51
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Holden DD, Brodbelt JS. Improving Performance Metrics of Ultraviolet Photodissociation Mass Spectrometry by Selective Precursor Ejection. Anal Chem 2016; 89:837-846. [PMID: 28105830 DOI: 10.1021/acs.analchem.6b03777] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Confident protein identifications derived from high-throughput bottom-up and top-down proteomics workflows depend on acquisition of thousands of tandem mass spectrometry (MS/MS) spectra with adequate signal-to-noise and accurate mass assignments of the fragment ions. Ultraviolet photodissociation (UVPD) using 193 nm photons has proven to be well-suited for activation and fragmentation of peptides and proteins in ion trap mass spectrometers, but the spectral signal-to-noise ratio (S/N) is typically lower than that obtained from collisional activation methods. The lower S/N is attributed to the dispersion of ion current among numerous fragment ion channels (a,b,c,x,y,z ions). In addition, frequently UVPD is performed such that a relatively large population of precursor ions remains undissociated after the UV photoactivation period in order to prevent overdissociation into small uninformative or internal fragment ions. Here we report a method to improve spectral S/N and increase the accuracy of mass assignments of UVPD mass spectra via resonance ejection of undissociated precursor ions after photoactivation. This strategy, termed precursor ejection UVPD or PE-UVPD, allows the ion trap to be filled with more ions prior to UVPD while at the same time alleviating the space charge problems that would otherwise contribute to the skewing of mass assignments and reduction of S/N. Here we report the performance gains by implementation of PE-UVPD for peptide analysis in an ion trap mass spectrometer.
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Affiliation(s)
- Dustin D Holden
- Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
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52
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Holden DD, Brodbelt JS. Ultraviolet Photodissociation of Native Proteins Following Proton Transfer Reactions in the Gas Phase. Anal Chem 2016; 88:12354-12362. [PMID: 28193062 DOI: 10.1021/acs.analchem.6b03565] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The growing use of mass spectrometry in the field of structural biology has catalyzed the development of many new strategies to examine intact proteins in the gas phase. Native mass spectrometry methods have further accelerated the need for methods that can manipulate proteins and protein complexes while minimizing disruption of noncovalent interactions critical for stabilizing conformations. Proton-transfer reactions (PTR) in the gas phase offer the ability to effectively modulate the charge states of proteins, allowing decongestion of mass spectra through separation of overlapping species. PTR was combined with ultraviolet photodissociation (UVPD) to probe the degree of structural changes that occur upon charge reduction reactions in the gas phase. For protein complexes myoglobin·heme (17.6 kDa) and dihydrofolate reductase·methotrexate (19.4 kDa), minor changes were found in the fragmentation patterns aside from some enhancement of fragmentation near the N- and C-terminal regions consistent with slight fraying. After finding little perturbation was caused by charge reduction using PTR, homodimeric superoxide dismutase/CuZn (31.4 kDa) was subjected to PTR in order to separate overlapping monomer and dimer species of the protein that were observed at identical m/z values.
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Affiliation(s)
- Dustin D Holden
- 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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53
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Zhou Y, Wu Y, Yao M, Liu Z, Chen J, Chen J, Tian L, Han G, Shen JR, Wang F. Probing the Lysine Proximal Microenvironments within Membrane Protein Complexes by Active Dimethyl Labeling and Mass Spectrometry. Anal Chem 2016; 88:12060-12065. [DOI: 10.1021/acs.analchem.6b02502] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ye Zhou
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Wu
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Mingdong Yao
- State
Key Laboratory of Catalysis, Dalian National Laboratory for Clean
Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Zheyi Liu
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jin Chen
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Chen
- State
Key Laboratory of Catalysis, Dalian National Laboratory for Clean
Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Lirong Tian
- Key
Laboratory of Photobiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangye Han
- Key
Laboratory of Photobiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
| | - Jian-Ren Shen
- Key
Laboratory of Photobiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
- Photosynthesis
Research Center, Graduate School of Natural Science and Technology, Okayama University, 1-1, Naka 3-chome, Tsushima, Okayama 700-8530, Japan
| | - Fangjun Wang
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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54
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Theisen A, Yan B, Brown JM, Morris M, Bellina B, Barran PE. Use of Ultraviolet Photodissociation Coupled with Ion Mobility Mass Spectrometry To Determine Structure and Sequence from Drift Time Selected Peptides and Proteins. Anal Chem 2016; 88:9964-9971. [DOI: 10.1021/acs.analchem.6b01705] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Alina Theisen
- Michael
Barber Centre for Collaborative Mass Spectrometry, Manchester Institute
