complexed to ligand bindings as well as to provide insights into the transport mechanism across the membrane, with complementary information coming from X-ray crystallography. This perspective article emphasizes MS findings coupled with X-ray crystallography in several membrane protein lipid complexes, in particular transporters, ion channels and molecular machines, with an overview of techniques that allows a more thorough structural interpretation of the results, which can help us to unravel hidden mysteries on the membrane protein function.
Collapse
Affiliation(s)
- Felipe A Montenegro
- Laboratory of Nanophysiology and Structural Biology, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jorge R Cantero
- Laboratory of Nanophysiology and Structural Biology, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Nelson P Barrera
- Laboratory of Nanophysiology and Structural Biology, Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
28
|
Bongiorno D, Indelicato S, Ceraulo L, Perricone U, Calabrese V, Almerico AM, Turco Liveri V, Tutone M. Micelles of the chiral biocompatible surfactant (1R,2S)-dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB): molecular dynamics and fragmentation patterns in the gas phase. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1158-1168. [PMID: 28444908 DOI: 10.1002/rcm.7888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 04/07/2017] [Accepted: 04/21/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE The study of self-assembly processes of surfactant molecules in the gas phase is of great interest for several theoretical and technological reasons related to their possible exploitation as drug carriers, protein shields and cleaning agents in the gas phase. METHODS The stability and fragmentation patterns of singly and multiply charged (either positively or negatively) aggregates of the surfactant (1R,2S)-dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethyl ammonium bromide (DMEB) in the gas phase have been studied by ion mobility mass spectrometry and tandem mass spectrometry. Molecular dynamics (MD) simulations of positively and negatively singly and multiply charged DMEB aggregates have been performed to obtain structural and energetics information. Finally, in order to ascertain some clues on the DMEB growth mechanism, quantum mechanics calculations were carried out. RESULTS It has been evidenced that positively and negatively singly charged aggregates at low collision energy decompose preferentially by loss of only one DMEB molecule. Increasing the collision energy, the loss of neutrals becomes increasingly abundant. Multiply charged DMEB aggregates are unstable and decompose forming singly charged monomers or dimers. MD simulations show reverse micelle-like structures with polar heads somewhat segregated into the aggregate interior. Finally, a good correlation between experimental and calculated collisional cross sections (CCS) was found. CONCLUSIONS The fragmentation pathways of DMEB charged species evidenced for singly charged aggregates exhibit features similar to that of other detergent aggregates, but multiply charged aggregates showed a system-specific behavior. QM calculations on the optimized structures (21+ , 31+ , 11- and 21- ) indicate that the most determinant interactions are due to an OH---Br hydrogen bonding that is also involved in the link between monomeric DMEB units. The MD models gave CCS values in good agreement with experimental ones, evidenced by a less strict reverse micelle-like structure and a reasonably spread bromine anion distribution Copyright © 2017 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- David Bongiorno
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| | - Serena Indelicato
- Università degli studi di Palermo, Dipartimento di Scienze della Terra e del Mare, (DISTEM), via Archirafi 26, 90123, Palermo, Italy
| | - Leopoldo Ceraulo
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| | - Ugo Perricone
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| | - Valentina Calabrese
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| | - Anna Maria Almerico
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| | - Vincenzo Turco Liveri
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| | - Marco Tutone
- Università degli studi di Palermo, Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche (STEBICEF), via Archirafi 32, 90123, Palermo, Italy
| |
Collapse
|
29
|
Indelicato S, Bongiorno D, Calabrese V, Perricone U, Almerico AM, Ceraulo L, Piazzese D, Tutone M. Micelles, Rods, Liposomes, and Other Supramolecular Surfactant Aggregates: Computational Approaches. Interdiscip Sci 2017; 9:392-405. [PMID: 28478537 DOI: 10.1007/s12539-017-0234-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/31/2017] [Accepted: 04/24/2017] [Indexed: 12/31/2022]
Abstract
Surfactants are an interesting class of compounds characterized by the segregation of polar and apolar domains in the same molecule. This peculiarity makes possible a whole series of microscopic and macroscopic effects. Among their features, their ability to segregate particles (fluids or entire domains) and to reduce the surface/interfacial tension is the utmost important. The interest in the chemistry of surfactants never weakened; instead, waves of increasing interest have occurred every time a new field of application of these molecules has been discovered. All these special characteristics depend largely on the ability of surfactants to self-assemble and constitute supramolecular structures where their chemical properties are amplified. The possibility to obtain structural and energy information and, above all, the possibility of forecast the self-organizing mechanisms of surfactants have had a significant boost via computational chemistry. The molecular dynamics models, initially coarse-grained and subsequently (with the increasing computer power) using more accurate models, allowed, over the years, to better understand different aspects of the processes of dispersion, self-assembly, segregation of surfactant. Moreover, several other aspects have been investigated as the effect of the counterions of many ionic surfactants in defining the final supramolecular structures, the mobility of side chains, and the capacity of some surfactant to envelope entire proteins. This review constitutes a perspective/prospective view of these results. On the other hand, some comparison of in silico results with experimental information recently acquired through innovative analytical techniques such as ion mobility mass spectrometry which have been introduced.
