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Hoare M, Tan R, Welle KA, Swovick K, Hryhorenko JR, Ghaemmaghami S. Methionine Alkylation as an Approach to Quantify Methionine Oxidation Using Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:433-440. [PMID: 38324783 PMCID: PMC10921467 DOI: 10.1021/jasms.3c00337] [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: 09/22/2023] [Revised: 01/08/2024] [Accepted: 01/12/2024] [Indexed: 02/09/2024]
Abstract
Post-translational oxidation of methionine residues can destabilize proteins or modify their functions. Although levels of methionine oxidation can provide important information regarding the structural integrity and regulation of proteins, their quantitation is often challenging as analytical procedures in and of themselves can artifactually oxidize methionines. Here, we develop a mass-spectrometry-based method called Methionine Oxidation by Blocking with Alkylation (MObBa) that quantifies methionine oxidation by selectively alkylating and blocking unoxidized methionines. Thus, alkylated methionines can be used as a stable proxy for unoxidized methionines. Using proof of concept experiments, we demonstrate that MObBa can be used to measure methionine oxidation levels within individual synthetic peptides and on proteome-wide scales. MObBa may provide a straightforward experimental strategy for mass spectrometric quantitation of methionine oxidation.
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Affiliation(s)
- Margaret Hoare
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States
| | - Ruiyue Tan
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States
| | - Kevin A. Welle
- University
of Rochester Mass Spectrometry Resource Laboratory, Rochester, New York 14627, United States
| | - Kyle Swovick
- University
of Rochester Mass Spectrometry Resource Laboratory, Rochester, New York 14627, United States
| | - Jennifer R. Hryhorenko
- University
of Rochester Mass Spectrometry Resource Laboratory, Rochester, New York 14627, United States
| | - Sina Ghaemmaghami
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States
- University
of Rochester Mass Spectrometry Resource Laboratory, Rochester, New York 14627, United States
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2
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König S, Schork K, Eisenacher M. Observations from the Proteomics Bench. Proteomes 2024; 12:6. [PMID: 38390966 PMCID: PMC10885119 DOI: 10.3390/proteomes12010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/26/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Abstract
Many challenges in proteomics result from the high-throughput nature of the experiments. This paper first presents pre-analytical problems, which still occur, although the call for standardization in omics has been ongoing for many years. This article also discusses aspects that affect bioinformatic analysis based on three sets of reference data measured with different orbitrap instruments. Despite continuous advances in mass spectrometer technology as well as analysis software, data-set-wise quality control is still necessary, and decoy-based estimation, although challenged by modern instruments, should be utilized. We draw attention to the fact that numerous young researchers perceive proteomics as a mature, readily applicable technology. However, it is important to emphasize that the maximum potential of the technology can only be realized by an educated handling of its limitations.
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Affiliation(s)
- Simone König
- IZKF Core Unit Proteomics, University of Münster, 48149 Münster, Germany
| | - Karin Schork
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany
- Center for Protein Diagnostics (PRODI), Medical Proteome Analysis, Ruhr-University Bochum, 44801 Bochum, Germany
- Core Unit for Bioinformatics (CUBiMed.RUB), Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Martin Eisenacher
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany
- Center for Protein Diagnostics (PRODI), Medical Proteome Analysis, Ruhr-University Bochum, 44801 Bochum, Germany
- Core Unit for Bioinformatics (CUBiMed.RUB), Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany
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3
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Rogers LM, Halcrow SE, Kleffmann T, King CL. Comparing Walker's (2008) skull trait sex estimation standard to proteomic sex estimation for a group of South Asian individuals. Forensic Sci Int Synerg 2024; 8:100450. [PMID: 38314398 PMCID: PMC10837481 DOI: 10.1016/j.fsisyn.2023.100450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/28/2023] [Accepted: 12/19/2023] [Indexed: 02/06/2024]
Abstract
This research assesses the potential for misidentification of sex in individuals of South Asian ancestry using the Walker (2008) morphological skull sex estimation standard [1]. Chromosomal sex was assessed using proteomic analysis targeting sex chromosome-specific amylogenic peptides. Results showed that the Walker method produced incorrect classification for 36.7 % of individuals. Overwhelmingly, those incorrectly assigned were chromosomally male. Misidentification was due to males within the group having lower trait scores (i.e., more gracile traits) than the standard would predict. There was also a high level of overlap in trait scores between male and females indicating reduced expression of sexual dimorphism. The use of established multivariate statistical techniques improved accuracy of sex estimation in some cases, but larger osteological data sets from South Asian individuals are required to develop population-specific standards. We suggest that peptide analysis may provide a useful tool for the forensic anthropologist when assessing sex in populations without population specific osteological standards.
