1
|
Kuo CY, Zheng YF, Wang WC, Toh JT, Hsu YM, Chien HJ, Chang CJ, Lai CC. Direct Identification of Intact Proteins Using a Low-Resolution Mass Spectrometer with CID n/ETnoD. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1507-1515. [PMID: 38905484 PMCID: PMC11228978 DOI: 10.1021/jasms.4c00108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/05/2024] [Accepted: 06/12/2024] [Indexed: 06/23/2024]
Abstract
Over the past decades, proteomics has become increasingly important and a heavily discussed topic. The identification of intact proteins remains a major focus in this field. While most intact proteins are analyzed using high-resolution mass spectrometry, identifying them through low-resolution mass spectrometry continues to pose challenges. In our study, we investigated the capability of identifying various intact proteins using collision-induced dissociation (CID) and electron transfer without dissociation (ETnoD). Using myoglobin as our test protein, stable product ions were generated with CID, and the identities of the product ions were identified with ETnoD. ETnoD uses a short activation time (AcT, 5 ms) to create sequential charge-reduced precursor ion (CRI). The charges of the fragments and their sequences were determined with corresponding CRI. The product ions can be selected for subsequent CID (termed CIDn) combined with ETnoD for further sequence identification and validation. We refer to this method as CIDn/ETnoD. The use of a multistage CID activation (CIDn) and ETnoD protocol has been applied to several intact proteins to obtain multiple sequence identifications.
Collapse
Affiliation(s)
- Cheng-Yu Kuo
- Institute
of Molecular Biology, National Chung Hsing
University, Taichung 402, Taiwan
| | - Yi-Feng Zheng
- Institute
of Molecular Biology, National Chung Hsing
University, Taichung 402, Taiwan
| | - Wei-Chen Wang
- Institute
of Molecular Biology, National Chung Hsing
University, Taichung 402, Taiwan
| | - Jie-Teng Toh
- Institute
of Molecular Biology, National Chung Hsing
University, Taichung 402, Taiwan
| | - Yu-Ming Hsu
- Institute
of Molecular Biology, National Chung Hsing
University, Taichung 402, Taiwan
| | - Han-Ju Chien
- Department
of Biochemical Science and Technology, National
Chiayi University, Chiayi 600, Taiwan
| | - Chih-Jui Chang
- Department
of Molecular Biology and Human Genetics, Tzu Chi University, Hualien City 970, Taiwan
| | - Chien-Chen Lai
- Institute
of Molecular Biology, National Chung Hsing
University, Taichung 402, Taiwan
- Advanced
Plant and Food Crop Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
- Graduate
Institute of Chinese Medical Science, China
Medical University, Taichung 406, Taiwan
- Doctoral
Program in Translational Medicine, National
Chung Hsing University, Taichung 402, Taiwan
- Rong
Hsing Translational Medicine Research Center, National Chung Hsing University, Taichung 402, Taiwan
| |
Collapse
|
2
|
Kang WY, Mondal A, Bonney JR, Perez A, Prentice BM. Structural Elucidation of Ubiquitin via Gas-Phase Ion/Ion Cross-Linking Reactions Using Sodium-Cationized Reagents Coupled with Infrared Multiphoton Dissociation. Anal Chem 2024; 96:8518-8527. [PMID: 38711366 PMCID: PMC11161031 DOI: 10.1021/acs.analchem.4c00442] [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] [Indexed: 05/08/2024]
Abstract
Accurate structural determination of proteins is critical to understanding their biological functions and the impact of structural disruption on disease progression. Gas-phase cross-linking mass spectrometry (XL-MS) via ion/ion reactions between multiply charged protein cations and singly charged cross-linker anions has previously been developed to obtain low-resolution structural information on proteins. This method significantly shortens experimental time relative to conventional solution-phase XL-MS but has several technical limitations: (1) the singly deprotonated N-hydroxysulfosuccinimide (sulfo-NHS)-based cross-linker anions are restricted to attachment at neutral amine groups of basic amino acid residues and (2) analyzing terminal cross-linked fragment ions is insufficient to unambiguously localize sites of linker attachment. Herein, we demonstrate enhanced structural information for alcohol-denatured A-state ubiquitin obtained from an alternative gas-phase XL-MS approach. Briefly, singly sodiated ethylene glycol bis(sulfosuccinimidyl succinate) (sulfo-EGS) cross-linker anions enable covalent cross-linking at both ammonium and amine groups. Additionally, covalently modified internal fragment ions, along with terminal b-/y-type counterparts, improve the determination of linker attachment sites. Molecular dynamics simulations validate experimentally obtained gas-phase conformations of denatured ubiquitin. This method has identified four cross-linking sites across 8+ ubiquitin, including two new sites in the N-terminal region of the protein that were originally inaccessible in prior gas-phase XL approaches. The two N-terminal cross-linking sites suggest that the N-terminal half of ubiquitin is more compact in gas-phase conformations. By comparison, the two C-terminal linker sites indicate the signature transformation of this region of the protein from a native to a denatured conformation. Overall, the results suggest that the solution-phase secondary structures of the A-state ubiquitin are conserved in the gas phase. This method also provides sufficient sensitivity to differentiate between two gas-phase conformers of the same charge state with subtle structural variations.
Collapse
Affiliation(s)
| | - Arup Mondal
- Department of Chemistry, University of Florida
| | | | | | | |
Collapse
|
3
|
Zviagin A, Boyarkin OV. Ion Spectroscopy Reveals Structural Difference for Proteins Microhydrated by Retention and Condensation of Water. J Phys Chem A 2024. [PMID: 38489273 DOI: 10.1021/acs.jpca.4c00263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
Protein ubiquitin in its +7 charge state microhydrated by 5 and 10 water molecules has been interrogated in the gas phase by cold ion UV/IR spectroscopy. The complexes were formed either by condensing water onto the unfolded bare proteins in a temperature-controlled ion trap or by incomplete dehydration of the folded proteins. In the case of cryogenic condensation, the UV spectra of the complexes exhibit a resolved vibrational structure, which looks similar to the spectrum of bare unfolded ubiquitin. The spectra become, however, broad-band with no structure when complexes of the same size are produced by incomplete dehydration under soft conditions of electrospray ionization. We attribute this spectroscopic dissimilarity to the structural difference of the protein: condensing a few water molecules cannot refold the gas-phase structure of the bare ubiquitin, while the retained water preserves its solution-like folded motif through evaporative cooling. This assessment is firmly confirmed by IR spectroscopy, which reveals the presence of free NH and carboxylic OH stretching vibrations only in the complexes with condensed water.
Collapse
Affiliation(s)
- Andrei Zviagin
- SCI-SB-RB Group, ISIC, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Oleg V Boyarkin
- SCI-SB-RB Group, ISIC, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| |
Collapse
|
4
|
Lanzillotti MB, Brodbelt JS. A High-Throughput Workflow for Mass Spectrometry Analysis of Nucleic Acids by Nanoflow Desalting. Anal Chem 2024. [PMID: 38330443 DOI: 10.1021/acs.analchem.3c05428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Broad interest in nucleic acids, both their therapeutic capabilities and understanding the nuances of their structure and resulting function, has increased in recent years. Post-transcriptional modifications, in particular, have become an important analysis target, as these covalent modifications to the sugars, nitrogenous bases, and phosphate backbone impart differential functionality to synthetic and biological nucleic acids. Characterizing these post-transcriptional modifications can be difficult with traditional sequencing workflows; however, advancements in top-down mass spectrometry address these challenges. Online desalting platforms have enabled facile sample cleanup and reliable ionization of increasingly large (100 nt) oligonucleotides, and application of existing tandem mass spectrometry techniques has yielded information-rich spectra which can be used to interrogate primary sequences. To extend the capabilities of top-down MS and its analysis of nucleic acids, we have developed a nanoflow desalting platform for high-throughput and low sample-use desalting coupled with collision-induced dissociation (CID), 213 nm ultraviolet photodissociation (UVPD), and activated-ion electron photodetachment dissociation (a-EPD) to yield high-quality MS/MS spectra. Fragments identified using an m/z-domain isotope matching strategy yielded high sequence coverage (>70%) of a yeast phenylalanine tRNA.
