1
|
Carlo MJ, Nanney ALM, Patrick AL. Energy-Resolved In-Source Collison-Induced Dissociation for Isomer Discrimination. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024. [PMID: 39016059 DOI: 10.1021/jasms.4c00118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
While mass spectrometry remains a gold-standard tool for analyte detection, characterization, and quantitation, isomer differentiation is often a challenge. Tandem mass spectrometry is a common approach to increase the selectivity of mass spectrometry and energy-resolved measurements can provide further improvements. However, not all mass spectrometers, especially those that are very compact and affordable, are amenable to such experiments. For instance, single-stage mass spectrometers with soft ionization provide no dissociation information and quadrupole ion trap instruments with resonant excitation do not necessarily provide as informative of energy-resolved curves, for instance when extensive sequential dissociation is responsible for much of the "fingerprint". In-source collision-induced dissociation (IS-CID) is one approach to overcoming these barriers to exploit the analytical selectivity of energy-resolved CID without the need for additional instrumentation; this approach could broaden the reach of these selectivity gains to additional user bases (e.g., educational settings, field portable devices). Here, we specifically investigate energy-resolved IS-CID with the goal of (1) comparing between energy-resolved appearance curves measured with true tandem mass spectrometry on a quadrupole time-of-flight instrument and those obtained using IS-CID, (2) evaluating the approach as a means of differentiating isomers/isobar sets, especially those with similar dissociation patterns, and (3) exploring additional analytical considerations relevant to method development and implementation. This proof-of-concept work establishes the analytical potential of this approach, opening doors for future method development for specific applications.
Collapse
Affiliation(s)
- Matthew J Carlo
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Andie L M Nanney
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| | - Amanda L Patrick
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, United States
| |
Collapse
|
2
|
Beszterda-Buszczak M, Frański R. Oligoester Identification in the Inner Coatings of Metallic Cans by High-Pressure Liquid Chromatography-Mass Spectrometry with Cone Voltage-Induced Fragmentation. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2771. [PMID: 38894033 PMCID: PMC11173705 DOI: 10.3390/ma17112771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/01/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
The application of polyesters as food contact materials is an alternative to epoxy resin coatings, which can be a source of endocrine migrants. By using high-pressure liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS) with cone voltage-induced fragmentation in-source, a number of polyester-derived migrants were detected in the extracts of inner coatings of metallic cans. The polyester-derived migrants were detected in each inner coating of fish product-containing cans (5/5) and in one inner coating of meat product-containing can (1/5). They were not detected in the inner coatings of vegetable/fruit product-containing cans (10 samples). The respective detected parent and product ions enabled differentiation between cyclic and linear compounds, as well as unambiguous identification of diol and diacid units. Most of the detected compounds, cyclic and linear, were composed of neopentyl glycol as diol and two diacid comonomers, namely isophthalic acid and hexahydrophthalic acid. The other detected oligoesters were composed of neopentyl glycol or propylene glycol and adipic acid/isophthalic acid as comonomers. The compounds containing propylene glycol as diol were found to be exclusively linear cooligoesters. On the basis of abundances of [M+Na]+ ions, the relative contents of cyclic and linear oligoesters were evaluated.
Collapse
Affiliation(s)
- Monika Beszterda-Buszczak
- Department of Food Biochemistry and Analysis, Poznań University of Life Sciences, Mazowiecka 48, 60-623 Poznań, Poland;
| | - Rafał Frański
- Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
| |
Collapse
|
3
|
Li W, Shi J, Liu W, Tu P. Full collision energy ramp-pseudo-multistage mass spectrometry facilitates aglycone identification for glycosides. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9735. [PMID: 38499470 DOI: 10.1002/rcm.9735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/20/2024]
Affiliation(s)
- Wenzheng Li
- Modern Research Center for Traditional Chinese Medicine, Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Jingjing Shi
- Modern Research Center for Traditional Chinese Medicine, Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Wenjing Liu
- School of Pharmacy, Henan University of Chinese Medicine, Zhengzhou, China
| | - Pengfei Tu
- Modern Research Center for Traditional Chinese Medicine, Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| |
Collapse
|
4
|
Kawa S, Kaur J, Knorke H, Warneke Z, Wadsack M, Rohdenburg M, Nierstenhöfer M, Jenne C, Kenttämaa H, Warneke J. Generation and reactivity of the fragment ion [B 12I 8S(CN)] - in the gas phase and on surfaces. Analyst 2024; 149:2573-2585. [PMID: 38469706 DOI: 10.1039/d3an02175k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Gaseous fragment ions generated in mass spectrometers may be employed as "building blocks" for the synthesis of novel molecules on surfaces using ion soft-landing. A fundamental understanding of the reactivity of the fragment ions is required to control bond formation of deposited fragments in surface layers. The fragment ion [B12X11]- (X = halogen) is formed by collision-induced dissociation (CID) from the precursor [B12X12]2- dianion. [B12X11]- is highly reactive and ion soft-landing experiments have shown that this ion binds to the alkyl chains of organic molecules on surfaces. In this work we investigate whether specific modifications of the precursor ion affect the chemical properties of the fragment ions to such an extent that attachment to functional groups of organic molecules on surfaces occurs and binding of alkyl chains is prevented. Therefore, a halogen substituent was replaced by a thiocyanate substituent. CID of the precursor [B12I11(SCN)]2- ion preferentially yields the fragment ion [B12I8S(CN)]-, which shows significantly altered reactivity compared to the fragment ions of [B12I12]2-. [B12I8S(CN)]- has a previously unknown structural element, wherein a sulfur atom bridges three boron atoms. Gas-phase reactions with different neutral reactants (cyclohexane, dimethyl sulfide, and dimethyl amine) accompanied by theoretical studies indicate that [B12I8S(CN)]- binds with higher selectivity to functional groups of organic molecules than fragment ions of [B12I12]2- (e.g., [B12I11]- and [B12I9]-). These findings were further confirmed by ion soft-landing experiments, which showed that [B12I8S(CN)]- ions attacked ester groups of adipates and phthalates, whereas [B12I11]- ions only bound to alkyl chains of the same reagents.
Collapse
Affiliation(s)
- Sebastian Kawa
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Jaskiran Kaur
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Harald Knorke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Ziyan Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Myriam Wadsack
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Markus Rohdenburg
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
| | - Marc Nierstenhöfer
- Anorganische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gaußstr. 20, 42119, Wuppertal, Germany
| | - Carsten Jenne
- Anorganische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, Gaußstr. 20, 42119, Wuppertal, Germany
| | - Hilkka Kenttämaa
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN, 47907, USA
| | - Jonas Warneke
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103, Leipzig, Germany.