Collapse
Affiliation(s)
- Serena Indelicato
- Dipartimento di Scienze della Terra e del Mare (DISTEM), Università degli Studi di Palermo, Palermo, Italy
| | - David Bongiorno
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo (STEBICEF), Palermo, Italy
| | - Valentina Calabrese
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo (STEBICEF), Palermo, Italy
| | - Ugo Perricone
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo (STEBICEF), Palermo, Italy
| | - Anna Maria Almerico
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo (STEBICEF), Palermo, Italy
| | - Leopoldo Ceraulo
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo (STEBICEF), Palermo, Italy
| | - Daniela Piazzese
- Dipartimento di Scienze della Terra e del Mare (DISTEM), Università degli Studi di Palermo, Palermo, Italy
| | - Marco Tutone
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Università degli Studi di Palermo (STEBICEF), Palermo, Italy.
| |
Collapse
|
30
|
Schmidt C, Macpherson JA, Lau AM, Tan KW, Fraternali F, Politis A. Surface Accessibility and Dynamics of Macromolecular Assemblies Probed by Covalent Labeling Mass Spectrometry and Integrative Modeling. Anal Chem 2017; 89:1459-1468. [PMID: 28208298 PMCID: PMC5299547 DOI: 10.1021/acs.analchem.6b02875] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 01/04/2017] [Indexed: 12/22/2022]
Abstract
Mass spectrometry (MS) has become an indispensable tool for investigating the architectures and dynamics of macromolecular assemblies. Here we show that covalent labeling of solvent accessible residues followed by their MS-based identification yields modeling restraints that allow mapping the location and orientation of subunits within protein assemblies. Together with complementary restraints derived from cross-linking and native MS, we built native-like models of four heterocomplexes with known subunit structures and compared them with available X-ray crystal structures. The results demonstrated that covalent labeling followed by MS markedly increased the predictive power of the integrative modeling strategy enabling more accurate protein assembly models. We applied this strategy to the F-type ATP synthase from spinach chloroplasts (cATPase) providing a structural basis for its function as a nanomotor. By subjecting the models generated by our restraint-based strategy to molecular dynamics (MD) simulations, we revealed the conformational states of the peripheral stalk and assigned flexible regions in the enzyme. Our strategy can readily incorporate complementary chemical labeling strategies and we anticipate that it will be applicable to many other systems providing new insights into the structure and function of protein complexes.
Collapse
Affiliation(s)
- Carla Schmidt
- Interdisciplinary
Research Center HALOmem, Martin Luther University
Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120 Halle/Saale, Germany
| | - Jamie A. Macpherson
- Division
of Cell & Molecular Biophysics, King’s
College London, New Hunt’s
House, SE1 1UL, London, United Kingdom
| | - Andy M. Lau
- Department
of Chemistry, King’s College London, 7 Trinity Street, SE1 1DB, London, United Kingdom
| | - Ken Wei Tan
- Department
of Chemistry, King’s College London, 7 Trinity Street, SE1 1DB, London, United Kingdom
| | - Franca Fraternali
- Division
of Cell & Molecular Biophysics, King’s
College London, New Hunt’s
House, SE1 1UL, London, United Kingdom
| | - Argyris Politis
- Department
of Chemistry, King’s College London, 7 Trinity Street, SE1 1DB, London, United Kingdom
| |
Collapse
|
31
|
Landreh M, Marklund EG, Uzdavinys P, Degiacomi MT, Coincon M, Gault J, Gupta K, Liko I, Benesch JLP, Drew D, Robinson CV. Integrating mass spectrometry with MD simulations reveals the role of lipids in Na +/H + antiporters. Nat Commun 2017; 8:13993. [PMID: 28071645 PMCID: PMC5234078 DOI: 10.1038/ncomms13993] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 11/18/2016] [Indexed: 12/15/2022] Open
Abstract
Na+/H+ antiporters are found in all kingdoms of life and exhibit catalysis rates that are among the fastest of all known secondary-active transporters. Here we combine ion mobility mass spectrometry and molecular dynamics simulations to study the conformational stability and lipid-binding properties of the Na+/H+ exchanger NapA from Thermus thermophilus and compare this to the prototypical antiporter NhaA from Escherichia coli and the human homologue NHA2. We find that NapA and NHA2, but not NhaA, form stable dimers and do not selectively retain membrane lipids. By comparing wild-type NapA with engineered variants, we show that the unfolding of the protein in the gas phase involves the disruption of inter-domain contacts. Lipids around the domain interface protect the native fold in the gas phase by mediating contacts between the mobile protein segments. We speculate that elevator-type antiporters such as NapA, and likely NHA2, use a subset of annular lipids as structural support to facilitate large-scale conformational changes within the membrane.
