1
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Xu T, Wang Q, Wang Q, Sun L. Mass spectrometry-intensive top-down proteomics: an update on technology advancements and biomedical applications. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2024. [PMID: 38973469 DOI: 10.1039/d4ay00651h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Proteoforms are all forms of protein molecules from the same gene because of variations at the DNA, RNA, and protein levels, e.g., alternative splicing and post-translational modifications (PTMs). Delineation of proteins in a proteoform-specific manner is crucial for understanding their biological functions. Mass spectrometry (MS)-intensive top-down proteomics (TDP) is promising for comprehensively characterizing intact proteoforms in complex biological systems. It has achieved substantial progress in technological development, including sample preparation, proteoform separations, MS instrumentation, and bioinformatics tools. In a single TDP study, thousands of proteoforms can be identified and quantified from a cell lysate. It has also been applied to various biomedical research to better our understanding of protein function in regulating cellular processes and to discover novel proteoform biomarkers of diseases for early diagnosis and therapeutic development. This review covers the most recent technological development and biomedical applications of MS-intensive TDP.
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Affiliation(s)
- Tian Xu
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, MI 48824, USA.
| | - Qianjie Wang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, MI 48824, USA.
| | - Qianyi Wang
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, MI 48824, USA.
| | - Liangliang Sun
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, MI 48824, USA.
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2
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Zhu Y, Liu Z, Liu J, Zhao H, Feng R, Shu K, Wang F, Chang C. Panda-UV Unlocks Deeper Protein Characterization with Internal Fragments in Ultraviolet Photodissociation Mass Spectrometry. Anal Chem 2024; 96:8474-8483. [PMID: 38739687 PMCID: PMC11140674 DOI: 10.1021/acs.analchem.4c00253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 05/06/2024] [Accepted: 05/06/2024] [Indexed: 05/16/2024]
Abstract
Ultraviolet photodissociation (UVPD) mass spectrometry unlocks insights into the protein structure and sequence through fragmentation patterns. While N- and C-terminal fragments are traditionally relied upon, this work highlights the critical role of internal fragments in achieving near-complete sequencing of protein. Previous limitations of internal fragment utilization, owing to their abundance and potential for random matching, are addressed here with the development of Panda-UV, a novel software tool combining spectral calibration, and Pearson correlation coefficient scoring for confident fragment assignment. Panda-UV showcases its power through comprehensive benchmarks on three model proteins. The inclusion of internal fragments boosts identified fragment numbers by 26% and enhances average protein sequence coverage to a remarkable 93% for intact proteins, unlocking the hidden region of the largest protein carbonic anhydrase II in model proteins. Notably, an average of 65% of internal fragments can be identified in multiple replicates, demonstrating the high confidence of the fragments Panda-UV provided. Finally, the sequence coverages of mAb subunits can be increased up to 86% and the complementary determining regions (CDRs) are nearly completely sequenced in a single experiment. The source codes of Panda-UV are available at https://github.com/PHOENIXcenter/Panda-UV.
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Affiliation(s)
- Yinlong Zhu
- Chongqing
Key Laboratory on Big Data for Bio Intelligence, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
- State
Key Laboratory of Medical Proteomics, Beijing
Proteome Research Center, National Center for Protein Sciences (Beijing),
Beijing Institute of Lifeomics, Beijing 102206, China
- CAS
Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian
Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China
| | - Zheyi Liu
- CAS
Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian
Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China
- State
Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of
Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Jialiang Liu
- CAS
Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian
Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China
- State
Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of
Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- School of
Pharmacy, China Medical University, Shenyang 110122, China
| | - Heng Zhao
- CAS
Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian
Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China
- State
Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of
Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Rui Feng
- State
Key Laboratory of Medical Proteomics, Beijing
Proteome Research Center, National Center for Protein Sciences (Beijing),
Beijing Institute of Lifeomics, Beijing 102206, China
| | - Kunxian Shu
- Chongqing
Key Laboratory on Big Data for Bio Intelligence, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Fangjun Wang
- CAS
Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian
Institute of Chemical Physics, Chinese Academy
of Sciences, Dalian 116023, China
- State
Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of
Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Cheng Chang
- State
Key Laboratory of Medical Proteomics, Beijing
Proteome Research Center, National Center for Protein Sciences (Beijing),
Beijing Institute of Lifeomics, Beijing 102206, China
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3
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Wei B, Lantz C, Loo RRO, Campuzano IDG, Loo JA. Internal Fragments Enhance Middle-Down Mass Spectrometry Structural Characterization of Monoclonal Antibodies and Antibody-Drug Conjugates. Anal Chem 2024; 96:2491-2499. [PMID: 38294207 PMCID: PMC11001303 DOI: 10.1021/acs.analchem.3c04526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) are important large biotherapeutics (∼150 kDa) and high structural complexity that require extensive sequence and structure characterization. Middle-down mass spectrometry (MD-MS) is an emerging technique that sequences and maps subunits larger than those released by trypsinolysis. It avoids potentially introducing artifactual modifications that may occur in bottom-up MS while achieving higher sequence coverage compared to top-down MS. However, returning complete sequence information by MD-MS is still challenging. Here, we show that assigning internal fragments in direct infusion MD-MS of a mAb and an ADC substantially improves their structural characterization. For MD-MS of the reduced NIST mAb, including internal fragments recovers nearly 100% of the sequence by accessing the middle sequence region that is inaccessible by terminal fragments. The identification of important glycosylations can also be improved after the inclusion of internal fragments. For the reduced lysine-linked IgG1-DM1 ADC, we show that considering internal fragments increases the DM1 conjugation sites coverage to 80%, comparable to the reported 83% coverage achieved by peptide mapping on the same ADC (Luo et al. Anal. Chem. 2016, 88, 695-702). This study expands our work on the application of internal fragment assignments in top-down MS of mAbs and ADCs and can be extended to other heterogeneous therapeutic molecules such as multispecifics and fusion proteins for more widespread applications.
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Affiliation(s)
- Benqian Wei
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, USA
| | - Carter Lantz
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, USA
| | - Rachel R. Ogorzalek Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, USA
- UCLA-DOE Institute, University of California-Los Angeles, Los Angeles, CA, USA
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, CA, USA
| | - Iain D. G. Campuzano
- Center for Research Acceleration by Digital Innovation, Molecular Analytics, Amgen Research, Thousand Oaks, CA, USA
| | - Joseph A. Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, USA
- Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, CA, USA
- UCLA-DOE Institute, University of California-Los Angeles, Los Angeles, CA, USA
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, CA, USA
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4
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Rahman M, Marzullo B, Holman SW, Barrow M, Ray AD, O’Connor PB. Advancing PROTAC Characterization: Structural Insights through Adducts and Multimodal Tandem-MS Strategies. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:285-299. [PMID: 38197777 PMCID: PMC10853971 DOI: 10.1021/jasms.3c00342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/21/2023] [Accepted: 12/25/2023] [Indexed: 01/11/2024]
Abstract
Proteolysis targeting chimeras (PROTACs) are specialized molecules that bind to a target protein and a ubiquitin ligase to facilitate protein degradation. Despite their significance, native PROTACs have not undergone tandem mass spectrometry (MS) analysis. To address this gap, we conducted a pioneering investigation on the fragmentation patterns of two PROTACs in development, dBET1 and VZ185. Employing diverse cations (sodium, lithium, and silver) and multiple tandem-MS techniques, we enhanced their structural characterization. Notably, lithium cations facilitated comprehensive positive-mode coverage for dBET1, while negative polarity mode offered richer insights. Employing de novo structure determination on 2DMS data from degradation studies yielded crucial insights. In the case of VZ185, various charge states were observed, with [M + 2H]2+ revealing fewer moieties than [M + H]+ due to charge-related factors. Augmenting structural details through silver adducts suggested both charge-directed and charge-remote fragmentation. This comprehensive investigation identifies frequently dissociated bonds across multiple fragmentation techniques, pinpointing optimal approaches for elucidating PROTAC structures. The findings contribute to advancing our understanding of PROTACs, pivotal for their continued development as promising therapeutic agents.
