1
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Tie C, Cui X, Zhang Z, Geng Y, Liu T, Rong X, Zheng X. Novel Structure-Driven Predict-to-Hit Strategy for PC Double Bond Positional Isomer Identification Based on Negative LC-MRM Analysis. Anal Chem 2024. [PMID: 38330201 DOI: 10.1021/acs.analchem.3c04032] [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
As the predominant phospholipids in mammalian cells, phosphatidylcholines (PCs) have been demonstrated to play a crucial role in a multitude of vital biological processes. Research has highlighted the significance of the diversity in PC isomers as instigators of both physiological and pathological responses, particularly those with variations in the position of double bonds within their fatty chains. Profiling these PC isomers is paramount to advancing our understanding of their biological functions. Despite the availability of analytical methods utilizing high-resolution secondary mass spectrometry (MS2) fragmentation, a novel approach was imperative to facilitate large-scale profiling of PC isomers while ensuring accessibility, facility, and reliability. In this study, an innovative strategy centered around structure-driven predict-to-hit profiling of the double bond positional isomers for PCs was meticulously developed, employing negative reversed-phase liquid chromatography-multiple reaction monitoring (RPLC-MRM). This novel methodology heightened the sensitivity. The analysis of rat lung tissue samples resulted in the identification of 130 distinct PC isomers. This approach transcended the confines of available PC isomer standards, thereby broadening the horizons of PC-related biofunction investigations. By optimizing the quantitation reliability, the scale of sample analysis was judiciously managed. This work pioneers a novel paradigm for the exploration of PC isomers, distinct from the conventional methods reliant on high-resolution mass spectrometry (HRMS). It equips researchers with potent tools to further explore the biofunctional aspects of lipids.
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Affiliation(s)
- Cai Tie
- State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources, Ding 11 Xueyuan Road, Beijing 100083, China
- School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Ding 11 Xueyuan Road, Beijing 100083, China
| | - Xinge Cui
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, State Key Laboratory of Complex Severe and Rare Diseases, NMPA Key Laboratory for Clinical Research and Evaluation of Drug, Beijing Key Laboratory of Clinical PK & PD Investigation for Innovative Drugs, Chinese Academy of Medical Sciences & Peking Union Medical College, No.1 Shuaifuyuan Wangfujing, Dongcheng District, Beijing 100730, China
| | - Zhijun Zhang
- School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Ding 11 Xueyuan Road, Beijing 100083, China
| | - Yicong Geng
- School of Chemical and Environmental Engineering, China University of Mining and Technology-Beijing, Ding 11 Xueyuan Road, Beijing 100083, China
| | - Ting Liu
- SCIEX, Analytical Instrument Trading Co., Ltd., 518 North Fuquan Road, Shanghai 200335, China
| | - Xiaojuan Rong
- Xinjiang Institute of Material Medica, 140 North Xinhua Road, Urumqi, Xinjiang 830004, China
| | - Xin Zheng
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, State Key Laboratory of Complex Severe and Rare Diseases, NMPA Key Laboratory for Clinical Research and Evaluation of Drug, Beijing Key Laboratory of Clinical PK & PD Investigation for Innovative Drugs, Chinese Academy of Medical Sciences & Peking Union Medical College, No.1 Shuaifuyuan Wangfujing, Dongcheng District, Beijing 100730, China
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2
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Hormann FL, Sommer S, Heiles S. Formation and Tandem Mass Spectrometry of Doubly Charged Lipid-Metal Ion Complexes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023. [PMID: 37315187 DOI: 10.1021/jasms.3c00126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Phospholipids are major components of most eukaryotic cell membranes. Changes in metabolic states are often accompanied by phospholipid structure variations. The structural changes of phospholipids are the hallmark of disease states, or specific lipid structures have been associated with distinct organisms. Prime examples are microorganisms that synthesize phospholipids with, for example, different branched chain fatty acids. Assignment and relative quantitation of structural isomers of phospholipids that arise from attachment of different fatty acids to the glycerophospholipid backbone are difficult with routine tandem mass spectrometry or with liquid chromatography without authentic standards. In this work, we report on the observation that all investigated phospholipid classes form doubly charged lipid-metal ion complexes during electrospray ionization (ESI) and show that these complexes can be used to assign lipid classes and fatty acid moieties, distinguish isomers of branched chain fatty acids, and relatively quantify these isomers in positive-ion mode. Use of water free methanol and addition of divalent metal salts (100 mol %) to ESI spray solutions afford highly abundant doubly charged lipid-metal ion complexes (up to 70 times of protonated compounds). Higher-energy collisional dissociation and collision-induced dissociation of doubly charged complexes yield a diverse set of lipid class-dependent fragment ions. In common for all lipid classes is the liberation of fatty acid-metal adducts that yield fragment ions from the fatty acid hydrocarbon chain upon activation. This ability is used to pinpoint sites of branching in saturated fatty acids and is showcased for free fatty acids as well as glycerophospholipids. The analytical utility of doubly charged phospholipid-metal ion complexes is demonstrated by distinguishing fatty acid branching-site isomers in phospholipid mixtures and relatively quantifying the corresponding isomeric compounds.