Collapse
Affiliation(s)
- Michael Landreh
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| | - Erik G. Marklund
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
- Department of Chemistry–BMC, Uppsala University, Box 576, Uppsala SE-751 23, Sweden
| | - Povilas Uzdavinys
- Centre for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Matteo T. Degiacomi
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| | - Mathieu Coincon
- Centre for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Joseph Gault
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| | - Kallol Gupta
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| | - Idlir Liko
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| | - Justin L. P. Benesch
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| | - David Drew
- Centre for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, Stockholm SE-106 91, Sweden
| | - Carol V. Robinson
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, Oxfordshire OX1 3QZ, UK
| |
Collapse
|
32
|
Natalello A, Santambrogio C, Grandori R. Are Charge-State Distributions a Reliable Tool Describing Molecular Ensembles of Intrinsically Disordered Proteins by Native MS? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:21-28. [PMID: 27730522 DOI: 10.1007/s13361-016-1490-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/13/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Native mass spectrometry (MS) has become a central tool of structural proteomics, but its applicability to the peculiar class of intrinsically disordered proteins (IDPs) is still object of debate. IDPs lack an ordered tridimensional structure and are characterized by high conformational plasticity. Since they represent valuable targets for cancer and neurodegeneration research, there is an urgent need of methodological advances for description of the conformational ensembles populated by these proteins in solution. However, structural rearrangements during electrospray-ionization (ESI) or after the transfer to the gas phase could affect data obtained by native ESI-MS. In particular, charge-state distributions (CSDs) are affected by protein conformation inside ESI droplets, while ion mobility (IM) reflects protein conformation in the gas phase. This review focuses on the available evidence relating IDP solution ensembles with CSDs, trying to summarize cases of apparent consistency or discrepancy. The protein-specificity of ionization patterns and their responses to ligands and buffer conditions suggests that CSDs are imprinted to protein structural features also in the case of IDPs. Nevertheless, it seems that these proteins are more easily affected by electrospray conditions, leading in some cases to rearrangements of the conformational ensembles. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy.
| |
Collapse
|
33
|
Hantke MF, Hasse D, Ekeberg T, John K, Svenda M, Loh D, Martin AV, Timneanu N, Larsson DSD, van der Schot G, Carlsson GH, Ingelman M, Andreasson J, Westphal D, Iwan B, Uetrecht C, Bielecki J, Liang M, Stellato F, DePonte DP, Bari S, Hartmann R, Kimmel N, Kirian RA, Seibert MM, Mühlig K, Schorb S, Ferguson K, Bostedt C, Carron S, Bozek JD, Rolles D, Rudenko A, Foucar L, Epp SW, Chapman HN, Barty A, Andersson I, Hajdu J, Maia FRNC. A data set from flash X-ray imaging of carboxysomes. Sci Data 2016; 3:160061. [PMID: 27479842 DOI: 10.1038/nphoton.2014.270] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/01/2016] [Indexed: 05/26/2023] Open
Abstract
Ultra-intense femtosecond X-ray pulses from X-ray lasers permit structural studies on single particles and biomolecules without crystals. We present a large data set on inherently heterogeneous, polyhedral carboxysome particles. Carboxysomes are cell organelles that vary in size and facilitate up to 40% of Earth's carbon fixation by cyanobacteria and certain proteobacteria. Variation in size hinders crystallization. Carboxysomes appear icosahedral in the electron microscope. A protein shell encapsulates a large number of Rubisco molecules in paracrystalline arrays inside the organelle. We used carboxysomes with a mean diameter of 115±26 nm from Halothiobacillus neapolitanus. A new aerosol sample-injector allowed us to record 70,000 low-noise diffraction patterns in 12 min. Every diffraction pattern is a unique structure measurement and high-throughput imaging allows sampling the space of structural variability. The different structures can be separated and phased directly from the diffraction data and open a way for accurate, high-throughput studies on structures and structural heterogeneity in biology and elsewhere.
Collapse
Affiliation(s)
- Max F Hantke
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Dirk Hasse
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Tomas Ekeberg
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Katja John
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Martin Svenda
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Duane Loh
- Centre for BioImaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Andrew V Martin
- ARC Centre of Excellence for Advanced Molecular Imaging, School of Physics, The University of Melbourne, Victoria 3010, Australia
| | - Nicusor Timneanu
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
- Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, Box 516, Uppsala SE- 751 20, Sweden
| | - Daniel S D Larsson
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Gijs van der Schot
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Gunilla H Carlsson
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Margareta Ingelman
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Jakob Andreasson
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
- ELI beamlines, Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, Prague 18221, Czech Republic
| | - Daniel Westphal
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Bianca Iwan
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Charlotte Uetrecht
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Johan Bielecki
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Mengning Liang
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
| | - Francesco Stellato
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
- I.N.F.N. and Physics Department, University of Rome 'Tor Vergata', Via della Ricerca Scientifica 1, Rome 00133, Italy
| | - Daniel P DePonte
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Sadia Bari
- European XFEL GmbH, Albert-Einstein-Ring 19, Hamburg 22761, Germany
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, Hamburg 22607, Germany
| | | | - Nils Kimmel
- Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, Garching 85741, Germany
| | - Richard A Kirian
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
