1
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Oney-Hawthorne SD, Barondeau DP. Fe-S cluster biosynthesis and maturation: Mass spectrometry-based methods advancing the field. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119784. [PMID: 38908802 DOI: 10.1016/j.bbamcr.2024.119784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/25/2024] [Accepted: 06/10/2024] [Indexed: 06/24/2024]
Abstract
Iron‑sulfur (FeS) clusters are inorganic protein cofactors that perform essential functions in many physiological processes. Spectroscopic techniques have historically been used to elucidate details of FeS cluster type, their assembly and transfer, and changes in redox and ligand binding properties. Structural probes of protein topology, complex formation, and conformational dynamics are also necessary to fully understand these FeS protein systems. Recent developments in mass spectrometry (MS) instrumentation and methods provide new tools to investigate FeS cluster and structural properties. With the unique advantage of sampling all species in a mixture, MS-based methods can be utilized as a powerful complementary approach to probe native dynamic heterogeneity, interrogate protein folding and unfolding equilibria, and provide extensive insight into protein binding partners within an entire proteome. Here, we highlight key advances in FeS protein studies made possible by MS methodology and contribute an outlook for its role in the field.
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Affiliation(s)
| | - David P Barondeau
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
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2
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Jia Y, Liu Y, Wang Y, Li J, Li G. Sialylation-induced stabilization of dynamic glycoprotein conformations unveiled by time-aligned parallel unfolding and glycan release mass spectrometry. Chem Sci 2024:d4sc03672g. [PMID: 39165727 PMCID: PMC11331314 DOI: 10.1039/d4sc03672g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Accepted: 08/09/2024] [Indexed: 08/22/2024] Open
Abstract
Sialylation, a critical post-translational modification, regulates glycoprotein structure and function by tuning their molecular heterogeneity. However, characterizing its subtle and dynamic conformational effects at the intact glycoprotein level remains challenging. We introduce a glycoform-resolved unfolding approach based on a high-throughput ion mobility-mass spectrometry (IM-MS) platform. This method integrates high-throughput unfolding with parallel fragmentation, enabling simultaneous analysis of sialylation patterns, stoichiometries, and their impact on conformational stability. Applying this approach to fetuin, we identified distinct sialylation patterns and their differential influence on protein conformation, namely sialylation-induced stabilization during early unfolding and increased flexibility in later unfolding stages. IM-MS-guided molecular dynamics simulations revealed that increased sialylation enhances the initial conformational stability, likely through enhanced electrostatic interactions and hydrogen bonding. These findings highlight the complex interplay between sialylation and protein dynamics and establish glycoform-resolved unfolding IM-MS as a powerful tool for characterizing glycoprotein conformational landscapes.
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Affiliation(s)
- Yifei Jia
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University Tianjin 300071 China
| | - Yichang Liu
- School of Pharmacy, Nantong University Nantong 226001 Jiangsu China
| | - Yamei Wang
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University Tianjin 300071 China
| | - Jinyu Li
- College of Chemistry, Fuzhou University Fuzhou 350108 Fujian China
| | - Gongyu Li
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University Tianjin 300071 China
- Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
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3
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Zhao Y, Zhang W, Hong J, Yang L, Wang Y, Qu F, Xu W. Mobility capillary electrophoresis-native mass spectrometry reveals the dynamic conformational equilibrium of calmodulin and its complexes. Analyst 2024; 149:3793-3802. [PMID: 38847183 DOI: 10.1039/d4an00378k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Benefitting from the rapid evolution of artificial intelligence and structural biology, an expanding collection of high-resolution protein structures has greatly improved our understanding of protein functions. Yet, proteins are inherently flexible, and these static structures can only offer limited snapshots of their true dynamic nature. The conformational and functional changes of calmodulin (CaM) induced by Ca2+ binding have always been a focus of research. In this study, the conformational dynamics of CaM and its complexes were investigated using a mobility capillary electrophoresis (MCE) and native mass spectrometry (native MS) based method. By analyzing the ellipsoidal geometries of CaM in the solution phase at different Ca2+ concentrations, it is interesting to discover that CaM molecules, whether bound to Ca2+ or not, possess both closed and open conformations. Moreover, each individual CaM molecule actively "jumps" (equilibrium exchange) between these two distinct conformations on a timescale ranging from milli- to micro-seconds. The binding of Ca2+ ions did not affect the structural dynamics of CaM, while the binding of a peptide ligand would stabilize CaM, leading to the observation of a single, compact conformation of the resulting protein complex. A target recognition mechanism was also proposed based on these new findings, suggesting that CaM's interaction with targets may favor a conformational selection model. This enriches our understanding of the binding principles between CaM and its numerous targets.