Collapse
Affiliation(s)
- Michael B Lanzillotti
- 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
| |
Collapse
|
5
|
Habeck T, Maciel EVS, Kretschmer K, Lermyte F. Charge site manipulation to enhance top-down fragmentation efficiency. Proteomics 2024; 24:e2300082. [PMID: 37043727 DOI: 10.1002/pmic.202300082] [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: 02/10/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/14/2023]
Abstract
In recent years, top-down mass spectrometry has become a widely used approach to study proteoforms; however, improving sequence coverage remains an important goal. Here, two different proteins, α-synuclein and bovine carbonic anhydrase, were subjected to top-down collision-induced dissociation (CID) after electrospray ionisation. Two high-boiling solvents, DMSO and propylene carbonate, were added to the protein solution in low concentration (2%) and the effects on the top-down fragmentation patterns of the proteins were systematically investigated. Each sample was measured in triplicate, which revealed highly reproducible differences in the top-down CID fragmentation patterns in the presence of a solution additive, even if the same precursor charge state was isolated in the quadrupole of the instrument. Further investigation supports the solution condition-dependent selective formation of different protonation site isomers as the underlying cause of these differences. Higher sequence coverage was often observed in the presence of additives, and the benefits of this approach became even more evident when datasets from different solution conditions were combined, as increases up to 35% in cleavage coverage were obtained. Overall, this approach therefore represents a promising opportunity to increase top-down fragmentation efficiency.
Collapse
Affiliation(s)
- Tanja Habeck
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Edvaldo Vasconcelos Soares Maciel
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Kevin Kretschmer
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Frederik Lermyte
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| |
Collapse
|
6
|
Schramm HM, Tamadate T, Hogan CJ, Clowers BH. Evaluation of Hydrogen-Deuterium Exchange during Transient Vapor Binding of MeOD with Model Peptide Systems Angiotensin II and Bradykinin. J Phys Chem A 2023; 127:8849-8861. [PMID: 37827113 DOI: 10.1021/acs.jpca.3c04608] [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: 10/14/2023]
Abstract
The advancement of hybrid mass spectrometric tools as an indirect probe of molecular structure and dynamics relies heavily upon a clear understanding between gas-phase ion reactivity and ion structural characteristics. This work provides new insights into gas-phase ion-neutral reactions of the model peptides (i.e., angiotensin II and bradykinin) on a per-residue basis by integrating hydrogen/deuterium exchange, ion mobility, tandem mass spectrometry, selective vapor binding, and molecular dynamics simulations. By comparing fragmentation patterns with simulated probabilities of vapor uptake, a clear link between gas-phase hydrogen/deuterium exchange and the probabilities of localized vapor association is established. The observed molecular dynamics trends related to the sites and duration of vapor binding track closely with experimental observation. Additionally, the influence of additional charges and structural characteristics on exchange kinetics and ion-neutral cluster formation is examined. These data provide a foundation for the analysis of solvation dynamics of larger, native-like conformations of proteins in the gas phase.
Collapse
Affiliation(s)
- Haley M Schramm
- Department of Chemistry, Washington State University, Pullman, Washington 99163, United States
| | - Tomoya Tamadate
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Christopher J Hogan
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Brian H Clowers
- Department of Chemistry, Washington State University, Pullman, Washington 99163, United States
| |
Collapse
|
7
|
Hua Y, Strauss M, Fisher S, Mauser MFX, Manchet P, Smacchia M, Geyer P, Shayeghi A, Pfeffer M, Eggenweiler TH, Daly S, Commandeur J, Mayor M, Arndt M, Šolomek T, Köhler V. Giving the Green Light to Photochemical Uncaging of Large Biomolecules in High Vacuum. JACS AU 2023; 3:2790-2799. [PMID: 37885583 PMCID: PMC10598566 DOI: 10.1021/jacsau.3c00351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/02/2023] [Accepted: 10/02/2023] [Indexed: 10/28/2023]
Abstract
The isolation of biomolecules in a high vacuum enables experiments on fragile species in the absence of a perturbing environment. Since many molecular properties are influenced by local electric fields, here we seek to gain control over the number of charges on a biopolymer by photochemical uncaging. We present the design, modeling, and synthesis of photoactive molecular tags, their labeling to peptides and proteins as well as their photochemical validation in solution and in the gas phase. The tailored tags can be selectively cleaved off at a well-defined time and without the need for any external charge-transferring agents. The energy of a single or two green photons can already trigger the process, and it is soft enough to ensure the integrity of the released biomolecular cargo. We exploit differences in the cleavage pathways in solution and in vacuum and observe a surprising robustness in upscaling the approach from a model system to genuine proteins. The interaction wavelength of 532 nm is compatible with various biomolecular entities, such as oligonucleotides or oligosaccharides.
Collapse
Affiliation(s)
- Yong Hua
- Department
of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
| | - Marcel Strauss
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Sergey Fisher
- Van’t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, PO Box 94157, 1090 GD Amsterdam, The Netherlands
| | - Martin F. X. Mauser
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Pierre Manchet
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Martina Smacchia
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Philipp Geyer
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Armin Shayeghi
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Michael Pfeffer
- Department
of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
| | - Tim Henri Eggenweiler
- Department
of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
| | - Steven Daly
- MS
Vision, Televisieweg
40, 1322 AM Almere, The Netherlands
| | - Jan Commandeur
- MS
Vision, Televisieweg
40, 1322 AM Almere, The Netherlands
| | - Marcel Mayor
- Department
of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
- Institute
for Nanotechnology (INT), Karlsruhe Institute
of Technology (KIT), P.O. Box 3640, DE-76021 Karlsruhe Eggenstein-Leopoldshafen, Germany
- Lehn Institute
of Functional Materials, School of Chemistry, Sun Yat-Sen University, Guangzhou 510274, P. R. China
| | - Markus Arndt
- Vienna
Faculty of Physics, University of Vienna,
VDSP & VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Tomáš Šolomek
- Van’t
Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, PO Box 94157, 1090 GD Amsterdam, The Netherlands
| | - Valentin Köhler
- Department
of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
| |
Collapse
|
8
|
Juetten KJ, Brodbelt JS. MS-TAFI: A Tool for the Analysis of Fragment Ions Generated from Intact Proteins. J Proteome Res 2023; 22:546-550. [PMID: 36516971 DOI: 10.1021/acs.jproteome.2c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Tandem mass spectrometry (MS/MS) spectra of intact proteins can be difficult to interpret owing to the variety of fragment ion types and abundances. This information is crucial for maximizing the information derived from top-down mass spectrometry of proteins and protein complexes. MS-TAFI (Mass Spectrometry Tool for the Analysis of Fragment Ions) is a free Python-based program which offers a streamlined approach to the data analysis and visualization of deconvoluted MS/MS data of intact proteins. The application also contains tools for native mass spectrometry experiments with the ability to search for fragment ions that retain ligands (holo ions) as well as visualize the location of charge sites obtained from 193 nm ultraviolet photodissociation data. The source code and complete application for MS-TAFI is available for download at https://github.com/kylejuetten.
Collapse
Affiliation(s)
- Kyle J Juetten
- 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
| |
Collapse
|
9
|
Zhou L, Liu Z, Guo Y, Liu S, Zhao H, Zhao S, Xiao C, Feng S, Yang X, Wang F. Ultraviolet Photodissociation Reveals the Molecular Mechanism of Crown Ether Microsolvation Effect on the Gas-Phase Native-like Protein Structure. J Am Chem Soc 2023; 145:1285-1291. [PMID: 36584399 DOI: 10.1021/jacs.2c11210] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Maintaining the protein high-order structures and interactions during the transition from aqueous solution to gas phase is essential to the structural analysis of native mass spectrometry (nMS). Herein, we systematically interrogate the effects of charge state and crown ether (CE) complexation on the gas-phase native-like protein structure by integrating nMS with 193 nm ultraviolet photodissociation (UVPD). The alterations of photofragmentation yields of protein residues and the charge site distribution of fragment ions reveal the specific sites and sequence regions where charge and CE take effect. Our results exhibit the CE complexation on protonated residues can largely alleviate the structure disruption induced by the intramolecular solvation of charged side chains. The influences of CE complexation and positive charge on gas-phase protein structure exhibit generally opposite trends because the CE microsolvation avoids the hydrogen-bonding formation between the charged side chains with backbone carbonyls. Thus, CE complexation leads to a more stable and native-like protein structure in the gas phase.