| | - M Marvin Seibert
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Kerstin Mühlig
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Sebastian Schorb
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Ken Ferguson
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Christoph Bostedt
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Sebastian Carron
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - John D Bozek
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Daniel Rolles
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
- Department of Physics, J.R. Macdonald Laboratory, Kansas State University, Cardwell Hall, Manhattan, Kansas 66506, USA
- Max Planck Institute for Medical Research, Jahnstraße 29, Heidelberg 69120, Germany
- Max Planck Advanced Study Group at the Center for Free-Electron Laser Science (CFEL), Notkestraße 85, Hamburg 22607, Germany
| | - Artem Rudenko
- Department of Physics, J.R. Macdonald Laboratory, Kansas State University, Cardwell Hall, Manhattan, Kansas 66506, USA
- Max Planck Advanced Study Group at the Center for Free-Electron Laser Science (CFEL), Notkestraße 85, Hamburg 22607, Germany
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, Heidelberg 69117, Germany
| | - Lutz Foucar
- Max Planck Institute for Medical Research, Jahnstraße 29, Heidelberg 69120, Germany
- Max Planck Advanced Study Group at the Center for Free-Electron Laser Science (CFEL), Notkestraße 85, Hamburg 22607, Germany
| | - Sascha W Epp
- Max Planck Advanced Study Group at the Center for Free-Electron Laser Science (CFEL), Notkestraße 85, Hamburg 22607, Germany
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, Heidelberg 69117, Germany
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Henry N Chapman
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
| | - Anton Barty
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
| | - Inger Andersson
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
| | - Janos Hajdu
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
- European XFEL GmbH, Albert-Einstein-Ring 19, Hamburg 22761, Germany
| | - Filipe R N C Maia
- Department of Cell and Molecular Biology, Laboratory of Molecular Biophysics, Uppsala University, Husargatan 3 (Box 596), Uppsala SE-751 24, Sweden
- NERSC, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| |
Collapse
|
34
|
Voronina L, Masson A, Kamrath M, Schubert F, Clemmer D, Baldauf C, Rizzo T. Conformations of Prolyl–Peptide Bonds in the Bradykinin 1–5 Fragment in Solution and in the Gas Phase. J Am Chem Soc 2016; 138:9224-33. [DOI: 10.1021/jacs.6b04550] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Liudmila Voronina
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - Antoine Masson
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - Michael Kamrath
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| | - Franziska Schubert
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany
| | - David Clemmer
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Carsten Baldauf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195 Berlin, Germany
| | - Thomas Rizzo
- Laboratoire
de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCPM, Station 6, CH-1015 Lausanne, Switzerland
| |
Collapse
|
35
|
Olivares-Quiroz L. Role of single-point mutations and deletions on transition temperatures in ideal proteinogenic heteropolymer chains in the gas phase. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2016; 45:393-403. [PMID: 26818963 DOI: 10.1007/s00249-015-1108-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 11/18/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
A coarse-grained statistical mechanics-based model for ideal heteropolymer proteinogenic chains of non-interacting residues is presented in terms of the size K of the chain and the set of helical propensities [Formula: see text] associated with each residue j along the chain. For this model, we provide an algorithm to compute the degeneracy tensor [Formula: see text] associated with energy level [Formula: see text] where [Formula: see text] is the number of residues with a native contact in a given conformation. From these results, we calculate the equilibrium partition function [Formula: see text] and characteristic temperature [Formula: see text] at which a transition from a low to a high entropy states is observed. The formalism is applied to analyze the effect on characteristic temperatures [Formula: see text] of single-point mutations and deletions of specific amino acids [Formula: see text] along the chain. Two probe systems are considered. First, we address the case of a random heteropolymer of size K and given helical propensities [Formula: see text] on a conformational phase space. Second, we focus our attention to a particular set of neuropentapeptides, [Met-5] and [Leu-5] enkephalins whose thermodynamic stability is a key feature on their coupling to [Formula: see text] and [Formula: see text] receptors and the triggering of biochemical responses.
Collapse
Affiliation(s)
- L Olivares-Quiroz
- Colegio de Ciencia y Tecnologia and Posgrado en Ciencias de la Complejidad, Universidad Autonoma de la Ciudad de Mexico, Prol Av San Isidro 151, Deleg Iztapalapa, CP 09760, Mexico, DF, Mexico.
| |
Collapse
|
36
|
Bellissent-Funel MC, Hassanali A, Havenith M, Henchman R, Pohl P, Sterpone F, van der Spoel D, Xu Y, Garcia AE. Water Determines the Structure and Dynamics of Proteins. Chem Rev 2016; 116:7673-97. [PMID: 27186992 DOI: 10.1021/acs.chemrev.5b00664] [Citation(s) in RCA: 528] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Water is an essential participant in the stability, structure, dynamics, and function of proteins and other biomolecules. Thermodynamically, changes in the aqueous environment affect the stability of biomolecules. Structurally, water participates chemically in the catalytic function of proteins and nucleic acids and physically in the collapse of the protein chain during folding through hydrophobic collapse and mediates binding through the hydrogen bond in complex formation. Water is a partner that slaves the dynamics of proteins, and water interaction with proteins affect their dynamics. Here we provide a review of the experimental and computational advances over the past decade in understanding the role of water in the dynamics, structure, and function of proteins. We focus on the combination of X-ray and neutron crystallography, NMR, terahertz spectroscopy, mass spectroscopy, thermodynamics, and computer simulations to reveal how water assist proteins in their function. The recent advances in computer simulations and the enhanced sensitivity of experimental tools promise major advances in the understanding of protein dynamics, and water surely will be a protagonist.