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Affiliation(s)
- Yi Zhao
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China.
| | - Wenjing Zhang
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China.
| | - Jie Hong
- Kunshan Nier Precision Instrumentation Inc. Kunshan, Suzhou, 215316, China
| | - Lei Yang
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China.
| | - Yuanyuan Wang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Feng Qu
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China.
| | - Wei Xu
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China.
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4
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Matney R, Gadkari VV. Recent advances in gas phase unfolding: Instrumentation and applications. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5059. [PMID: 38894609 DOI: 10.1002/jms.5059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 05/11/2024] [Accepted: 05/13/2024] [Indexed: 06/21/2024]
Abstract
Broader adoption of native mass spectrometry (MS) and ion mobility-mass spectrometry (IM-MS) has propelled the development of several techniques which take advantage of the selectivity, sensitivity, and speed of MS to make measurements of complex biological molecules in the gas phase. One such method, collision induced unfolding (CIU), has risen to prominence in recent years, due to its well documented capability to detect shifts in structural stability of biological molecules in response to external stimuli (e.g., mutations, stress, non-covalent interactions, sample conditions etc.). This increase in reported CIU measurements is enabled partly due to advances in IM-MS instrumentation by vendors, and also innovative method development by researchers. This perspective highlights a few of these advances and concludes with a look forward toward the future of the gas phase unfolding field.
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Affiliation(s)
- Rowan Matney
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
| | - Varun V Gadkari
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
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5
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Villacob RA, Feizi N, Beno SC, Solouki T. Collision-Induced Unfolding, Tandem MS, Bottom-up Proteomics, and Interactomics for Identification of Protein Complexes in Native Surface Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:13-30. [PMID: 38095581 DOI: 10.1021/jasms.3c00261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Endogenously occurring salts and nonvolatile matrix components in untreated biological surfaces can suppress protein ionization and promote adduct formation, challenging protein identification. Characterization of labile proteins within biological specimens is particularly demanding because additional purification or sample treatment steps can be time-intensive and can disrupt noncovalent interactions. It is demonstrated that the combined use of collision-induced unfolding, tandem mass spectrometry, and bottom-up proteomics improves protein characterization in native surface mass spectrometry (NSMS). This multiprong analysis is achieved by acquiring NSMS, MS/MS, ion mobility (IM), and bottom-up proteomics data from a single surface extracted sample. The validity of this multiprong approach was confirmed by the successful characterization of nine surface-deposited proteins, with molecular weights ranging from 8 to 147 kDa, in two separate mixtures. Bottom-up proteomics provided a list of proteins to match against observed proteins in NSMS and their detected subunits in tandem MS. The method was applied to characterize endogenous proteins from untreated chicken liver samples. The subcapsular liver sampling for NSMS analysis allowed for the detection of endogenous proteins with molecular weights of up to ∼220 kDa. Moreover, using IM-MS, collision cross sections and collision-induced unfolding pathways of enzymatic proteins and protein complexes of up to 145 kDa were obtained.
