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Rahman M, Marzullo B, Holman SW, Barrow M, Ray AD, O’Connor PB. Advancing PROTAC Characterization: Structural Insights through Adducts and Multimodal Tandem-MS Strategies. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:285-299. [PMID: 38197777 PMCID: PMC10853971 DOI: 10.1021/jasms.3c00342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/21/2023] [Accepted: 12/25/2023] [Indexed: 01/11/2024]
Abstract
Proteolysis targeting chimeras (PROTACs) are specialized molecules that bind to a target protein and a ubiquitin ligase to facilitate protein degradation. Despite their significance, native PROTACs have not undergone tandem mass spectrometry (MS) analysis. To address this gap, we conducted a pioneering investigation on the fragmentation patterns of two PROTACs in development, dBET1 and VZ185. Employing diverse cations (sodium, lithium, and silver) and multiple tandem-MS techniques, we enhanced their structural characterization. Notably, lithium cations facilitated comprehensive positive-mode coverage for dBET1, while negative polarity mode offered richer insights. Employing de novo structure determination on 2DMS data from degradation studies yielded crucial insights. In the case of VZ185, various charge states were observed, with [M + 2H]2+ revealing fewer moieties than [M + H]+ due to charge-related factors. Augmenting structural details through silver adducts suggested both charge-directed and charge-remote fragmentation. This comprehensive investigation identifies frequently dissociated bonds across multiple fragmentation techniques, pinpointing optimal approaches for elucidating PROTAC structures. The findings contribute to advancing our understanding of PROTACs, pivotal for their continued development as promising therapeutic agents.
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Affiliation(s)
- Mohammed Rahman
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
- Department
of Physics, University of Warwick, Coventry, CV4 7AL, U.K.
| | - Bryan Marzullo
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
| | - Stephen W. Holman
- Chemical
Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, SK10 4TF, U.K.
| | - Mark Barrow
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
| | - Andrew D. Ray
- New
Modalities and Parenteral Development, Pharmaceutical Technology &
Development, Operations, AstraZeneca, Macclesfield, SK10 4TF, U.K.
| | - Peter B. O’Connor
- Department
of Chemistry, University of Warwick, Coventry, CV4 7AL, U.K.
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2
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Morgan TE, Floyd TG, Marzullo BP, Wootton CA, Barrow MP, Bristow AWT, Perrier S, O'Connor PB. Stochasticity of poly(2-oxazoline) oligomer hydrolysis determined by tandem mass spectrometry. Polym Chem 2022; 13:4162-4169. [PMID: 35923808 PMCID: PMC9294869 DOI: 10.1039/d2py00437b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022]
Abstract
Understanding modification of synthetic polymer structures is necessary for their accurate synthesis and potential applications. In this contribution, a series of partially hydrolyzed poly(2-oxazoline) species were produced forming poly[(2-polyoxazoline)-co-(ethylenimine)] (P(EtOx-co-EI)) copolymers; EI being the hydrolyzed product of Ox. Bulk mass spectrometry (MS) measurements accurately measured the EI content. Tandem mass spectrometry analysis of the EI content in the copolymer samples determined the distribution of each monomer within the copolymer and corresponded to a theoretically modelled random distribution. The EI distribution across the polymers was shown to be effected by the choice of terminus, with a permanent hydrolysis event observed at an OH terminus. A neighbouring group effect wasn't observed at the polymer length analysed (approximately 25-mer species), suggesting that previously observed neighbouring group effects require a larger polymer chain. Although clearly useful for random polymer distribution this approach may be applied to many systems containing non-specific modifications to determine if they are directed or random locations across peptides, proteins, polymers, and nucleic acids. Tandem mass spectrometry can be used to better understand modification sites of synthetic polymer structures providing more complete chemical knowledge which is necessary for their accurate synthesis and potential applications.![]()
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Affiliation(s)
- Tomos E Morgan
- Department of Chemistry, University of Warwick Coventry CV4 7AL UK
| | - Thomas G Floyd
- Department of Chemistry, University of Warwick Coventry CV4 7AL UK
| | - Bryan P Marzullo
- Department of Chemistry, University of Warwick Coventry CV4 7AL UK
| | | | - Mark P Barrow
- Department of Chemistry, University of Warwick Coventry CV4 7AL UK
| | - Anthony W T Bristow
- Chemical Development, Pharmaceutical Technology and Development, Operations, AstraZeneca Charter Way Macclesfield SK102NA UK
| | - Sébastien Perrier
- Department of Chemistry, University of Warwick Coventry CV4 7AL UK
- Warwick Medical School, University of Warwick Coventry CV4 7AL UK
- Faculty of Pharmaceutical Sciences, Monash University 381 Royal Parade Parkville VIC 3052 Australia
| | - Peter B O'Connor
- Department of Chemistry, University of Warwick Coventry CV4 7AL UK
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3