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Affiliation(s)
- Felix-Levin Hormann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Straße 6b, 44139 Dortmund, Germany
- Lipidomics, Faculty of Chemistry, University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
| | - Simon Sommer
- Institute of Inorganic and Analytical Chemistry, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Sven Heiles
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Straße 6b, 44139 Dortmund, Germany
- Lipidomics, Faculty of Chemistry, University of Duisburg-Essen, Universitätsstrasse 5, 45141 Essen, Germany
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3
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Blevins MS, Shields SWJ, Cui W, Fallatah W, Moser AB, Braverman NE, Brodbelt JS. Structural Characterization and Quantitation of Ether-Linked Glycerophospholipids in Peroxisome Biogenesis Disorder Tissue by Ultraviolet Photodissociation Mass Spectrometry. Anal Chem 2022; 94:12621-12629. [PMID: 36070546 PMCID: PMC9631334 DOI: 10.1021/acs.analchem.2c01274] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biological impact of ether glycerophospholipids (GP) in peroxisomal disorders and other diseases makes them significant targets as biomarkers for diagnostic assays or deciphering pathology of the disorders. Ether lipids include both plasmanyl and plasmenyl lipids, which each contain an ether or a vinyl ether bond at the sn-1 linkage position, respectively. This linkage, in contrast to traditional diacyl GPs, precludes their detailed characterization by mass spectrometry via traditional collisional-based MS/MS techniques. Additionally, the isomeric nature of plasmanyl and plasmenyl pairs of ether lipids introduces a further level of complexity that impedes analysis of these species. Here, we utilize 213 nm ultraviolet photodissociation mass spectrometry (UVPD-MS) for detailed characterization of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) plasmenyl and plasmanyl lipids in mouse brain tissue. 213 nm UVPD-MS enables the successful differentiation of these four ether lipid subtypes for the first time. We couple this UVPD-MS methodology to reversed-phase liquid chromatography (RPLC) for characterization and relative quantitation of ether lipids from normal and diseased (Pex7 deficiency modeling the peroxisome biogenesis disorder, RCDP) mouse brain tissue, highlighting the ability to pinpoint specific structural features of ether lipids that are important for monitoring aberrant lipid metabolism in peroxisomal disorders.
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Affiliation(s)
- Molly S Blevins
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Samuel W J Shields
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | | | - Wedad Fallatah
- Department of Medical Genetics, King Abdul-Aziz University, Jeddah, 21423, Saudi Arabia
| | - Ann B Moser
- Kennedy Krieger Institute, Baltimore, Maryland 21205, United States
- School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, United States
| | | | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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4
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Xu L, Guan H, Liu L, Mao S, Feng J, Su Z, Liu L. Determining the double-bond positions of monounsaturated compounds in the alcohol fraction in seep carbonate. J Chromatogr A 2022; 1672:463009. [DOI: 10.1016/j.chroma.2022.463009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 10/18/2022]
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5
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Lin Q, Li P, Jian R, Xia Y. Localization of Intrachain Modifications in Bacterial Lipids Via Radical-Directed Dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:714-721. [PMID: 35195000 DOI: 10.1021/jasms.2c00011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Intrachain modifications of membrane glycerophospholipids (GPLs) due to formation of the carbon-carbon double bond (C═C), cyclopropane ring, and methyl branching are crucial for bacterial membrane homeostasis. Conventional collision-induced dissociation (CID) of even-electron ions of GPL favors charge-directed fragmentation channels, and thus little structurally informative fragments can be detected for locating intrachain modifications. In this study, we report a radical-directed dissociation (RDD) approach for characterization of the intrachain modifications within phosphoethanolamines (PEs), a major lipid component in bacterial membrane. In this method, a radical precursor that can produce benzyl or pyridine methyl radical upon low-energy CID at high efficiency is conjugated onto the amine group of PEs. The carbon-centered radical ions subsequently initiate RDD along the fatty acyl chain, producing fragment patterns key to the assignment and localization of intrachain modifications including C═C, cyclopropane rings, and methyl branching. Besides intrachain fragmentation, RDD on the glycerol backbone produces fatty acyl loss as radicals, allowing one to identify the fatty acyl chain composition of PE. Moreover, RDD of lyso-PEs produces radical losses for distinguishing the sn-isomers. The above RDD approach has been incorporated onto a liquid chromatography-mass spectrometry workflow and applied for the analysis of lipid extracts from Escherichia coli and Bacillus subtilis.