Collapse
Affiliation(s)
- Lingqiang Zhou
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, 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.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongjie Guo
- 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
| | - Shiwen Liu
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Heng Zhao
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Shan Zhao
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Chunlei Xiao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Shun Feng
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, 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
| |
Collapse
|
10
|
Xia F, Wan JB. Chemical derivatization strategy for mass spectrometry-based lipidomics. MASS SPECTROMETRY REVIEWS 2023; 42:432-452. [PMID: 34486155 DOI: 10.1002/mas.21729] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/02/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Lipids, serving as the structural components of cellular membranes, energy storage, and signaling molecules, play the essential and multiple roles in biological functions of mammals. Mass spectrometry (MS) is widely accepted as the first choice for lipid analysis, offering good performance in sensitivity, accuracy, and structural characterization. However, the untargeted qualitative profiling and absolute quantitation of lipids are still challenged by great structural diversity and high structural similarity. In recent decade, chemical derivatization mainly targeting carboxyl group and carbon-carbon double bond of lipids have been developed for lipidomic analysis with diverse advantages: (i) offering more characteristic structural information; (ii) improving the analytical performance, including chromatographic separation and MS sensitivity; (iii) providing one-to-one chemical isotope labeling internal standards based on the isotope derivatization regent in quantitative analysis. Moreover, the chemical derivatization strategy has shown great potential in combination with ion mobility mass spectrometry and ambient mass spectrometry. Herein, we summarized the current states and advances in chemical derivatization-assisted MS techniques for lipidomic analysis, and their strengths and challenges are also given. In summary, the chemical derivatization-based lipidomic approach has become a promising and reliable technique for the analysis of lipidome in complex biological samples.
Collapse
Affiliation(s)
- Fangbo Xia
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, China
| | - Jian-Bo Wan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, China
| |
Collapse
|
11
|
Cheung See Kit M, Webb IK. Application of Multiple Length Cross-linkers to the Characterization of Gaseous Protein Structure. Anal Chem 2022; 94:13301-13310. [DOI: 10.1021/acs.analchem.2c03044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Melanie Cheung See Kit
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
| | - Ian K. Webb
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| |
Collapse
|
12
|
Sipe SN, Jeanne Dit Fouque K, Garabedian A, Leng F, Fernandez-Lima F, Brodbelt JS. Exploring the Conformations and Binding Location of HMGA2·DNA Complexes Using Ion Mobility Spectrometry and 193 nm Ultraviolet Photodissociation Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1092-1102. [PMID: 35687872 PMCID: PMC9274541 DOI: 10.1021/jasms.2c00083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Although it is widely accepted that protein function is largely dependent on its structure, intrinsically disordered proteins (IDPs) lack defined structure but are essential in proper cellular processes. Mammalian high mobility group proteins (HMGA) are one such example of IDPs that perform a number of crucial nuclear activities and have been highly studied due to their involvement in the proliferation of a variety of disease and cancers. Traditional structural characterization methods have had limited success in understanding HMGA proteins and their ability to coordinate to DNA. Ion mobility spectrometry and mass spectrometry provide insights into the diversity and heterogeneity of structures adopted by IDPs and are employed here to interrogate HMGA2 in its unbound states and bound to two DNA hairpins. The broad distribution of collision cross sections observed for the apo-protein are restricted when HMGA2 is bound to DNA, suggesting that increased protein organization is promoted in the holo-form. Ultraviolet photodissociation was utilized to probe the changes in structures for the compact and elongated structures of HMGA2 by analyzing backbone cleavage propensities and solvent accessibility based on charge-site analysis, which revealed a spectrum of conformational possibilities. Namely, preferential binding of the DNA hairpins with the second of three AT-hooks of HMGA2 is suggested based on the suppression of backbone fragmentation and distribution of DNA-containing protein fragments.
Collapse
Affiliation(s)
- Sarah N Sipe
- Department of Chemistry, University of Texas, Austin, Texas 78712 United States
| | - Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Alyssa Garabedian
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Fenfei Leng
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
- Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas, Austin, Texas 78712 United States
| |
Collapse
|
13
|
Sipe SN, Lancaster EB, Butalewicz JP, Whitman CP, Brodbelt JS. Symmetry of 4-Oxalocrotonate Tautomerase Trimers Influences Unfolding and Fragmentation in the Gas Phase. J Am Chem Soc 2022; 144:12299-12309. [PMID: 35767842 DOI: 10.1021/jacs.2c03564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The recent discovery of asymmetric arrangements of trimers in the tautomerase superfamily (TSF) adds structural diversity to this already mechanistically diverse superfamily. Classification of asymmetric trimers has previously been determined using X-ray crystallography. Here, native mass spectrometry (MS) and ultraviolet photodissociation (UVPD) are employed as an integrated strategy for more rapid and sensitive differentiation of symmetric and asymmetric trimers. Specifically, the unfolding of symmetric and asymmetric trimers initiated by collisional heating was probed using UVPD, which revealed unique gas-phase unfolding pathways. Variations in UVPD patterns from native-like, compact trimeric structures to unfolded, extended conformations indicate a rearrangement of higher-order structure in the asymmetric trimers that are believed to be stabilized by salt-bridge triads, which are absent from the symmetric trimers. Consequently, the symmetric trimers were found to be less stable in the gas phase, resulting in enhanced UVPD fragmentation overall and a notable difference in higher-order re-structuring based on the extent of hydrogen migration of protein fragments. The increased stability of the asymmetric trimers may justify their evolution and concomitant diversification of the TSF. Facilitating the classification of TSF members as symmetric or asymmetric trimers assists in delineating the evolutionary history of the TSF.
Collapse
Affiliation(s)
- Sarah N Sipe
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Emily B Lancaster
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States
| | - Jamie P Butalewicz
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Christian P Whitman
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, University of Texas, Austin, Texas 78712, United States.,Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Macias LA, Wang X, Davies BW, Brodbelt JS. Mapping paratopes of nanobodies using native mass spectrometry and ultraviolet photodissociation. Chem Sci 2022; 13:6610-6618. [PMID: 35756525 PMCID: PMC9172568 DOI: 10.1039/d2sc01536f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/16/2022] [Indexed: 11/21/2022] Open
Abstract
Following immense growth and maturity of the field in the past decade, native mass spectrometry has garnered widespread adoption for the structural characterization of macromolecular complexes. Routine analysis of biotherapeutics by this technique has become commonplace to assist in the development and quality control of immunoglobulin antibodies. Concurrently, 193 nm ultraviolet photodissociation (UVPD) has been developed as a structurally sensitive ion activation technique capable of interrogating protein conformational changes. Here, UVPD was applied to probe the paratopes of nanobodies, a class of single-domain antibodies with an expansive set of applications spanning affinity reagents, molecular imaging, and biotherapeutics. Comparing UVPD sequence fragments for the free nanobodies versus nanobody·antigen complexes empowered assignment of nanobody paratopes and intermolecular salt-bridges, elevating the capabilities of UVPD as a new strategy for characterization of nanobodies. Ultraviolet photodissociation mass spectrometry is used to probe the paratopes of nanobodies, a class of single-domain antibodies, and to determine intersubunit salt-bridges and explore the nanobody·antigen interfaces.![]()
Collapse
Affiliation(s)
- Luis A Macias
- Department of Chemistry, University of Texas at Austin Austin TX 78712 USA
| | - Xun Wang
- Department of Molecular Biosciences, University of Texas at Austin Austin TX 78712 USA
| | - Bryan W Davies
- Department of Molecular Biosciences, University of Texas at Austin Austin TX 78712 USA
| | | |
Collapse
|
16
|
Zviagin A, Kopysov V, Nagornova NS, Boyarkin OV. Tracking local and global structural changes in a protein by cold ion spectroscopy. Phys Chem Chem Phys 2022; 24:8158-8165. [PMID: 35332911 DOI: 10.1039/d2cp00217e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Characterization of native structures of proteins in the gas phase remains challenging due to the unpredictable conformational changes the molecules undergo during desolvation and ionization. We spectroscopically studied cryogenically cooled protonated protein ubiquitin and its microhydrated complexes prepared in the gas phase in a range of charge states under different ionization conditions. The UV spectra appear vibrationally resolved for the unfolded protein, but become redshifted and smooth for the native-like structures of ubiquitin. This spectroscopic change results from the H-bonding of the hydroxyl of Tyr to the amide group of Glu-51 in the compact structures; the minimum length of this bond was estimated to be ∼1.7 Å. IR spectroscopy reflects the global structural change by observing redshifts of free NH/OH-stretch vibrational transitions. Evaporative cooling of microhydrated complexes of ubiquitin keeps the protein chilly during ionization, enabling native-like conformers with up to eight protons to survive in the gas phase.