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Affiliation(s)
- Laura M Rogers
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Siân E Halcrow
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Torsten Kleffmann
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Charlotte L King
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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König S, Marco HG, Gäde G. Oxidation Products of Tryptophan and Proline in Adipokinetic Hormones-Artifacts or Post-Translational Modifications? Life (Basel) 2023; 13:2315. [PMID: 38137917 PMCID: PMC10744910 DOI: 10.3390/life13122315] [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: 10/24/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND Adipokinetic hormones (AKHs) regulate important physiological processes in insects. AKHs are short peptides with blocked termini and Trp in position 8. Often, proline occupies position 6. Few post-translational modifications have been found, including hydroxyproline ([Hyp6]) and kynurenine. Our recent data suggest that the Hyp- and Kyn-containing AKHs occur more often than originally thought and we here investigate if they are natural or artifactual. METHODS From crude extracts of the corpora cardiaca (CC) of various insect species, AKHs were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-MS). Synthetic [Hyp6]-AKHs were tested in an in vivo metabolic assay. Freshly dissected Periplaneta americana and Blaberus atropos CCs (with precautions taken against oxidation) were analyzed. B. atropos CC were placed into a depolarizing saline and the released AKHs were measured. RESULTS Hyp was detected in several decapeptides from cockroaches. The modified form accompanied the AKH at concentrations below 7%. The [Hyp6]-AKHs of B. atropos were present in fresh CC preparations and were shown to be releasable from the CC ex vivo. Synthetic [Hyp6]-containing peptides tested positively in a hypertrehalosemic bioassay. Hydroxyprolination was also detected for Manto-CC from the termite Kalotermes flavicollis and for Tetsu-AKH of the grasshopper, Tetrix subulata. Oxidized Trp-containing forms of Nicve-AKH were found in species of the burying beetle genus Nicrophorus. CONCLUSIONS Trp oxidation is known to occur easily during sample handling and is likely the reason for the present findings. For hydroxyprolination, however, the experimental evidence suggests endogenous processes.
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Affiliation(s)
- Simone König
- IZKF Core Unit Proteomics, Interdisciplinary Center for Clinical Research, University of Münster, Röntgenstr. 21, 48149 Münster, Germany
| | - Heather G. Marco
- Department of Biological Sciences, University of Cape Town, Private Bag, Rondebosch, Cape Town 7700, South Africa; (H.G.M.); (G.G.)
| | - Gerd Gäde
- Department of Biological Sciences, University of Cape Town, Private Bag, Rondebosch, Cape Town 7700, South Africa; (H.G.M.); (G.G.)
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Neale Q, Prefontaine A, Battellino T, Mizero B, Yeung D, Spicer V, Budisa N, Perreault H, Zahedi RP, Krokhin OV. Compendium of Chromatographic Behavior of Post-translationally and Chemically Modified Peptides in Bottom-Up Proteomic Experiments. Anal Chem 2023; 95:14634-14642. [PMID: 37739932 DOI: 10.1021/acs.analchem.3c02412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
We have systematically evaluated the chromatographic behavior of post-translationally/chemically modified peptides using data spanning over 70 of the most relevant modifications. These retention properties were measured for standard bottom-up proteomic settings (fully porous C18 separation media, 0.1% formic acid as ion-pairing modifier) using collections of modified/nonmodified peptide pairs. These pairs were generated by spontaneous degradation, chemical or enzymatic treatment, analysis of synthetic peptides, or the cotranslational incorporation of noncanonical proline analogues. In addition, these measurements were validated using external data acquired for synthetic peptides and enzymatically induced citrullination. Working in units of hydrophobicity index (HI, % ACN) and evaluating the average retention shifts (ΔHI) represent the simplest approach to describe the effect of modifications from a didactic point of view. Plotting HI values for modified (y-axis) vs nonmodified (x-axis) counterparts generates unique slope and intercept values for each modification defined by the chemistry of the modifying moiety: its hydrophobicity, size, pKa of ionizable groups, and position of the altered residue. These composition-dependent correlations can be used for coarse incorporation of PTMs into models for prediction of peptide retention. More accurate predictions would require the development of specific sequence-dependent algorithms to predict ΔHI values.