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Affiliation(s)
- Raul A Villacob
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Neda Feizi
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Sarah C Beno
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Touradj Solouki
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
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6
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Ryan JP, Kostelic MM, Hsieh CC, Powers J, Aspinwall C, Dodds JN, Schiel JE, Marty MT, Baker ES. Characterizing Adeno-Associated Virus Capsids with Both Denaturing and Intact Analysis Methods. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2811-2821. [PMID: 38010134 DOI: 10.1021/jasms.3c00321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Adeno-associated virus (AAV) capsids are among the leading gene delivery platforms used to treat a vast array of human diseases and conditions. AAVs exist in a variety of serotypes due to differences in viral protein (VP) sequences with distinct serotypes targeting specific cells and tissues. As the utility of AAVs in gene therapy increases, ensuring their specific composition is imperative for the correct targeting and gene delivery. From a quality control perspective, current analytical tools are limited in their selectivity for viral protein (VP) subunits due to their sequence similarities, instrumental difficulties in assessing the large molecular weights of intact capsids, and the uncertainty in distinguishing empty and filled capsids. To address these challenges, we combined two distinct analytical workflows that assess the intact capsids and VP subunits separately. First, a selective temporal overview of resonant ion (STORI)-based charge detection-mass spectrometry (CD-MS) was applied for characterization of the intact capsids. Liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) separations were then used for the capsid denaturing measurements. This multimethod combination was applied to three AAV serotypes (AAV2, AAV6, and AAV8) to evaluate their intact empty and filled capsid ratios and then examine the distinct VP sequences and modifications present.
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Affiliation(s)
- Jack P Ryan
- University of North Carolina, Department of Chemistry, Chapel Hill, North Carolina 27599, United States
| | - Marius M Kostelic
- University of Arizona, Department of Chemistry and Biochemistry, Tucson, Arizona 85721, United States
| | - Chih-Chieh Hsieh
- University of Arizona, Department of Chemistry and Biochemistry, Tucson, Arizona 85721, United States
| | - Joshua Powers
- Institute for Bioscience and Biotechnology Research (NIST), Gaithersburg Maryland 20899, United States
- North Carolina State University, Biomanufacturing Training and Education Center (BTEC), Raleigh, North Carolina 27695, United States
| | - Craig Aspinwall
- University of Arizona, Department of Chemistry and Biochemistry, Tucson, Arizona 85721, United States
| | - James N Dodds
- University of North Carolina, Department of Chemistry, Chapel Hill, North Carolina 27599, United States
| | - John E Schiel
- Institute for Bioscience and Biotechnology Research (NIST), Gaithersburg Maryland 20899, United States
| | - Michael T Marty
- University of Arizona, Department of Chemistry and Biochemistry, Tucson, Arizona 85721, United States
| | - Erin S Baker
- University of North Carolina, Department of Chemistry, Chapel Hill, North Carolina 27599, United States
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7
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Zhao R, Liu N, Zheng Z, Li G. Enhanced Stability Differentiation of Therapeutic Polyclonal Antibodies with All Ion Unfolding-Ion Mobility-Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2289-2295. [PMID: 37682774 DOI: 10.1021/jasms.3c00215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Compared with monoclonal antibodies, polyclonal antibodies (pAbs) have rather significant characteristics, including lower cost, shorter production cycle, and higher affinity. Therefore, to facilitate their applications in clinic, it is equally critical to comprehensively characterize the conformational stabilities of pAb at the molecular weight-resolved scale, which is technically challenging due to the lack of an effective analytical tool capable of simultaneously providing both stability and molecular weight information within an acceptable error range. Ion mobility-mass spectrometry (IM-MS) has grown as an alternative to rapidly assess protein conformational stability with accurate molecular weight information maintained, especially when equipped with a collision-induced unfolding (CIU) regime. Dynamic and transient conformational intermediates can be captured with the CIU-IM-MS technique, adding to traditional static structural measurements with collisional cross section. Most CIU-IM-MS-centered protocols are focusing on the application to isolated, targeted protein ions, namely, analyzing one single charge state at one time, limiting its analytical throughput and speed. In this study, we employed an enhanced unfolding regime, all ion unfolding (AIU), capable of the simultaneous operation of numerous ions at a time during stepped unfolding processes to analyze pAb. Results show that AIU can quantitatively characterize the subtle differences in conformational stability among four structurally similar pAbs with improved resolving capability by around a 2-4-fold increment in both stability and structure differentiating parameters. Besides, AIU also benefits from considerably saved time cost and improved spectrum quality with an elevated signal-to-noise ratio.