Collapse
Affiliation(s)
| | - Ali Hassanali
- International Center for Theoretical Physics, Condensed Matter and Statistical Physics 34151 Trieste, Italy
| | - Martina Havenith
- Ruhr-Universität Bochum , Faculty of Chemistry and Biochemistry Universitätsstraße 150 Building NC 7/72, D-44780 Bochum, Germany
| | - Richard Henchman
- Manchester Institute of Biotechnology The University of Manchester , 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Peter Pohl
- Johannes Kepler University , Gruberstrasse, 40 4020 Linz, Austria
| | - Fabio Sterpone
- Institut de Biologie Physico-Chimique Laboratoire de Biochimie Théorique 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - David van der Spoel
- Department of Cell and Molecular Biology, Computational and Systems Biology, Uppsala University , 751 24 Uppsala, Sweden
| | - Yao Xu
- Ruhr-Universität Bochum , Faculty of Chemistry and Biochemistry Universitätsstraße 150 Building NC 7/72, D-44780 Bochum, Germany
| | - Angel E Garcia
- Center for Non Linear Studies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| |
Collapse
|
37
|
Two-dimensional honeycomb network through sequence-controlled self-assembly of oligopeptides. Nat Commun 2016; 7:10335. [PMID: 26755352 PMCID: PMC4729956 DOI: 10.1038/ncomms10335] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 11/30/2015] [Indexed: 01/06/2023] Open
Abstract
The sequence of a peptide programs its self-assembly and hence the expression of specific properties through non-covalent interactions. A large variety of peptide nanostructures has been designed employing different aspects of these non-covalent interactions, such as dispersive interactions, hydrogen bonding or ionic interactions. Here we demonstrate the sequence-controlled fabrication of molecular nanostructures using peptides as bio-organic building blocks for two-dimensional (2D) self-assembly. Scanning tunnelling microscopy reveals changes from compact or linear assemblies (angiotensin I) to long-range ordered, chiral honeycomb networks (angiotensin II) as a result of removal of steric hindrance by sequence modification. Guided by our observations, molecular dynamic simulations yield atomistic models for the elucidation of interpeptide-binding motifs. This new approach to 2D self-assembly on surfaces grants insight at the atomic level that will enable the use of oligo- and polypeptides as large, multi-functional bio-organic building blocks, and opens a new route towards rationally designed, bio-inspired surfaces. Peptide nanostructures are currently arousing interest thanks to their potential applications in medicine, electronics and coatings. Here, through experiment and theory, the authors demonstrate exquisite control over surface peptide assembly behaviour through manipulation of amino acid sequence.
Collapse
|
38
|
Li J, Santambrogio C, Brocca S, Rossetti G, Carloni P, Grandori R. Conformational effects in protein electrospray-ionization mass spectrometry. MASS SPECTROMETRY REVIEWS 2016; 35:111-22. [PMID: 25952139 DOI: 10.1002/mas.21465] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 01/14/2015] [Indexed: 05/11/2023]
Abstract
Electrospray-ionization mass spectrometry (ESI-MS) is a key tool of structural biology, complementing the information delivered by conventional biochemical and biophysical methods. Yet, the mechanism behind the conformational effects in protein ESI-MS is an object of debate. Two parameters-solvent-accessible surface area (As) and apparent gas-phase basicity (GBapp)-are thought to play a role in controlling the extent of protein ionization during ESI-MS experiments. This review focuses on recent experimental and theoretical investigations concerning the influence of these parameters on ESI-MS results and the structural information that can be derived. The available evidence supports a unified model for the ionization mechanism of folded and unfolded proteins. These data indicate that charge-state distribution (CSD) analysis can provide valuable structural information on normally folded, as well as disordered structures.
Collapse
Affiliation(s)
- Jinyu Li
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University, 52057 Aachen, Germany
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Giulia Rossetti
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Supercomputing Centre, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Paolo Carloni
- Computational Biophysics, German Research School for Simulation Sciences, and Computational Biomedicine, Institute for Advanced Simulation IAS-5 and Institute of Neuroscience and Medicine INM-9, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| |
Collapse
|
39
|
Bongiorno D, Ceraulo L, Indelicato S, Turco Liveri V, Indelicato S. Charged supramolecular assemblies of surfactant molecules in gas phase. MASS SPECTROMETRY REVIEWS 2016; 35:170-187. [PMID: 26113001 DOI: 10.1002/mas.21476] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Indexed: 06/04/2023]
Abstract
The aim of this review is to critically analyze recent literature on charged supramolecular assemblies formed by surfactant molecules in gas phase. Apart our specific interest on this research area, the stimuli to undertake the task arise from the widespread theoretical and applicative benefits emerging from a comprehensive view of this topic. In fact, the study of the formation, stability, and physicochemical peculiarities of non-covalent assemblies of surfactant molecules in gas phase allows to unveil interesting aspects such as the role of attractive, repulsive, and steric intermolecular interactions as driving force of supramolecular organization in absence of interactions with surrounding medium and the size and charge state dependence of aggregate structural and dynamical properties. Other interesting aspects worth to be investigated are joined to the ability of these assemblies to incorporate selected solubilizates molecules as well as to give rise to chemical reactions within a single organized structure. In particular, the incorporation of large molecules such as proteins has been of recent interest with the objective to protect their structure and functionality during the transition from solution to gas phase. Exciting fall-out of the study of gas phase surfactant aggregates includes mass and energy transport in the atmosphere, origin of life and simulation of supramolecular aggregation in the interstellar space. Moreover, supramolecular assemblies of amphiphilic molecules in gas phase could find remarkable applications as atmospheric cleaning agents, nanosolvents and nanoreactors for specialized chemical processes in confined space. Mass spectrometry techniques have proven to be particularly suitable to generate these assemblies and to furnish useful information on their size, size polydispersity, stability, and structural organization. On the other hand molecular dynamics simulations have been very useful to rationalize many experimental findings and to furnish a vivid picture of the structural and dynamic features of these aggregates. Thus, in this review, we will focus on the most important achievements gained in recent years by both these investigative tools.