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Affiliation(s)
- Quinn Neale
- Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg R3T 2N2, Manitoba, Canada
| | - Alexandre Prefontaine
- Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg R3T 2N2, Manitoba, Canada
| | - Taylor Battellino
- Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg R3T 2N2, Manitoba, Canada
| | - Benilde Mizero
- Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg R3T 2N2, Manitoba, Canada
| | - Darien Yeung
- Department of Biochemistry and Medical Genetics, University of Manitoba, 336 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg R3E 0J9, Manitoba, Canada
| | - Victor Spicer
- Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Manitoba, Canada
| | - Nediljko Budisa
- Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg R3T 2N2, Manitoba, Canada
| | - Helene Perreault
- Department of Chemistry, University of Manitoba, 360 Parker Building, Winnipeg R3T 2N2, Manitoba, Canada
| | - Rene P Zahedi
- Department of Biochemistry and Medical Genetics, University of Manitoba, 336 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg R3E 0J9, Manitoba, Canada
- Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Manitoba, Canada
- Department of Internal Medicine, University of Manitoba, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Manitoba, Canada
- CancerCare Manitoba Research Institute, 675 McDermot Avenue, Winnipeg R3E 0 V9, Manitoba, Canada
| | - Oleg V Krokhin
- Department of Biochemistry and Medical Genetics, University of Manitoba, 336 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg R3E 0J9, Manitoba, Canada
- Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Manitoba, Canada
- Department of Internal Medicine, University of Manitoba, 799 JBRC, 715 McDermot Avenue, Winnipeg R3E 3P4, Manitoba, Canada
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Maurer J, Grouzmann E, Eugster PJ. Tutorial review for peptide assays: An ounce of pre-analytics is worth a pound of cure. J Chromatogr B Analyt Technol Biomed Life Sci 2023; 1229:123904. [PMID: 37832388 DOI: 10.1016/j.jchromb.2023.123904] [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: 09/07/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023]
Abstract
The recent increase in peptidomimetic-based medications and the growing interest in peptide hormones has brought new attention to the quantification of peptides for diagnostic purposes. Indeed, the circulating concentrations of peptide hormones in the blood provide a snapshot of the state of the body and could eventually lead to detecting a particular health condition. Although extremely useful, the quantification of such molecules, preferably by liquid chromatography coupled to mass spectrometry, might be quite tricky. First, peptides are subjected to hydrolysis, oxidation, and other post-translational modifications, and, most importantly, they are substrates of specific and nonspecific proteases in biological matrixes. All these events might continue after sampling, changing the peptide hormone concentrations. Second, because they include positively and negatively charged groups and hydrophilic and hydrophobic residues, they interact with their environment; these interactions might lead to a local change in the measured concentrations. A phenomenon such as nonspecific adsorption to lab glassware or materials has often a tremendous effect on the concentration and needs to be controlled with particular care. Finally, the circulating levels of peptides might be low (pico- or femtomolar range), increasing the impact of the aforementioned effects and inducing the need for highly sensitive instruments and well-optimized methods. Thus, despite the extreme diversity of these peptides and their matrixes, there is a common challenge for all the assays: the need to keep concentrations unchanged from sampling to analysis. While significant efforts are often placed on optimizing the analysis, few studies consider in depth the impact of pre-analytical steps on the results. By working through practical examples, this solution-oriented tutorial review addresses typical pre-analytical challenges encountered during the development of a peptide assay from the standpoint of a clinical laboratory. We provide tips and tricks to avoid pitfalls as well as strategies to guide all new developments. Our ultimate goal is to increase pre-analytical awareness to ensure that newly developed peptide assays produce robust and accurate results.