Collapse
Affiliation(s)
- Andrei Zviagin
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - Vladimir Kopysov
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - Natalia S Nagornova
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| | - Oleg V Boyarkin
- Laboratoire de Chimie Physique Moléculaire, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
17
|
Webb IK. Recent technological developments for native mass spectrometry. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140732. [PMID: 34653668 DOI: 10.1016/j.bbapap.2021.140732] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 11/16/2022]
Abstract
Native mass spectrometry (MS), the analysis of proteins and protein complexes from solutions that stabilize native solution structures, is a rapidly expanding area. There is strong evidence supporting the retention of proteins' native folds in the absence of solvent under the experimental timescales of MS experiments. Therefore, instrumentation has been developed to use gas-phase native-like protein ions to exploit the speed, sensitivity, and selectivity of mass spectrometry approaches to solve emerging problems in structural biology. This article reviews some of the recent advances and applications in gas-phase instrumentation for structural proteomics.
Collapse
Affiliation(s)
- Ian K Webb
- Department of Chemistry and Chemical Biology, Purdue School of Science, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, United States of America; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, United States of America.
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Evaluating the Performance of 193 nm Ultraviolet Photodissociation for Tandem Mass Tag Labeled Peptides. ANALYTICA 2021. [DOI: 10.3390/analytica2040014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite the successful application of tandem mass tags (TMT) for peptide quantitation, missing reporter ions in higher energy collisional dissociation (HCD) spectra remains a challenge for consistent quantitation, especially for peptides with labile post-translational modifications. Ultraviolet photodissociation (UVPD) is an alternative ion activation method shown to provide superior coverage for sequencing of peptides and intact proteins. Here, we optimized and evaluated 193 nm UVPD for the characterization of TMT-labeled model peptides, HeLa proteome, and N-glycopeptides from model proteins. UVPD yielded the same TMT reporter ions as HCD, at m/z 126–131. Additionally, UVPD produced a wide range of fragments that yielded more complete characterization of glycopeptides and less frequent missing TMT reporter ion channels, whereas HCD yielded a strong tradeoff between characterization and quantitation of TMT-labeled glycopeptides. However, the lower fragmentation efficiency of UVPD yielded fewer peptide identifications than HCD. Overall, 193 nm UVPD is a valuable tool that provides an alternative to HCD for the quantitation of large and highly modified peptides with labile PTMs. Continued development of instrumentation specific to UVPD will yield greater fragmentation efficiency and fulfil the potential of UVPD to be an all-in-one spectrum ion activation method for broad use in the field of proteomics.
Collapse
|
20
|
Santos IC, Brodbelt JS. Structural Characterization of Carbonic Anhydrase-Arylsulfonamide Complexes Using Ultraviolet Photodissociation Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1370-1379. [PMID: 33683877 PMCID: PMC8377746 DOI: 10.1021/jasms.1c00004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Numerous mass spectrometry-based strategies ranging from hydrogen-deuterium exchange to ion mobility to native mass spectrometry have been developed to advance biophysical and structural characterization of protein conformations and determination of protein-ligand interactions. In this study, we focus on the use of ultraviolet photodissociation (UVPD) to examine the structure of human carbonic anhydrase II (hCAII) and its interactions with arylsulfonamide inhibitors. Carbonic anhydrase, which catalyzes the conversion of carbon dioxide to bicarbonate, has been the target of countless thermodynamic and kinetic studies owing to its well-characterized active site, binding cavity, and mechanism of inhibition by hundreds of ligands. Here, we showcase the application of UVPD for evaluating structural changes of hCAII upon ligand binding on the basis of variations in fragmentation of hCAII versus hCAII-arylsulfonamide complexes, particularly focusing on the hydrophobic pocket. To extend the coverage in the midregion of the protein sequence, a supercharging agent was added to the solutions to increase the charge states of the complexes. The three arylsulfonamides examined in this study largely shift the fragmentation patterns in similar ways, despite their differences in binding affinities.
Collapse
Affiliation(s)
- Inês C Santos
- 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
| |
Collapse
|
21
|
Kit MCS, Carvalho VV, Vilseck JZ, Webb IK. Gas-Phase Ion/Ion Chemistry for Structurally Sensitive Probes of Gaseous Protein Ion Structure: Electrostatic and Electrostatic to Covalent Cross-Linking. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2021; 463:116549. [PMID: 33716558 PMCID: PMC7946065 DOI: 10.1016/j.ijms.2021.116549] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Intramolecular interactions within a protein are key in maintaining protein tertiary structure and understanding how proteins function. Ion mobility-mass spectrometry (IM-MS) has become a widely used approach in structural biology since it provides rapid measurements of collision cross sections (CCS), which inform on the gas-phase conformation of the biomolecule under study. Gas-phase ion/ion reactions target amino acid residues with specific chemical properties and the modified sites can be identified by MS. In this study, electrostatically reactive, gas-phase ion/ion chemistry and IM-MS are combined to characterize the structural changes between ubiquitin electrosprayed from aqueous and denaturing conditions. The electrostatic attachment of sulfo-NHS acetate to ubiquitin via ion/ion reactions and fragmentation by electron-capture dissociation (ECD) provide the identification of the most accessible protonated sites within ubiquitin as the sulfonate group forms an electrostatic complex with accessible protonated side chains. The protonated sites identified by ECD from the different solution conditions are distinct and, in some cases, reflect the disruption of interactions such as salt bridges that maintain the native protein structure. This agrees with previously published literature demonstrating that a high methanol concentration at low pH causes the structure of ubiquitin to change from a native (N) state to a more elongated A state. Results using gas-phase, electrostatic cross-linking reagents also point to similar structural changes and further confirm the role of methanol and acid in favoring a more unfolded conformation. Since cross-linking reagents have a distance constraint for the two reactive sites, the data is valuable in guiding computational structures generated by molecular dynamics. The research presented here describes a promising strategy that can detect subtle changes in the local environment of targeted amino acid residues to inform on changes in the overall protein structure.
Collapse
Affiliation(s)
- Melanie Cheung See Kit
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, USA
| | - Veronica V. Carvalho
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, USA
| | - Jonah Z. Vilseck
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| | - Ian K. Webb
- Department of Chemistry and Chemical Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, USA
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| |
Collapse
|
22
|
Asami H, Kawauchi N, Kohno JY. Gas-phase hydration of the lysozyme ion produced by infrared-laser ablation of a droplet beam studied by photodissociation and fluorescence spectroscopy. JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4620. [PMID: 32721078 DOI: 10.1002/jms.4620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
Biomolecules function in an aqueous environment. Elucidation of the hydration structures of biomolecules is hence important to understand their functions. Here, we investigated the hydration structure of lysozyme (Lys) in the gas phase by photodissociation and fluorescence spectroscopy in combination with droplet-beam laser ablation mass spectrometry. We found that water molecules are held inside and on the surface of the Lys molecule, and the hydration structure around the tryptophan residue changes by photoexcitation. This study provides a novel method to observe the hydration structures of large biomolecules at the molecular level.
Collapse
Affiliation(s)
- Hiroya Asami
- Department of Chemistry, Faculty of Science, Gakushuin University, Tokyo, Japan
| | - Norishi Kawauchi
- Department of Chemistry, Faculty of Science, Gakushuin University, Tokyo, Japan
| | - Jun-Ya Kohno
- Department of Chemistry, Faculty of Science, Gakushuin University, Tokyo, Japan
| |
Collapse
|
23
|
Lermyte F, Theisen A, O'Connor PB. Solution Condition-Dependent Formation of Gas-Phase Protomers of Alpha-Synuclein in Electrospray Ionization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:364-372. [PMID: 33237779 DOI: 10.1021/jasms.0c00373] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
One of the main characteristics of biomolecular ions in mass spectrometry is their net charge, and a range of approaches exist to either increase or decrease this quantity in the gas phase. In the context of small molecules, it is well known that, in addition to the charge state, the charge site also has a profound effect on an ion's gas-phase behavior; however, this effect has been far less explored for peptides and intact proteins. Methods exist to determine charge sites of protein ions, and others have observed that the interplay of electrostatic repulsion and inherent basicity leads to different sites gaining or losing a charge depending on the total net charge. Here, we report two distinct protonation site isomers ("protomers") of α-synuclein occurring at the same charge state. The protomers showed important differences in their gas-phase fragmentation behavior and were furthermore distinguishable by ion mobility spectrometry. One protomer was produced under standard electrospray conditions, while the other was observed after addition of 10% dimethyl sulfoxide to the protein solution. Charge sites for both protomers were determined using ultraviolet photodissociation.