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Marzullo BP, Morgan TE, Theisen A, Haris A, Wootton CA, Perry SJ, Saeed M, Barrow MP, O'Connor PB. Combining Ultraviolet Photodissociation and Two-Dimensional Mass Spectrometry: A Contemporary Approach for Characterizing Singly Charged Agrochemicals. Anal Chem 2021; 93:9462-9470. [PMID: 34192872 DOI: 10.1021/acs.analchem.1c01185] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ultraviolet photodissociation (UVPD) has been shown to produce extensive structurally informative data for a variety of chemically diverse compounds. Herein, we demonstrate the performance of the 193 nm UVPD fragmentation technique on structural/moiety characterization of 14 singly charged agrochemicals. Two-dimensional mass spectrometry (2DMS) using infrared multiphoton dissociation (IRMPD) and electron-induced dissociation (EID) have previously been applied to a select range of singly charged pesticides. The ≥80% moiety coverage achieved for the majority of the species by the UVPD and 2D-UVPD methods was on par with and, in some cases, superior to the data obtained by other fragmentation techniques in previous studies, demonstrating that UVPD is viable for these types of species. A three-dimensional (3D) peak picking method was implemented to extract the data from the 2DMS spectrum, overcoming the limitations of the line extraction method used in previous studies, successfully separating precursor specific fragments with milli-Dalton accuracy. Whole spectrum internal calibration combined with 3D peak picking obtained sub-part-per-million (ppm) to part-per-billion (ppb) mass accuracies across the entire 2DMS spectrum.
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Affiliation(s)
- Bryan P Marzullo
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Tomos E Morgan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Alina Theisen
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Anisha Haris
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | | | - Simon J Perry
- Product Metabolism & Analytical Sciences, Jealott's Hill International Research Centre, Syngenta, Bracknell, Berkshire RG42 6EY, United Kingdom
| | - Mansoor Saeed
- Product Metabolism & Analytical Sciences, Jealott's Hill International Research Centre, Syngenta, Bracknell, Berkshire RG42 6EY, United Kingdom
| | - Mark P Barrow
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Peter B O'Connor
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
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4
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Rathod S, Bahadur P, Tiwari S. Nanocarriers based on vitamin E-TPGS: Design principle and molecular insights into improving the efficacy of anticancer drugs. Int J Pharm 2021; 592:120045. [DOI: 10.1016/j.ijpharm.2020.120045] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 02/06/2023]
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5
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Morgan TE, Kerr A, Wootton CA, Barrow MP, Bristow AW, Perrier S, O’Connor PB. Electron Capture Dissociation of Trithiocarbonate-Terminated Acrylamide Homo- and Copolymers: A Terminus-Directed Mechanism? Anal Chem 2020; 92:12852-12859. [DOI: 10.1021/acs.analchem.0c01224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Tomos E. Morgan
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | - Andrew Kerr
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | | | - Mark P. Barrow
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | - Anthony W.T. Bristow
- Chemical Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, Cheshire SK10 2NA, U.K
| | - Sébastien Perrier
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, U.K
- Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Peter B. O’Connor
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
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6
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Shen Y, Yao J, Son J, Zhu Z, Yu XY. Liquid ToF-SIMS revealing the oil, water, and surfactant interface evolution. Phys Chem Chem Phys 2020; 22:11771-11782. [PMID: 32227050 DOI: 10.1039/d0cp00528b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Bilge water from ships is regarded as a major pollutant in the marine environment. Bilge water exists in a stable oil-in-water (O/W) emulsion form. However, little is known about the O/W liquid-liquid (l-l) interface. Traditional bulk characterization approaches are not capable of capturing the chemical changes at the O/W l-l interface. Although surfactants are deemed essential in droplet formation, their roles in bilge water stabilization have not been fully revealed. We have utilized novel in situ chemical imaging tools including in situ scanning electron microscopy (SEM) and in situ time-of-flight secondary ion mass spectrometry (ToF-SIMS) to study the evolving O/W interface using a NAVY bilge model for the first time. The droplet size distribution (DSD) does not change significantly without the addition of X-100 surfactants under static or rocking conditions. Both the oil components and the water clusters are shown to evolve over time at the O/W droplet interface by in situ liquid SIMS imaging. Of particular interest to droplet stabilization, the contribution of surfactants to the aged bilge droplets becomes more significant as the droplet size increases. The higher mass surfactant component does not appear on the droplet surface immediately while many lower mass surfactants are solvated inside the droplet. We have provided the first three-dimensional images of the evolving O/W interface and demonstrated that in situ surface chemical mapping is powerful enough to reveal the complex and dynamic l-l interface in the liquid state. Our observational insights suggest that surfactants are important in mediating droplet growth and facilitating effective separation of bilge water emulsion.