Collapse
Affiliation(s)
- David Bongiorno
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Via Archirafi 32, I-90123, Palermo, Italy
- Centro Grandi Apparecchiature-UniNetLab, Università degli Studi di Palermo, Via Marini 14, I-90128, Palermo, Italy
| | - Leopoldo Ceraulo
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Via Archirafi 32, I-90123, Palermo, Italy
- Centro Grandi Apparecchiature-UniNetLab, Università degli Studi di Palermo, Via Marini 14, I-90128, Palermo, Italy
| | - Sergio Indelicato
- Core Laboratory of Quality control and Chemical Risk, Policlinico P. Giaccone, Università di Palermo, via del Vespro 129, I-90127, Palermo, Italy
| | - Vincenzo Turco Liveri
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Via Archirafi 32, I-90123, Palermo, Italy
| | - Serena Indelicato
- Dipartimento di Scienze e Tecnologie Biologiche Chimiche Farmaceutiche (STEBICEF), Università degli Studi di Palermo, Via Archirafi 32, I-90123, Palermo, Italy
- Centro Grandi Apparecchiature-UniNetLab, Università degli Studi di Palermo, Via Marini 14, I-90128, Palermo, Italy
| |
Collapse
|
40
|
Sun Y, Vahidi S, Sowole MA, Konermann L. Protein Structural Studies by Traveling Wave Ion Mobility Spectrometry: A Critical Look at Electrospray Sources and Calibration Issues. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:31-40. [PMID: 26369778 DOI: 10.1007/s13361-015-1244-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 07/27/2015] [Accepted: 07/29/2015] [Indexed: 06/05/2023]
Abstract
The question whether electrosprayed protein ions retain solution-like conformations continues to be a matter of debate. One way to address this issue involves comparisons of collision cross sections (Ω) measured by ion mobility spectrometry (IMS) with Ω values calculated for candidate structures. Many investigations in this area employ traveling wave IMS (TWIMS). It is often implied that nanoESI is more conducive for the retention of solution structure than regular ESI. Focusing on ubiquitin, cytochrome c, myoglobin, and hemoglobin, we demonstrate that Ω values and collisional unfolding profiles are virtually indistinguishable under both conditions. These findings suggest that gas-phase structures and ion internal energies are independent of the type of electrospray source. We also note that TWIMS calibration can be challenging because differences in the extent of collisional activation relative to drift tube reference data may lead to ambiguous peak assignments. It is demonstrated that this problem can be circumvented by employing collisionally heated calibrant ions. Overall, our data are consistent with the view that exposure of native proteins to electrospray conditions can generate kinetically trapped ions that retain solution-like structures on the millisecond time scale of TWIMS experiments. ᅟ
Collapse
Affiliation(s)
- Yu Sun
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Siavash Vahidi
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Modupeola A Sowole
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada.
| |
Collapse
|
41
|
McAllister RG, Metwally H, Sun Y, Konermann L. Release of Native-like Gaseous Proteins from Electrospray Droplets via the Charged Residue Mechanism: Insights from Molecular Dynamics Simulations. J Am Chem Soc 2015; 137:12667-76. [DOI: 10.1021/jacs.5b07913] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Robert G. McAllister
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Haidy Metwally
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Yu Sun
- 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
| |
Collapse
|
42
|
Han L, Ruotolo BT. Ion Mobility-Mass Spectrometry Differentiates Protein Quaternary Structures Formed in Solution and in Electrospray Droplets. Anal Chem 2015; 87:6808-13. [PMID: 26075825 DOI: 10.1021/acs.analchem.5b01010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Electrospray ionization coupled to mass spectrometry is a key technology for determining the stoichiometries of multiprotein complexes. Despite highly accurate results for many assemblies, challenging samples can generate signals for artifact protein-protein binding born of the crowding forces present within drying electrospray droplets. Here, for the first time, we study the formation of preferred protein quaternary structures within such rapidly evaporating nanodroplets. We use ion mobility and tandem mass spectrometry to investigate glutamate dehydrogenase dodecamers and serum amyloid P decamers as a function of protein concentration, along with control experiments using carefully chosen protein analogues, to both establish the formation of operative mechanisms and assign the bimodal conformer populations observed. Further, we identify an unprecedented symmetric collision-induced dissociation pathway that we link directly to the quaternary structures of the precursor ions selected.