Collapse
Affiliation(s)
- Frederik Lermyte
- Department of Chemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany
- School of Engineering, University of Warwick, Coventry CV4 7AL, U.K
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Alina Theisen
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Peter B O'Connor
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| |
Collapse
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
Carvalho VV, Cheung See Kit M, Webb IK. Ion Mobility and Gas-Phase Covalent Labeling Study of the Structure and Reactivity of Gaseous Ubiquitin Ions Electrosprayed from Aqueous and Denaturing Solutions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:1037-1046. [PMID: 32255627 PMCID: PMC7205579 DOI: 10.1021/jasms.9b00138] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Gas-phase ion/ion chemistry was coupled to ion mobility/mass spectrometry analysis to correlate the structure of gaseous ubiquitin to its solution structures with selective covalent structural probes. Collision cross section (CCS) distributions were measured to ensure the ubiquitin ions were not unfolded when they were introduced to the gas phase. Aqueous solutions stabilizing the native state of ubiquitin yielded folded ubiquitin structures with CCS values consistent with previously published literature. Denaturing solutions favored several families of unfolded conformations for most of the charge states evaluated. Gas-phase covalent labeling via ion/ion reactions was followed by collision-induced dissociation of the intact, labeled protein to determine which residues were labeled. Ubiquitin 5+ and 6+ electrosprayed from aqueous conditions were covalently modified preferentially at the lysine 29 and arginine 54 positions, indicating that elements of three-dimensional structure were maintained in the gas phase. On the other hand, most ubiquitin ions produced in denaturing conditions were labeled at various other lysine residues, likely due to the availability of additional sites following methanol- and low-pH-induced unfolding. These data support the conservation of ubiquitin structural elements in the gas phase. The research presented here provides the basis for residue-specific characterization of biomolecules in the gas phase.
Collapse
Affiliation(s)
| | | | - Ian K. Webb
- Indiana University Purdue University Indianapolis, Indianapolis, IN, USA 46202
| |
Collapse
|
26
|
Brodbelt JS, Morrison LJ, Santos I. Ultraviolet Photodissociation Mass Spectrometry for Analysis of Biological Molecules. Chem Rev 2020; 120:3328-3380. [PMID: 31851501 PMCID: PMC7145764 DOI: 10.1021/acs.chemrev.9b00440] [Citation(s) in RCA: 139] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The development of new ion-activation/dissociation methods continues to be one of the most active areas of mass spectrometry owing to the broad applications of tandem mass spectrometry in the identification and structural characterization of molecules. This Review will showcase the impact of ultraviolet photodissociation (UVPD) as a frontier strategy for generating informative fragmentation patterns of ions, especially for biological molecules whose complicated structures, subtle modifications, and large sizes often impede molecular characterization. UVPD energizes ions via absorption of high-energy photons, which allows access to new dissociation pathways relative to more conventional ion-activation methods. Applications of UVPD for the analysis of peptides, proteins, lipids, and other classes of biologically relevant molecules are emphasized in this Review.
Collapse
Affiliation(s)
- Jennifer S. Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Lindsay J. Morrison
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Inês Santos
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
27
|
Zhou M, Liu W, Shaw JB. Charge Movement and Structural Changes in the Gas-Phase Unfolding of Multimeric Protein Complexes Captured by Native Top-Down Mass Spectrometry. Anal Chem 2020; 92:1788-1795. [PMID: 31869201 DOI: 10.1021/acs.analchem.9b03469] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The extent to which noncovalent protein complexes retain native structure in the gas phase is highly dependent on experimental conditions. Energetic collisions with background gas can cause structural changes ranging from unfolding to subunit dissociation. Additionally, recent studies have highlighted the role of charge in such structural changes, but the mechanism is not completely understood. In this study, native top down (native TD) mass spectrometry was used to probe gas-phase structural changes of alcohol dehydrogenase (ADH, 4mer) under varying degrees of in-source activation. Changes in covalent backbone fragments produced by electron capture dissociation (ECD) or 193 nm ultraviolet photodissociation (UVPD) were attributed to structural changes of the ADH 4mer. ECD fragments indicated unfolding started at the N-terminus, and the charge states of UVPD fragments enabled monitoring of charge migration to the unfolded regions. Interestingly, UVPD fragments also indicated that the charge at the "unfolding" N-terminus of ADH decreased at high in-source activation energies after the initial increase. We proposed a possible "refolding-after-unfolding" mechanism, as further supported by monitoring hydrogen elimination from radical a-ions produced by UVPD at the N-terminus of ADH. However, "refolding-after-unfolding" with increasing in-source activation was not observed for charge-reduced ADH, which likely adopted compact structures that are resistant to both charge migration and unfolding. When combined, these results support a charge-directed unfolding mechanism for protein complexes. Overall, an experimental framework was outlined for utilizing native TD to generate structure-informative mass spectral signatures for protein complexes that complement other structure characterization techniques, such as ion mobility and computational modeling.
Collapse
Affiliation(s)
- Mowei Zhou
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , 3335 Innovation Boulevard , Richland , Washington 99354 , United States
| | - Weijing Liu
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , 3335 Innovation Boulevard , Richland , Washington 99354 , United States
| | - Jared B Shaw
- Environmental Molecular Sciences Laboratory , Pacific Northwest National Laboratory , 3335 Innovation Boulevard , Richland , Washington 99354 , United States
| |
Collapse
|
28
|
Lermyte F, Everett J, Lam YPY, Wootton CA, Brooks J, Barrow MP, Telling ND, Sadler PJ, O'Connor PB, Collingwood JF. Metal Ion Binding to the Amyloid β Monomer Studied by Native Top-Down FTICR Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2123-2134. [PMID: 31350722 PMCID: PMC6805827 DOI: 10.1007/s13361-019-02283-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 07/01/2019] [Accepted: 07/01/2019] [Indexed: 05/22/2023]
Abstract
Native top-down mass spectrometry is a fast, robust biophysical technique that can provide molecular-scale information on the interaction between proteins or peptides and ligands, including metal cations. Here we have analyzed complexes of the full-length amyloid β (1-42) monomer with a range of (patho)physiologically relevant metal cations using native Fourier transform ion cyclotron resonance mass spectrometry and three different fragmentation methods-collision-induced dissociation, electron capture dissociation, and infrared multiphoton dissociation-all yielding consistent results. Amyloid β is of particular interest as its oligomerization and aggregation are major events in the etiology of Alzheimer's disease, and it is known that interactions between the peptide and bioavailable metal cations have the potential to significantly damage neurons. Those metals which exhibited the strongest binding to the peptide (Cu2+, Co2+, Ni2+) all shared a very similar binding region containing two of the histidine residues near the N-terminus (His6, His13). Notably, Fe3+ bound to the peptide only when stabilized toward hydrolysis, aggregation, and precipitation by a chelating ligand, binding in the region between Ser8 and Gly25. We also identified two additional binding regions near the flexible, hydrophobic C-terminus, where other metals (Mg2+, Ca2+, Mn2+, Na+, and K+) bound more weakly-one centered on Leu34, and one on Gly38. Unexpectedly, collisional activation of the complex formed between the peptide and [CoIII(NH3)6]3+ induced gas-phase reduction of the metal to CoII, allowing the peptide to fragment via radical-based dissociation pathways. This work demonstrates how native mass spectrometry can provide new insights into the interactions between amyloid β and metal cations.
Collapse
Affiliation(s)
- Frederik Lermyte
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK.
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
| | - James Everett
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK
- Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent, Staffordshire, ST4 7QB, UK
| | - Yuko P Y Lam
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | | | - Jake Brooks
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK
| | - Mark P Barrow
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Neil D Telling
- Institute for Science and Technology in Medicine, Keele University, Stoke-on-Trent, Staffordshire, ST4 7QB, UK
| | - Peter J Sadler
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Peter B O'Connor
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | | |
Collapse
|
29
|
Bashyal A, Sanders JD, Holden DD, Brodbelt JS. Top-Down Analysis of Proteins in Low Charge States. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:704-717. [PMID: 30796622 PMCID: PMC6447437 DOI: 10.1007/s13361-019-02146-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 05/08/2023]
Abstract
The impact of charging methods on the dissociation behavior of intact proteins in low charge states is investigated using HCD and 193 nm UVPD. Low charge states are produced for seven different proteins using the following four different methods: (1) proton transfer reactions of ions in high charge states generated from conventional denaturing solutions; (2) ESI of proteins in solutions of high ionic strength to enhance retention of folded native-like conformations; (3) ESI of proteins in high pH solutions to limit protonation; and (4) ESI of carbamylated proteins. Comparison of sequence coverages, degree of preferential cleavages, and types and distribution of fragment ions reveals a number of differences in the fragmentation patterns depending on the method used to generate the ions. More notable differences in these metrics are observed upon HCD than upon UVPD. The fragmentation caused by HCD is influenced more significantly by the presence/absence of mobile protons, a factor that modulates the degree of preferential cleavages and net sequence coverages. Carbamylation of the lysines and the N-terminus of the proteins alters the proton mobility by reducing the number of proton-sequestering, highly basic sites as evidenced by decreased preferential fragmentation C-terminal to Asp or N-terminal to Pro upon HCD. UVPD is less dependent on the method used to generate the low charge states and favors non-specific fragmentation, an outcome which is important for obtaining high sequence coverage of intact proteins.