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Affiliation(s)
- Yanjie Shen
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
| | - Jenn Yao
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
| | - Jiyoung Son
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
| | - Zihua Zhu
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Xiao-Ying Yu
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
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7
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Castilla C, Rüger CP, Marcotte S, Lavanant H, Afonso C. Direct Inlet Probe Atmospheric Pressure Photo and Chemical Ionization Coupled to Ultrahigh Resolution Mass Spectrometry for the Description of Lignocellulosic Biomass. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:822-831. [PMID: 32134658 DOI: 10.1021/jasms.9b00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Lignocellulosic biomass, in particular wood, is a complex mixture containing cellulose, hemicellulose, lignin, and other trace compounds. Chemical analysis of these biomasses, especially lignin components, is a challenge. Lignin is a highly reticulated polymer that is poorly soluble and usually requires chemical, enzymatic, or thermal degradation for its analysis. Here, we studied the thermal degradation of lignocellulosic biomass using a direct insertion probe (DIP). The DIP was used with two ionization sources: atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) coupled to ultrahigh-resolution mass spectrometry. Beech lignocellulosic biomass samples were used to develop the DIP-APCI/APPI methodology. Two other wood species (maple and oak) were analyzed after optimization of DIP parameters. The two ionization sources were compared at first and showed different responses toward beech samples, according to the source specificity. APPI was more specific to lignin degradation compounds, whereas APCI covered a larger variety of oxygenated compounds, e.g., fatty acids and polyphenolics compounds, in addition to lignin degradation products. The study of the thermodesorption profile gave information on the different steps of lignocellulosic biomass pyrolysis. The comparison of the three feed sample types (oak, maple, and beech), using principal component analysis (PCA) with DIP-APCI experiments, showed molecular level differences between beech wood pellets and the two other wood species (maple and oak).
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Affiliation(s)
- Clément Castilla
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, COBRA, 76000 Rouen, France
| | - Christopher P Rüger
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, COBRA, 76000 Rouen, France
- Institut für Chemie, Abteilung für Analytische und Technische Chemie, Universität Rostock, Dr.-Lorenz.-Weg 1, Rostock, 18059, Germany
| | - Stéphane Marcotte
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, COBRA, 76000 Rouen, France
| | - Hélène Lavanant
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, COBRA, 76000 Rouen, France
| | - Carlos Afonso
- Normandie Université, UNIROUEN, INSA Rouen, CNRS, COBRA, 76000 Rouen, France
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8
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Marzullo BP, Morgan TE, Wootton CA, Li M, Perry SJ, Saeed M, Barrow MP, O'Connor PB. Comparison of Fragmentation Techniques for the Structural Characterization of Singly Charged Agrochemicals. Anal Chem 2020; 92:3143-3151. [PMID: 31909982 DOI: 10.1021/acs.analchem.9b04820] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Investigating the structure of active ingredients, such as agrochemicals and their associated metabolites, is a crucial requisite in the discovery and development of these molecules. In this study, structural characterization by electron-induced dissociation (EID) was compared to collisionally activated dissociation (CAD) on a series of agrochemicals. EID fragmentation produced a greater variety of fragment ions and complementary ion pairs leading to more complete functional group characterization compared to CAD. The results obtained displayed many more cross-ring fragmentation of the pyrimidine ring compared to the pyridine ring. Compounds that consisted of one aromatic heterocyclic moiety (azoxystrobin, fluazifop acid, fluazifop-p-butyl, and pirimiphos-methyl) displayed cross-ring fragmentation while compounds with only aromatic hydrocarbon rings (fenpropidin and S-metolachlor) displayed no cross-ring fragmentation. The advantages of high-resolution accurate mass spectrometry (HRAM MS) are shown with the majority of assignments at ppb range error values and the ability to differentiate ions with the same nominal mass but different elemental composition. This highlights the potential for HRAM MS and EID to be used as a tool for structural characterization of small molecules with a wide variety of functional groups and structural motifs.