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, 04318, Leipzig, Germany
| |
Collapse
|
5
|
Grotjahn S, Graf C, Zelenka J, Pattanaik A, Müller L, Kutta RJ, Rehbein J, Roithová J, Gschwind RM, Nuernberger P, König B. Reactivity of Superbasic Carbanions Generated via Reductive Radical-Polar Crossover in the Context of Photoredox Catalysis. Angew Chem Int Ed Engl 2024; 63:e202400815. [PMID: 38408163 DOI: 10.1002/anie.202400815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 02/28/2024]
Abstract
Photocatalytic reactions involving a reductive radical-polar crossover (RRPCO) generate intermediates with carbanionic reactivity. Many of these proposed intermediates resemble highly reactive organometallic compounds. However, conditions of their formation are generally not tolerated by their isolated organometallic versions and often a different reactivity is observed. Our investigations on their nature and reactivity under commonly used photocatalytic conditions demonstrate that these intermediates are indeed best described as free, superbasic carbanions capable of deprotonating common polar solvents usually assumed to be inert such as acetonitrile, dimethylformamide, and dimethylsulfoxide. Their basicity not only towards solvents but also towards electrophiles, such as aldehydes, ketones, and esters, is comparable to the reactivity of isolated carbanions in the gas-phase. Previously unsuccessful transformations thought to result from a lack of reactivity are explained by their high reactivity towards the solvent and weakly acidic protons of reaction partners. An intuitive explanation for the mode of action of photocatalytically generated carbanions is provided, which enables methods to verify reaction mechanisms proposed to involve an RRPCO step and to identify the reasons for the limitations of current methods.
Collapse
Affiliation(s)
- Sascha Grotjahn
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Christina Graf
- Faculty of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Jan Zelenka
- Department of Spectroscopy and Catalysis, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ, Nijmegen, the Netherlands
| | - Aryaman Pattanaik
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Lea Müller
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Roger Jan Kutta
- Faculty of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Julia Rehbein
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Jana Roithová
- Department of Spectroscopy and Catalysis, Radboud University Nijmegen, Heyendaalseweg 135, 6525AJ, Nijmegen, the Netherlands
| | - Ruth M Gschwind
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Patrick Nuernberger
- Faculty of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Burkhard König
- Faculty of Chemistry and Pharmacy, Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| |
Collapse
|
6
|
Le MT, Holden DT, Manheim JM, Dziekonski ET, Iyer K, Graham Cooks R. Two-Dimensional Tandem Mass Spectrometry for Biopolymer Structural Analysis. Angew Chem Int Ed Engl 2024; 63:e202315904. [PMID: 38117612 DOI: 10.1002/anie.202315904] [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: 11/10/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 12/22/2023]
Abstract
Biopolymer analysis, including proteomics and glycomics, relies heavily on the use of mass spectrometry for structural elucidation, including sequence determination. Novel methods to improve sample workup, instrument performance, and data analysis continue to be developed to address shortcomings associated with sample preparation, analysis time, data quality, and data interpretation. Here, we present a new method that couples in-source collision-induced dissociation (IS-CID) with two-dimensional tandem mass spectrometry (2D MS/MS) as a way to simplify proteomics and glycomics workflows while also providing additional insight into analyte structures over traditional MS/MS experiments. Specifically, IS-CID is employed as a gas-phase digestion method, i.e., to break down intact full-length polysaccharide or peptide ions prior to mass analysis. The resulting mixtures of oligomeric ions are analyzed by 2D-MS/MS, a technique that allows association of product ions with their precursor ions without isolation of the latter. A novel data analysis strategy is introduced to leverage the second dimension of 2D MS/MS spectra, in which stairstep patterns, representing outputs of a molecule's MSn scans, are extracted for structural interconnectivity information on the oligomer. The results demonstrate the potential applicability of 2D MS/MS strategies to the modern omics workflow and structural analysis of various classes of biopolymers.
Collapse
Affiliation(s)
- MyPhuong T Le
- Purdue University, Department of Chemistry, West Lafayette, IN 47907, USA
| | - Dylan T Holden
- Purdue University, Department of Chemistry, West Lafayette, IN 47907, USA
| | - Jeremy M Manheim
- Merck & Co., Inc., Analytical Research and Development, Rahway, NJ 07065, USA
| | - Eric T Dziekonski
- Purdue University, Department of Chemistry, West Lafayette, IN 47907, USA
| | - Kiran Iyer
- Merck & Co., Inc., Analytical Research and Development, Rahway, NJ 07065, USA
| | - R Graham Cooks
- Purdue University, Department of Chemistry, West Lafayette, IN 47907, USA
| |
Collapse
|
7
|
Carlo MJ, Patrick AL. Further exploration of the collision-induced dissociation of select beta blockers: Acebutolol, atenolol, bisoprolol, carteolol, and labetalol. JOURNAL OF MASS SPECTROMETRY : JMS 2023; 58:e4985. [PMID: 37990768 DOI: 10.1002/jms.4985] [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: 09/01/2023] [Revised: 10/20/2023] [Accepted: 10/27/2023] [Indexed: 11/23/2023]
Abstract
Beta blockers are a class of drugs commonly used to treat heart-related diseases; they are also regulated under the World Anti-Doping Agency. Tandem mass spectrometry is often used in the pharmaceutical industry, clinical analysis laboratory, and antidoping laboratory for detection and characterization of drugs and their metabolites. A deeper chemical understanding of dissociation pathways may eventually lead to an improved ability to predict tandem mass spectra of compounds based strictly on their chemical structure (or vice versa), which is especially important for characterization of unknowns such as emerging designer drugs or novel metabolites. In addition to providing insights into dissociation pathways, the use of energy-resolved breakdown curves can produce improved selectivity and lend insights into optimal fragmentation conditions for liquid chromatography-tandem mass spectrometry LC-MS/MS workflows. Here, we perform energy-resolved collision cell and multistage ion trap collision-induced dissociation-mass spectrometry (CID-MS) experiments, along with complementary density functional theory calculations, on five beta blockers (acebutolol, atenolol, bisoprolol, carteolol, and labetalol), to better understand the details of the pathways giving rise to the observed MS/MS patterns. Results from this work are contextualized within previously reported literature on these compounds. New insights into the formation of the characteristic product ion m/z 116 and the pathway leading to characteristic loss of 77 u are highlighted. We also present comparisons of breakdown curves obtained via qToF, quadrupole ion trap, and in-source CID, allowing for differences between the data to be noted and providing a step toward allowing for improved selectivity of breakdown curves to be realized on simple instruments such as single quadrupoles or ion traps.