Collapse
Affiliation(s)
- Linjie Han
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, United States
| |
Collapse
|
43
|
Longhi G, Fornili SL, Turco Liveri V. Structural organization of surfactant aggregates in vacuo: a molecular dynamics and well-tempered metadynamics study. Phys Chem Chem Phys 2015; 17:16512-8. [DOI: 10.1039/c5cp01926e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
MD and well tempered metadynamics indicate that the structural organization of large surfactant aggregates in the gas phase and in the condensed apolar phase are different.
Collapse
Affiliation(s)
- Giovanna Longhi
- Dipartimento di Medicina Molecolare e Traslazionale
- Università di Brescia
- 25123 Brescia
- Italy
- CNISM
| | - Sandro L. Fornili
- Dipartimento di Informatica
- Università di Milano
- 26013 Crema (CR)
- Italy
| | - Vincenzo Turco Liveri
- Dipartimento di Scienze e Tecnologie Biologiche
- Chimiche e Farmaceutiche “STEBICEF”
- Università degli Studi di Palermo
- Viale delle Scienze I
- 90128 Palermo
| |
Collapse
|
44
|
Voronina L, Rizzo TR. Spectroscopic studies of kinetically trapped conformations in the gas phase: the case of triply protonated bradykinin. Phys Chem Chem Phys 2015; 17:25828-36. [DOI: 10.1039/c5cp01651g] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We explore conformational space of triply protonated bradykinin. Three conformational families are mobility-separated and spectroscopically characterized. Kinetically trapped structures are identified via annealing.
Collapse
Affiliation(s)
- Liudmila Voronina
- Laboratoire de Chimie Physique Moléculaire
- École Polytechnique Fédérale de Lausanne
- EPFL SB ISIC LCPM
- CH-1015 Lausanne
- Switzerland
| | - Thomas R. Rizzo
- Laboratoire de Chimie Physique Moléculaire
- École Polytechnique Fédérale de Lausanne
- EPFL SB ISIC LCPM
- CH-1015 Lausanne
- Switzerland
| |
Collapse
|
45
|
Fort KL, Silveira JA, Pierson NA, Servage KA, Clemmer DE, Russell DH. From Solution to the Gas Phase: Factors That Influence Kinetic Trapping of Substance P in the Gas Phase. J Phys Chem B 2014; 118:14336-44. [DOI: 10.1021/jp5103687] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Kyle L. Fort
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Joshua A. Silveira
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Nicholas A. Pierson
- Department
of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Kelly A. Servage
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - David E. Clemmer
- Department
of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - David H. Russell
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| |
Collapse
|
46
|
Rinke G, Rauschenbach S, Harnau L, Albarghash A, Pauly M, Kern K. Active conformation control of unfolded proteins by hyperthermal collision with a metal surface. NANO LETTERS 2014; 14:5609-5615. [PMID: 25198655 DOI: 10.1021/nl502122j] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The physical and chemical properties of macromolecules like proteins are strongly dependent on their conformation. The degrees of freedom of their chemical bonds generate a huge conformational space, of which, however, only a small fraction is accessible in thermal equilibrium. Here we show that soft-landing electrospray ion beam deposition (ES-IBD) of unfolded proteins allows to control their conformation. The dynamics and result of the deposition process can be actively steered by selecting the molecular ion beam's charge state or tuning the incident energy. Using these parameters, protein conformations ranging from fully extended to completely compact can be prepared selectively on a surface, as evidenced on the subnanometer/amino acid resolution level by scanning tunneling microscopy (STM). Supported by molecular dynamics (MD) simulations, our results demonstrate that the final conformation on the surface is reached through a mechanical deformation during the hyperthermal ion surface collision. Our experimental results independently confirm the findings of ion mobility spectrometry (IMS) studies of protein gas phase conformations. Moreover, we establish a new route for the processing of macromolecular materials, with the potential to reach conformations that would be inaccessible otherwise.
Collapse
Affiliation(s)
- Gordon Rinke
- Max-Planck-Institute for Solid State Research , 70569 Stuttgart, Germany
| | | | | | | | | | | |
Collapse
|
47
|
Molecular simulation-based structural prediction of protein complexes in mass spectrometry: the human insulin dimer. PLoS Comput Biol 2014; 10:e1003838. [PMID: 25210764 PMCID: PMC4161290 DOI: 10.1371/journal.pcbi.1003838] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 07/26/2014] [Indexed: 01/02/2023] Open
Abstract
Protein electrospray ionization (ESI) mass spectrometry (MS)-based techniques are widely used to provide insight into structural proteomics under the assumption that non-covalent protein complexes being transferred into the gas phase preserve basically the same intermolecular interactions as in solution. Here we investigate the applicability of this assumption by extending our previous structural prediction protocol for single proteins in ESI-MS to protein complexes. We apply our protocol to the human insulin dimer (hIns2) as a test case. Our calculations reproduce the main charge and the collision cross section (CCS) measured in ESI-MS experiments. Molecular dynamics simulations for 0.075 ms show that the complex maximizes intermolecular non-bonded interactions relative to the structure in water, without affecting the cross section. The overall gas-phase structure of hIns2 does exhibit differences with the one in aqueous solution, not inferable from a comparison with calculated CCS. Hence, care should be exerted when interpreting ESI-MS proteomics data based solely on NMR and/or X-ray structural information.