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Affiliation(s)
- Mohammed Rahman
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
- Department
of Physics, University of Warwick, Coventry, CV4 7AL, U.K.
| | - Bryan Marzullo
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
| | - Stephen W. Holman
- Chemical
Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, SK10 4TF, U.K.
| | - Mark Barrow
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
| | - Andrew D. Ray
- New
Modalities and Parenteral Development, Pharmaceutical Technology &
Development, Operations, AstraZeneca, Macclesfield, SK10 4TF, U.K.
| | - Peter B. O’Connor
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
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5
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Beaumal C, Deslignière E, Diemer H, Carapito C, Cianférani S, Hernandez-Alba O. Improved characterization of trastuzumab deruxtecan with PTCR and internal fragments implemented in middle-down MS workflows. Anal Bioanal Chem 2024; 416:519-532. [PMID: 38008785 DOI: 10.1007/s00216-023-05059-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/28/2023]
Abstract
Antibody-drug conjugates (ADCs) are highly complex proteins mainly due to the structural microvariability of the mAb, along with the additional heterogeneity afforded by the bioconjugation process. Top-down (TD) and middle-down (MD) strategies allow the straightforward fragmentation of proteins to elucidate the conjugated amino acid residues. Nevertheless, these spectra are very crowded with multiple overlapping and unassigned ion fragments. Here we report on the use of dedicated software (ClipsMS) and application of proton transfer charge reduction (PTCR), to respectively expand the fragment ion search space to internal fragments and improve the separation of overlapping fragment ions for a more comprehensive characterization of a recently approved ADC, trastuzumab deruxtecan (T-DXd). Subunit fragmentation allowed between 70 and 90% of sequence coverage to be obtained. Upon addition of internal fragment assignment, the three subunits were fully sequenced, although internal fragments did not contribute significantly to the localization of the payloads. Finally, the use of PTCR after subunit fragmentation provided a moderate sequence coverage increase between 2 and 13%. The reaction efficiently decluttered the fragmentation spectra allowing increasing the number of fragment ions characteristic of the conjugation site by 1.5- to 2.5-fold. Altogether, these results show the interest in the implementation of internal fragment ion searches and more particularly the use of PTCR reactions to increase the number of signature ions to elucidate the conjugation sites and enhance the overall sequence coverage of ADCs, making this approach particularly appealing for its implementation in R&D laboratories.
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Affiliation(s)
- Corentin Beaumal
- Laboratoire de Spectrométrie de Masse Bio Organique, IPHC UMR 7178, CNRS, Université de Strasbourg, 67087, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Evolène Deslignière
- Laboratoire de Spectrométrie de Masse Bio Organique, IPHC UMR 7178, CNRS, Université de Strasbourg, 67087, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Hélène Diemer
- Laboratoire de Spectrométrie de Masse Bio Organique, IPHC UMR 7178, CNRS, Université de Strasbourg, 67087, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse Bio Organique, IPHC UMR 7178, CNRS, Université de Strasbourg, 67087, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse Bio Organique, IPHC UMR 7178, CNRS, Université de Strasbourg, 67087, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Oscar Hernandez-Alba
- Laboratoire de Spectrométrie de Masse Bio Organique, IPHC UMR 7178, CNRS, Université de Strasbourg, 67087, Strasbourg, France.
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France.
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6
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Kenderdine T, McIntyre W, Yassaghi G, Rollo D, Bunkowski A, Goerlach L, Suckau D, Tremintin G, Greig M, Bell C, Fabris D. Integrating Internal Fragments in the Interpretation of Top-Down Sequencing Data of Larger Oligonucleotides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2296-2307. [PMID: 37729585 DOI: 10.1021/jasms.3c00207] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
In the context of direct top-down analysis or concerted bottom-up characterization of nucleic acid samples, the waning yield of terminal fragments as a function of precursor ion size poses a significant challenge to the gas-phase sequencing of progressively larger oligonucleotides. In this report, we examined the behavior of oligoribonucleotide samples ranging from 20 to 364 nt upon collision-induced dissociation (CID). The experimental data showed a progressive shift from terminal to internal fragments as a function of size. The systematic evaluation of experimental factors, such as collision energy, precursor charge, sample temperature, and the presence of chaotropic agents, showed that this trend could be modestly alleviated but not suppressed. This inexorable effect, which has been reported also for other activation techniques, prompted a re-examination of the features that have traditionally discouraged the utilization of internal fragments as a source of sequence information in data interpretation procedures. Our simulations highlighted the ability of internal fragments to produce self-consistent ladders with either end corresponding to each nucleotide in the sequence, which enables both proper alignment and correct recognition of intervening nucleotides. In turn, contiguous ladders display extensive overlaps with one another and with the ladders formed by terminal fragments, which unambiguously constrain their mutual placement within the analyte sequence. The experimental data borne out the predictions by showing ladders with extensive overlaps, which translated into uninterrupted "walks" covering the entire sequence with no gaps from end to end. More significantly, the results showed that combining the information afforded by internal and terminal ladders resulted in much a greater sequence coverage and nucleotide coverage depth than those achievable when either type of information was considered separately. The examination of a series of 58-mer oligonucleotides with high sequence homology showed that the assignment ambiguities engendered by internal fragments did not significantly exceed those afforded by the terminal ones. Therefore, the balance between potential benefits and perils of including the former makes a compelling argument for the development of integrated data interpretation strategies, which are better equipped for dealing with the changing fragmentation patterns obtained from progressively larger oligonucleotides.
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Affiliation(s)
| | - William McIntyre
- University of Connecticut, Storrs, Connecticut 06269, United States
| | | | - Daniele Rollo
- University of Connecticut, Storrs, Connecticut 06269, United States
| | | | | | - Detlev Suckau
- Bruker Daltonics GmbH & Co. KG, 28359 Bremen, Germany
| | | | - Michael Greig
- Bruker Scientific LLC, San Jose, California 95134, United States
| | | | - Daniele Fabris
- University of Connecticut, Storrs, Connecticut 06269, United States
- Ribodynamics LLC, Manchester, Connecticut 06040, United States
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7
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Macias LA, Garcia SP, Back KM, Wu Y, Johnson GH, Kathiresan S, Bellinger AM, Rohde E, Freitas MA, Madsen JA. Spacer Fidelity Assessments of Guide RNA by Top-Down Mass Spectrometry. ACS CENTRAL SCIENCE 2023; 9:1437-1452. [PMID: 37521788 PMCID: PMC10375574 DOI: 10.1021/acscentsci.3c00289] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Indexed: 08/01/2023]
Abstract
The advancement of CRISPR-based gene editing tools into biotherapeutics offers the potential for cures to genetic disorders and for new treatment paradigms for even common diseases. Arguably, the most important component of a CRISPR-based medicine is the guide RNA, which is generally large (>100-mer) synthetic RNA composed of a "tracr" and "spacer" region, the latter of which dictates the on-target editing site as well as potential undesired off-target edits. Aiming to advance contemporary capabilities for gRNA characterization to ensure the spacer region is of high fidelity, top-down mass spectrometry was herein implemented to provide direct and quantitative assessments of highly modified gRNA. In addition to sequencing the spacer region and pinpointing modifications, top-down mass spectra were utilized to quantify single-base spacer substitution impurities down to <1% and to decipher highly dissimilar spacers. To accomplish these results in an automated fashion, we devised custom software capable of sequencing and quantifying impurities in gRNA spacers. Notably, we developed automated tools that enabled the quantification of single-base substitutions, including advanced isotopic pattern matching for C > U and U > C substitutions, and created a de novo sequencing strategy to facilitate the identification and quantification of gRNA impurities with highly dissimilar spacer regions.