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Affiliation(s)
- Rui Zhao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Ning Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zhen Zheng
- School of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Gongyu Li
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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8
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Edwards AN, Blue AJ, Conforti JM, Cordes MS, Trakselis MA, Gallagher ES. Gas-phase stability and thermodynamics of ligand-bound, binary complexes of chloramphenicol acetyltransferase reveal negative cooperativity. Anal Bioanal Chem 2023; 415:6201-6212. [PMID: 37542535 DOI: 10.1007/s00216-023-04891-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/07/2023]
Abstract
The biological role of the bacterial chloramphenicol (Chl)-resistance enzyme, chloramphenicol acetyltransferase (CAT), has seen renewed interest due to the resurgent use of Chl against multi-drug-resistant microbes. This looming threat calls for more rationally designed antibiotic derivatives that have improved antimicrobial properties and reduced toxicity in humans. Herein, we utilize native ion mobility spectrometry-mass spectrometry (IMS-MS) to investigate the gas-phase structure and thermodynamic stability of the type I variant of CAT from Escherichia coli (EcCATI) and several EcCATI:ligand-bound complexes. EcCATI readily binds multiple Chl without incurring significant changes to its gas-phase structure or stability. A non-hydrolyzable acetyl-CoA derivative (S-ethyl-CoA, S-Et-CoA) was used to kinetically trap EcCATI and Chl in a ternary, ligand-bound state (EcCATI:S-Et-CoA:Chl). Using collision-induced unfolding (CIU)-IMS-MS, we find that Chl dissociates from EcCATI:S-Et-CoA:Chl complexes at low collision energies, while S-Et-CoA remains bound to EcCATI even as protein unfolding occurs. Gas-phase binding constants further suggest that EcCATI binds S-Et-CoA more tightly than Chl. Both ligands exhibit negative cooperativity of subsequent ligand binding in their respective binary complexes. While we observe no significant change in structure or stability to EcCATI when bound to either or both ligands, we have elucidated novel gas-phase unfolding and dissociation behavior and provided a foundation for further characterization of alternative substrates and/or inhibitors of EcCATI.
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Affiliation(s)
- Alexis N Edwards
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Anthony J Blue
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Jessica M Conforti
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Michael S Cordes
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Michael A Trakselis
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Elyssia S Gallagher
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA.
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9
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Zheng Z, Ma M, Jia Y, Cui Y, Zhao R, Li S, Wenthur C, Li L, Li G. Expedited Evaluation of Conformational Stability-Heterogeneity Associations for Crude Polyclonal Antibodies in Response to Conjugate Vaccines. Anal Chem 2023; 95:10895-10902. [PMID: 37433088 PMCID: PMC10695093 DOI: 10.1021/acs.analchem.3c00223] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
Conjugate vaccines have been demonstrated to be a promising strategy for immunotherapeutic intervention in substance use disorder, wherein a hapten structurally similar to the target drug is conjugated to an immunogenic carrier protein. The antibodies generated following immunization with these species can provide long-lasting protection against overdose through sequestration of the abused drug in the periphery, which mitigates its ability to cross the blood-brain barrier. However, these antibodies exhibit a high degree of heterogeneity in structure. The resultant variations in chemical and structural compositions have not yet been clearly linked to the stability that directly affects their in vivo functional performance. In this work, we describe a rapid mass-spectrometry-based analytical workflow capable of simultaneous and comprehensive interrogation of the carrier protein-dependent heterogeneity and stability of crude polyclonal antibodies in response to conjugate vaccines. Quantitative collision-induced unfolding-ion mobility-mass spectrometry with an all-ion mode is adapted to rapidly assess the conformational heterogeneity and stability of crude serum antibodies collected from four different vaccine conditions, in an unprecedented manner. A series of bottom-up glycoproteomic experiments was performed to reveal the driving force underlying these observed heterogeneities. Overall, this study not only presents a generally applicable workflow for fast assessment of crude antibody conformational stability and heterogeneity at the intact protein level but also leverages carrier protein optimization as a simple solution to antibody quality control.