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Affiliation(s)
- Jonathan Maurer
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Eric Grouzmann
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Philippe J Eugster
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
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Elander PH, Holla S, Sabljić I, Gutierrez-Beltran E, Willems P, Bozhkov PV, Minina EA. Interactome of Arabidopsis ATG5 Suggests Functions beyond Autophagy. Int J Mol Sci 2023; 24:12300. [PMID: 37569688 PMCID: PMC10418956 DOI: 10.3390/ijms241512300] [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: 07/05/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023] Open
Abstract
Autophagy is a catabolic pathway capable of degrading cellular components ranging from individual molecules to organelles. Autophagy helps cells cope with stress by removing superfluous or hazardous material. In a previous work, we demonstrated that transcriptional upregulation of two autophagy-related genes, ATG5 and ATG7, in Arabidopsis thaliana positively affected agronomically important traits: biomass, seed yield, tolerance to pathogens and oxidative stress. Although the occurrence of these traits correlated with enhanced autophagic activity, it is possible that autophagy-independent roles of ATG5 and ATG7 also contributed to the phenotypes. In this study, we employed affinity purification and LC-MS/MS to identify the interactome of wild-type ATG5 and its autophagy-inactive substitution mutant, ATG5K128R Here we present the first interactome of plant ATG5, encompassing not only known autophagy regulators but also stress-response factors, components of the ubiquitin-proteasome system, proteins involved in endomembrane trafficking, and potential partners of the nuclear fraction of ATG5. Furthermore, we discovered post-translational modifications, such as phosphorylation and acetylation present on ATG5 complex components that are likely to play regulatory functions. These results strongly indicate that plant ATG5 complex proteins have roles beyond autophagy itself, opening avenues for further investigations on the complex roles of autophagy in plant growth and stress responses.
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Affiliation(s)
- Pernilla H. Elander
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (P.H.E.); (S.H.); (I.S.); (P.V.B.)
| | - Sanjana Holla
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (P.H.E.); (S.H.); (I.S.); (P.V.B.)
| | - Igor Sabljić
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (P.H.E.); (S.H.); (I.S.); (P.V.B.)
| | - Emilio Gutierrez-Beltran
- Instituto de Bioquımica Vegetal y Fotosıntesis, Universidad de Sevilla and Consejo Superior de Investigaciones Cientıficas, 41092 Sevilla, Spain;
- Departamento de Bioquimica Vegetal y Biologia Molecular, Facultad de Biologia, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Patrick Willems
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium;
- Department of Biomolecular Medicine, Ghent University, 9000 Ghent, Belgium
| | - Peter V. Bozhkov
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (P.H.E.); (S.H.); (I.S.); (P.V.B.)
| | - Elena A. Minina
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, 750-07 Uppsala, Sweden; (P.H.E.); (S.H.); (I.S.); (P.V.B.)
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8
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Lethcoe K, Fox CA, Hafiane A, Kiss RS, Ryan RO. Isolation of recombinant apolipoprotein E4 N-terminal domain by foam fractionation. Protein Expr Purif 2023; 210:106319. [PMID: 37290717 DOI: 10.1016/j.pep.2023.106319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/01/2023] [Accepted: 06/05/2023] [Indexed: 06/10/2023]
Abstract
Apolipoprotein (apo) E functions in lipoprotein metabolism as a low density lipoprotein receptor ligand. ApoE is comprised of two structural domains, a 22 kDa N-terminal (NT) domain that adopts a helix bundle conformation and a 10 kDa C-terminal domain with strong lipid binding affinity. The NT domain is capable of transforming aqueous phospholipid dispersions into discoidal reconstituted high density lipoprotein (rHDL) particles. Given the utility of apoE-NT as a structural component of rHDL, expression studies were conducted. A plasmid construct encoding a pelB leader sequence fused to the N-terminus of human apoE4 (residues 1-183) was transformed into Escherichia coli. Upon expression, the fusion protein is directed to the periplasmic space where leader peptidase cleaves the pelB sequence, generating mature apoE4-NT. In shaker flask expression cultures, apoE4-NT escapes the bacteria and accumulates in the medium. In a bioreactor setting, however, apoE4-NT was found to combine with gas and liquid components in the culture medium to generate large quantities of foam. When this foam was collected in an external vessel and collapsed into a liquid foamate, analysis revealed that apoE4-NT was the sole major protein present. The product protein was further isolated by heparin affinity chromatography (60-80 mg/liter bacterial culture), shown to be active in rHDL formulation, and documented to serve as an acceptor of effluxed cellular cholesterol. Thus, foam fractionation provides a streamlined process to produce recombinant apoE4-NT for biotechnology applications.