Collapse
Affiliation(s)
- Matthew J Carlo
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
| | - Amanda L Patrick
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
| |
Collapse
|
8
|
Murray KJ, Villalta PW, Griffin TJ, Balbo S. Discovery of Modified Metabolites, Secondary Metabolites, and Xenobiotics by Structure-Oriented LC-MS/MS. Chem Res Toxicol 2023; 36:1666-1682. [PMID: 37862059 DOI: 10.1021/acs.chemrestox.3c00209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Exogenous compounds and metabolites derived from therapeutics, microbiota, or environmental exposures directly interact with endogenous metabolic pathways, influencing disease pathogenesis and modulating outcomes of clinical interventions. With few spectral library references, the identification of covalently modified biomolecules, secondary metabolites, and xenobiotics is a challenging task using global metabolomics profiling approaches. Numerous liquid chromatography-coupled mass spectrometry (LC-MS) small molecule analytical workflows have been developed to curate global profiling experiments for specific compound groups of interest. These workflows exploit shared structural moiety, functional groups, or elemental composition to discover novel and undescribed compounds through nontargeted small molecule discovery pipelines. This Review introduces the concept of structure-oriented LC-MS discovery methodology and aims to highlight common approaches employed for the detection and characterization of covalently modified biomolecules, secondary metabolites, and xenobiotics. These approaches represent a combination of instrument-dependent and computational techniques to rapidly curate global profiling experiments to detect putative ions of interest based on fragmentation patterns, predictable phase I or phase II metabolic transformations, or rare elemental composition. Application of these methods is explored for the detection and identification of novel and undescribed biomolecules relevant to the fields of toxicology, pharmacology, and drug discovery. Continued advances in these methods expand the capacity for selective compound discovery and characterization that promise remarkable insights into the molecular interactions of exogenous chemicals with host biochemical pathways.
Collapse
Affiliation(s)
- Kevin J Murray
- Department of Biochemistry, Molecular Biology, and Biophysics, College of Biological Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Peter W Villalta
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Timothy J Griffin
- Department of Biochemistry, Molecular Biology, and Biophysics, College of Biological Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Silvia Balbo
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
9
|
Ledergerber TD, Feeney W, Arroyo L, Trejos T. A feasibility study of direct analysis in real time-mass spectrometry for screening organic gunshot residues from various substrates. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2023; 15:4744-4757. [PMID: 37694390 DOI: 10.1039/d3ay01258a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
This study reports the use of direct analysis in real time-mass spectrometry (DART-MS) for the detection of organic gunshot residues (OGSR) in a variety of matrices of interest for forensics, customs, and homeland security. Detection limits ranged from (0.075 to 12) ng, with intra- and inter-day reproducibility below 0.0012% CV. The collection of mass spectra at multiple in-source collision-induced dissociation (is-CID) voltages produced distinctive mass spectral signatures with varying levels of fragmentation and allowed differentiation of isomers. To test method performance, a collection of 330 authentic specimens from various substrates were analyzed - (1) neat smokeless powders, (2) spent cartridge cases, (3) burnt particles removed from clothing via carbon stubs or (4) with tweezers, and hand samples from (5) non-shooters, and (6) shooters. A subset of hand specimens (n = 80) was further analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for confirmation and comparison. Seven types of ammunition from five manufacturers and two calibers were monitored for OGSR profiles with similar compositions observed for paired sets (e.g., unburnt smokeless powder and the respective residues on spent cartridges, clothing, and hands). No false positives were observed across all datasets. A 100% true positive rate (TPR) was observed for all substrates except the shooters' hands. Depending on the ammunition type and classification criteria, the shooters' hands exhibited a TPR ranging from 19% to 73%. The results show that DART-MS is feasible and versatile for fast screening of OGSR across various substrates but may benefit from alternative approaches to improve detection at trace levels.
Collapse
Affiliation(s)
| | - William Feeney
- National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD 20899, USA
| | - Luis Arroyo
- Department of Chemistry, West Virginia University, Morgantown, WV 26506, USA.
- Department of Forensic and Investigative Science, West Virginia University, Morgantown, WV 26506, USA
| | - Tatiana Trejos
- Department of Chemistry, West Virginia University, Morgantown, WV 26506, USA.
- Department of Forensic and Investigative Science, West Virginia University, Morgantown, WV 26506, USA
| |
Collapse
|
10
|
Dias DM, Coombes SR, Benstead D, Whittaker DTE, Ray A, Xu J. Advances in the Specificity of Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy Based Structural Characterisation Methods for Synthetic Oligonucleotides. J Pharm Sci 2023; 112:2524-2531. [PMID: 37105438 DOI: 10.1016/j.xphs.2023.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/20/2023] [Accepted: 04/20/2023] [Indexed: 04/29/2023]
Abstract
Identity testing is a critical part in the development of a therapeutic synthetic oligonucleotide. Tandem Mass Spectrometry (MS/MS) is commonly used for the analysis of oligonucleotides to obtain structural and sequence information, however there are challenges resulting from chemical modifications introduced to improve their pharmacokinetics and stability. For these structurally complex oligonucleotides, Nuclear Magnetic Resonance (NMR) Spectroscopy has found limited use for characterisation and identity testing, as only partial NMR resonance assignment for oligonucleotides is achieved without isotopic labelling methodologies. Regardless of the choice of method used for oligonucleotide analysis, the specificity is of critical importance. In this work, in-source dissociation mass spectrometry and proton (1H) and carbon (13C) NMR at high temperature were used to analyse danvatirsen, a 16 nucleotide phosphorothioate antisense oligonucleotide, and its closely related switch sequences. Both approaches have shown specificity to distinguish danvatirsen from these similar sequences.
Collapse
Affiliation(s)
- David M Dias
- Chemical Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, UK
| | - Steven R Coombes
- Chemical Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, UK
| | - David Benstead
- Chemical Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, UK
| | - David T E Whittaker
- Early Chemical Development, Pharmaceutical Sciences, R&D, AstraZeneca, Macclesfield, UK
| | - Andrew Ray
- New Modalities Parenteral Development, Pharmaceutical Technology & Development, Operations, AstraZeneca, Macclesfield, UK.
| | - Jingshu Xu
- Cellzome, Meyerhofstraße, Heidelberg, Germany
| |
Collapse
|
11
|
Song Y, Song Q, Liu W, Li J, Tu P. High-confidence structural identification of metabolites relying on tandem mass spectrometry through isomeric identification: A tutorial. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.116982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
|
12
|
Zhang Y, Li W, Lei H, Dong X, Kenttämaa H. Differentiation of Seven Isomeric n-Pentylquinoline Radical Cations Based on Energy-Resolved Medium-Energy Collision-Activated Dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:48-63. [PMID: 36507850 DOI: 10.1021/jasms.2c00239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Asphaltenes, a major and undesirable component of heavy crude oil, contain many different types of large aromatic compounds. These compounds include nitrogen-containing heteroaromatic compounds that are thought to be the main culprit in the deactivation of catalysts in crude oil refinery processes. Unfortunately, prevention of this is challenging as the structures and properties of the nitrogen-containing heteroaromatic compounds are poorly understood. To facilitate their structural characterization, an approach based on ion-trap collision-activated dissociation (ITCAD) tandem mass spectrometry followed by energy-resolved medium-energy collision-activated dissociation (ER-MCAD) was developed for the differentiation of seven isomeric molecular radical cations of n-pentylquinoline. The fragmentation of each isomer was found to be distinctly different and depended largely on the site of the alkyl side chain in the quinoline ring. In order to better understand the observed fragmentation pathways, mechanisms for the formation of several fragment ions were delineated based on quantum chemical calculations. The fast benzylic α-bond cleavage that dominates the fragmentation of analogous nonheteroaromatic alkylbenzenes was only observed for the 3-isomer as the major pathway due to the lack of favorable low-energy rearrangement reactions. All the other isomeric ions underwent substantially lower-energy rearrangement reactions as their alkyl chains were found to interact mostly via 6-membered transition states either with the quinoline nitrogen (2- and 8-isomers) or the adjacent carbon atom in the quinoline core (4-, 5-, 6-, and 7-isomers), which lowered the activation energies of the fragmentation reactions. The presented analytical approach will facilitate the structural characterization of nitrogen-containing heteroaromatic compounds in asphaltenes.