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Affiliation(s)
- Luis A. Macias
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - Sara P. Garcia
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - Kayla M. Back
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - Yue Wu
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - G. Hall Johnson
- MassMatrix,
Inc., 600 Teteridge Road, Columbus, Ohio 43214, United States
| | - Sekar Kathiresan
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - Andrew M. Bellinger
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - Ellen Rohde
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
| | - Michael A. Freitas
- MassMatrix,
Inc., 600 Teteridge Road, Columbus, Ohio 43214, United States
- The
Ohio State University, 281 West Lane Avenue, Columbus, Ohio 43210, United States
| | - James A. Madsen
- Verve
Therapeutics, 201 Brookline Avenue, Suite 601, Boston, Massachusetts 02215, United States
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8
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Wei B, Lantz C, Liu W, Viner R, Loo RRO, Campuzano IDG, Loo JA. Added Value of Internal Fragments for Top-Down Mass Spectrometry of Intact Monoclonal Antibodies and Antibody-Drug Conjugates. Anal Chem 2023; 95:9347-9356. [PMID: 37278738 PMCID: PMC10954349 DOI: 10.1021/acs.analchem.3c01426] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Monoclonal antibodies (mAbs) and antibody-drug conjugates (ADCs) are two of the most important therapeutic drug classes that require extensive characterization, whereas their large size and structural complexity make them challenging to characterize and demand the use of advanced analytical methods. Top-down mass spectrometry (TD-MS) is an emerging technique that minimizes sample preparation and preserves endogenous post-translational modifications (PTMs); however, TD-MS of large proteins suffers from low fragmentation efficiency, limiting the sequence and structure information that can be obtained. Here, we show that including the assignment of internal fragments in native TD-MS of an intact mAb and an ADC can improve their molecular characterization. For the NIST mAb, internal fragments can access the sequence region constrained by disulfide bonds to increase the TD-MS sequence coverage to over 75%. Important PTM information, including intrachain disulfide connectivity and N-glycosylation sites, can be revealed after including internal fragments. For a heterogeneous lysine-linked ADC, we show that assigning internal fragments improves the identification of drug conjugation sites to achieve a coverage of 58% of all putative conjugation sites. This proof-of-principle study demonstrates the potential value of including internal fragments in native TD-MS of intact mAbs and ADCs, and this analytical strategy can be extended to bottom-up and middle-down MS approaches to achieve even more comprehensive characterization of important therapeutic molecules.
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Affiliation(s)
- Benqian Wei
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, 90095 USA
| | - Carter Lantz
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, 90095 USA
| | - Weijing Liu
- Thermo Fisher Scientific, San Jose, CA, 95134 USA
| | - Rosa Viner
- Thermo Fisher Scientific, San Jose, CA, 95134 USA
| | - Rachel R. Ogorzalek Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, 90095 USA
- UCLA-DOE Institute, University of California-Los Angeles, Los Angeles, CA, 90095 USA
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, CA, 90095 USA
| | - Iain D. G. Campuzano
- Amgen Research, Center for Research Acceleration and Digital Innovation, Molecular Analytics, Thousand Oaks, CA, 91320 USA
| | - Joseph A. Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles-Los Angeles, CA, 90095 USA
- Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, CA, 90095 USA
- UCLA-DOE Institute, University of California-Los Angeles, Los Angeles, CA, 90095 USA
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, CA, 90095 USA
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9
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Dunham SD, Wei B, Lantz C, Loo JA, Brodbelt JS. Impact of Internal Fragments on Top-Down Analysis of Intact Proteins by 193 nm UVPD. J Proteome Res 2023; 22:170-181. [PMID: 36503236 DOI: 10.1021/acs.jproteome.2c00583] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
193 nm ultraviolet photodissociation (UVPD) allows high sequence coverage to be obtained for intact proteins using terminal fragments alone. However, internal fragments, those that contain neither N- nor C- terminus, are typically ignored, neglecting their potential to bolster characterization of intact proteins. Here, we explore internal fragments generated by 193 nm UVPD for proteins ranging in size from 17-47 kDa and using the ClipsMS algorithm to facilitate searches for internal fragments. Internal fragments were only retained if identified in multiple replicates in order to reduce spurious assignments and to explore the reproducibility of internal fragments generated by UVPD. Inclusion of internal fragment improved sequence coverage by an average of 18% and 32% for UVPD and HCD, respectively, across all proteins and charge states studied. However, only an average of 18% of UVPD internal fragments were identified in two out of three replicates relative to the average number identified across all replicates for all proteins studied. Conversely, for HCD, an average of 63% of internal fragments were retained across replicates. These trends reflect an increased risk of false-positive identifications and a need for caution when considering internal fragments for UVPD. Additionally, proton-transfer charge reduction (PTCR) reactions were performed following UVPD or HCD to assess the impact on internal fragment identifications, allowing up to 20% more fragment ions to be retained across multiple replicates. At this time, it is difficult to recommend the inclusion of the internal fragment when searching UVPD spectra without further work to develop strategies for reducing the possibilities of false-positive identifications. All mass spectra are available in the public repository jPOST with the accession number JPST001885.
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Affiliation(s)
- Sean D Dunham
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Benqian Wei
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Carter Lantz
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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10
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Wei B, Zenaidee MA, Lantz C, Williams BJ, Totten S, Ogorzalek Loo RR, Loo JA. Top-down mass spectrometry and assigning internal fragments for determining disulfide bond positions in proteins. Analyst 2022; 148:26-37. [PMID: 36399030 PMCID: PMC9772244 DOI: 10.1039/d2an01517j] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Disulfide bonds in proteins have a substantial impact on protein structure, stability, and biological activity. Localizing disulfide bonds is critical for understanding protein folding and higher-order structure. Conventional top-down mass spectrometry (TD-MS), where only terminal fragments are assigned for disulfide-intact proteins, can access disulfide information, but suffers from low fragmentation efficiency, thereby limiting sequence coverage. Here, we show that assigning internal fragments generated from TD-MS enhances the sequence coverage of disulfide-intact proteins by 20-60% by returning information from the interior of the protein sequence, which cannot be obtained by terminal fragments alone. The inclusion of internal fragments can extend the sequence information of disulfide-intact proteins to near complete sequence coverage. Importantly, the enhanced sequence information that arise from the assignment of internal fragments can be used to determine the relative position of disulfide bonds and the exact disulfide connectivity between cysteines. The data presented here demonstrates the benefits of incorporating internal fragment analysis into the TD-MS workflow for analyzing disulfide-intact proteins, which would be valuable for characterizing biotherapeutic proteins such as monoclonal antibodies and antibody-drug conjugates.
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Affiliation(s)
- Benqian Wei
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA.
| | - Muhammad A Zenaidee
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA.
- Australian Proteome Analysis Facility, Macquarie University, Macquarie Park, NSW, Australia
| | - Carter Lantz
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA.
| | | | | | - Rachel R Ogorzalek Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA.
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA, USA
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11
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Lantz C, Wei B, Zhao B, Jung W, Goring AK, Le J, Miller J, Loo RRO, Loo JA. Native Top-Down Mass Spectrometry with Collisionally Activated Dissociation Yields Higher-Order Structure Information for Protein Complexes. J Am Chem Soc 2022; 144:21826-21830. [PMID: 36441927 PMCID: PMC10017227 DOI: 10.1021/jacs.2c06726] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Native mass spectrometry (MS) of proteins and protein assemblies reveals size and binding stoichiometry, but elucidating structures to understand their function is more challenging. Native top-down MS (nTDMS), i.e., fragmentation of the gas-phase protein, is conventionally used to derive sequence information, locate post-translational modifications (PTMs), and pinpoint ligand binding sites. nTDMS also endeavors to dissociate covalent bonds in a conformation-sensitive manner, such that information about higher-order structure can be inferred from the fragmentation pattern. However, the activation/dissociation method used can greatly affect the resulting information on protein higher-order structure. Methods such as electron capture/transfer dissociation (ECD and ETD, or ExD) and ultraviolet photodissociation (UVPD) can produce product ions that are sensitive to structural features of protein complexes. For multi-subunit complexes, a long-held belief is that collisionally activated dissociation (CAD) induces unfolding and release of a subunit, and thus is not useful for higher-order structure characterization. Here we show not only that sequence information can be obtained directly from CAD of native protein complexes but that the fragmentation pattern can deliver higher-order structural information about their gas- and solution-phase structures. Moreover, CAD-generated internal fragments (i.e., fragments containing neither N-/C-termini) reveal structural aspects of protein complexes.