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Affiliation(s)
- Kyle Lethcoe
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557, USA
| | - Colin A Fox
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557, USA
| | - Anouar Hafiane
- Department of Medicine, Division of Cardiology, McGill University, Montreal, QC, Canada
| | - Robert S Kiss
- Department of Medicine, Division of Cardiology, McGill University, Montreal, QC, Canada
| | - Robert O Ryan
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557, USA.
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Han Z, Omata N, Matsuda T, Hishida S, Takiguchi S, Komori R, Suzuki R, Chen LC. Tuning oxidative modification by a strong electric field using nanoESI of highly conductive solutions near the minimum flow rate. Chem Sci 2023; 14:4506-4515. [PMID: 37152264 PMCID: PMC10155921 DOI: 10.1039/d2sc07113d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/27/2023] [Indexed: 05/09/2023] Open
Abstract
Oxidative modification is usually used in mass spectrometry (MS) for labeling and structural analysis. Here we report a highly tunable oxidation that can be performed in line with the nanoESI-MS analysis at the same ESI emitter without the use of oxidative reagents such as ozone and H2O2, and UV activation. The method is based on the high-pressure nanoESI of a highly conductive (conductivity >3.8 S m-1) aqueous solution near the minimum flow rate. The ion source is operated under super-atmospheric pressure (0.5 MPa gauge pressure) to avoid the contribution of electric discharge. The analyte at the tip of the Taylor cone or in the emitter droplet can be locally oxidized in an on-demand manner by varying the nanoflow rate. With an offline nanoESI, the degree of oxidation, i.e., the average number of incorporated oxygen atoms, can be finely tuned by voltage modulation using spray current as the feedback signal. Oxidations of easily oxidized residues present in peptides/proteins and the double bonds of the unsaturated phosphatidylcholine occur at low flow rate operation (<5 nL min-1) when the electric field at the tip of the Taylor cone and the initially produced charged droplet reaches approximately 1.3 V nm-1. The oxidized ion signal responds instantaneously to changes in flow rate, indicating that the oxidation is highly localized. Using isotope labeling, it was found that the incorporated oxygen primarily originates from the gas phase, suggesting a direct oxidation pathway for the analyte enriched on the liquid surface via the reactive oxygen atoms formed by the strong electric field.
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Affiliation(s)
- Zhongbao Han
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Nozomu Omata
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Takeshi Matsuda
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Shoki Hishida
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Shuuhei Takiguchi
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Ryoki Komori
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Riku Suzuki
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
| | - Lee Chuin Chen
- Faculty of Engineering, University of Yamanashi 4-3-11, Takeda Kofu Yamanashi 400-8511 Japan +81-55-220-8072
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10
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Han Z, Komori R, Suzuki R, Omata N, Matsuda T, Hishida S, Shuuhei T, Chen LC. Bipolar Electrospray from Electrodeless Emitters for ESI without Electrochemical Reactions in the Sprayer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:728-736. [PMID: 36815710 DOI: 10.1021/jasms.2c00382] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A bipolar ESI source is developed to generate a simultaneous emission of charged liquid jets of opposite polarity from an electrodeless sprayer. The sprayer consists of two emitters, and the electrosprays are initiated by applying a high potential difference (HV) across the counter electrodes facing each emitter. The sprayer and the liquid delivery system are made of all insulators without metal components, thus enabling the total elimination of electrochemical reactions taking place at the liquid-electrode interface in the typical electrosprayer. The bipolar electrospray has been implemented using an online configuration that uses a syringe pump for flow rate regulation and an offline configuration that relies on HV for adjusting the flow rate. The voltage-current and flow rate-current relationships of bipolar electrospray were found to be similar to the standard electrospray. The application of bipolar ESI to the mass spectrometry of protein, peptide, and metallocene without electrochemically induced oxidation/reduction is demonstrated.