Collapse
Affiliation(s)
- Yuyang Zhang
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Wanru Li
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Haoran Lei
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Xueming Dong
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Hilkka Kenttämaa
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| |
Collapse
|
13
|
Metabolite Profiling of Tartary Buckwheat Extracts in Rats Following Co-Administration of Ethanol Using UFLC-Q-Orbitrap High-Resolution Mass Spectrometry. SEPARATIONS 2022. [DOI: 10.3390/separations9120407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tartary buckwheat, a gluten-free pseudocereal, has received considerable attention owing to its unique nutritional ingredients and beneficial health effects such as anti-tumor, anti-oxidation, anti-inflammation and hepatoprotective activities. Pharmacokinetic and metabolite profiling have been preliminarily assessed for Tartary buckwheat extracts. However, its metabolites have not yet been characterized in vivo after co-administration with ethanol when Tartary buckwheat extracts are used for the treatment of alcoholic liver disease. In this paper, a Q-Exactive orbitrap high-resolution mass spectrometer was employed to identify the metabolites of Tartary buckwheat extracts in rat biological samples. Compared with previous metabolite profiling results, a total of 26 novel metabolites were found in rat biological samples, including 11, 10, 2 and 5 novel metabolites in rat plasma, bile, urine and feces, respectively, after oral co-administration of 240 mg/kg Tartary buckwheat extracts with ethanol (42%, v/v). The major metabolic pathways of the constituents in Tartary buckwheat extracts involved hydroxylation, methylation, glucuronidation, acetylation and sulfation. Quercetin and its metabolites may be the pharmacological material basis of Tartary buckwheat for the protective effect against alcoholic liver injury. The research enriched in vivo metabolite profiling of Tartary buckwheat extracts, which provided experimental data for a comprehensive understanding and rational use of Tartary buckwheat against alcoholic liver disease.
Collapse
|
14
|
Kaeslin J, Wüthrich C, Giannoukos S, Zenobi R. How Soft Is Secondary Electrospray Ionization? JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1967-1974. [PMID: 36111835 DOI: 10.1021/jasms.2c00201] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Secondary electrospray ionization (SESI) mass spectrometry (MS) is a direct infusion technique often used for untargeted metabolomics, e.g., for online breath analysis. SESI is thought to be a soft ionization method, which is important to avoid interference from in-source fragments and to simplify compound annotation. In this work, benzylammonium ions, formed from volatile benzylamines, with known bond dissociation enthalpies were used as thermometer ions to investigate the internal energy distribution of ions that are produced by SESI. It is shown that SESI is softer than electrospray ionization (ESI), and therefore, SESI indeed qualifies as a soft ionization technique. However, we also found that the standard MS instrument settings used in the SESI community are relatively harsh. Proper soft tuning of the instrument is essential to fully benefit from the softness that SESI can provide. Moreover, there is evidence from in-source collision-induced dissociation (CID) experiments that analytes can be solvated in SESI under soft conditions, which supports a recently proposed SESI mechanism referred to as ligand switching.
Collapse
Affiliation(s)
- Jérôme Kaeslin
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Cedric Wüthrich
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Stamatios Giannoukos
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Renato Zenobi
- Department of Chemistry and Applied Biosciences, ETH Zürich, CH-8093 Zürich, Switzerland
| |
Collapse
|
15
|
Sharp J, Do D, Tyler Davidson J. Assessment of the similarity between in-source collision-induced dissociation (IS-CID) fragment ion spectra and tandem mass spectrometry (MS/MS) product ion spectra for seized drug identifications. Forensic Chem 2022. [DOI: 10.1016/j.forc.2022.100441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
16
|
Zelenka J, Pereverzev A, Jahn U, Roithová J. Sulfonyl Nitrene and Amidyl Radical: Structure and Reactivity. Chemistry 2022; 28:e202104493. [PMID: 35266598 PMCID: PMC9323475 DOI: 10.1002/chem.202104493] [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: 12/17/2021] [Indexed: 11/10/2022]
Abstract
Photocatalytic generation of nitrenes and radicals can be used to tune or even control their reactivity. Photocatalytic activation of sulfonyl azides leads to the elimination of N2 and the resulting reactive species initiate C−H activations and amide formation reactions. Here, we present reactive radicals that are generated from sulfonyl azides: sulfonyl nitrene radical anion, sulfonyl nitrene and sulfonyl amidyl radical, and test their gas phase reactivity in C−H activation reactions. The sulfonyl nitrene radical anion is the least reactive and its reactivity is governed by the proton coupled electron transfer mechanism. In contrast, sulfonyl nitrene and sulfonyl amidyl radicals react via hydrogen atom transfer pathways. These reactivities and detailed characterization of the radicals with vibrational spectroscopy and with DFT calculations provide information necessary for taking control over the reactivity of these intermediates.
Collapse
Affiliation(s)
- Jan Zelenka
- Department of Spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen, Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Aleksandr Pereverzev
- Department of Spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen, Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Ullrich Jahn
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague 6 Czech Republic
| | - Jana Roithová
- Department of Spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen, Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| |
Collapse
|
17
|
Mamani-Huanca M, Gradillas A, López-Gonzálvez Á, Barbas C. In-Source Fragmentation for the Identification of Compounds by CE-ESI-TOF in Human Plasma. L-Proline as Case Study. Methods Mol Biol 2022; 2531:185-202. [PMID: 35941486 DOI: 10.1007/978-1-0716-2493-7_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
One of the aims of untargeted metabolomics is searching for selective biomarkers of different pathophysiological conditions. Modified amino acids originated from the posttranslational modification of proteins play a key role as potential biomarkers; however, they are very often still classified as unknown after metabolite annotation. We have developed an analytical workflow for the targeted screening of these compounds using CE-ESI-MS. The workflow is based on the in-source fragmentation of molecules that produces diagnostic ions that we have collected in an open-source library. In this chapter, we describe in detail the strategy for the targeted screening of modified amino acids (MAAs), using as an example L-proline and its modified derivatives. We illustrate the strategy with two case studies in human plasma.