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Affiliation(s)
- Qiaohong Lin
- Department of Chemistry, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 10084, China
| | - Pengyun Li
- National Engineering Research Center for the Emergency Drug, Beijing Institute of Pharmacology and Toxicology, Beijing 100850, China
| | - Ruijun Jian
- Department of Chemistry, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 10084, China
| | - Yu Xia
- Department of Chemistry, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 10084, China
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6
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Narreddula VR, McKinnon BI, Marlton SJP, Marshall DL, Boase NRB, Poad BLJ, Trevitt AJ, Mitchell TW, Blanksby SJ. Next-generation derivatization reagents optimized for enhanced product ion formation in photodissociation-mass spectrometry of fatty acids. Analyst 2021; 146:156-169. [DOI: 10.1039/d0an01840f] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Next-generation derivatives for photodissociation-mass spectrometry for fatty acids generating photoproduct yields of up to 97% at 266 nm.
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Affiliation(s)
- Venkateswara R. Narreddula
- School of Chemistry and Physics
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
- Australia
| | - Benjamin I. McKinnon
- Molecular Horizons and School of Chemistry and Molecular Bioscience
- University of Wollongong
- Wollongong
- Australia
| | - Samuel J. P. Marlton
- Molecular Horizons and School of Chemistry and Molecular Bioscience
- University of Wollongong
- Wollongong
- Australia
| | - David L. Marshall
- Central Analytical Research Facility
- Institute for Future Environments
- Queensland University of Technology
- Brisbane
- Australia
| | - Nathan R. B. Boase
- School of Chemistry and Physics
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
- Australia
| | - Berwyck L. J. Poad
- Central Analytical Research Facility
- Institute for Future Environments
- Queensland University of Technology
- Brisbane
- Australia
| | - Adam J. Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience
- University of Wollongong
- Wollongong
- Australia
| | - Todd W. Mitchell
- School of Medicine
- University of Wollongong
- Wollongong
- Australia
- Illawarra Health and Medical Research Institute
| | - Stephen J. Blanksby
- School of Chemistry and Physics
- Science and Engineering Faculty
- Queensland University of Technology
- Brisbane
- Australia
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7
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Randolph CE, Blanksby SJ, McLuckey SA. Enhancing detection and characterization of lipids using charge manipulation in electrospray ionization-tandem mass spectrometry. Chem Phys Lipids 2020; 232:104970. [PMID: 32890498 PMCID: PMC7606777 DOI: 10.1016/j.chemphyslip.2020.104970] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/25/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022]
Abstract
Heightened awareness regarding the implication of disturbances in lipid metabolism with respect to prevalent human-related pathologies demands analytical techniques that provide unambiguous structural characterization and accurate quantitation of lipids in complex biological samples. The diversity in molecular structures of lipids along with their wide range of concentrations in biological matrices present formidable analytical challenges. Modern mass spectrometry (MS) offers an unprecedented level of analytical power in lipid analysis, as many advancements in the field of lipidomics have been facilitated through novel applications of and developments in electrospray ionization tandem mass spectrometry (ESI-MS/MS). ESI allows for the formation of intact lipid ions with little to no fragmentation and has become widely used in contemporary lipidomics experiments due to its sensitivity, reproducibility, and compatibility with condensed-phase modes of separation, such as liquid chromatography (LC). Owing to variations in lipid functional groups, ESI enables partial chemical separation of the lipidome, yet the preferred ion-type is not always formed, impacting lipid detection, characterization, and quantitation. Moreover, conventional ESI-MS/MS approaches often fail to expose diverse subtle structural features like the sites of unsaturation in fatty acyl constituents or acyl chain regiochemistry along the glycerol backbone, representing a significant challenge for ESI-MS/MS. To overcome these shortcomings, various charge manipulation strategies, including charge-switching, have been developed to transform ion-type and charge state, with aims of increasing sensitivity and selectivity of ESI-MS/MS approaches. Importantly, charge manipulation approaches afford enhanced ionization efficiency, improved mixture analysis performance, and access to informative fragmentation channels. Herein, we present a critical review of the current suite of solution-based and gas-phase strategies for the manipulation of lipid ion charge and type relevant to ESI-MS/MS.
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Affiliation(s)
- Caitlin E Randolph
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA
| | - Stephen J Blanksby
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Scott A McLuckey
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA.