Collapse
Affiliation(s)
- Aarti Bashyal
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - James D Sanders
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Dustin D Holden
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
30
|
Bakhtiari M, Konermann L. Protein Ions Generated by Native Electrospray Ionization: Comparison of Gas Phase, Solution, and Crystal Structures. J Phys Chem B 2019; 123:1784-1796. [DOI: 10.1021/acs.jpcb.8b12173] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Maryam Bakhtiari
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| |
Collapse
|
31
|
Dyachenko A, Tamara S, Heck AJR. Distinct Stabilities of the Structurally Homologous Heptameric Co-Chaperonins GroES and gp31. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:7-15. [PMID: 29736602 PMCID: PMC6318259 DOI: 10.1007/s13361-018-1910-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/01/2018] [Accepted: 02/01/2018] [Indexed: 05/06/2023]
Abstract
The GroES heptamer is the molecular co-chaperonin that partners with the tetradecamer chaperonin GroEL, which assists in the folding of various nonnative polypeptide chains in Escherichia coli. Gp31 is a structural and functional analogue of GroES encoded by the bacteriophage T4, becoming highly expressed in T4-infected E. coli, taking over the role of GroES, favoring the folding of bacteriophage proteins. Despite being slightly larger, gp31 is quite homologous to GroES in terms of its tertiary and quaternary structure, as well as in its function and mode of interaction with the chaperonin GroEL. Here, we performed a side-by-side comparison of GroES and gp31 heptamer complexes by (ion mobility) tandem mass spectrometry. Surprisingly, we observed quite distinct fragmentation mechanisms for the GroES and gp31 heptamers, whereby GroES displays a unique and unusual bimodal charge distribution in its released monomers. Not only the gas-phase dissociation but also the gas-phase unfolding of GroES and gp31 were found to be very distinct. We rationalize these observations with the similar discrepancies we observed in the thermal unfolding characteristics and surface contacts within GroES and gp31 in the solution. From our data, we propose a model that explains the observed simultaneous dissociation pathways of GroES and the differences between GroES and gp31 gas-phase dissociation and unfolding. We conclude that, although GroES and gp31 exhibit high homology in tertiary and quaternary structure, they are quite distinct in their solution and gas-phase (un)folding characteristics and stability. Graphical Abstract.
Collapse
Affiliation(s)
- Andrey Dyachenko
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Sem Tamara
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
- Netherlands Proteomics Centre, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
| |
Collapse
|
32
|
Theisen A, Black R, Corinti D, Brown JM, Bellina B, Barran PE. Initial Protein Unfolding Events in Ubiquitin, Cytochrome c and Myoglobin Are Revealed with the Use of 213 nm UVPD Coupled to IM-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:24-33. [PMID: 29949061 PMCID: PMC6318241 DOI: 10.1007/s13361-018-1992-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 05/11/2023]
Abstract
The initial stages of protein unfolding may reflect the stability of the entire fold and can also reveal which parts of a protein can be perturbed, without restructuring the rest. In this work, we couple UVPD with activated ion mobility mass spectrometry to measure how three model proteins start to unfold. Ubiquitin, cytochrome c and myoglobin ions produced via nESI from salty solutions are subjected to UV irradiation pre-mobility separation; experiments are conducted with a range of source conditions which alter the conformation of the precursor ion as shown by the drift time profiles. For all three proteins, the compact structures result in less fragmentation than more extended structures which emerge following progressive in-source activation. Cleavage sites are found to differ between conformational ensembles, for example, for the dominant charge state of cytochrome c [M + 7H]7+, cleavage at Phe10, Thr19 and Val20 was only observed in activating conditions whilst cleavage at Ala43 is dramatically enhanced. Mapping the photo-cleaved fragments onto crystallographic structures provides insight into the local structural changes that occur as protein unfolding progresses, which is coupled to global restructuring observed in the drift time profiles. Graphical Abstract.
Collapse
Affiliation(s)
- Alina Theisen
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology and Photon Science Institute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Rachelle Black
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology and Photon Science Institute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Davide Corinti
- Dipartimento di Chimica e Tecnologie del Farmaco, Università di Roma "La Sapienza", 00185, Rome, Italy
| | - Jeffery M Brown
- Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK
| | - Bruno Bellina
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology and Photon Science Institute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Perdita E Barran
- Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology and Photon Science Institute, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK.
| |
Collapse
|
33
|
Egorov D, Bari S, Boll R, Dörner S, Deinert S, Techert S, Hoekstra R, Zamudio-Bayer V, Lindblad R, Bülow C, Timm M, von Issendorff B, Lau JT, Schlathölter T. Near-Edge Soft X-ray Absorption Mass Spectrometry of Protonated Melittin. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:2138-2151. [PMID: 30047073 DOI: 10.1007/s13361-018-2035-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 07/10/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
We have investigated the photoionization and photofragmentation yields of gas-phase multiply protonated melittin cations for photon energies at the K-shell absorption edges of carbon, nitrogen, and oxygen. Two similar experimental approaches were employed. In both experiments, mass selected [melittin+qH]q+ (q=2-4) ions were accumulated in radiofrequency ion traps. The trap content was exposed to intense beams of monochromatic soft X-ray photons from synchrotron beamlines and photoproducts were analyzed by means of time-of-flight mass spectrometry. Mass spectra were recorded for fixed photon energies, and partial ion yield spectra were recorded as a function of photon energy. The combination of mass spectrometry and soft X-ray spectroscopy allows for a direct correlation of protein electronic structure with various photoionization channels. Non-dissociative single and double ionization are used as a reference. The contribution of both channels to various backbone scission channels is quantified and related to activation energies and protonation sites. Soft X-ray absorption mass spectrometry combines fast energy deposition with single and double ionization and could complement established activation techniques. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Dmitrii Egorov
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Rebecca Boll
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Simon Dörner
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Sascha Deinert
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Simone Techert
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
- Institute of X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Ronnie Hoekstra
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands
| | - Vicente Zamudio-Bayer
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Physikalisches Institut, Universität Freiburg, Hermann-Herder-Str. 3, 79104, Freiburg, Germany
| | - Rebecka Lindblad
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Synkrotronljusfysik, Lunds Universitet, 22100, Lund, Sweden
| | - Christine Bülow
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Martin Timm
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Bernd von Issendorff
- Physikalisches Institut, Universität Freiburg, Hermann-Herder-Str. 3, 79104, Freiburg, Germany
| | - J Tobias Lau
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Thomas Schlathölter
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG, Groningen, Netherlands.
| |
Collapse
|
34
|
Lermyte F, Valkenborg D, Loo JA, Sobott F. Radical solutions: Principles and application of electron-based dissociation in mass spectrometry-based analysis of protein structure. MASS SPECTROMETRY REVIEWS 2018; 37:750-771. [PMID: 29425406 PMCID: PMC6131092 DOI: 10.1002/mas.21560] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 05/11/2023]
Abstract
In recent years, electron capture (ECD) and electron transfer dissociation (ETD) have emerged as two of the most useful methods in mass spectrometry-based protein analysis, evidenced by a considerable and growing body of literature. In large part, the interest in these methods is due to their ability to induce backbone fragmentation with very little disruption of noncovalent interactions which allows inference of information regarding higher order structure from the observed fragmentation behavior. Here, we review the evolution of electron-based dissociation methods, and pay particular attention to their application in "native" mass spectrometry, their mechanism, determinants of fragmentation behavior, and recent developments in available instrumentation. Although we focus on the two most widely used methods-ECD and ETD-we also discuss the use of other ion/electron, ion/ion, and ion/neutral fragmentation methods, useful for interrogation of a range of classes of biomolecules in positive- and negative-ion mode, and speculate about how this exciting field might evolve in the coming years.