Collapse
Affiliation(s)
- Maricruz Mamani-Huanca
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, Madrid, Spain
| | - Ana Gradillas
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, Madrid, Spain
| | - Ángeles López-Gonzálvez
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, Madrid, Spain
| | - Coral Barbas
- Centro de Metabolómica y Bioanálisis (CEMBIO), Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, Madrid, Spain.
| |
Collapse
|
18
|
An N, Zhu QF, Wang YZ, Xiong CF, Hu YN, Feng YQ. Integration of Chemical Derivatization and in-Source Fragmentation Mass Spectrometry for High-Coverage Profiling of Submetabolomes. Anal Chem 2021; 93:11321-11328. [PMID: 34369157 DOI: 10.1021/acs.analchem.1c02673] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In-source fragmentation-based high-resolution mass spectrometry (ISF-HRMS) is a potential analytical technique, which is usually used to profile some specific compounds that can generate diagnostic neutral loss (NL) or fragment ion (FI) in ion source inherently. However, the ISF-HRMS method does not work for those compounds that cannot inherently produce diagnostic NL or FI in ion source. In this study, a derivatization-based in-source fragmentation-information-dependent acquisition (DISF-IDA) strategy was proposed for profiling the metabolites with easily labeled functional groups (submetabolomes) by liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (LC-ESI-Q-TOF MS). As a proof-of-concept study, 36 carboxylated compounds labeled with N,N-dimethylethylenediamine (DMED) were selected as model compounds to examine performance of DISF-IDA strategy in screening the carboxylated metabolites and acquiring their MSn spectra. In ESI source, the DEMD-derived carboxylated compounds were fragmented to produce characteristic neutral losses of 45.0578, 63.0684, and/or 88.1000 Da that were further used as diagnostic features for screening the carboxylated metabolites by DISF-IDA-based LC-Q-TOF MS. Furthermore, high-resolution MSn spectra of the model compounds were also obtained within a single run of DISF-IDA-based LC-Q-TOF MS analysis, which contributed to the improvement of the annotation confidence. To further verify its applicability, DISF-IDA strategy was used for profiling carboxylated submetabolome in mice feces. Using this strategy, a total of 351 carboxylated metabolites were detected from mice feces, of which 178 metabolites (51% of the total) were positively or putatively identified. Moreover, DISF-IDA strategy was also demonstrated to be applicable for profiling other submetabolomes with easily labeled functional groups such as amino, carbonyl, and cis-diol groups. Overall, our proposed DISF-IDA strategy is a promising technique for high-coverage profiling of submetabolomes with easily labeled functional groups in biological samples.
Collapse
Affiliation(s)
- Na An
- Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Quan-Fei Zhu
- Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Yan-Zhen Wang
- Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Cai-Feng Xiong
- Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Yu-Ning Hu
- Department of Chemistry, Wuhan University, Wuhan 430072, PR China
| | - Yu-Qi Feng
- Department of Chemistry, Wuhan University, Wuhan 430072, PR China.,Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430072, PR China.,School of Health Sciences, Wuhan University, Wuhan 430071, PR China
| |
Collapse
|
19
|
Koopman J, Grimme S. From QCEIMS to QCxMS: A Tool to Routinely Calculate CID Mass Spectra Using Molecular Dynamics. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:1735-1751. [PMID: 34080847 DOI: 10.1021/jasms.1c00098] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mass spectrometry (MS) is a powerful tool in chemical research and substance identification. For the computational modeling of electron ionization MS, we have developed the quantum-chemical electron ionization mass spectra (QCEIMS) program. Here, we present an extension of QCEIMS to calculate collision-induced dissociation (CID) spectra. The more general applicability is accounted for by the new name QCxMS, where "x" refers to EI or CID. To this end, fragmentation and rearrangement reactions are computed "on-the-fly" in Born-Oppenheimer molecular dynamics (MD) simulations with the semiempirical GFN2-xTB Hamiltonian, which provides an efficient quantum mechanical description of all elements up to Z = 86 (Rn). Through the explicit modeling of multicollision processes between precursor ions and neutral gas atoms as well as temperature-induced decomposition reactions, QCxMS provides detailed insight into the collision kinetics and fragmentation pathways. In combination with the CREST program to determine the preferential protonation sites, QCxMS becomes the first standalone MD-based program that can predict mass spectra based solely on molecular structures as input. We demonstrate this for six organic molecules with masses ranging from 159 to 296 Da, for which QCxMS yields CID spectra in reasonable agreement with experiments.
Collapse
Affiliation(s)
- Jeroen Koopman
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| |
Collapse
|
20
|
Cejkov M, Greer T, Johnson RO, Zheng X, Li N. Electron Transfer Dissociation Parameter Optimization Using Design of Experiments Increases Sequence Coverage of Monoclonal Antibodies. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:762-771. [PMID: 33596068 DOI: 10.1021/jasms.0c00458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Middle-down analysis of monoclonal antibodies (mAbs) by tandem mass spectrometry (MS2) can provide detailed insight into their primary structure with minimal sample preparation. The middle-down approach uses an enzyme to cleave mAbs into Fc/2, LC, and Fd subunits that are then analyzed by reversed phase liquid chromatography tandem mass spectrometry (RPLC-MS2). As maximum sequence coverage is desired to obtain meaningful structural information at the subunit level, a host of dissociation methods have been developed, and sometimes combined, to bolster fragmentation and increase the number of identified fragments. Here, we present a design of experiments (DOE) approach to optimize MS2 parameters, in particular those that may influence electron transfer dissociation (ETD) efficiency to increase the sequence coverage of antibody subunits. Applying this approach to the NIST monoclonal antibody standard (NISTmAb) using three RPLC-MS2 runs resulted in high sequence coverages of 67%, 67%, and 52% for Fc/2, LC, and Fd subunits, respectively. In addition, we apply this DOE strategy to model the parameters required to maximize the number of fragments produced in "low", "medium", and "high" mass ranges, which ultimately resulted in even higher sequence coverages of NISTmAb subunits (75%, 78%, and 64% for Fc/2, LC, and Fd subunits, respectively). The DOE approach provides high sequence coverage percentages utilizing only one fragmentation method, ETD, and could be extended to other state-of-the-art techniques that combine multiple fragmentation mechanisms to increase coverage.