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8
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Murtada R, Fabijanczuk K, Gaspar K, Dong X, Alzarieni KZ, Calix K, Manriquez E, Bakestani RM, Kenttämaa HI, Gao J. Free-Radical-Mediated Glycan Isomer Differentiation. Anal Chem 2020; 92:13794-13802. [PMID: 32935980 DOI: 10.1021/acs.analchem.0c02213] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The inherent structural complexity and diversity of glycans pose a major analytical challenge to their structural analysis. Radical chemistry has gained considerable momentum in the field of mass spectrometric biomolecule analysis, including proteomics, glycomics, and lipidomics. Herein, seven isomeric disaccharides and two isomeric tetrasaccharides with subtle structural differences are distinguished rapidly and accurately via one-step radical-induced dissociation. The free-radical-activated glycan-sequencing reagent (FRAGS) selectively conjugates to the unique reducing terminus of glycans in which a localized nascent free radical is generated upon collisional activation and simultaneously induces glycan fragmentation. Higher-energy collisional dissociation (HCD) and collision-induced dissociation (CID) are employed to provide complementary structural information for the identification and discrimination of glycan isomers by providing different fragmentation pathways to generate informative, structurally significant product ions. Furthermore, multiple-stage tandem mass spectrometry (MS3 CID) provides supplementary and valuable structural information through the generation of characteristic parent-structure-dependent fragment ions.
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Affiliation(s)
- Rayan Murtada
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
| | - Kimberly Fabijanczuk
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
| | - Kaylee Gaspar
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
| | - Xueming Dong
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Kawthar Zeyad Alzarieni
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Kimberly Calix
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
| | - Edgar Manriquez
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
| | - Rose Mery Bakestani
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
| | - Hilkka I Kenttämaa
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Jinshan Gao
- Department of Chemistry and Biochemistry, Montclair State University, 1 Normal Avenue, Montclair, New Jersey 07043, United States
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9
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Narreddula VR, Sadowski P, Boase NRB, Marshall DL, Poad BLJ, Trevitt AJ, Mitchell TW, Blanksby SJ. Structural elucidation of hydroxy fatty acids by photodissociation mass spectrometry with photolabile derivatives. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8741. [PMID: 32012356 DOI: 10.1002/rcm.8741] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 06/10/2023]
Abstract
RATIONALE Eicosanoids are short-lived bio-responsive lipids produced locally from oxidation of polyunsaturated fatty acids (FAs) via a cascade of enzymatic or free radical reactions. Alterations in the composition and concentration of eicosanoids are indicative of inflammation responses and there is strong interest in developing analytical methods for the sensitive and selective detection of these lipids in biological mixtures. Most eicosanoids are hydroxy FAs (HFAs), which present a particular analytical challenge due to the presence of regioisomers arising from differing locations of hydroxylation and unsaturation within their structures. METHODS In this study, the recently developed derivatization reagent 1-(3-(aminomethyl)-4-iodophenyl)pyridin-1-ium (4-I-AMPP+ ) was applied to a representative set of HFAs including bioactive eicosanoids. Photodissociation (PD) mass spectra obtained at 266 nm of 4-I-AMPP+ -modified HFAs exhibit abundant product ions arising from photolysis of the aryl-iodide bond within the derivative with subsequent migration of the radical to the hydroxyl group promoting fragmentation of the FA chain and facilitating structural assignment. RESULTS Representative polyunsaturated HFAs (from the hydroxyeicosatetraenoic acid and hydroxyeicosapentaenoic acid families) were derivatized with 4-I-AMPP+ and subjected to a reversed-phase liquid chromatography workflow that afforded chromatographic resolution of isomers in conjunction with structurally diagnostic PD mass spectra. CONCLUSIONS PD of these complex HFAs was found to be sensitive to the locations of hydroxyl groups and carbon-carbon double bonds, which are structural properties strongly associated with the biosynthetic origins of these lipid mediators.
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Affiliation(s)
- Venkateswara R Narreddula
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4000, Australia
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Pawel Sadowski
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Nathan R B Boase
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - David L Marshall
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Berwyck L J Poad
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, 4000, Australia
| | - Adam J Trevitt
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Todd W Mitchell
- School of Medicine, University of Wollongong, Wollongong, NSW, 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia
| | - Stephen J Blanksby
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, 4000, Australia
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD, 4000, Australia
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10
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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.