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Affiliation(s)
- Zhongbao Han
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Ryoki Komori
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Riku Suzuki
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Nozomu Omata
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Takeshi Matsuda
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Shoki Hishida
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Takiguchi Shuuhei
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
| | - Lee Chuin Chen
- Faculty of Engineering, University of Yamanashi, 4-3-11, Takeda, Kofu, Yamanashi 400-8511, Japan
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11
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Silva CJ, Erickson-Beltran ML. General Method of Quantifying the Extent of Methionine Oxidation in the Prion Protein. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:255-263. [PMID: 36608322 DOI: 10.1021/jasms.2c00280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The normal cellular prion protein (PrPC) and its infectious conformer, PrPSc, possess a disproportionately greater amount of methionines than would be expected for a typical mammalian protein. The thioether of methionine can be readily oxidized to the corresponding sulfoxide, which means that oxidation of methionine can be used to map the surface of the conformation of PrPC or PrPSc, as covalent changes are retained after denaturation. We identified a set of peptides (TNMK, MLGSAMSR, LLGSAMSR, PMIHFGNDWEDR, ENMNR, ENMYR, IMER, MMER, MIER, VVEQMCVTQYQK, and VVEQMCITQYQR) that contains every methionine in sheep, cervid, mouse, and bank vole PrP. Each is the product of a tryptic digestion and is suitable for a multiple reaction monitoring (MRM) based analysis. The peptides chromatograph well. The oxidized and unoxidized peptides containing one methionine readily separate. The unoxidized, two singly oxidized, and doubly oxidized forms of the MLGSAMSR and MMER peptides are also readily distinguishable. This approach can be used to determine the surface exposure of each methionine by measuring its oxidation after reaction with added hydrogen peroxide.
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Affiliation(s)
- Christopher J Silva
- Produce Safety and Microbiology Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, United States
| | - Melissa L Erickson-Beltran
- Produce Safety and Microbiology Research Unit, Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, 800 Buchanan Street, Albany, California 94710, United States
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12
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Bettinger JQ, Simon M, Korotkov A, Welle KA, Hryhorenko JR, Seluanov A, Gorbunova V, Ghaemmaghami S. Accurate Proteomewide Measurement of Methionine Oxidation in Aging Mouse Brains. J Proteome Res 2022; 21:1495-1509. [PMID: 35584362 PMCID: PMC9171897 DOI: 10.1021/acs.jproteome.2c00127] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation of methionine has emerged as an important post-translational modification of proteins. A number of studies have suggested that the oxidation of methionines in select proteins can have diverse impacts on cell physiology, ranging from detrimental effects on protein stability to functional roles in cell signaling. Despite its importance, the large-scale investigation of methionine oxidation in a complex matrix, such as the cellular proteome, has been hampered by technical limitations. We report a methodology, methionine oxidation by blocking (MobB), that allows for accurate and precise quantification of low levels of methionine oxidation typically observed in vivo. To demonstrate the utility of this methodology, we analyzed the brain tissues of young (6 m.o.) and old (20 m.o.) mice and identified over 280 novel sites for in vivo methionine oxidation. We further demonstrated that oxidation stoichiometries for specific methionine residues are highly consistent between individual animals and methionine sulfoxides are enriched in clusters of functionally related gene products including membrane and extracellular proteins. However, we did not detect significant changes in methionine oxidation in brains of old mice. Our results suggest that under normal conditions, methionine oxidation may be a biologically regulated process rather than a result of stochastic chemical damage.
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Affiliation(s)
- John Q. Bettinger
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States
| | - Matthew Simon
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States
| | - Anatoly Korotkov
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States
| | - Kevin A. Welle
- Department
of Medicine, University of Rochester Medical
Center, Rochester, New York 14627, United States
| | - Jennifer R. Hryhorenko
- Department
of Medicine, University of Rochester Medical
Center, Rochester, New York 14627, United States
| | - Andrei Seluanov
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States,Department
of Medicine, University of Rochester Medical
Center, Rochester, New York 14627, United States
| | - Vera Gorbunova
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States,Department
of Medicine, University of Rochester Medical
Center, Rochester, New York 14627, United States
| | - Sina Ghaemmaghami
- Department
of Biology, University of Rochester, Rochester, New York 14627, United States,University
of Rochester Mass Spectrometry Resource Laboratory, Rochester, New York 14627, United States,. Phone: 585-275-4829
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13
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The RHIM of the Immune Adaptor Protein TRIF Forms Hybrid Amyloids with Other Necroptosis-Associated Proteins. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27113382. [PMID: 35684320 PMCID: PMC9182532 DOI: 10.3390/molecules27113382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/22/2022] [Accepted: 05/23/2022] [Indexed: 12/19/2022]
Abstract
TIR-domain-containing adapter-inducing interferon-β (TRIF) is an innate immune protein that serves as an adaptor for multiple cellular signalling outcomes in the context of infection. TRIF is activated via ligation of Toll-like receptors 3 and 4. One outcome of TRIF-directed signalling is the activation of the programmed cell death pathway necroptosis, which is governed by interactions between proteins that contain a RIP Homotypic Interaction Motif (RHIM). TRIF contains a RHIM sequence and can interact with receptor interacting protein kinases 1 (RIPK1) and 3 (RIPK3) to initiate necroptosis. Here, we demonstrate that the RHIM of TRIF is amyloidogenic and supports the formation of homomeric TRIF-containing fibrils. We show that the core tetrad sequence within the RHIM governs the supramolecular organisation of TRIF amyloid assemblies, although the stable amyloid core of TRIF amyloid fibrils comprises a much larger region than the conserved RHIM only. We provide evidence that RHIMs of TRIF, RIPK1 and RIPK3 interact directly to form heteromeric structures and that these TRIF-containing hetero-assemblies display altered and emergent properties that likely underlie necroptosis signalling in response to Toll-like receptor activation.