of Biotechnology, and Photon Science Insitute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Bin Yan
- Michael
Barber Centre for Collaborative Mass Spectrometry, Manchester Institute
of Biotechnology, and Photon Science Insitute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Jeffery M. Brown
- Waters Corporation, Stamford
Avenue, Altrincham Road, Wilmslow, SK9 4AX, United Kingdom
| | - Michael Morris
- Waters Corporation, Stamford
Avenue, Altrincham Road, Wilmslow, SK9 4AX, United Kingdom
| | - Bruno Bellina
- Michael
Barber Centre for Collaborative Mass Spectrometry, Manchester Institute
of Biotechnology, and Photon Science Insitute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Perdita E. Barran
- Michael
Barber Centre for Collaborative Mass Spectrometry, Manchester Institute
of Biotechnology, and Photon Science Insitute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
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55
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Cammarata MB, Schardon CL, Mehaffey MR, Rosenberg J, Singleton J, Fast W, Brodbelt JS. Impact of G12 Mutations on the Structure of K-Ras Probed by Ultraviolet Photodissociation Mass Spectrometry. J Am Chem Soc 2016; 138:13187-13196. [DOI: 10.1021/jacs.6b04474] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael B. Cammarata
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - Christopher L. Schardon
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - M. Rachel Mehaffey
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - Jake Rosenberg
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - Jonathan Singleton
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - Walter Fast
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - Jennifer S. Brodbelt
- Department of Chemistry, ‡Graduate Program in Biochemistry, and §Division of Chemical Biology and
Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
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56
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Halim MA, Girod M, MacAleese L, Lemoine J, Antoine R, Dugourd P. Combined Infrared Multiphoton Dissociation with Ultraviolet Photodissociation for Ubiquitin Characterization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1435-42. [PMID: 27287047 PMCID: PMC5031736 DOI: 10.1007/s13361-016-1419-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/10/2016] [Accepted: 05/11/2016] [Indexed: 05/10/2023]
Abstract
Herein we report the successful implementation of the consecutive and simultaneous photodissociation with high (213 nm) and low (10.6 μm) energy photons (HiLoPD, high-low photodissociation) on ubiquitin in a quadrupole-Orbitrap mass spectrometer. Absorption of high-energy UV photon is dispersed over the whole protein and stimulates extensive C-Cα backbone fragmentation, whereas low-energy IR photon gradually increases the internal energy and thus preferentially dissociates the most labile amide (C-N) bonds. We noticed that simultaneous irradiation of UV and IR lasers on intact ubiquitin in a single MS/MS experiment provides a rich and well-balanced fragmentation array of a/x, b/y, and z ions. Moreover, secondary fragmentation from a/x and z ions leads to the formation of satellite side-chain ions (d, v, and w) and can help to distinguish isomeric residues in a protein. Implementation of high-low photodissociation in a high-resolution mass spectrometer may offer considerable benefits to promote a comprehensive portrait of protein characterization. Graphical Abstract ᅟ.
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Affiliation(s)
- Mohammad A Halim
- Institut Lumière Matière, Université Lyon 1 - CNRS, Université de Lyon, 69622, Villeurbanne, France
| | - Marion Girod
- Université de Lyon, Institut des Sciences Analytiques, UMR 5280, CNRS, Université Lyon 1, ENS Lyon, 69100, Villeurbanne, France
| | - Luke MacAleese
- Institut Lumière Matière, Université Lyon 1 - CNRS, Université de Lyon, 69622, Villeurbanne, France
| | - Jérôme Lemoine
- Université de Lyon, Institut des Sciences Analytiques, UMR 5280, CNRS, Université Lyon 1, ENS Lyon, 69100, Villeurbanne, France
| | - Rodolphe Antoine
- Institut Lumière Matière, Université Lyon 1 - CNRS, Université de Lyon, 69622, Villeurbanne, France
| | - Philippe Dugourd
- Institut Lumière Matière, Université Lyon 1 - CNRS, Université de Lyon, 69622, Villeurbanne, France.
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57
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Morrison LJ, Brodbelt JS. 193 nm Ultraviolet Photodissociation Mass Spectrometry of Tetrameric Protein Complexes Provides Insight into Quaternary and Secondary Protein Topology. J Am Chem Soc 2016; 138:10849-59. [PMID: 27480400 DOI: 10.1021/jacs.6b03905] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein-protein interfaces and architecture are critical to the function of multiprotein complexes. Mass spectrometry-based techniques have emerged as powerful strategies for characterization of protein complexes, particularly for heterogeneous mixtures of structures. In the present study, activation and dissociation of three tetrameric protein complexes (streptavidin, transthyretin, and hemoglobin) in the gas phase was undertaken by 193 nm ultraviolet photodissociation (UVPD) for the characterization of higher order structure. High pulse energy UVPD resulted in the production of dimers and low charged monomers exhibiting symmetrical charge partitioning among the subunits (the so-called symmetrical dissociation pathways), consistent with the subunit organization of the complexes. In addition, UVPD promoted backbone cleavages of the monomeric subunits, the abundances of which corresponded to the more flexible loop regions of the proteins.