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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
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11
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Narreddula VR, Boase NR, Ailuri R, Marshall DL, Poad BL, Kelso MJ, Trevitt AJ, Mitchell TW, Blanksby SJ. Introduction of a Fixed-Charge, Photolabile Derivative for Enhanced Structural Elucidation of Fatty Acids. Anal Chem 2019; 91:9901-9909. [DOI: 10.1021/acs.analchem.9b01566] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Venkateswara R. Narreddula
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Nathan R. Boase
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Ramesh Ailuri
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - David L. Marshall
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Berwyck L.J. Poad
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Michael J. Kelso
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Adam J. Trevitt
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Todd W. Mitchell
- School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Stephen J. Blanksby
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Central Analytical Research Facility, Institute for Future Environments, Queensland University of Technology, Brisbane, QLD 4000, Australia
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12
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Gaspar K, Fabijanczuk K, Otegui T, Acosta J, Gao J. Development of Novel Free Radical Initiated Peptide Sequencing Reagent: Application to Identification and Characterization of Peptides by Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:548-556. [PMID: 30547308 PMCID: PMC6417990 DOI: 10.1007/s13361-018-2114-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/12/2018] [Accepted: 11/23/2018] [Indexed: 05/19/2023]
Abstract
By incorporating a high proton affinity moiety to the charge localized free radical-initiated peptide sequencing (CL-FRIPS) reagent, FRIPS-MS technique has extended the applicability to hydrophobic peptides and peptides without basic amino acid residues (lysine, arginine, and histidine). Herein, the CL-FRIPS reagent has three moieties: (1) pyridine acting as the basic site to locate the proton, (2) 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO, a stable free radical) acting as the free radical precursor to generate the nascent free radical in the gas phase, and (3) N-hydroxysuccinimide (NHS) activated carboxylic acid acting as the coupling site to derivatize the N-terminus of peptides. The CL-FRIPS reagent allows for the characterization of peptides by generating sequencing ions, enzymatic cleavage-like radical-induced side chain losses, and the loss of TEMPO simultaneously via one-step collisional activation. Further collisional activation of enzymatic cleavage-like radical-induced side chain loss ions provides more information for the structure determination of peptides. The application of CL-FRIPS reagent to characterize peptides is proved by employing bovine insulin as the model peptide. Both scaffold structure of bovine insulin and sequencing information of each chain are achieved. Graphical Abstract.
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Affiliation(s)
- Kaylee Gaspar
- Department of Chemistry and Biochemistry, Center for Quantitative Obesity Research, Montclair State University, 1 Normal Avenue, Montclair, NJ, 07043, USA
| | - Kimberly Fabijanczuk
- Department of Chemistry and Biochemistry, Center for Quantitative Obesity Research, Montclair State University, 1 Normal Avenue, Montclair, NJ, 07043, USA
| | - Tara Otegui
- Department of Chemistry and Biochemistry, Center for Quantitative Obesity Research, Montclair State University, 1 Normal Avenue, Montclair, NJ, 07043, USA
| | - Jose Acosta
- Department of Chemistry and Biochemistry, Center for Quantitative Obesity Research, Montclair State University, 1 Normal Avenue, Montclair, NJ, 07043, USA
| | - Jinshan Gao
- Department of Chemistry and Biochemistry, Center for Quantitative Obesity Research, Montclair State University, 1 Normal Avenue, Montclair, NJ, 07043, USA.
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13
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Ma HF, Wei F, Wu BF, Yang C, Xie Y, Wu ZY, Lv X, Chen H. Profiling and quantification of aminophospholipids based on chemical derivatization coupled with HPLC-MS. J Lipid Res 2018; 60:121-134. [PMID: 30482807 DOI: 10.1194/jlr.m089482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/01/2018] [Indexed: 01/21/2023] Open
Abstract
In this study, a novel strategy based on acetone stable-isotope derivatization coupled with HPLC-MS for profiling and accurate quantification of aminophospholipids (phosphatidylethanolamine and phosphatidylserine) in biological samples was developed. Acetone derivatization leads to alkylation of the primary amino groups of aminophospholipids with an isopropyl moiety; the use of deuterium-labeled acetone (d6-acetone) introduced a 6 Da mass shift that was ideally suited for profiling and quantification analysis with high selectivity and accuracy. After derivatization, significantly increased column efficiency for chromatographic separation and detection sensitivity for MS analysis of aminophospholipids was observed. Furthermore, an accuracy quantification method was developed. Aminophospholipids in biological samples were derivatized with d0-acetone; while more than two aminophospholipid standards were selected for each class of aminophospholipid and derivatized with d6-acetone, which were then used as the internal standards to typically construct a calibration curve for each class to normalize the nonuniformity response caused by the differential fragmentation kinetics resulting from the distinct chemical constitution of individual aminophospholipid species in the biological samples. The excellent applicability of the developed method was validated by profiling and quantification of aminophospholipids presented in liver samples from rats fed with different diets.