Collapse
Affiliation(s)
- Milos Cejkov
- Analytical Chemistry, Regeneron Pharmaceuticals Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707, United States
| | - Tyler Greer
- Analytical Chemistry, Regeneron Pharmaceuticals Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707, United States
| | - Reid O'Brien Johnson
- Analytical Chemistry, Regeneron Pharmaceuticals Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707, United States
| | - Xiaojing Zheng
- Analytical Chemistry, Regeneron Pharmaceuticals Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707, United States
| | - Ning Li
- Analytical Chemistry, Regeneron Pharmaceuticals Inc., 777 Old Saw Mill River Road, Tarrytown, New York 10591-6707, United States
| |
Collapse
|
21
|
Davidson JT, Sasiene ZJ, Jackson GP. Comparison of in-source collision-induced dissociation and beam-type collision-induced dissociation of emerging synthetic drugs using a high-resolution quadrupole time-of-flight mass spectrometer. JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4679. [PMID: 33410270 DOI: 10.1002/jms.4679] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/09/2020] [Accepted: 11/01/2020] [Indexed: 06/12/2023]
Abstract
In-source collision-induced dissociation (CID) is commonly used with single-stage high-resolution mass spectrometers to gather both a molecular formula and structural information through the collisional activation of analytes with residual background gas in the source region of the mass spectrometer. However, unlike tandem mass spectrometry, in-source CID does not involve an isolation step prior to collisional activation leading to a product ion spectrum composed of fragment ions from any analyte present during the activation event. This work provides the first comparison of in-source CID and beam-type CID spectra of emerging synthetic drugs on the same instrument to understand the fragmentation differences between the two techniques and to contribute to the scientific foundations of in-source CID. Electrospray ionization-quadrupole time-of-flight (ESI-Q-TOF) mass spectrometry was used to generate product ion spectra from in-source CID and beam-type CID for a series of well-characterized fentanyl analogs and synthetic cathinones. A comparison between the fragmentation patterns and relative ion abundances for each technique was performed over a range of fragmentor offset voltages for in-source CID and a range of collision energies for beam-type CID. The results indicate that large fragmentor potentials for in-source CID tend to favor higher energy fragmentation pathways that result in both kinetically favored pathways and consecutive neutral losses, both of which produce more abundant lower mass product ions relative to beam-type CID. Although conditions can be found in which in-source CID and beam-type CID provide similar overall spectra, the in-source CID spectra tend to contain elevated noise and additional chemical background peaks relative to beam-type CID.
Collapse
Affiliation(s)
- J Tyler Davidson
- Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia, USA
- Department of Forensic Science, Sam Houston State University, Huntsville, Texas, USA
| | - Zachary J Sasiene
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Glen P Jackson
- Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia, USA
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia, USA
| |
Collapse
|
22
|
Borden SA, Palaty J, Termopoli V, Famiglini G, Cappiello A, Gill CG, Palma P. MASS SPECTROMETRY ANALYSIS OF DRUGS OF ABUSE: CHALLENGES AND EMERGING STRATEGIES. MASS SPECTROMETRY REVIEWS 2020; 39:703-744. [PMID: 32048319 DOI: 10.1002/mas.21624] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
Mass spectrometry has been the "gold standard" for drugs of abuse (DoA) analysis for many decades because of the selectivity and sensitivity it affords. Recent progress in all aspects of mass spectrometry has seen significant developments in the field of DoA analysis. Mass spectrometry is particularly well suited to address the rapidly proliferating number of very high potency, novel psychoactive substances that are causing an alarming number of fatalities worldwide. This review surveys advancements in the areas of sample preparation, gas and liquid chromatography-mass spectrometry, as well as the rapidly emerging field of ambient ionization mass spectrometry. We have predominantly targeted literature progress over the past ten years and present our outlook for the future. © 2020 Periodicals, Inc. Mass Spec Rev.
Collapse
Affiliation(s)
- Scott A Borden
- Applied Environmental Research Laboratories (AERL), Department of Chemistry, Vancouver Island University, Nanaimo, BC, V9R 5S5, Canada
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Jan Palaty
- LifeLabs Medical Laboratories, Burnaby, BC, V3W 1H8, Canada
| | - Veronica Termopoli
- LC-MS Laboratory, Department of Pure and Applied Sciences, University of Urbino Carlo Bo, 61029, Urbino, Italy
| | - Giorgio Famiglini
- LC-MS Laboratory, Department of Pure and Applied Sciences, University of Urbino Carlo Bo, 61029, Urbino, Italy
| | - Achille Cappiello
- Applied Environmental Research Laboratories (AERL), Department of Chemistry, Vancouver Island University, Nanaimo, BC, V9R 5S5, Canada
- LC-MS Laboratory, Department of Pure and Applied Sciences, University of Urbino Carlo Bo, 61029, Urbino, Italy
| | - Chris G Gill
- Applied Environmental Research Laboratories (AERL), Department of Chemistry, Vancouver Island University, Nanaimo, BC, V9R 5S5, Canada
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195
| | - Pierangela Palma
- Applied Environmental Research Laboratories (AERL), Department of Chemistry, Vancouver Island University, Nanaimo, BC, V9R 5S5, Canada
- LC-MS Laboratory, Department of Pure and Applied Sciences, University of Urbino Carlo Bo, 61029, Urbino, Italy
| |
Collapse
|
23
|
Wang M, Yu P, Chittiboyina AG, Chen D, Zhao J, Avula B, Wang YH, Khan IA. Characterization, Quantification and Quality Assessment of Avocado ( Persea americana Mill.) Oils. Molecules 2020; 25:molecules25061453. [PMID: 32213805 PMCID: PMC7145317 DOI: 10.3390/molecules25061453] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 01/30/2023] Open
Abstract
Avocado oil is prized for its high nutritional value due to the substantial amounts of triglycerides (TGs) and unsaturated fatty acids (FAs) present. While avocado oil is traditionally extracted from mature fruit flesh, alternative sources such as avocado seed oil have recently increased in popularity. Unfortunately, sufficient evidence is not available to support the claimed health benefit and safe use of such oils. To address potential quality issues and identify possible adulteration, authenticated avocado oils extracted from the fruit peel, pulp and seed by supercritical fluid extraction (SFE), as well as commercial avocado pulp and seed oils sold in US market were analyzed for TGs and FAs in the present study. Characterization and quantification of TGs were conducted using UHPLC/ESI-MS. Thirteen TGs containing saturated and unsaturated fatty acids in avocado oils were unambiguously identified. Compared to traditional analytical methods, which are based only on the relative areas of chromatographic peaks neglecting the differences in the relative response of individual TG, our method improved the quantification of TGs by using the reference standards whenever possible or the reference standards with the same equivalent carbon number (ECN). To verify the precision and accuracy of the UHPLC/ESI-MS method, the hydrolysis and transesterification products of avocado oil were analyzed for fatty acid methyl esters using a GC/MS method. The concentrations of individual FA were calculated, and the results agreed with the UHPLC/ESI-MS method. Although chemical profiles of avocado oils from pulp and peel are very similar, a significant difference was observed for the seed oil. Principal component analysis (PCA) based on TG and FA compositional data allowed correct identification of individual avocado oil and detection of possible adulteration.
Collapse
Affiliation(s)
- Mei Wang
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA; (M.W.); (A.G.C.); (J.Z.); (B.A.); (Y.-H.W.)
| | - Ping Yu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330031, China;
- Jiangxi Province Key Laboratory of Edible and Medicinal Resources Exploitation, Nanchang University, Nanchang 330031, China
- School of Resource and Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Amar G. Chittiboyina
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA; (M.W.); (A.G.C.); (J.Z.); (B.A.); (Y.-H.W.)
| | - Dilu Chen
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China;
| | - Jianping Zhao
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA; (M.W.); (A.G.C.); (J.Z.); (B.A.); (Y.-H.W.)
| | - Bharathi Avula
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA; (M.W.); (A.G.C.); (J.Z.); (B.A.); (Y.-H.W.)
| | - Yan-Hong Wang
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA; (M.W.); (A.G.C.); (J.Z.); (B.A.); (Y.-H.W.)
| | - Ikhlas A. Khan
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, MS 38677, USA; (M.W.); (A.G.C.); (J.Z.); (B.A.); (Y.-H.W.)