Collapse
Affiliation(s)
- Frederik Lermyte
- Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, Antwerp, Belgium
- Centre for Proteomics, University of Antwerp, Antwerp, Belgium
- School of Engineering, University of Warwick, Coventry, United Kingdom
| | - Dirk Valkenborg
- Centre for Proteomics, University of Antwerp, Antwerp, Belgium
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Agoralaan, Diepenbeek, Belgium
- Applied Bio and Molecular Systems, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Joseph A Loo
- Department of Biological Chemistry, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California
- UCLA/DOE Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, California
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California
| | - Frank Sobott
- Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp, Antwerp, Belgium
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
- School of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
35
|
Crittenden CM, Morrison LJ, Fitzpatrick MD, Myers AP, Novelli ET, Rosenberg J, Akin LD, Srinivasa S, Shear JB, Brodbelt JS. Towards mapping electrostatic interactions between Kdo 2-lipid A and cationic antimicrobial peptides via ultraviolet photodissociation mass spectrometry. Analyst 2018; 143:3607-3618. [PMID: 29968868 PMCID: PMC6056329 DOI: 10.1039/c8an00652k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cationic antimicrobial peptides (CAMPs) have been known to act as multi-modal weapons against Gram-negative bacteria. As a new approach to investigate the nature of the interactions between CAMPs and the surfaces of bacteria, native mass spectrometry and two MS/MS strategies (ultraviolet photodissociation (UVPD) and higher energy collisional activation (HCD)) are used to examine formation and disassembly of saccharolipid·peptide complexes. Kdo2-lipid A (KLA) is used as a model saccharolipid to evaluate complexation with a series of cationic peptides (melittin and three analogs). Collisional activation of the KLA·peptide complexes results in the disruption of electrostatic interactions, resulting in apo-sequence ions with shifts in the distribution of ions compared to the fragmentation patterns of the apo-peptides. UVPD of the KLA·peptide complexes results in both apo- and holo-sequence ions of the peptides, the latter in which the KLA remains bound to the truncated peptide fragment despite cleavage of a covalent bond of the peptide backbone. Mapping both the N- and C-terminal holo-product ions gives insight into the peptide motifs (specifically an electropositive KRKR segment and a proline residue) that are responsible for mediating the electrostatic interactions between the cationic peptides and saccharolipid.
Collapse
Affiliation(s)
| | - Lindsay J Morrison
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Mignon D Fitzpatrick
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Allison P Myers
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Elisa T Novelli
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Jake Rosenberg
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Lucas D Akin
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Sorin Srinivasa
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Jason B Shear
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA.
| |
Collapse
|
36
|
Rosenberg J, Parker WR, Cammarata MB, Brodbelt JS. UV-POSIT: Web-Based Tools for Rapid and Facile Structural Interpretation of Ultraviolet Photodissociation (UVPD) Mass Spectra. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1323-1326. [PMID: 29626295 PMCID: PMC6004247 DOI: 10.1007/s13361-018-1918-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 02/11/2018] [Accepted: 02/11/2018] [Indexed: 05/23/2023]
Abstract
UV-POSIT (Ultraviolet Photodissociation Online Structure Interrogation Tools) is a suite of web-based tools designed to facilitate the rapid interpretation of data from native mass spectrometry experiments making use of 193 nm ultraviolet photodissociation (UVPD). The suite includes four separate utilities which assist in the calculation of fragment ion abundances as a function of backbone cleavage sites and sequence position; the localization of charge sites in intact proteins; the calculation of hydrogen elimination propensity for a-type fragment ions; and mass-offset searching of UVPD spectra to identify unknown modifications and assess false positive fragment identifications. UV-POSIT is implemented as a Python/Flask web application hosted at http://uv-posit.cm.utexas.edu . UV-POSIT is available under the MIT license, and the source code is available at https://github.com/jarosenb/UV_POSIT . Graphical Abstract.
Collapse
Affiliation(s)
- Jake Rosenberg
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - W Ryan Parker
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Michael B Cammarata
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jennifer S Brodbelt
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA.
| |
Collapse
|
37
|
Morrison LJ, Chai W, Rosenberg JA, Henkelman G, Brodbelt JS. Characterization of hydrogen bonding motifs in proteins: hydrogen elimination monitoring by ultraviolet photodissociation mass spectrometry. Phys Chem Chem Phys 2018; 19:20057-20074. [PMID: 28722742 DOI: 10.1039/c7cp04073c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Determination of structure and folding of certain classes of proteins remains intractable by conventional structural characterization strategies and has spurred the development of alternative methodologies. Mass spectrometry-based approaches have a unique capacity to differentiate protein heterogeneity due to the ability to discriminate populations, whether minor or major, featuring modifications or complexation with non-covalent ligands on the basis of m/z. Cleavage of the peptide backbone can be further utilized to obtain residue-specific structural information. Here, hydrogen elimination monitoring (HEM) upon ultraviolet photodissociation (UVPD) of proteins transferred to the gas phase via nativespray ionization is introduced as an innovative approach to deduce backbone hydrogen bonding patterns. Using well-characterized peptides and a series of proteins, prediction of the engagement of the amide carbonyl oxygen of the protein backbone in hydrogen bonding using UVPD-HEM is demonstrated to show significant agreement with the hydrogen-bonding motifs derived from molecular dynamics simulations and X-ray crystal structures.
Collapse
|
38
|
Ciach MA, Łącki MK, Miasojedow B, Lermyte F, Valkenborg D, Sobott F, Gambin A. Estimation of Rates of Reactions Triggered by Electron Transfer in Top-Down Mass Spectrometry. J Comput Biol 2017; 25:282-301. [PMID: 28945460 DOI: 10.1089/cmb.2017.0156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Electron transfer dissociation (ETD) is a versatile technique used in mass spectrometry for the high-throughput characterization of proteins. It consists of several concurrent reactions triggered by the transfer of an electron from its anion source to sample cations. Transferring an electron causes peptide backbone cleavage while leaving labile post-translational modifications intact. The obtained fragmentation spectra provide valuable information for sequence and structure analyses. In this study, we propose a formal mathematical model of the ETD fragmentation process in the form of a system of stochastic differential equations describing its joint dynamics. Parameters of the model correspond to the rates of occurring reactions. Their estimates for various experimental settings give insight into the dynamics of the ETD process. We estimate the model parameters from the relative quantities of fragmentation products in a given mass spectrum by solving a nonlinear optimization problem. The cost function penalizes for the differences between the analytically derived average number of reaction products and their experimental counterparts. The presented method proves highly robust to noise in silico. Moreover, the model can explain a considerable amount of experimental results for a wide range of instrumentation settings. The implementation of the presented workflow, code-named ETDetective, is freely available under the two-clause BSD license.
Collapse
Affiliation(s)
| | | | - Błażej Miasojedow
- 1 Faculty of Mathematics, Informatics, and Mechanics, University of Warsaw , Warsaw, Poland
| | - Frederik Lermyte
- 2 Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp , Antwerp, Belgium .,3 Centre for Proteomics, University of Antwerp , Antwerp, Belgium
| | - Dirk Valkenborg
- 3 Centre for Proteomics, University of Antwerp , Antwerp, Belgium .,4 Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University , Hasselt, Belgium
| | - Frank Sobott
- 2 Biomolecular and Analytical Mass Spectrometry Group, Department of Chemistry, University of Antwerp , Antwerp, Belgium
| | - Anna Gambin
- 1 Faculty of Mathematics, Informatics, and Mechanics, University of Warsaw , Warsaw, Poland
| |
Collapse
|
39
|
R Julian R. The Mechanism Behind Top-Down UVPD Experiments: Making Sense of Apparent Contradictions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:1823-1826. [PMID: 28702929 PMCID: PMC5711567 DOI: 10.1007/s13361-017-1721-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/15/2017] [Accepted: 05/22/2017] [Indexed: 05/21/2023]
Abstract
Top-down ultraviolet photodissociation (UVPD) allows greater sequence coverage than any other currently available method, often fracturing the vast majority of peptide bonds in whole proteins. At the same time, UVPD can be used to dissociate noncovalent complexes assembled from multiple proteins without breaking any covalent bonds. Although the utility of these experiments is unquestioned, the mechanism underlying these seemingly contradictory results has been the subject of many discussions. Herein, some fundamental considerations of photochemistry are briefly summarized within the context of a proposed mechanism that rationalizes the experimental results obtained by UVPD. Considerations for future instrument design, in terms of wavelength choice and power, are briefly discussed. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
- Ryan R Julian
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA.
| |
Collapse
|
40
|
Bonner J, Lyon YA, Nellessen C, Julian RR. Photoelectron Transfer Dissociation Reveals Surprising Favorability of Zwitterionic States in Large Gaseous Peptides and Proteins. J Am Chem Soc 2017; 139:10286-10293. [PMID: 28678494 PMCID: PMC5543396 DOI: 10.1021/jacs.7b02428] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Structural
characterization of proteins in the gas phase is becoming
increasingly popular, highlighting the need for a greater understanding
of how proteins behave in the absence of solvent. It is clear that
charged residues exert significant influence over structures in the
gas phase due to strong Coulombic and hydrogen-bonding interactions.