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Affiliation(s)
- Hui-Fang Ma
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Fang Wei
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Bang-Fu Wu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Chen Yang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Ya Xie
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Zong-Yuan Wu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Xin Lv
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
| | - Hong Chen
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, and Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan 430062, China
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14
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Pepin R, Layton ED, Liu Y, Afonso C, Tureček F. Where Does the Electron Go? Stable and Metastable Peptide Cation Radicals Formed by Electron Transfer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:164-181. [PMID: 27709510 DOI: 10.1007/s13361-016-1512-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/12/2016] [Accepted: 09/15/2016] [Indexed: 06/06/2023]
Abstract
Electron transfer to doubly and triply charged heptapeptide ions containing polar residues Arg, Lys, and Asp in combination with nonpolar Gly, Ala, and Pro or Leu generates stable and metastable charge-reduced ions, (M + 2H)+●, in addition to standard electron-transfer dissociation (ETD) fragment ions. The metastable (M + 2H)+● ions spontaneously dissociate upon resonant ejection from the linear ion trap, giving irregularly shaped peaks with offset m/z values. The fractions of stable and metastable (M + 2H)+● ions and their mass shifts depend on the presence of Pro-4 and Leu-4 residues in the peptides, with the Pro-4 sequences giving larger fractions of the stable ions while showing smaller mass shifts for the metastables. Conversion of the Asp and C-terminal carboxyl groups to methyl esters further lowers the charge-reduced ion stability. Collisional activation and photodissociation at 355 nm of mass-selected (M + 2H)+● results in different dissociations that give sequence specific MS3 spectra. With a single exception of charge-reduced (LKGLADR + 2H)+●, the MS3 spectra do not produce ETD sequence fragments of the c and z type. Hence, these (M + 2H)+● ions are covalent radicals, not ion-molecule complexes, undergoing dramatically different dissociations in the ground and excited electronic states. The increased stability of the Pro-4 containing (M + 2H)+● ions is attributed to radicals formed by opening of the Pro ring and undergoing further stabilization by hydrogen atom migrations. UV-VIS photodissociation action spectroscopy and time-dependent density functional theory calculations are used in a case in point study of the stable (LKGPADR + 2H)+● ion produced by ETD. In contrast to singly-reduced peptide ions, doubly reduced (M + 3H)+ ions are stable only when formed from the Pro-4 precursors and show all characteristics of even electron ions regarding no photon absorption at 355 nm or ion-molecule reactions, and exhibiting proton driven collision induced dissociations. Graphical Abstract ᅟ.
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Affiliation(s)
- Robert Pepin
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - Erik D Layton
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - Yang Liu
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA
| | - Carlos Afonso
- INSA Rouen, UNIROUEN, CNRS, COBRA, Normandie University, 76000, Rouen, France
| | - František Tureček
- Department of Chemistry, University of Washington, Bagley Hall, Box 351700, Seattle, WA, 98195-1700, USA.
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15
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Yang S, You M, Yang L, Zhang F, Wang Q, He P. A recyclable electrochemical sensing platform for breast cancer diagnosis based on homogeneous DNA hybridization and host-guest interaction between cucurbit [7]uril and ferrocene-nanosphere with signal amplification. J Electroanal Chem (Lausanne) 2016. [DOI: 10.1016/j.jelechem.2016.11.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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16
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Ryan E, Reid GE. Chemical Derivatization and Ultrahigh Resolution and Accurate Mass Spectrometry Strategies for "Shotgun" Lipidome Analysis. Acc Chem Res 2016; 49:1596-604. [PMID: 27575732 DOI: 10.1021/acs.accounts.6b00030] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Lipids play critical structural and functional roles in the regulation of cellular homeostasis, and it is increasingly recognized that the disruption of lipid metabolism or signaling or both is associated with the onset and progression of certain metabolically linked diseases. As a result, the field of lipidomics has emerged to comprehensively identify and structurally characterize the diverse range of lipid species within a sample of interest and to quantitatively monitor their abundances under different physiological or pathological conditions. Mass spectrometry (MS) has become a critical enabling platform technology for lipidomic researchers. However, the presence of isobaric (i.e., same nominal mass) and isomeric (i.e., same exact mass) lipids within complex lipid extracts means that MS-based identification and quantification of individual lipid species remains a significant analytical challenge. Ultrahigh resolution and accurate mass spectrometry (UHRAMS) offers a convenient solution to the isobaric mass overlap problem, while a range of chromatographic separation, differential extraction, intrasource separation and selective ionization methods, or tandem mass spectrometry (MS/MS) strategies may be used to address some types of isomeric mass lipid overlaps. Alternatively, chemical derivatization strategies represent a more recent approach for the separation of lipids within complex mixtures, including for isomeric lipids. In this Account, we highlight the key components of a lipidomics workflow developed in our laboratory, whereby certain lipid classes or subclasses, namely, aminophospholipids and O-alk-1'-enyl (i.e., plasmalogen) ether-containing lipids, are shifted in mass following sequential functional group selective chemical derivatization reactions prior to "shotgun" nano-ESI-UHRAMS analysis, "targeted" MS/MS, and automated database searching. This combined derivatization and UHRAMS approach resolves both isobaric mass lipids and certain categories of isomeric mass lipids within crude lipid extracts, with no requirement for extensive sample handling prior to analysis, with additional potential for enhanced ionization efficiencies, improved molecular level structural characterization, and multiplexed relative quantification. When integrated with a monophasic method for the simultaneous global extraction of both highly polar and nonpolar lipids, this workflow has been shown to enable the sum composition level identification and relative quantification of 500-600 individual lipid species across four lipid categories and from 36 lipid classes and subclasses, in only 1-2 min data acquisition time and with minimal sample consumption. Thus, while some analytical challenges remain to be addressed, shotgun lipidomics workflows encompassing chemical derivatization strategies have particular promise for the analysis of samples with limited availability that require rapid and unbiased assessment of global lipid metabolism.