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Affiliation(s)
- Carter Lantz
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Benqian Wei
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Boyu Zhao
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Wonhyeuk Jung
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Andrew K Goring
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Jessie Le
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Justin Miller
- Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Rachel R Ogorzalek Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States.,UCLA-DOE Institute, University of California-Los Angeles, Los Angeles, California 90095, United States.,Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States.,Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, California 90095, United States.,UCLA-DOE Institute, University of California-Los Angeles, Los Angeles, California 90095, United States.,Molecular Biology Institute, University of California-Los Angeles, Los Angeles, California 90095, United States
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12
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Brodbelt JS. Deciphering combinatorial post-translational modifications by top-down mass spectrometry. Curr Opin Chem Biol 2022; 70:102180. [PMID: 35779351 PMCID: PMC9489649 DOI: 10.1016/j.cbpa.2022.102180] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 12/15/2022]
Abstract
Post-translational modifications (PTMs) create vast structural and functional diversity of proteins, ultimately modulating protein function and degradation, influencing cellular signaling, and regulating transcription. The combinatorial patterns of PTMs increase the heterogeneity of proteins and further mediates their interactions. Advances in mass spectrometry-based proteomics have resulted in identification of thousands of proteins and allowed characterization of numerous types and sites of PTMs. Examination of intact proteins, termed the top-down approach, offers the potential to map protein sequences and localize multiple PTMs on each protein, providing the most comprehensive cataloging of proteoforms. This review describes some of the dividends of using mass spectrometry to analyze intact proteins and showcases innovative strategies that have enhanced the promise of top-down proteomics for exploring the impact of combinatorial PTMs in unsurpassed detail.
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Affiliation(s)
- Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
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13
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Dafun AS, Marcoux J. Structural mass spectrometry of membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140813. [PMID: 35750312 DOI: 10.1016/j.bbapap.2022.140813] [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: 04/06/2021] [Revised: 06/10/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
The analysis of proteins and protein complexes by mass spectrometry (MS) has come a long way since the invention of electrospray ionization (ESI) in the mid 80s. Originally used to characterize small soluble polypeptide chains, MS has progressively evolved over the past 3 decades towards the analysis of samples of ever increasing heterogeneity and complexity, while the instruments have become more and more sensitive and resolutive. The proofs of concepts and first examples of most structural MS methods appeared in the early 90s. However, their application to membrane proteins, key targets in the biopharma industry, is more recent. Nowadays, a wealth of information can be gathered from such MS-based methods, on all aspects of membrane protein structure: sequencing (and more precisely proteoform characterization), but also stoichiometry, non-covalent ligand binding (metals, drug, lipids, carbohydrates), conformations, dynamics and distance restraints for modelling. In this review, we present the concept and some historical and more recent applications on membrane proteins, for the major structural MS methods.
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Affiliation(s)
- Angelique Sanchez Dafun
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Julien Marcoux
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France.
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14
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Yang M, Hu H, Su P, Thomas PM, Camarillo JM, Greer JB, Early BP, Fellers RT, Kelleher NL, Laskin J. Proteoform-Selective Imaging of Tissues Using Mass Spectrometry. Angew Chem Int Ed Engl 2022; 61:e202200721. [PMID: 35446460 PMCID: PMC9276647 DOI: 10.1002/anie.202200721] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Indexed: 01/28/2023]
Abstract
Unraveling the complexity of biological systems relies on the development of new approaches for spatially resolved proteoform‐specific analysis of the proteome. Herein, we employ nanospray desorption electrospray ionization mass spectrometry imaging (nano‐DESI MSI) for the proteoform‐selective imaging of biological tissues. Nano‐DESI generates multiply charged protein ions, which is advantageous for their structural characterization using tandem mass spectrometry (MS/MS) directly on the tissue. Proof‐of‐concept experiments demonstrate that nano‐DESI MSI combined with on‐tissue top‐down proteomics is ideally suited for the proteoform‐selective imaging of tissue sections. Using rat brain tissue as a model system, we provide the first evidence of differential proteoform expression in different regions of the brain.
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Affiliation(s)
- Manxi Yang
- Department of ChemistryPurdue University560 Oval DriveWest LafayetteIN 47907USA
| | - Hang Hu
- Department of ChemistryPurdue University560 Oval DriveWest LafayetteIN 47907USA
| | - Pei Su
- Department of ChemistryPurdue University560 Oval DriveWest LafayetteIN 47907USA
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Paul M. Thomas
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Jeannie M. Camarillo
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Joseph B. Greer
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Bryan P. Early
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Ryan T. Fellers
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Neil L. Kelleher
- Departments of Chemistry and Molecular BiosciencesNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Julia Laskin
- Department of ChemistryPurdue University560 Oval DriveWest LafayetteIN 47907USA
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15
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Liu R, Xia S, Li H. Native top-down mass spectrometry for higher-order structural characterization of proteins and complexes. MASS SPECTROMETRY REVIEWS 2022:e21793. [PMID: 35757976 DOI: 10.1002/mas.21793] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Progress in structural biology research has led to a high demand for powerful and yet complementary analytical tools for structural characterization of proteins and protein complexes. This demand has significantly increased interest in native mass spectrometry (nMS), particularly native top-down mass spectrometry (nTDMS) in the past decade. This review highlights recent advances in nTDMS for structural research of biological assemblies, with a particular focus on the extra multi-layers of information enabled by TDMS. We include a short introduction of sample preparation and ionization to nMS, tandem fragmentation techniques as well as mass analyzers and software/analysis pipelines used for nTDMS. We highlight unique structural information offered by nTDMS and examples of its broad range of applications in proteins, protein-ligand interactions (metal, cofactor/drug, DNA/RNA, and protein), therapeutic antibodies and antigen-antibody complexes, membrane proteins, macromolecular machineries (ribosome, nucleosome, proteosome, and viruses), to endogenous protein complexes. The challenges, potential, along with perspectives of nTDMS methods for the analysis of proteins and protein assemblies in recombinant and biological samples are discussed.
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Affiliation(s)
- Ruijie Liu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shujun Xia
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Huilin Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
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16
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Yang M, Hu H, Su P, Thomas PM, Camarillo JM, Greer JB, Early BP, Fellers RT, Kelleher NL, Laskin J. Proteoform‐Selective Imaging of Tissues Using Mass Spectrometry. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Manxi Yang
- Purdue University Department of Chemistry chemistry 560 Oval Dr. 47906 West Lafayette UNITED STATES
| | - Hang Hu
- Purdue University Chemistry UNITED STATES
| | - Pei Su
- Northwestern University Chemistry and Molecular Biosciences UNITED STATES
| | - Paul M. Thomas
- Northwestern University Chemistry and Molecular Biosciences UNITED STATES
| | | | - Joseph B. Greer
- Northwestern University Chemistry and Molecular Biosciences UNITED STATES
| | - Bryan P. Early
- Northwestern University Chemistry and Molecular Biosciences UNITED STATES
| | - Ryan T. Fellers
- Northwestern University Chemistry and Molecular Biosciences UNITED STATES
| | - Neil L. Kelleher
- Northwestern University Chemistry and Molecular Biosciences UNITED STATES
| | - Julia Laskin
- Purdue University Department of Chemistry 560 Oval Dr. 47907 West Lafayette UNITED STATES
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17
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Dunham SD, Sanders JD, Holden DD, Brodbelt JS. Improving the Center Section Sequence Coverage of Large Proteins Using Stepped-Fragment Ion Protection Ultraviolet Photodissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:446-456. [PMID: 35119856 DOI: 10.1021/jasms.1c00296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ultraviolet photodissociation (UVPD) mass spectrometry has gained attention in recent years for its ability to provide high sequence coverage of intact proteins. However, secondary dissociation of fragment ions, in which fragment ions subjected to multiple laser pulses decompose into small products, is a common phenomenon during UVPD that contributes to limited coverage in the midsection of protein sequences. To counter secondary dissociation, a method involving the application of notched waveforms to modulate the trajectories of fragment ions away from the laser beam, termed fragment ion protection (FIP), was previously developed to reduce the probability of secondary dissociation. This, in turn, increased the number of identified large fragment ions. In the present study, FIP was applied to UVPD of large proteins ranging in size from 29 to 55 kDa, enhancing the abundances of large fragment ions. A stepped-FIP strategy was implemented in which UVPD mass spectra were collected using multiple different amplitudes of the FIP waveforms and then the results from the mass spectra were combined. By using stepped-FIP, the number of fragment ions in the midsections of the sequences increased for all proteins. For example, whereas no fragment ions were identified in the middle section of the sequence for glutamate dehydrogenase (55 kDa, 55+ charge state), 10 sequence ions were identified by using UVPD-FIP.