The net charge for a gaseous ion is easily identified by mass spectrometry,
but the presence of zwitterionic pairs or salt bridges has previously
been more difficult to detect. We show that these sites can be revealed
by photoinduced electron transfer dissociation, which produces characteristic
c and z ions only if zwitterionic species are present. Although previous
work on small molecules has shown that zwitterionic pairs are rarely
stable in the gas phase, we now demonstrate that charge-separated
states are favored in larger molecules. Indeed, we have detected zwitterionic
pairs in peptides and proteins where the net charge equals the number
of basic sites, requiring additional protonation at nonbasic residues.
For example, the small protein ubiquitin can sustain a zwitterionic
conformer for all charge states up to 14+, despite having only 13
basic sites. Virtually all of the peptides/proteins examined herein
contain zwitterionic sites if both acidic and basic residues are present
and the overall charge density is low. This bias in favor of charge-separated
states has important consequences for efforts to model gaseous proteins
via computational analysis, which should consider not only charge
state isomers that include salt bridges but also protonation at nonbasic
residues.
Collapse
Affiliation(s)
- James Bonner
- Department of Chemistry, University of California , Riverside, California 92521, United States
| | - Yana A Lyon
- Department of Chemistry, University of California , Riverside, California 92521, United States
| | - Christopher Nellessen
- Department of Chemistry, University of California , Riverside, California 92521, United States
| | - Ryan R Julian
- Department of Chemistry, University of California , Riverside, California 92521, United States
| |
Collapse
|
41
|
Riley NM, Westphall MS, Coon JJ. Activated Ion-Electron Transfer Dissociation Enables Comprehensive Top-Down Protein Fragmentation. J Proteome Res 2017; 16:2653-2659. [PMID: 28608681 DOI: 10.1021/acs.jproteome.7b00249] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Here we report the first demonstration of near-complete sequence coverage of intact proteins using activated ion-electron transfer dissociation (AI-ETD), a method that leverages concurrent infrared photoactivation to enhance electron-driven dissociation. AI-ETD produces mainly c/z-type product ions and provides comprehensive (77-97%) protein sequence coverage, outperforming HCD, ETD, and EThcD for all proteins investigated. AI-ETD also maintains this performance across precursor ion charge states, mitigating charge-state dependence that limits traditional approaches.
Collapse
Affiliation(s)
| | | | - Joshua J Coon
- Morgridge Institute for Research , Madison, Wisconsin 53715, United States
| |
Collapse
|
42
|
Cleland TP, DeHart CJ, Fellers RT, VanNispen AJ, Greer JB, LeDuc RD, Parker WR, Thomas PM, Kelleher NL, Brodbelt JS. High-Throughput Analysis of Intact Human Proteins Using UVPD and HCD on an Orbitrap Mass Spectrometer. J Proteome Res 2017; 16:2072-2079. [PMID: 28412815 DOI: 10.1021/acs.jproteome.7b00043] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The analysis of intact proteins (top-down strategy) by mass spectrometry has great potential to elucidate proteoform variation, including patterns of post-translational modifications (PTMs), which may not be discernible by analysis of peptides alone (bottom-up approach). To maximize sequence coverage and localization of PTMs, various fragmentation modes have been developed to produce fragment ions from deep within intact proteins. Ultraviolet photodissociation (UVPD) has recently been shown to produce high sequence coverage and PTM retention on a variety of proteins, with increasing evidence of efficacy on a chromatographic time scale. However, utilization of UVPD for high-throughput top-down analysis to date has been limited by bioinformatics. Here we detected 153 proteins and 489 proteoforms using UVPD and 271 proteins and 982 proteoforms using higher energy collisional dissociation (HCD) in a comparative analysis of HeLa whole-cell lysate by qualitative top-down proteomics. Of the total detected proteoforms, 286 overlapped between the UVPD and HCD data sets, with 68% of proteoforms having C scores greater than 40 for UVPD and 63% for HCD. The average sequence coverage (28 ± 20% for UVPD versus 17 ± 8% for HCD, p < 0.0001) was found to be higher for UVPD than HCD and with a trend toward improvement in q value for the UVPD data set. This study demonstrates the complementarity of UVPD and HCD for more extensive protein profiling and proteoform characterization.
Collapse
Affiliation(s)
- Timothy P Cleland
- Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| | - Caroline J DeHart
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States
| | - Ryan T Fellers
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States
| | - Alexandra J VanNispen
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States
| | - Joseph B Greer
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States
| | - Richard D LeDuc
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States
| | - W Ryan Parker
- Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| | - Paul M Thomas
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States.,Departments of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University , Evanston, Illinois 60208, United States
| | - Neil L Kelleher
- National Resource for Translational and Developmental Proteomics, Northwestern University , Evanston, Illinois 60208, United States.,Departments of Chemistry, Molecular Biosciences, and the Feinberg School of Medicine, Northwestern University , Evanston, Illinois 60208, United States
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States
| |
Collapse
|
43
|
Cammarata M, Thyer R, Lombardo M, Anderson A, Wright D, Ellington A, Brodbelt JS. Characterization of trimethoprim resistant E. coli dihydrofolate reductase mutants by mass spectrometry and inhibition by propargyl-linked antifolates. Chem Sci 2017; 8:4062-4072. [PMID: 29967675 PMCID: PMC6020862 DOI: 10.1039/c6sc05235e] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/24/2017] [Indexed: 12/12/2022] Open
Abstract
Native mass spectrometry, size exclusion chromatography, and kinetic assays were employed to study trimethoprim resistance in E. coli caused by mutations P21L and W30R of dihydrofolate reductase.
Pathogenic Escherichia coli, one of the primary causes of urinary tract infections, has shown significant resistance to the most popular antibiotic, trimethoprim (TMP), which inhibits dihydrofolate reductase (DHFR). The resistance is modulated by single point mutations of DHFR. The impact of two clinically relevant mutations, P21L and W30R, on the activity of DHFR was evaluated via measurement of Michaelis–Menten and inhibitory kinetics, and structural characterization was undertaken by native mass spectrometry with ultraviolet photodissociation (UVPD). Compared to WT-DHFR, both P21L and W30R mutants produced less stable complexes with TMP in the presence of co-factor NADPH as evidenced by the relative abundances of complexes observed in ESI mass spectra. Moreover, based on variations in the fragmentation patterns obtained by UVPD mass spectrometry of binary and ternary DHFR complexes, notable structural changes were localized to the substrate binding pocket for W30R and to the M20 loop region as well as the C-terminal portion containing the essential G–H functional loop for the P21L mutant. The results suggest that the mutations confer resistance through distinctive mechanisms. A novel propargyl-linked antifolate compound 1038 was shown to be a reasonably effective inhibitor of the P21L mutant.
Collapse
Affiliation(s)
- Michael Cammarata
- Department of Chemistry , University of Texas , Austin , TX 78712 , USA .
| | - Ross Thyer
- Center for Systems and Synthetic Biology , University of Texas , Austin , TX 78712 , USA
| | - Michael Lombardo
- Department of Pharmaceutical Sciences , University of Connecticut , Storrs , CT 06269 , USA
| | - Amy Anderson
- Department of Pharmaceutical Sciences , University of Connecticut , Storrs , CT 06269 , USA
| | - Dennis Wright
- Department of Pharmaceutical Sciences , University of Connecticut , Storrs , CT 06269 , USA
| | - Andrew Ellington
- Center for Systems and Synthetic Biology , University of Texas , Austin , TX 78712 , USA
| | | |
Collapse
|
44
|
Egorov D, Hoekstra R, Schlathölter T. A comparative VUV absorption mass-spectroscopy study on protonated peptides of different size. Phys Chem Chem Phys 2017; 19:20608-20618. [DOI: 10.1039/c7cp03203j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The response of gas-phase peptides upon vacuum ultraviolet absorption depends strongly on the peptide size.
Collapse
Affiliation(s)
- D. Egorov
- Zernike Institute for Advanced Materials
- University of Groningen
- 9747AG Groningen
- The Netherlands
| | - R. Hoekstra
- Zernike Institute for Advanced Materials
- University of Groningen
- 9747AG Groningen
- The Netherlands
| | - T. Schlathölter
- Zernike Institute for Advanced Materials
- University of Groningen
- 9747AG Groningen
- The Netherlands
| |
Collapse
|
45
|
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.
Collapse
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
| |
Collapse
|
46
|
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.
Collapse
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
| |
Collapse
|