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Affiliation(s)
- Eileen Ryan
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Gavin E. Reid
- School
of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
- Department
of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
- Bio21
Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3010, Australia
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17
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Stinson CA, Xia Y. A method of coupling the Paternò–Büchi reaction with direct infusion ESI-MS/MS for locating the CC bond in glycerophospholipids. Analyst 2016; 141:3696-704. [PMID: 26892746 DOI: 10.1039/c6an00015k] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Conducting the Paternò–Büchi reaction in a microflow photo-reactor enables its coupling with ESI-MS/MS and CC location determination for shotgun lipid analysis.
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Affiliation(s)
| | - Yu Xia
- Department of Chemistry
- Purdue University
- West Lafayette
- USA
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18
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Pham HT, Julian RR. Characterization of glycosphingolipid epimers by radical-directed dissociation mass spectrometry. Analyst 2016; 141:1273-8. [DOI: 10.1039/c5an02383a] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Radical chemistry can efficiently distinguish isomers varying in position at a single alcohol.
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19
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Yang L, Li M, Shan Y, Shen S, Bai Y, Liu H. Recent advances in lipidomics for disease research. J Sep Sci 2015; 39:38-50. [PMID: 26394722 DOI: 10.1002/jssc.201500899] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 12/15/2022]
Abstract
Lipidomics is an important branch of metabolomics, which aims at the detailed analysis of lipid species and their multiple roles in the living system. In recent years, the development of various analytical methods for effective identification and characterization of lipids has greatly promoted the process of lipidomics. Meanwhile, as many diseases demonstrate a remarkable alteration in lipid profiles compared with that of healthy people, lipidomics has been extensively introduced to disease research. The comprehensive lipid profiling provides a chance to discover novel biomarkers for specific disease. In addition, it plays a crucial role in the study of lipid metabolism, which could illuminate the pathogenesis of diseases. In this review, after brief discussion of analytical methods for lipidomics in clinical research, we focus on the recent advances of lipidomics related to four types of diseases, including cancer, atherosclerosis, diabetes mellitus, and Alzheimer's disease.
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Affiliation(s)
- Li Yang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Min Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Yabing Shan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.,National Research Center for Geoanalysis, Beijing, China
| | - Sensen Shen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Yu Bai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Huwei Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
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20
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Marek A, Shaffer CJ, Pepin R, Slováková K, Laszlo KJ, Bush MF, Tureček F. Electron transfer reduction of the diazirine ring in gas-phase peptide ions. On the peculiar loss of [NH4O] from photoleucine. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:415-431. [PMID: 25515220 DOI: 10.1007/s13361-014-1047-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/22/2014] [Accepted: 11/02/2014] [Indexed: 06/04/2023]
Abstract
Electron transfer to gas-phase peptide ions with diazirine-containing amino acid residue photoleucine (L*) triggers diazirine ring reduction followed by cascades of residue-specific radical reactions. Upon electron transfer, substantial fractions of (GL*GGR +2H)(+[Symbol: see text]) cation-radicals undergo elimination of [NH(4)O] radicals and N(2)H(2) molecules from the side chain. The side-chain dissociations are particularly prominent on collisional activation of long-lived (GL*GGR +2H)(+[Symbol: see text]) cation-radicals formed by electron transfer dissociation of noncovalent peptide-18-crown-6-ether ion complexes. The ion dissociation products were characterized by multistage tandem mass spectrometry (MS(n)) and ion mobility measurements. The elimination of [NH(4)O] was elucidated with the help of (2)H, (15) N, and (18)O-labeled peptide ions and found to specifically involve the amide oxygen of the N-terminal residue. The structures, energies, and electronic states of the peptide radical species were elucidated by a combination of near-UV photodissociation experiments and electron structure calculations combining ab initio and density functional theory methods. Electron transfer reaching the ground electronic states of charge reduced (GL*GGR +2H)(+[Symbol: see text]) cation-radicals was found to reduce the diazirine ring. In contrast, backbone N - Cα bond dissociations that represent a 60%-75% majority of all dissociations because of electron transfer are predicted to occur from excited electronic states.