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Affiliation(s)
- Sean D Dunham
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - James D Sanders
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Dustin D Holden
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
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18
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Towards understanding the formation of internal fragments generated by collisionally activated dissociation for top-down mass spectrometry. Anal Chim Acta 2022; 1194:339400. [PMID: 35063165 PMCID: PMC9088748 DOI: 10.1016/j.aca.2021.339400] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/30/2021] [Accepted: 12/23/2021] [Indexed: 12/15/2022]
Abstract
Top-down mass spectrometry (TD-MS) generates fragment ions that returns information on the polypeptide amino acid sequence. In addition to terminal fragments, internal fragments that result from multiple cleavage events can also be formed. Traditionally, internal fragments are largely ignored due to a lack of available software to reliably assign them, mainly caused by a poor understanding of their formation mechanism. To accurately assign internal fragments, their formation process needs to be better understood. Here, we applied a statistical method to compare fragmentation patterns of internal and terminal fragments of peptides and proteins generated by collisionally activated dissociation (CAD). Internal fragments share similar fragmentation propensities with terminal fragments (e.g., enhanced cleavages N-terminal to proline and C-terminal to acidic residues), suggesting that their formation follows conventional CAD pathways. Internal fragments should be generated by subsequent cleavages of terminal fragments and their formation can be explained by the well-known mobile proton model. In addition, internal fragments can be coupled with terminal fragments to form complementary product ions that span the entire protein sequence. These enhance our understanding of internal fragment formation and can help improve sequencing algorithms to accurately assign internal fragments, which will ultimately lead to more efficient and comprehensive TD-MS analysis of proteins and proteoforms.
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19
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Rolfs Z, Smith LM. Internal Fragment Ions Disambiguate and Increase Identifications in Top-Down Proteomics. J Proteome Res 2021; 20:5412-5418. [PMID: 34738820 DOI: 10.1021/acs.jproteome.1c00599] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A large fraction of observed fragment ion intensity remains unidentified in top-down proteomics. The elucidation of these unknown fragment ions could enable researchers to identify additional proteoforms and reduce proteoform ambiguity in their analyses. Internal fragment ions have received considerable attention as a major source of these unidentified fragment ions. Internal fragments are product ions that contain neither protein terminus, in contrast with terminal ions that contain a single terminus. There are many more possible internal fragments than terminal fragments, and the resulting computational complexity has historically limited the application of internal fragment ions to low-complexity samples containing only one or a few proteins of interest. We implemented internal fragment ion functionality in MetaMorpheus to allow the proteome-wide annotation of internal fragment ions. MetaMorpheus first uses terminal fragment ions to identify putative proteoforms and then employs internal fragment ions to disambiguate similar proteoforms. In the analysis of mammalian cell lysates, we found that MetaMorpheus could disambiguate over half of its previously ambiguous proteoforms while also providing up to a 7% increase in proteoform-spectrum matches identified at a 1% false discovery rate.
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Affiliation(s)
- Zach Rolfs
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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20
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Macias LA, Sipe SN, Santos IC, Bashyal A, Mehaffey MR, Brodbelt JS. Influence of Primary Structure on Fragmentation of Native-Like Proteins by Ultraviolet Photodissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:2860-2873. [PMID: 34714071 PMCID: PMC8639798 DOI: 10.1021/jasms.1c00269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Analysis of native-like protein structures in the gas phase via native mass spectrometry and auxiliary techniques has become a powerful tool for structural biology applications. In combination with ultraviolet photodissociation (UVPD), native top-down mass spectrometry informs backbone flexibility, topology, hydrogen bonding networks, and conformational changes in protein structure. Although it is known that the primary structure affects dissociation of peptides and proteins in the gas phase, its effect on the types and locations of backbone cleavages promoted by UVPD and concomitant influence on structural characterization of native-like proteins is not well understood. Here, trends in the fragmentation of native-like proteins were evaluated by tracking the propensity of 10 fragment types (a, a+1, b, c, x, x+1, y, y-1, Y, and z) in relation to primary structure in a native-top down UVPD data set encompassing >9600 fragment ions. Differing fragmentation trends are reported for the production of distinct fragment types, attributed to a combination of both direct dissociation pathways from excited electronic states and those surmised to involve intramolecular vibrational energy redistribution after internal conversion. The latter pathways were systematically evaluated to evince the role of proton mobility in the generation of "CID-like" fragments through UVPD, providing pertinent insight into the characterization of native-like proteins. Fragmentation trends presented here are envisioned to enhance analysis of the protein higher-order structure or augment scoring algorithms in the high-throughput analysis of intact proteins.
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Affiliation(s)
- Luis A Macias
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sarah N Sipe
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Inês C Santos
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Aarti Bashyal
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - M Rachel Mehaffey
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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21
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Brown KA, Anderson C, Reilly L, Sondhi K, Ge Y, Eckhardt LL. Proteomic Analysis of the Functional Inward Rectifier Potassium Channel (Kir) 2.1 Reveals Several Novel Phosphorylation Sites. Biochemistry 2021; 60:3292-3301. [PMID: 34676745 DOI: 10.1021/acs.biochem.1c00555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Membrane proteins represent a large family of proteins that perform vital physiological roles and represent key drug targets. Despite their importance, bioanalytical methods aiming to comprehensively characterize the post-translational modification (PTM) of membrane proteins remain challenging compared to other classes of proteins in part because of their inherent low expression and hydrophobicity. The inward rectifier potassium channel (Kir) 2.1, an integral membrane protein, is critical for the maintenance of the resting membrane potential and phase-3 repolarization of the cardiac action potential in the heart. The importance of this channel to cardiac physiology is highlighted by the recognition of several sudden arrhythmic death syndromes, Andersen-Tawil and short QT syndromes, which are associated with loss or gain of function mutations in Kir2.1, often triggered by changes in the β-adrenergic tone. Therefore, understanding the PTMs of this channel (particularly β-adrenergic tone-driven phosphorylation) is important for arrhythmia prevention. Here, we developed a proteomic method, integrating both top-down (intact protein) and bottom-up (after enzymatic digestion) proteomic analyses, to characterize the PTMs of recombinant wild-type and mutant Kir2.1, successfully mapping five novel sites of phosphorylation and confirming a sixth site. Our study provides a framework for future work to assess the role of PTMs in regulating Kir2.1 functions.
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Affiliation(s)
- Kyle A Brown
- Department of Surgery, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.,Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Corey Anderson
- Cellular and Molecular Arrhythmia Research Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Louise Reilly
- Cellular and Molecular Arrhythmia Research Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kunal Sondhi
- Cellular and Molecular Arrhythmia Research Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ying Ge
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.,Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Lee L Eckhardt
- Cellular and Molecular Arrhythmia Research Program, Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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22
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Beckman JS, Voinov VG, Hare M, Sturgeon D, Vasil’ev Y, Oppenheimer D, Shaw JB, Wu S, Glaskin R, Klein C, Schwarzer C, Stafford G. Improved Protein and PTM Characterization with a Practical Electron-Based Fragmentation on Q-TOF Instruments. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:2081-2091. [PMID: 33914527 PMCID: PMC8343505 DOI: 10.1021/jasms.0c00482] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Electron-based dissociation (ExD) produces uncluttered mass spectra of intact proteins while preserving labile post-translational modifications. However, technical challenges have limited this option to only a few high-end mass spectrometers. We have developed an efficient ExD cell that can be retrofitted in less than an hour into current LC/Q-TOF instruments. Supporting software has been developed to acquire, process, and annotate peptide and protein ExD fragmentation spectra. In addition to producing complementary fragmentation, ExD spectra enable many isobaric leucine/isoleucine and isoaspartate/aspartate pairs to be distinguished by side-chain fragmentation. The ExD cell preserves phosphorylation and glycosylation modifications. It also fragments longer peptides more efficiently to reveal signaling cross-talk between multiple post-translational modifications on the same protein chain and cleaves disulfide bonds in cystine knotted proteins and intact antibodies. The ability of the ExD cell to combine collisional activation with electron fragmentation enables more complete sequence coverage by disrupting intramolecular electrostatic interactions that can hold fragments of large peptides and proteins together. These enhanced capabilities made possible by the ExD cell expand the size of peptides and proteins that can be analyzed as well as the analytical certainty of characterizing their post-translational modifications.