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Affiliation(s)
- Bryan P Marzullo
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Tomos E Morgan
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | | | - Meng Li
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Simon J Perry
- Syngenta, Jealott's Hill International Research Centre , Product Metabolism & Analytical Sciences , RG42 6EY Berkshire , United Kingdom
| | - Mansoor Saeed
- Syngenta, Jealott's Hill International Research Centre , Product Metabolism & Analytical Sciences , RG42 6EY Berkshire , United Kingdom
| | - Mark P Barrow
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Peter B O'Connor
- Department of Chemistry , University of Warwick , Coventry CV4 7AL , United Kingdom
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9
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Morgan TE, Ellacott SH, Wootton CA, Barrow MP, Bristow AWT, Perrier S, O’Connor PB. Coupling Electron Capture Dissociation and the Modified Kendrick Mass Defect for Sequencing of a Poly(2-ethyl-2-oxazoline) Polymer. Anal Chem 2018; 90:11710-11715. [DOI: 10.1021/acs.analchem.8b03591] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Tomos E. Morgan
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | - Sean H. Ellacott
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | | | - Mark P. Barrow
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | | | - Sebastien Perrier
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
| | - Peter B. O’Connor
- Department of Chemistry, University of Warwick, Coventry, Midlands CV4 7AL, U.K
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10
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Ahmadi S, Winter D. Identification of Poly(ethylene glycol) and Poly(ethylene glycol)-Based Detergents Using Peptide Search Engines. Anal Chem 2018; 90:6594-6600. [DOI: 10.1021/acs.analchem.8b00365] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Shiva Ahmadi
- Institute for Biochemistry and Molecular Biology, University of Bonn, 53115 Bonn, Germany
| | - Dominic Winter
- Institute for Biochemistry and Molecular Biology, University of Bonn, 53115 Bonn, Germany
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11
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Floris F, Vallotto C, Chiron L, Lynch AM, Barrow MP, Delsuc MA, O’Connor PB. Polymer Analysis in the Second Dimension: Preliminary Studies for the Characterization of Polymers with 2D MS. Anal Chem 2017; 89:9892-9899. [DOI: 10.1021/acs.analchem.7b02086] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Federico Floris
- University of Warwick, Department of Chemistry, Coventry, CV4 7AL, United Kingdom
| | - Claudio Vallotto
- University of Warwick, Department of Chemistry, Coventry, CV4 7AL, United Kingdom
| | - Lionel Chiron
- CASC4DE, 20 Avenue du Neuhof, 67100, Strasbourg, France
| | - Alice M. Lynch
- University of Warwick, Department of Chemistry, Coventry, CV4 7AL, United Kingdom
| | - Mark P. Barrow
- University of Warwick, Department of Chemistry, Coventry, CV4 7AL, United Kingdom
| | - Marc-André Delsuc
- CASC4DE, 20 Avenue du Neuhof, 67100, Strasbourg, France
- Institut
de Génétique et de Biologie Moléculaire et Cellulaire,
Institut National de la Santé et de la Recherche, U596, Centre
National de la Recherche Scientifique, Unité Mixte de Recherche
7104, Université de Strasbourg, 67404 Illkirch-Graffenstaden, France
| | - Peter B. O’Connor
- University of Warwick, Department of Chemistry, Coventry, CV4 7AL, United Kingdom
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12
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Qi Y, Volmer DA. Electron-based fragmentation methods in mass spectrometry: An overview. MASS SPECTROMETRY REVIEWS 2017; 36:4-15. [PMID: 26445267 DOI: 10.1002/mas.21482] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/03/2015] [Accepted: 07/03/2015] [Indexed: 05/21/2023]
Abstract
Tandem mass spectrometry (MS/MS) provides detailed information for structural characterization of biomolecules. The combination of electron capture dissociation (ECD) techniques with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) often provides unique ion-electron reactions and fragmentation channels in MS/MS. ECD is often a complimentary, sometimes even a superior tool to conventional MS/MS techniques. This article is aimed at providing a short overview of ECD-based fragmentation techniques (ExD) and optimization of ECD experiments for FTICR mass analyzers. Most importantly, it is meant to pique the interest of potential users for this exciting research field. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:4-15, 2017.