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Affiliation(s)
- Zhen Zheng
- State Key Laboratory of Pharmaceutical Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
- School of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Min Ma
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Yifei Jia
- State Key Laboratory of Pharmaceutical Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yusi Cui
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Rui Zhao
- State Key Laboratory of Pharmaceutical Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Shuangshuang Li
- School of Pharmacy, Tianjin Medical University, Tianjin 300070, China
| | - Cody Wenthur
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Lingjun Li
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- Lachman Institute for Pharmaceutical Development, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Gongyu Li
- State Key Laboratory of Pharmaceutical Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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10
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James VK, Sanders JD, Aizikov K, Fort KL, Grinfeld D, Makarov A, Brodbelt JS. Expanding Orbitrap Collision Cross-Section Measurements to Native Protein Applications Through Kinetic Energy and Signal Decay Analysis. Anal Chem 2023; 95:7656-7664. [PMID: 37133913 DOI: 10.1021/acs.analchem.3c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The measurement of collision cross sections (CCS, σ) offers supplemental information about sizes and conformations of ions beyond mass analysis alone. We have previously shown that CCSs can be determined directly from the time-domain transient decay of ions in an Orbitrap mass analyzer as ions oscillate around the central electrode and collide with neutral gas, thus removing them from the ion packet. Herein, we develop the modified hard collision model, thus deviating from the prior FT-MS hard sphere model, to determine CCSs as a function of center-of-mass collision energy in the Orbitrap analyzer. With this model, we aim to increase the upper mass limit of CCS measurement for native-like proteins, characterized by low charge states and presumed to be in more compact conformations. We also combine CCS measurements with collision induced unfolding and tandem mass spectrometry experiments to monitor protein unfolding and disassembly of protein complexes and measure CCSs of ejected monomers from protein complexes.
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Affiliation(s)
- Virginia K James
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - James D Sanders
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | | | - Kyle L Fort
- Thermo Fisher Scientific, Bremen 28199, Germany
| | | | - Alexander Makarov
- Thermo Fisher Scientific, Bremen 28199, Germany
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Utrecht 3584, The Netherlands
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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11
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Villacob RA, Egbejiogu BC, Feizi N, Hogan C, Murray KK, Solouki T. Native Mass Spectrometry and Collision-Induced Unfolding of Laser-Ablated Proteins. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:2215-2225. [PMID: 36346890 DOI: 10.1021/jasms.2c00184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Infrared laser ablation sample transfer (LAST) was used to collect samples from solid surfaces for mass spectrometry under native spray conditions. Native mass spectrometry was utilized to probe the charge states and collision-induced unfolding (CIU) characteristics of bovine serum albumin (BSA), bovine hemoglobin (BHb), and jack-bean concanavalin A (ConA) via direct injection electrospray, after liquid extraction surface sampling, and after LAST. Each protein was deposited from solution on solid surfaces and laser-ablated for off-line analysis or sampled for online analysis. It was found that the protein ion gas-phase charge-state distributions were comparable for direct infusion, liquid extraction, and laser ablation experiments. Moreover, calculated average collision cross section (CCS) values from direct injection, liquid extraction, and laser ablation experiments were consistent with previously reported literature values. Additionally, an equivalent number of mobility features and conformational turnovers were identified from unfolding pathways from all three methods for all charge states of each protein analyzed in this work. The presented work suggests that laser ablation yields intact proteins (BSA, BHb, and ConA), is compatible with native mass spectrometry, and could be suitable for spatially resolved interrogation of unfolding pathways of proteins.
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Affiliation(s)
| | | | - Neda Feizi
- Baylor University, Waco, Texas 76706, United States
| | - Cole Hogan
- Baylor University, Waco, Texas 76706, United States
| | - Kermit K Murray
- Louisiana State University, Baton Rouge, Louisiana 70803, United States
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