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Affiliation(s)
- Joseph S. Beckman
- e-MSion,
Inc, Corvallis, Oregon 97330, United
States
- Department
of Biochemistry and Biophysics, Linus Pauling Institute 2011 ALS, Oregon State University Corvallis, Oregon 97330, United States
| | - Valery G. Voinov
- e-MSion,
Inc, Corvallis, Oregon 97330, United
States
- Department
of Biochemistry and Biophysics, Linus Pauling Institute 2011 ALS, Oregon State University Corvallis, Oregon 97330, United States
| | - Michael Hare
- e-MSion,
Inc, Corvallis, Oregon 97330, United
States
| | | | - Yury Vasil’ev
- e-MSion,
Inc, Corvallis, Oregon 97330, United
States
- Department
of Biochemistry and Biophysics, Linus Pauling Institute 2011 ALS, Oregon State University Corvallis, Oregon 97330, United States
| | | | - Jared B. Shaw
- e-MSion,
Inc, Corvallis, Oregon 97330, United
States
| | - Shuai Wu
- Agilent
Technologies, Inc Santa Clara, California 95051, United States
| | - Rebecca Glaskin
- Agilent
Technologies, Inc Santa Clara, California 95051, United States
| | - Christian Klein
- Agilent
Technologies, Inc Santa Clara, California 95051, United States
| | - Cody Schwarzer
- Agilent
Technologies, Inc Santa Clara, California 95051, United States
| | - George Stafford
- Agilent
Technologies, Inc Santa Clara, California 95051, United States
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23
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Baba T, Ryumin P, Duchoslav E, Chen K, Chelur A, Loyd B, Chernushevich I. Dissociation of Biomolecules by an Intense Low-Energy Electron Beam in a High Sensitivity Time-of-Flight Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1964-1975. [PMID: 34080873 DOI: 10.1021/jasms.0c00425] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We report the progress on an electron-activated dissociation (EAD) device coupled to a quadrupole TOF mass spectrometer (QqTOF MS) developed in our group. This device features a new electron beam optics design allowing up to 100 times stronger electron currents in the reaction cell. The electron beam current reached the space-charge limit of 0.5 μA at near-zero electron kinetic energies. These advances enable fast and efficient dissociation of various analytes ranging from singly charged small molecules to multiply protonated proteins. Tunable electron energy provides access to different fragmentation regimes: ECD, hot ECD, and electron-impact excitation of ions from organics (EIEIO). The efficiency of the device was tested on a wide range of precursor charge states. The EAD device was installed in a QqTOF MS employing a novel trap-and-release strategy facilitating spatial mass focusing of ions at the center of the TOF accelerator. This technique increased the sensitivity 6-10 times and allows for the first time comprehensive structural lipidomics on an LC time scale. The system was evaluated for other compound classes such as intact proteins and glycopeptides. Application of hot ECD for the analysis of glycopeptides resulted in rich fragmentation with predominantly peptide backbone fragments; however, glycan fragments attributed to the ECD process were also observed. A standard small protein ubiquitin (8.6 kDa) was sequenced with 90% cleavage coverage at spectrum accumulation times of 100 ms and 98% at 800 ms. Comparable cleavage coverage for a medium-size protein (carbonic anhydrase: 29 kDa) could be achieved, albeit with longer accumulation times.
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Affiliation(s)
- Takashi Baba
- Sciex, 71 Four Valley Drive Concord, Ontario L4K 4V8, Canada
| | - Pavel Ryumin
- Sciex, 71 Four Valley Drive Concord, Ontario L4K 4V8, Canada
| | - Eva Duchoslav
- Sciex, 71 Four Valley Drive Concord, Ontario L4K 4V8, Canada
| | - Keqin Chen
- Sciex, 71 Four Valley Drive Concord, Ontario L4K 4V8, Canada
| | - Anjali Chelur
- Sciex, 71 Four Valley Drive Concord, Ontario L4K 4V8, Canada
| | - Bill Loyd
- Sciex, 71 Four Valley Drive Concord, Ontario L4K 4V8, Canada
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24
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Zenaidee MA, Wei B, Lantz C, Wu HT, Lambeth TR, Diedrich JK, Loo RRO, Julian RR, Loo JA. Internal Fragments Generated from Different Top-Down Mass Spectrometry Fragmentation Methods Extend Protein Sequence Coverage. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1752-1758. [PMID: 34101447 PMCID: PMC9090460 DOI: 10.1021/jasms.1c00113] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Top-down mass spectrometry (TD-MS) of intact proteins results in fragment ions that can be correlated to the protein primary sequence. Fragments generated can either be terminal fragments that contain the N- or C-terminus or internal fragments that contain neither termini. Traditionally in TD-MS experiments, the generation of internal fragments has been avoided because of ambiguity in assigning these fragments. Here, we demonstrate that in TD-MS experiments internal fragments can be formed and assigned in collision-based, electron-based, and photon-based fragmentation methods and are rich with sequence information, allowing for a greater extent of the primary protein sequence to be explained. For the three test proteins cytochrome c, myoglobin, and carbonic anhydrase II, the inclusion of internal fragments in the analysis resulted in approximately 15-20% more sequence coverage, with no less than 85% sequence coverage obtained. Combining terminal fragment and internal fragment assignments results in near complete protein sequence coverage. Hence, by including both terminal and internal fragment assignments in TD-MS analysis, deep protein sequence analysis, allowing for the localization of modification sites more reliably, can be possible.
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Affiliation(s)
- Muhammad A. Zenaidee
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095
| | - Benqian Wei
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095
| | - Carter Lantz
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095
| | - Hoi Ting Wu
- Department of Chemistry, University of California Riverside, Riverside, CA 92521
| | - Tyler R. Lambeth
- Department of Chemistry, University of California Riverside, Riverside, CA 92521
| | - Jolene K. Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Rachel R. Ogorzalek Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095
| | - Ryan R. Julian
- Department of Chemistry, University of California Riverside, Riverside, CA 92521
| | - Joseph A. Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA 90095
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, CA 90095
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Schachner LF, Tran DP, Lee A, McGee JP, Jooss K, Durbin K, Seckler HDS, Adams L, Cline E, Melani R, Ives AN, Des Soye B, Kelleher NL, Patrie SM. Reassembling protein complexes after controlled disassembly by top-down mass spectrometry in native mode. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2021; 465:116591. [PMID: 34539228 PMCID: PMC8445521 DOI: 10.1016/j.ijms.2021.116591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The combined use of electrospray ionization run in so-called "native mode" with top-down mass spectrometry (nTDMS) is enhancing both structural biology and discovery proteomics by providing three levels of information in a single experiment: the intact mass of a protein or complex, the masses of its subunits and non-covalent cofactors, and fragment ion masses from direct dissociation of subunits that capture the primary sequence and combinations of diverse post-translational modifications (PTMs). While intact mass data are readily deconvoluted using well-known software options, the analysis of fragmentation data that result from a tandem MS experiment - essential for proteoform characterization - is not yet standardized. In this tutorial, we offer a decision-tree for the analysis of nTDMS experiments on protein complexes and diverse bioassemblies. We include an overview of strategies to navigate this type of analysis, provide example data sets, and highlight software for the hypothesis-driven interrogation of fragment ions for localization of PTMs, metals, and cofactors on native proteoforms. Throughout we have emphasized the key features (deconvolution, search mode, validation, other) that the reader can consider when deciding upon their specific experimental and data processing design using both open-access and commercial software.