Collapse
|
48
|
Yue X, Vahidi S, Konermann L. Insights into the mechanism of protein electrospray ionization from salt adduction measurements. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1322-1331. [PMID: 24839193 DOI: 10.1007/s13361-014-0905-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/03/2014] [Indexed: 06/03/2023]
Abstract
The mechanisms whereby protein ions are liberated from charged droplets during electrospray ionization (ESI) remain under investigation. Compact conformers electrosprayed from aqueous solution in positive ion mode likely follow the charged residue model (CRM), which envisions analyte release after solvent evaporation to dryness. The concentration of nonvolatile salts such as NaCl increases sharply within vanishing CRM droplets, promoting nonspecific pairing of Cl(-) and Na(+) with charged groups on the protein surface. For unfolded proteins, it has been proposed that ion formation occurs via the chain ejection model (CEM). During the CEM proteins are expelled from the droplet long before complete solvent evaporation has taken place. Here we examine whether salt adduction levels support the view that folded and unfolded proteins follow different ESI mechanisms. Solvent evaporation during the CEM is expected to be less extensive and, hence, the salt concentration at the point of protein release should be substantially lower than for the CRM. CEM ions should therefore exhibit lower adduction levels than CRM species. We explore the adduction behavior of several proteins that were chosen to allow comparative studies on folded and unfolded structures in the same solution. In-source activation eliminates chloride adducts via HCl release, generating protein ions that are heterogeneously charged because of sodiation and protonation. Sodiation levels measured under such conditions provide estimates of the salt adduction behavior experienced by the "nascent" analyte ions. Sodiation levels are significantly reduced for unfolded proteins, supporting the view that these species are indeed formed via the CEM.
Collapse
Affiliation(s)
- Xuanfeng Yue
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
| | | | | |
Collapse
|
49
|
Li L, Li C, Alexov E. On the Modeling of Polar Component of Solvation Energy using Smooth Gaussian-Based Dielectric Function. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2014; 13. [PMID: 25018579 DOI: 10.1142/s0219633614400021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Traditional implicit methods for modeling electrostatics in biomolecules use a two-dielectric approach: a biomolecule is assigned low dielectric constant while the water phase is considered as a high dielectric constant medium. However, such an approach treats the biomolecule-water interface as a sharp dielectric border between two homogeneous dielectric media and does not account for inhomogeneous dielectric properties of the macromolecule as well. Recently we reported a new development, a smooth Gaussian-based dielectric function which treats the entire system, the solute and the water phase, as inhomogeneous dielectric medium (J Chem Theory Comput. 2013 Apr 9; 9(4): 2126-2136.). Here we examine various aspects of the modeling of polar solvation energy in such inhomogeneous systems in terms of the solute-water boundary and the inhomogeneity of the solute in the absence of water surrounding. The smooth Gaussian-based dielectric function is implemented in the DelPhi finite-difference program, and therefore the sensitivity of the results with respect to the grid parameters is investigated, and it is shown that the calculated polar solvation energy is almost grid independent. Furthermore, the results are compared with the standard two-media model and it is demonstrated that on average, the standard method overestimates the magnitude of the polar solvation energy by a factor 2.5. Lastly, the possibility of the solute to have local dielectric constant larger than of a bulk water is investigated in a benchmarking test against experimentally determined set of pKa's and it is speculated that side chain rearrangements could result in local dielectric constant larger than 80.
Collapse
Affiliation(s)
- Lin Li
- Computational Biophysics and Bioinformatics, Department of Physics, Clemson University, Clemson, SC 29634, USA
| | - Chuan Li
- Computational Biophysics and Bioinformatics, Department of Physics, Clemson University, Clemson, SC 29634, USA
| | - Emil Alexov
- Computational Biophysics and Bioinformatics, Department of Physics, Clemson University, Clemson, SC 29634, USA
| |
Collapse
|
50
|
Twenty years of gas phase structural biology. Structure 2014; 21:1541-50. [PMID: 24010713 DOI: 10.1016/j.str.2013.08.002] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 01/01/2023]
Abstract
Over the past two decades, mass spectrometry (MS) of protein complexes from their native state has made inroads into structural biology. To coincide with the 20(th) anniversary of Structure, and given that it is now approximately 20 years since the first mass spectra of noncovalent protein complexes were reported, it is timely to consider progress of MS as a structural biology tool. Early reports focused on soluble complexes, contributing to ligand binding studies, subunit interaction maps, and topological models. Recent discoveries have enabled delivery of membrane complexes, encapsulated in detergent micelles, prompting new opportunities. By maintaining interactions between membrane and cytoplasmic subunits in the gas phase, it is now possible to investigate the effects of lipids, nucleotides, and drugs on intact membrane assemblies. These investigations reveal allosteric and synergistic effects of small molecule binding and expose the consequences of posttranslational modifications. In this review, we consider recent progress in the study of protein complexes, focusing particularly on complexes extracted from membranes, and outline future prospects for gas phase structural biology.
Collapse
|