- Division of Pharmacognosy, Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, University, MS 38677, USA
- Correspondence: ; Tel.: +1-662-915-7821
| |
Collapse
|
24
|
Mamani-Huanca M, Gradillas A, Gil de la Fuente A, López-Gonzálvez Á, Barbas C. Unveiling the Fragmentation Mechanisms of Modified Amino Acids as the Key for Their Targeted Identification. Anal Chem 2020; 92:4848-4857. [DOI: 10.1021/acs.analchem.9b04313] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Maricruz Mamani-Huanca
- Centre for Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, Spain
| | - Ana Gradillas
- Centre for Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, Spain
| | - Alberto Gil de la Fuente
- Centre for Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, Spain
- Department of Information Technology, Escuela Politécnica Superior, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, Spain
| | - Ángeles López-Gonzálvez
- Centre for Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, Spain
| | - Coral Barbas
- Centre for Metabolomics and Bioanalysis (CEMBIO), Department of Chemistry and Biochemistry, Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, Spain
| |
Collapse
|
25
|
Nahar A, Baker AL, Nichols DS, Bowman JP, Britz ML. Application of Thin-Layer Chromatography-Flame Ionization Detection (TLC-FID) to Total Lipid Quantitation in Mycolic-Acid Synthesizing Rhodococcus and Williamsia Species. Int J Mol Sci 2020; 21:ijms21051670. [PMID: 32121355 PMCID: PMC7084869 DOI: 10.3390/ijms21051670] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/15/2020] [Accepted: 02/25/2020] [Indexed: 12/25/2022] Open
Abstract
In addition to cell membrane phospholipids, Actinobacteria in the order Corynebacteriales possess a waxy cell envelope containing mycolic acids (MA). In optimized culture condition, some species can also accumulate high concentrations of intracellular triacylglycerols (TAG), which are a potential source of biodiesel. Bacterial lipid classes and composition alter in response to environmental stresses, including nutrient availability, thus understanding carbon flow into different lipid classes is important when optimizing TAG synthesis. Quantitative and qualitative analysis of lipid classes normally requires combinations of different extraction, derivatization, chromatographic and detection methods. In this study, a single-step thin-layer chromatography-flame ionization detection (TLC-FID) technique was applied to quantify lipid classes in six sub-Antarctic Corynebacteriales strains identified as Rhodococcus and Williamsia species. A hexane:diethyl-ether:acetic acid solvent system separated the total cellular lipids extracted from cells lysed by bead beating, which released more bound and unbound MA than sonication. Typical profiles included a major broad non-polar lipid peak, TAG and phospholipids, although trehalose dimycolates, when present, co-eluted with phospholipids. Ultra-performance liquid chromatography-tandem mass-spectrometry and nuclear magnetic resonance spectroscopy detected MA signatures in the non-polar lipid peak and indicated that these lipids were likely bound, at least in part, to sugars from cell wall arabinogalactan. Waxy esters were not detected. The single-solvent TLC-FID procedure provides a useful platform for the quantitation and preliminary screening of cellular lipid classes when testing the impacts of growth conditions on TAG synthesis.
Collapse
Affiliation(s)
- Akhikun Nahar
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7005, Australia; (A.N.); (A.L.B.); (J.P.B.)
| | - Anthony L. Baker
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7005, Australia; (A.N.); (A.L.B.); (J.P.B.)
| | - David S. Nichols
- Central Science Laboratory, Division of Research, University of Tasmania, Hobart, TAS 7005, Australia;
| | - John P. Bowman
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7005, Australia; (A.N.); (A.L.B.); (J.P.B.)
| | - Margaret L. Britz
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, TAS 7005, Australia; (A.N.); (A.L.B.); (J.P.B.)
- Correspondence:
| |
Collapse
|
26
|
Kumar R, Yerabolu R, Kenttämaa HI. Effects of Residual Water in a Linear Quadrupole Ion Trap on the Protonation Sites of 4-Aminobenzoic Acid. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:124-131. [PMID: 32881520 DOI: 10.1021/jasms.9b00001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In solution, the most basic site in 4-aminobenzoic acid is the amino nitrogen, while the carboxylic acid oxygen is the most basic site in the gas phase. However, the protonation site in the gas phase has been demonstrated to depend on the ionization solvents when ionized using positive ion mode electrospray ionization (ESI). In many of these studies, collision-activated dissociation (CAD) was used to differentiate the protomers. To explore the influence of different CAD conditions on the manifested protonation site, 4-aminobenzoic acid dissolved either in 1:1 acetonitrile-water or 3:1 methanol-water was ionized by ESI and subjected to three different CAD experiments in a linear quadrupole ion trap/orbitrap mass spectrometer. Based on in-source CAD (ISCAD) and beam-type medium-energy CAD (MCAD), the proton resided on the nitrogen atom (N-protomer) when acetonitrile-water was used as the solvent system but on the oxygen atom (O-protomer) when methanol-water was used. Interestingly, a predominant N-protomer was observed when CAD was performed in the linear quadrupole ion trap (ITCAD), irrespective of the solvents used, in disagreement with literature. This unexpected result is rationalized based on the formation of long-lived water clusters of varying sizes for the protomers in the quadrupole ion trap due to residual water, low ion kinetic energies, long ion storage times, and relatively high pressure. Further, addition of extra water into the quadrupole ion trap resulted in nearly identical protomer distributions for both protomers. Therefore, this distribution must be near the equilibrium distribution caused by the presence of water clusters of varying sizes, some favoring the N-protomer and others the O-protomer.
Collapse
Affiliation(s)
- Rashmi Kumar
- Chemistry Department, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Ravikiran Yerabolu
- Chemistry Department, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Hilkka I Kenttämaa
- Chemistry Department, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| |
Collapse
|
27
|
Damont A, Olivier MF, Warnet A, Lyan B, Pujos-Guillot E, Jamin EL, Debrauwer L, Bernillon S, Junot C, Tabet JC, Fenaille F. Proposal for a chemically consistent way to annotate ions arising from the analysis of reference compounds under ESI conditions: A prerequisite to proper mass spectral database constitution in metabolomics. JOURNAL OF MASS SPECTROMETRY : JMS 2019; 54:567-582. [PMID: 31083780 DOI: 10.1002/jms.4372] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
Nowadays, high-resolution mass spectrometry is widely used for metabolomic studies. Thanks to its high sensitivity, it enables the detection of a large range of metabolites. In metabolomics, the continuous quest for a metabolite identification as complete and accurate as possible has led during the last decade to an ever increasing development of public MS databases (including LC-MS data) concomitantly with bioinformatic tool expansion. To facilitate the annotation process of MS profiles obtained from biological samples, but also to ease data sharing, exchange, and exploitation, the standardization and harmonization of the way to describe and annotate mass spectra seemed crucial to us. Indeed, under electrospray (ESI) conditions, a single metabolite does not produce a unique ion corresponding to its protonated or deprotonated form but could lead to a complex mixture of signals. These MS signals result from the existence of different natural isotopologues of the same compound and also to the potential formation of adduct ions, homomultimeric and heteromultimeric ions, fragment ions resulting from "prompt" in-source dissociations. As a joint reflection process within the French Infrastructure for Metabolomics and Fluxomics (MetaboHUB) and with the purpose of developing a robust and exchangeable annotated MS database made from pure reference compounds (chemical standards) analysis, it appeared to us that giving the metabolomics community some clues to standardize and unambiguously annotate each MS feature was a prerequisite to data entry and further efficient querying of the mass spectral database. The use of a harmonized notation is also mandatory for interlaboratory MS data exchange. Additionally, thorough description of the variety of MS signals arising from the analysis of a unique metabolite might provide greater confidence on its annotation.