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Affiliation(s)
- Luis F. Schachner
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Denise P. Tran
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Alexander Lee
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - John P. McGee
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Kevin Jooss
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Kenneth Durbin
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Henrique Dos Santos Seckler
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Lauren Adams
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Erika Cline
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Rafael Melani
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Ashley N. Ives
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Benjamin Des Soye
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Neil L. Kelleher
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
| | - Steven M. Patrie
- Departments of Chemistry, Chemical and Biological Engineering, and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, 2170 Tech Dr., Silverman Hall, 60208, Evanston, IL, USA
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26
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Melby JA, Roberts DS, Larson EJ, Brown KA, Bayne EF, Jin S, Ge Y. Novel Strategies to Address the Challenges in Top-Down Proteomics. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1278-1294. [PMID: 33983025 PMCID: PMC8310706 DOI: 10.1021/jasms.1c00099] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Top-down mass spectrometry (MS)-based proteomics is a powerful technology for comprehensively characterizing proteoforms to decipher post-translational modifications (PTMs) together with genetic variations and alternative splicing isoforms toward a proteome-wide understanding of protein functions. In the past decade, top-down proteomics has experienced rapid growth benefiting from groundbreaking technological advances, which have begun to reveal the potential of top-down proteomics for understanding basic biological functions, unraveling disease mechanisms, and discovering new biomarkers. However, many challenges remain to be comprehensively addressed. In this Account & Perspective, we discuss the major challenges currently facing the top-down proteomics field, particularly in protein solubility, proteome dynamic range, proteome complexity, data analysis, proteoform-function relationship, and analytical throughput for precision medicine. We specifically review the major technology developments addressing these challenges with an emphasis on our research group's efforts, including the development of top-down MS-compatible surfactants for protein solubilization, functionalized nanoparticles for the enrichment of low-abundance proteoforms, strategies for multidimensional chromatography separation of proteins, and a new comprehensive user-friendly software package for top-down proteomics. We have also made efforts to connect proteoforms with biological functions and provide our visions on what the future holds for top-down proteomics.
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Affiliation(s)
- Jake A Melby
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - David S Roberts
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Eli J Larson
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Kyle A Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Surgery, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Elizabeth F Bayne
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
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Schmitt ND, Berger JM, Conway JB, Agar JN. Increasing Top-Down Mass Spectrometry Sequence Coverage by an Order of Magnitude through Optimized Internal Fragment Generation and Assignment. Anal Chem 2021; 93:6355-6362. [DOI: 10.1021/acs.analchem.0c04670] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Nicholas D. Schmitt
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
- Barnett Institute for Chemical and Biological Analysis, Northeastern University, Boston, Massachusetts 02115, United States
| | - Joshua M. Berger
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
- Barnett Institute for Chemical and Biological Analysis, Northeastern University, Boston, Massachusetts 02115, United States
| | - Jeremy B. Conway
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
- Barnett Institute for Chemical and Biological Analysis, Northeastern University, Boston, Massachusetts 02115, United States
| | - Jeffrey N. Agar
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts 02115, United States
- Barnett Institute for Chemical and Biological Analysis, Northeastern University, Boston, Massachusetts 02115, United States
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28
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Lantz C, Zenaidee MA, Wei B, Hemminger Z, Ogorzalek Loo RR, Loo JA. ClipsMS: An Algorithm for Analyzing Internal Fragments Resulting from Top-Down Mass Spectrometry. J Proteome Res 2021; 20:1928-1935. [PMID: 33650866 DOI: 10.1021/acs.jproteome.0c00952] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Top-down mass spectrometry (TD-MS) of peptides and proteins results in product ions that can be correlated to polypeptide sequence. Fragments can either be terminal fragments, which contain either the N- or the C-terminus, or internal fragments that contain neither termini. Normally, only terminal fragments are assigned due to the computational difficulties of assigning internal fragments. Here we describe ClipsMS, an algorithm that can assign both terminal and internal fragments generated by top-down MS fragmentation. Further, ClipsMS can be used to locate various modifications on the protein sequence. Using ClipsMS to assign TD-MS generated product ions, we demonstrate that for apo-myoglobin, the inclusion of internal fragments increases the sequence coverage up to 78%. Interestingly, many internal fragments cover complementary regions to the terminal fragments that enhance the information that is extracted from a single top-down mass spectrum. Analysis of oxidized apo-myoglobin using terminal and internal fragment matching by ClipsMS confirmed the locations of oxidation sites on the two methionine residues. Internal fragments can be beneficial for top-down protein fragmentation analysis, and ClipsMS can be a valuable tool for assigning both terminal and internal fragments present in a top-down mass spectrum. Data are available via the MassIVE community resource with the identifiers MSV000086788 and MSV000086789.
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Affiliation(s)
- Carter Lantz
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Muhammad A Zenaidee
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Benqian Wei
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Zachary Hemminger
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Rachel R Ogorzalek Loo
- Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States.,Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095, United States
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29
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Brown KA, Tucholski T, Alpert AJ, Eken C, Wesemann L, Kyrvasilis A, Jin S, Ge Y. Top-Down Proteomics of Endogenous Membrane Proteins Enabled by Cloud Point Enrichment and Multidimensional Liquid Chromatography-Mass Spectrometry. Anal Chem 2020; 92:15726-15735. [PMID: 33231430 PMCID: PMC7968110 DOI: 10.1021/acs.analchem.0c02533] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Although top-down proteomics has emerged as a powerful strategy to characterize proteins in biological systems, the analysis of endogenous membrane proteins remains challenging due to their low solubility, low abundance, and the complexity of the membrane subproteome. Here, we report a simple but effective enrichment and separation strategy for top-down proteomics of endogenous membrane proteins enabled by cloud point extraction and multidimensional liquid chromatography coupled to high-resolution mass spectrometry (MS). The cloud point extraction efficiently enriched membrane proteins using a single extraction, eliminating the need for time-consuming ultracentrifugation steps. Subsequently, size-exclusion chromatography (SEC) with an MS-compatible mobile phase (59% water, 40% isopropanol, 1% formic acid) was used to remove the residual surfactant and fractionate intact proteins (6-115 kDa). The fractions were separated further by reversed-phase liquid chromatography (RPLC) coupled with MS for protein characterization. This method was applied to human embryonic kidney cells and cardiac tissue lysates to enable the identification of 188 and 124 endogenous integral membrane proteins, respectively, some with as many as 19 transmembrane domains.
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Affiliation(s)
- Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Trisha Tucholski
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Andrew J. Alpert
- PolyLC Inc., Columbia, Maryland 21045, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Christian Eken
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Lucas Wesemann
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Andreas Kyrvasilis
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
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30
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Zhou M, Lantz C, Brown KA, Ge Y, Paša-Tolić L, Loo JA, Lermyte F. Higher-order structural characterisation of native proteins and complexes by top-down mass spectrometry. Chem Sci 2020; 11:12918-12936. [PMID: 34094482 PMCID: PMC8163214 DOI: 10.1039/d0sc04392c] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/05/2020] [Indexed: 12/11/2022] Open
Abstract
In biology, it can be argued that if the genome contains the script for a cell's life cycle, then the proteome constitutes an ensemble cast of actors that brings these instructions to life. Their interactions with each other, co-factors, ligands, substrates, and so on, are key to understanding nearly any biological process. Mass spectrometry is well established as the method of choice to determine protein primary structure and location of post-translational modifications. In recent years, top-down fragmentation of intact proteins has been increasingly combined with ionisation of noncovalent assemblies under non-denaturing conditions, i.e., native mass spectrometry. Sequence, post-translational modifications, ligand/metal binding, protein folding, and complex stoichiometry can thus all be probed directly. Here, we review recent developments in this new and exciting field of research. While this work is written primarily from a mass spectrometry perspective, it is targeted to all bioanalytical scientists who are interested in applying these methods to their own biochemistry and chemical biology research.