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14
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Wang Q, Liu Z, Liu Y, Chen H. Absolute Quantitation of N-Nitrosamines by Coulometric Mass Spectrometry without Using Standards. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:875-884. [PMID: 35446584 PMCID: PMC9119692 DOI: 10.1021/jasms.2c00064] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Carcinogenic N-nitrosamines were recently found in the sartan family of drugs and caused many drug recalls. Both of their detection and quantification are therefore important. Methods reported for N-nitrosamine quantitation rely on the use of standards and are just applicable to simple N-nitrosamines. There is an urgent need to quantify N-nitrosamines derived from drugs with a complicated structure that lack standards. To tackle the issue, this study describes a novel absolute quantitation strategy for N-nitrosamines using coulometric mass spectrometry (CMS) without standards. In our approach, N-nitrosamine is first converted into electrochemically active hydrazine via zinc reduction under acidic condition and the resulting hydrazine can then be easily quantified using CMS. To validate our method, six simple N-nitrosamines, N-nitrosodiethylamine (NDEA), N-nitroso-4-phenylpiperidine (NPhPIP), N-nitrosodiphenylamine (NDPhA), N-nitrosodibutylamine (NDBA), N-nitrosodipropylamine (NDPA), and N-nitrosopiperidine (NPIP), were chosen as test samples, and they all were quantified with excellent measurement accuracy (quantitation error ≤1.1%). Taking this one step further, as a demonstration of the method utility, a drug-like N-nitrosamine, (R)-N-(2-(6-chloro-5-methyl-1'-nitroso-2,3-dihydrospiro[indene-1,4'-piperidin]-3-yl)propan-2-yl)acetamide (VII), was also synthesized and successfully quantified using our method at 15 ppb level in a complex formulation matrix, following solvent extraction, N-nitrosamine isolation, and reductive conversion. Because of the feature of requiring no standards, CMS provides a simple and powerful approach for N-nitrosamine absolute quantitation and has great potential for analysis of other drug impurities or metabolites.
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Affiliation(s)
- Qi Wang
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
| | - Zhijian Liu
- Department of Process Research and Development, Merck Research Laboratories, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Yong Liu
- Analytical Research and Development, Merck Research Laboratories, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Hao Chen
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
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15
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Silva CJ, Erickson-Beltran M. Detecting Differences in Prion Protein Conformation by Quantifying Methionine Oxidation. ACS OMEGA 2022; 7:2649-2660. [PMID: 35097263 PMCID: PMC8793083 DOI: 10.1021/acsomega.1c04989] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
A prion's pathogenic character is enciphered in its conformation, which also defines the chemical environments of its amino acids. Differences in chemical environments influence the reactivity of amino acid side chains, in a conformation-dependent manner. Chemical oxidation of susceptible methionines would identify those methionines on the surface of a prion, which would reveal conformation-dependent information. We identified a set of methionine-containing peptides derived from the tryptic, chymotryptic, or tryptic/chymotryptic digestion of recombinant prion protein and the Sc237 strain of hamster-adapted scrapie. We developed a multiple reaction monitoring-based method of quantifying the extent of the methionine oxidation in those peptides. This approach can be used to define a prion's conformation and to distinguish among prion strains, which is an important component of food safety.