Collapse
Affiliation(s)
- Annelaure Damont
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Marie-Françoise Olivier
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Anna Warnet
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Bernard Lyan
- Plateforme d'Exploration du Métabolisme, MetaboHUB Clermont, Université Clermont Auvergne, INRA, UNH, F-63000, Clermont-Ferrand, France
| | - Estelle Pujos-Guillot
- Plateforme d'Exploration du Métabolisme, MetaboHUB Clermont, Université Clermont Auvergne, INRA, UNH, F-63000, Clermont-Ferrand, France
| | - Emilien L Jamin
- Toxalim (Research Centre in Food Toxicology), Metatoul-AXIOM platform, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, F-31027, Toulouse, France
| | - Laurent Debrauwer
- Toxalim (Research Centre in Food Toxicology), Metatoul-AXIOM platform, Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, F-31027, Toulouse, France
| | - Stéphane Bernillon
- UMR1332 Biologie du Fruit et Pathologie, INRA, Univ. Bordeaux, Plateforme Métabolome du Centre de Génomique Fonctionnelle Bordeaux-MetaboHUB, IBVM, Centre INRA de Nouvelle Aquitaine-Bordeaux, 71 av Edouard Bourlaux, 33140, Villenave d'Ornon, France
| | - Christophe Junot
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| | - Jean-Claude Tabet
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
- CNRS, Institut Parisien de Chimie Moléculaire, IPCM, Sorbonne Université, 75005, Paris, France
| | - François Fenaille
- Service de Pharmacologie et Immuno-Analyse (SPI), Laboratoire d'Etude du Métabolisme des Médicaments, CEA, INRA, Université Paris Saclay, MetaboHUB, F-91191, Gif-sur-Yvette, France
| |
Collapse
|
28
|
Li X, Yang X, Hoang V, Liu YH. Characterization of Protein Disulfide Linkages by MS In-Source Dissociation Comparing to CID and ETD Tandem MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:519-528. [PMID: 30478816 DOI: 10.1007/s13361-018-2103-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/18/2018] [Accepted: 11/01/2018] [Indexed: 05/19/2023]
Abstract
Direct characterization of disulfide linkages in proteins by mass spectrometry has been challenging. Here, we report analysis of disulfide linkages in insulin variant, endothelin 3, and relaxin 2 by in-source dissociation (ISD) during LC-MS. A duplet insulin peptide from Glu-C digestion that contains peptides p1 and p2 (from chains A and B, respectively) was selected as a model peptide. This duplet peptide has an inter-chain disulfide bond between p1 and p2, and an intra-chain disulfide bond in p1. To compare the gas-phase fragmentation, it was subjected to ISD MS and MS/MS methods, including collision-induced dissociation (CID) and electron transfer dissociation (ETD). The pattern and efficiency of peptide backbone and disulfide cleavage varied with these dissociation methods. ETD, CID, and ISD were able to generate single backbone, double backbone, and triple (double backbone and single disulfide bond) cleavages in this model peptide, respectively. Specifically, CID did not cleave disulfide bonds and ETD was able to only cleave the inter-chain disulfide bond at low efficiency, limiting their usage in this disulfide analysis. In contrast, ISD was able to cleave the intra-chain disulfide bond in addition to peptide backbone, creating multiple fragment ions that allow accurate assignment of both intra- and inter-chain disulfide linkages. ISD was also successfully applied to determine double disulfide linkages in endothelin 3 and relaxin 2 peptides. This study contributes to the fundamental understanding of disulfide bond cleavages in different gas-phase fragmentations and provides an efficient cleavage strategy for identification of disulfide bonds in proteins by ISD ESI-MS. Graphical Abstract.
Collapse
Affiliation(s)
- Xiaojuan Li
- Bioprocess Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA.
| | - Xiaoyu Yang
- Bioprocess Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Van Hoang
- Bioprocess Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Yan-Hui Liu
- Bioprocess Development, MRL, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| |
Collapse
|
29
|
Vincent D, Mertens D, Rochfort S. Optimisation of Milk Protein Top-Down Sequencing Using In-Source Collision-Induced Dissociation in the Maxis Quadrupole Time-of-Flight Mass Spectrometer. Molecules 2018; 23:molecules23112777. [PMID: 30373172 PMCID: PMC6278275 DOI: 10.3390/molecules23112777] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 10/24/2018] [Accepted: 10/25/2018] [Indexed: 12/25/2022] Open
Abstract
Top-down sequencing in proteomics has come of age owing to continuous progress in LC-MS. With their high resolution and broad mass range, Quadrupole Time-of-Flight (Q-ToF) hybrid mass spectrometers equipped with electrospray ionisation source and tandem MS capability by collision-induced dissociation (CID) can be employed to analyse intact proteins and retrieve primary sequence information. To our knowledge, top-down proteomics methods with Q-ToF have only been evaluated using samples of relatively low complexity. Furthermore, the in-source CID (IS-CID) capability of Q-ToF instruments has been under-utilised. This study aimed at optimising top-down sequencing of intact milk proteins to achieve the greatest sequence coverage possible from samples of increasing complexity, assessed using nine known proteins. Eleven MS/MS methods varying in their IS-CID and conventional CID parameters were tested on individual and mixed protein standards as well as raw milk samples. Top-down sequencing results from the nine most abundant proteoforms of caseins, alpha-lactalbumin and beta-lactoglubulins were compared. Nine MS/MS methods achieved more than 70% sequence coverage overall to distinguish between allelic proteoforms, varying only by one or two amino acids. The optimal methods utilised IS-CID at low energy. This experiment demonstrates the utility of Q-ToF systems for top-down proteomics and that IS-CID could be more frequently employed.
Collapse
Affiliation(s)
- Delphine Vincent
- Department of Economic Development, Jobs, Transport and Resources, AgriBio Centre, Bundoora, Victoria 3083, Australia.
| | | | - Simone Rochfort
- Department of Economic Development, Jobs, Transport and Resources, AgriBio Centre, Bundoora, Victoria 3083, Australia.
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria 3083, Australia.
| |
Collapse
|