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Affiliation(s)
- Mowei Zhou
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland WA 99354 USA
| | - Carter Lantz
- Department of Chemistry and Biochemistry, Department of Biological Chemistry, University of California-Los Angeles Los Angeles CA 90095 USA
| | - Kyle A Brown
- Department of Chemistry, University of Wisconsin-Madison Madison WI 53706 USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison Madison WI 53706 USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison Madison WI 53706 USA
| | - Ljiljana Paša-Tolić
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland WA 99354 USA
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, Department of Biological Chemistry, University of California-Los Angeles Los Angeles CA 90095 USA
| | - Frederik Lermyte
- Department of Chemistry, Institute of Chemistry and Biochemistry, Technical University of Darmstadt 64287 Darmstadt Germany
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liège 4000 Liège Belgium
- School of Engineering, University of Warwick Coventry CV4 7AL UK
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31
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Brown KA, Melby JA, Roberts DS, Ge Y. Top-down proteomics: challenges, innovations, and applications in basic and clinical research. Expert Rev Proteomics 2020; 17:719-733. [PMID: 33232185 PMCID: PMC7864889 DOI: 10.1080/14789450.2020.1855982] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022]
Abstract
Introduction- A better understanding of the underlying molecular mechanism of diseases is critical for developing more effective diagnostic tools and therapeutics toward precision medicine. However, many challenges remain to unravel the complex nature of diseases. Areas covered- Changes in protein isoform expression and post-translation modifications (PTMs) have gained recognition for their role in underlying disease mechanisms. Top-down mass spectrometry (MS)-based proteomics is increasingly recognized as an important method for the comprehensive characterization of proteoforms that arise from alternative splicing events and/or PTMs for basic and clinical research. Here, we review the challenges, technological innovations, and recent studies that utilize top-down proteomics to elucidate changes in the proteome with an emphasis on its use to study heart diseases. Expert opinion- Proteoform-resolved information can substantially contribute to the understanding of the molecular mechanisms underlying various diseases and for the identification of novel proteoform targets for better therapeutic development . Despite the challenges of sequencing intact proteins, top-down proteomics has enabled a wealth of information regarding protein isoform switching and changes in PTMs. Continuous developments in sample preparation, intact protein separation, and instrumentation for top-down MS have broadened its capabilities to characterize proteoforms from a range of samples on an increasingly global scale.
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Affiliation(s)
- Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Jake A. Melby
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - David S. Roberts
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, United States
- Human Proteomics Program, University of Wisconsin-Madison, Madison, Wisconsin, United States
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32
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Srzentić K, Fornelli L, Tsybin YO, Loo JA, Seckler H, Agar JN, Anderson LC, Bai DL, Beck A, Brodbelt JS, van der Burgt YEM, Chamot-Rooke J, Chatterjee S, Chen Y, Clarke DJ, Danis PO, Diedrich JK, D'Ippolito RA, Dupré M, Gasilova N, Ge Y, Goo YA, Goodlett DR, Greer S, Haselmann KF, He L, Hendrickson CL, Hinkle JD, Holt MV, Hughes S, Hunt DF, Kelleher NL, Kozhinov AN, Lin Z, Malosse C, Marshall AG, Menin L, Millikin RJ, Nagornov KO, Nicolardi S, Paša-Tolić L, Pengelley S, Quebbemann NR, Resemann A, Sandoval W, Sarin R, Schmitt ND, Shabanowitz J, Shaw JB, Shortreed MR, Smith LM, Sobott F, Suckau D, Toby T, Weisbrod CR, Wildburger NC, Yates JR, Yoon SH, Young NL, Zhou M. Interlaboratory Study for Characterizing Monoclonal Antibodies by Top-Down and Middle-Down Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1783-1802. [PMID: 32812765 PMCID: PMC7539639 DOI: 10.1021/jasms.0c00036] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The Consortium for Top-Down Proteomics (www.topdownproteomics.org) launched the present study to assess the current state of top-down mass spectrometry (TD MS) and middle-down mass spectrometry (MD MS) for characterizing monoclonal antibody (mAb) primary structures, including their modifications. To meet the needs of the rapidly growing therapeutic antibody market, it is important to develop analytical strategies to characterize the heterogeneity of a therapeutic product's primary structure accurately and reproducibly. The major objective of the present study is to determine whether current TD/MD MS technologies and protocols can add value to the more commonly employed bottom-up (BU) approaches with regard to confirming protein integrity, sequencing variable domains, avoiding artifacts, and revealing modifications and their locations. We also aim to gather information on the common TD/MD MS methods and practices in the field. A panel of three mAbs was selected and centrally provided to 20 laboratories worldwide for the analysis: Sigma mAb standard (SiLuLite), NIST mAb standard, and the therapeutic mAb Herceptin (trastuzumab). Various MS instrument platforms and ion dissociation techniques were employed. The present study confirms that TD/MD MS tools are available in laboratories worldwide and provide complementary information to the BU approach that can be crucial for comprehensive mAb characterization. The current limitations, as well as possible solutions to overcome them, are also outlined. A primary limitation revealed by the results of the present study is that the expert knowledge in both experiment and data analysis is indispensable to practice TD/MD MS.
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Affiliation(s)
- Kristina Srzentić
- Northwestern University, Evanston, Illinois 60208-0001, United States
| | - Luca Fornelli
- Northwestern University, Evanston, Illinois 60208-0001, United States
| | - Yury O Tsybin
- Spectroswiss, EPFL Innovation Park, Building I, 1015 Lausanne, Switzerland
| | - Joseph A Loo
- University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Henrique Seckler
- Northwestern University, Evanston, Illinois 60208-0001, United States
| | - Jeffrey N Agar
- Northeastern University, Boston, Massachusetts 02115, United States
| | - Lissa C Anderson
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Dina L Bai
- University of Virginia, Charlottesville, Virginia 22901, United States
| | - Alain Beck
- Centre d'immunologie Pierre Fabre, 74160 Saint-Julien-en-Genevois, France
| | | | | | | | | | - Yunqiu Chen
- Biogen, Inc., Cambridge, Massachusetts 02142-1031, United States
| | - David J Clarke
- The University of Edinburgh, EH9 3FJ Edinburgh, United Kingdom
| | - Paul O Danis
- Consortium for Top-Down Proteomics, Cambridge, Massachusetts 02142, United States
| | - Jolene K Diedrich
- The Scripps Research Institute, La Jolla, California 92037, United States
| | | | | | - Natalia Gasilova
- Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Ying Ge
- University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Young Ah Goo
- University of Maryland, Baltimore, Maryland 21201, United States
| | - David R Goodlett
- University of Maryland, Baltimore, Maryland 21201, United States
| | - Sylvester Greer
- University of Texas at Austin, Austin, Texas 78712-1224, United States
| | | | - Lidong He
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | | | - Joshua D Hinkle
- University of Virginia, Charlottesville, Virginia 22901, United States
| | - Matthew V Holt
- Baylor College of Medicine, Houston, Texas 77030-3411, United States
| | - Sam Hughes
- The University of Edinburgh, EH9 3FJ Edinburgh, United Kingdom
| | - Donald F Hunt
- University of Virginia, Charlottesville, Virginia 22901, United States
| | - Neil L Kelleher
- Northwestern University, Evanston, Illinois 60208-0001, United States
| | - Anton N Kozhinov
- Spectroswiss, EPFL Innovation Park, Building I, 1015 Lausanne, Switzerland
| | - Ziqing Lin
- University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | | | - Alan G Marshall
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
- Florida State University, Tallahassee, Florida 32310-4005, United States
| | - Laure Menin
- Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Robert J Millikin
- University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | | | - Simone Nicolardi
- Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
| | - Ljiljana Paša-Tolić
- Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | | | - Neil R Quebbemann
- University of California-Los Angeles, Los Angeles, California 90095, United States
| | | | - Wendy Sandoval
- Genentech, Inc., South San Francisco, California 94080-4990, United States
| | - Richa Sarin
- Biogen, Inc., Cambridge, Massachusetts 02142-1031, United States
| | | | | | - Jared B Shaw
- Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | | | - Lloyd M Smith
- University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Frank Sobott
- University of Antwerp, 2000 Antwerp, Belgium
- University of Leeds, LS2 9JT Leeds, United Kingdom
| | | | - Timothy Toby
- Northwestern University, Evanston, Illinois 60208-0001, United States
| | - Chad R Weisbrod
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Norelle C Wildburger
- Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - John R Yates
- The Scripps Research Institute, La Jolla, California 92037, United States
| | - Sung Hwan Yoon
- University of Maryland, Baltimore, Maryland 21201, United States
| | - Nicolas L Young
- Baylor College of Medicine, Houston, Texas 77030-3411, United States
| | - Mowei Zhou
- Pacific Northwest National Laboratory, Richland, Washington 99354, United States
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