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Affiliation(s)
- Lindsay J Morrison
- 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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58
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Fort KL, Dyachenko A, Potel CM, Corradini E, Marino F, Barendregt A, Makarov AA, Scheltema RA, Heck AJR. Implementation of Ultraviolet Photodissociation on a Benchtop Q Exactive Mass Spectrometer and Its Application to Phosphoproteomics. Anal Chem 2016; 88:2303-10. [DOI: 10.1021/acs.analchem.5b04162] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Kyle L. Fort
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Andrey Dyachenko
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Clement M. Potel
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Eleonora Corradini
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Fabio Marino
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Arjan Barendregt
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Alexander A. Makarov
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Richard A. Scheltema
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
| | - Albert J. R. Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute of Pharmaceutical Sciences, Utrecht University, 3584 Utrecht, The Netherlands
- Netherlands Proteomics Center, 3584 Utrecht, The Netherlands
- Thermo Fisher Scientific (Bremen), 28199 Bremen, Germany
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59
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Affiliation(s)
- Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
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60
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Holden DD, McGee WM, Brodbelt JS. Integration of Ultraviolet Photodissociation with Proton Transfer Reactions and Ion Parking for Analysis of Intact Proteins. Anal Chem 2015; 88:1008-16. [DOI: 10.1021/acs.analchem.5b03911] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Dustin D. Holden
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - William M. McGee
- 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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61
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Iyer LK, Moorthy BS, Topp EM. Photolytic Cross-Linking to Probe Protein-Protein and Protein-Matrix Interactions in Lyophilized Powders. Mol Pharm 2015. [PMID: 26204425 DOI: 10.1021/acs.molpharmaceut.5b00183] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Protein structure and local environment in lyophilized formulations were probed using high-resolution solid-state photolytic cross-linking with mass spectrometric analysis (ssPC-MS). In order to characterize structure and microenvironment, protein-protein, protein-excipient, and protein-water interactions in lyophilized powders were identified. Myoglobin (Mb) was derivatized in solution with the heterobifunctional probe succinimidyl 4,4'-azipentanoate (SDA) and the structural integrity of the labeled protein (Mb-SDA) confirmed using CD spectroscopy and liquid chromatography/mass spectrometry (LC-MS). Mb-SDA was then formulated with and without excipients (raffinose, guanidine hydrochloride (Gdn HCl)) and lyophilized. The freeze-dried powder was irradiated with ultraviolet light at 365 nm for 30 min to produce cross-linked adducts that were analyzed at the intact protein level and after trypsin digestion. SDA-labeling produced Mb carrying up to five labels, as detected by LC-MS. Following lyophilization and irradiation, cross-linked peptide-peptide, peptide-water, and peptide-raffinose adducts were detected. The exposure of Mb side chains to the matrix was quantified based on the number of different peptide-peptide, peptide-water, and peptide-excipient adducts detected. In the absence of excipients, peptide-peptide adducts involving the CD, DE, and EF loops and helix H were common. In the raffinose formulation, peptide-peptide adducts were more distributed throughout the molecule. The Gdn HCl formulation showed more protein-protein and protein-water adducts than the other formulations, consistent with protein unfolding and increased matrix interactions. The results demonstrate that ssPC-MS can be used to distinguish excipient effects and characterize the local protein environment in lyophilized formulations with high resolution.