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Affiliation(s)
- Aleš Marek
- Department of Chemistry, Bagley Hall, University of Washington, Seattle, WA, 98195-1700, USA
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21
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Gilbert JD, Fisher CM, Bu J, Prentice BM, Redwine JG, McLuckey SA. Strategies for generating peptide radical cations via ion/ion reactions. JOURNAL OF MASS SPECTROMETRY : JMS 2015; 50:418-26. [PMID: 25800024 PMCID: PMC4372815 DOI: 10.1002/jms.3548] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 11/14/2014] [Accepted: 11/16/2014] [Indexed: 05/25/2023]
Abstract
Several approaches for the generation of peptide radical cations using ion/ion reactions coupled with either collision induced dissociation (CID) or ultraviolet photo dissociation (UVPD) are described here. Ion/ion reactions are used to generate electrostatic or covalent complexes comprised of a peptide and a radical reagent. The radical site of the reagent can be generated multiple ways. Reagents containing a carbon-iodine (C-I) bond are subjected to UVPD with 266-nm photons, which selectively cleaves the C-I bond homolytically. Alternatively, reagents containing azo functionalities are collisionally activated to yield radical sites on either side of the azo group. Both of these methods generate an initial radical site on the reagent, which then abstracts a hydrogen from the peptide while the peptide and reagent are held together by either electrostatic interactions or a covalent linkage. These methods are demonstrated via ion/ion reactions between the model peptide RARARAA (doubly protonated) and various distonic anionic radical reagents. The radical site abstracts a hydrogen atom from the peptide, while the charge site abstracts a proton. The net result is the conversion of a doubly protonated peptide to a peptide radical cation. The peptide radical cations have been fragmented via CID and the resulting product ion mass spectra are compared to the control CID spectrum of the singly protonated, even-electron species. This work is then extended to bradykinin, a more broadly studied peptide, for comparison with other radical peptide generation methods. The work presented here provides novel methods for generating peptide radical cations in the gas phase through ion/ion reaction complexes that do not require modification of the peptide in solution or generation of non-covalent complexes in the electrospray process.
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Affiliation(s)
| | | | | | | | | | - Scott A. McLuckey
- Address reprint requests to: Dr. S. A. McLuckey 560 Oval Drive Department of Chemistry Purdue University West Lafayette, IN 47907-2084, USA Phone: (765) 494-5270 Fax: (765) 494-0239
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22
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Lintonen TPI, Baker PRS, Suoniemi M, Ubhi BK, Koistinen KM, Duchoslav E, Campbell JL, Ekroos K. Differential mobility spectrometry-driven shotgun lipidomics. Anal Chem 2014; 86:9662-9. [PMID: 25160652 DOI: 10.1021/ac5021744] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The analysis of lipids by mass spectrometry (MS) can provide in-depth characterization for many forms of biological samples. However, such workflows can also be hampered by challenges like low chromatographic resolution for lipid separations and the convolution of mass spectra from isomeric and isobaric species. To address these issues, we describe the use of differential mobility spectrometry (DMS) as a rapid and predictable separation technique within a shotgun lipidomics workflow, with a special focus on phospholipids (PLs). These analytes, ionized by electrospray ionization (ESI), are filtered using DMS prior to MS analysis. The observed separation (measured in terms of DMS compensation voltage) is affected by several factors, including the m/z of the lipid ion, the structure of an individual ion, and the presence of chemical modifiers in the DMS cell. Such DMS separations can simplify the analysis of complex extracts in a robust and reproducible manner, independent of utilized MS instrumentation. The predictable separation achieved with DMS can facilitate correct lipid assignments among many isobaric and isomeric species independent of the resolution settings of the MS analysis. This leads to highly comprehensive and quantitative lipidomic outputs through rapid profiling analyses, such as Q1 and MRM scans. The ultimate benefit of the DMS separation in this unique shotgun lipidomics workflow is its ability to separate many isobaric and isomeric lipids that by standard shotgun lipidomics workflows are difficult to assess precisely, for example, ether and diacyl species and phosphatidylcholine (PC) and sphingomyelin (SM) lipids.
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