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Affiliation(s)
- Yulin Qi
- Institute of Bioanalytical Chemistry, Saarland University, Campus B2.2, Saarbrücken, 66123, Germany
| | - Dietrich A Volmer
- Institute of Bioanalytical Chemistry, Saarland University, Campus B2.2, Saarbrücken, 66123, Germany
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13
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Qi Y, Volmer DA. Structural analysis of small to medium-sized molecules by mass spectrometry after electron-ion fragmentation (ExD) reactions. Analyst 2016; 141:794-806. [PMID: 26725919 DOI: 10.1039/c5an02171e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electron capture dissociation (ECD) is a tandem mass spectrometry (MS/MS) method that utilizes the interaction of ions and electrons. Its unique ability to preserve labile bonds distinguishes it from conventional threshold-based MS/MS methods, the most important of which is collision-induced dissociation (CID). During the last decade, ECD has opened up several new venues in protein analyses, for example top-down sequencing, identification of post-translational modifications, and characterization of protein-protein interactions. In recent years, a number of related dissociation techniques, so-called ExD techniques, particularly electron transfer dissociation (ETD), electron detachment dissociation (EDD), electron induced dissociation (EID), and negative electron transfer dissociation (NETD), have emerged and have extended the application range of ion-electron dissociations further. Importantly, ExD techniques have been applied beyond protein analyses, which is the focus of the current paper. This short introduction describes the application of ExD to small and medium-sized molecules and reviews important applications to natural products, biomedical compounds, synthetic molecules, crude oils, and environmental toxins.
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Affiliation(s)
- Yulin Qi
- Institute of Bioanalytical Chemistry, Saarland University, 66123 Saarbrücken, Germany.
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Wei J, Bristow AWT, O'Connor PB. The Competitive influence of Li+, Na+, K+, Ag+, and H+ on the fragmentation of a PEGylated polymeric excipient. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:166-173. [PMID: 25326058 DOI: 10.1007/s13361-014-1009-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/11/2014] [Accepted: 09/11/2014] [Indexed: 06/04/2023]
Abstract
The collisionally activated dissociation (CAD) and electron capture dissociation (ECD) of doubly charged tocopheryl polyethylene glycol succinate (TPGS) have been examined. Li(+), Na(+), K(+), Ag(+), and H(+) were selected in the study, and the competitive influence of each ion was investigated by fragmenting TPGS attached with two different cations, [M + X1 + X2](2+) (X1 and X2 refer to Li(+), Na(+), K(+), Ag(+), H(+)). For metallic adducts, CAD results show that the dissociation of ionic adducts from the precursor is most likely depending on the binding strength, where the affinity of each ion to the TPGS is in the order of Ag(+) ≈ Li(+) ˃ Na(+) ˃ K(+). Introducing more strongly bound adducts increases fragmentation. During ECD, however, the silver cation is lost most easily compared with the other alkali metal ions, but silver also shows a dominant role in producing fragmentations. Moreover, the charge carriers are lost in an order (Ag(+) ˃ Na(+) ˃ K(+) ≥ Li(+) where the loss of Ag is most easily) that appears to correlate with the standard reduction potential of the metallic ions (Ag(+) ˃ Na(+) ˃ K(+) ˃ Li(+)). The ECD results suggest that the reduction potential of the charge carrier could be an important factor influencing the fragmentation, where the ion with a high reduction potential is more effective in capturing electrons, but may also be lost easily before leading to any fragmentation. Finally, a proton has the weakest binding with the TPGS according to the CAD results, and its dissociation in ECD follows the order of the reduction potential (Ag(+) ˃ H(+) ˃ Na(+) ˃ K(+) > Li(+)).
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Affiliation(s)
- Juan Wei
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
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