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Affiliation(s)
- Lavanya K Iyer
- Department of Industrial and Physical Pharmacy, Purdue University , West Lafayette, Indiana 47907-2091, United States
| | - Balakrishnan S Moorthy
- Department of Industrial and Physical Pharmacy, Purdue University , West Lafayette, Indiana 47907-2091, United States
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy, Purdue University , West Lafayette, Indiana 47907-2091, United States
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62
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Cammarata MB, Thyer R, Rosenberg J, Ellington A, Brodbelt JS. Structural Characterization of Dihydrofolate Reductase Complexes by Top-Down Ultraviolet Photodissociation Mass Spectrometry. J Am Chem Soc 2015; 137:9128-35. [PMID: 26125523 DOI: 10.1021/jacs.5b04628] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The stepwise reduction of dihydrofolate to tetrahydrofolate entails significant conformational changes of dihydrofolate reductase (DHFR). Binary and ternary complexes of DHFR containing cofactor NADPH, inhibitor methotrexate (MTX), or both NADPH and MTX were characterized by 193 nm ultraviolet photodissociation (UVPD) mass spectrometry. UVPD yielded over 80% sequence coverage of DHFR and resulted in production of fragment ions that revealed the interactions between DHFR and each ligand. UVPD of the binary DHFR·NADPH and DHFR·MTX complexes led to an unprecedented number of fragment ions containing either an N- or C-terminal protein fragment still bound to the ligand via retention of noncovalent interactions. In addition, holo-fragments retaining both ligands were observed upon UVPD of the ternary DHFR·NADPH·MTX complex. The combination of extensive holo and apo fragment ions allowed the locations of the NADPH and MTX ligands to be mapped, with NADPH associated with the adenosine binding domain of DHFR and MTX interacting with the loop domain. These findings are consistent with previous crystallographic evidence. Comparison of the backbone cleavage propensities for apo DHFR and its holo counterparts revealed significant variations in UVPD fragmentation in the regions expected to experience conformational changes upon binding NADPH, MTX, or both ligands. In particular, the subdomain rotation and loop movements, which are believed to occur upon formation of the transition state of the ternary complex, are reflected in the UVPD mass spectra. The UVPD spectra indicate enhanced backbone cleavages in regions that become more flexible or show suppressed backbone cleavages for those regions either shielded by the ligand or involved in new intramolecular interactions. This study corroborates the versatility of 193 nm UVPD mass spectrometry as a sensitive technique to track enzymatic cycles that involve conformational rearrangements.
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Affiliation(s)
- Michael B Cammarata
- †Department of Chemistry and ‡Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712, United States
| | - Ross Thyer
- †Department of Chemistry and ‡Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jake Rosenberg
- †Department of Chemistry and ‡Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrew Ellington
- †Department of Chemistry and ‡Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jennifer S Brodbelt
- †Department of Chemistry and ‡Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712, United States
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63
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Zhao Y, Riley NM, Sun L, Hebert AS, Yan X, Westphall MS, Rush MJP, Zhu G, Champion MM, Medie FM, DiGiuseppe Champion PA, Coon JJ, Dovichi NJ. Coupling capillary zone electrophoresis with electron transfer dissociation and activated ion electron transfer dissociation for top-down proteomics. Anal Chem 2015; 87:5422-9. [PMID: 25893372 PMCID: PMC4439324 DOI: 10.1021/acs.analchem.5b00883] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Top-down proteomics offers the potential for full protein characterization, but many challenges remain for this approach, including efficient protein separations and effective fragmentation of intact proteins. Capillary zone electrophoresis (CZE) has shown great potential for separation of intact proteins, especially for differentially modified proteoforms of the same gene product. To date, however, CZE has been used only with collision-based fragmentation methods. Here we report the first implementation of electron transfer dissociation (ETD) with online CZE separations for top-down proteomics, analyzing a mixture of four standard proteins and a complex protein mixture from the Mycobacterium marinum bacterial secretome. Using a multipurpose dissociation cell on an Orbitrap Elite system, we demonstrate that CZE is fully compatible with ETD as well as higher energy collisional dissociation (HCD), and that the two complementary fragmentation methods can be used in tandem on the electrophoretic time scale for improved protein characterization. Furthermore, we show that activated ion electron transfer dissociation (AI-ETD), a recently introduced method for enhanced ETD fragmentation, provides useful performance with CZE separations to greatly increase protein characterization. When combined with HCD, AI-ETD improved the protein sequence coverage by more than 200% for proteins from both standard and complex mixtures, highlighting the benefits electron-driven dissociation methods can add to CZE separations.
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Affiliation(s)
- Yimeng Zhao
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Nicholas M. Riley
- Department of Biomolecular Chemistry, Genome Center of Wisconsin, and Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Liangliang Sun
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Alexander S. Hebert
- Department of Biomolecular Chemistry, Genome Center of Wisconsin, and Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Xiaojing Yan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Michael S. Westphall
- Department of Biomolecular Chemistry, Genome Center of Wisconsin, and Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Matthew J. P. Rush
- Department of Biomolecular Chemistry, Genome Center of Wisconsin, and Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Guijie Zhu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Matthew M. Champion
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Felix Mba Medie
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA
| | | | - Joshua J. Coon
- Department of Biomolecular Chemistry, Genome Center of Wisconsin, and Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Norman J. Dovichi
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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