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16
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Guo Y, Li S, Chen H, Wang Y, Cao S, Zhao Y. Gas-phase fragmentation of protonated 3-phenoxy imidazo[1,2-a] pyridines using tandem mass spectrometry and computational chemistry. JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4794. [PMID: 34881486 DOI: 10.1002/jms.4794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/12/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
Imidazo[1,2-a] pyridine is one of the pharmaceutically important scaffolds and has been widely studied due to its extensive biological activities. In this work, electrospray ionization tandem mass spectrometry (ESI-MS/MS) in positive mode was used to study the gas-phase fragmentation behavior of a series of 3-phenoxy imidazo[1,2-a] pyridines. Proposed fragmentation pathways were supported by ESI-MS/MS data and computational thermochemistry. Homolytic cleavage of the 3-phenoxy C-O bond was the characteristic fragmentation of 3-phenoxy imidazo [1,2-a] pyridines. The eliminations of the one substituted phenoxy radical and CO produced other diagnostic ions for 3-phenoxy imidazo [1,2-a] pyridines, which were useful to identify the 3-phenoxy group and imidazo [1,2-a] pyridine scaffold. The results contribute to the further understanding of the gas-phase fragmentation of 3-phenoxy imidazo [1,2-a] pyridines and the identification of other analogs using tandem mass spectrometry techniques.
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Affiliation(s)
- Yanchun Guo
- College of Chemistry, The Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, China
| | - Shigai Li
- College of Chemistry, The Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, China
| | - Hong Chen
- College of Chemistry, The Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, China
| | - Yuexiu Wang
- College of Chemistry, The Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, China
| | - Shuxia Cao
- College of Chemistry, The Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, China
| | - Yufen Zhao
- College of Chemistry, The Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Zhengzhou University, Zhengzhou, China
- Institute of Drug Discovery Technology, Ningbo University, Ningbo, China
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17
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Baumans F, Hanozin E, Baiwir D, Decroo C, Wattiez R, De Pauw E, Eppe G, Mazzucchelli G. Liquid chromatography setup-dependent artefactual methionine oxidation of peptides: The importance of an adapted quality control process. J Chromatogr A 2021; 1654:462449. [PMID: 34399143 DOI: 10.1016/j.chroma.2021.462449] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/26/2022]
Abstract
In both biologics quality control experiments and protein post-translational modification studies, the analytical system used is not supposed to bring any artefactual modifications which could impair the results. In this work, we investigated oxidation of methionine-containing peptides during reversed-phase (RP) chromatographic separation. We first used a synthetic methionine-containing peptide to evaluate this artefactual phenomenon and then considered more complex samples (i.e., plasma and HeLa protein digests). The methionine oxidation levels of the peptides were systematically assessed and compared for the long-term use of the analytical column, the sample trapping time, the gradient length, the sample load and the nature of the stationary phase (HSS T3 from Waters, YMC Triart C18 from YMC Europe GmbH and BEH130 C18 from Waters). In addition to the oxidation of methionine in solution, we observed on the HSS T3 and the BEH130 stationary phases an additional broad peak corresponding to an on-column oxidized species. Considering the HSS T3 phase, our results highlight that the on-column oxidation level significantly increases with the age of the analytical column and the gradient length and reaches 56 % when a 1-year-old column set is used with a 180 min-long LC method. These levels go to 0 % and 18 % for the YMC Triart C18 and the BEH130 C18 phases respectively. Interestingly, the on-column oxidation proportion decreases as the injected sample load increases suggesting the presence of a discrete number of oxidation sites within the stationary phase of the analytical column. Those findings observed in different laboratories using distinct set of columns, albeit to varying degrees, strengthen the need for a standard of methionine-containing peptide that could be used as a quality control to appraise the status of the liquid chromatographic columns.
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Affiliation(s)
- France Baumans
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege 4000, Belgium
| | - Emeline Hanozin
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege 4000, Belgium
| | - Dominique Baiwir
- GIGA Proteomics Facility, University of Liege, Liege 4000, Belgium
| | - Corentin Decroo
- Proteomics and Microbiology Laboratory, University of Mons, Mons 7000, Belgium
| | - Ruddy Wattiez
- Proteomics and Microbiology Laboratory, University of Mons, Mons 7000, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege 4000, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege 4000, Belgium
| | - Gabriel Mazzucchelli
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege 4000, Belgium.
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18
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Sagandykova GN, Szultka-Młyńska M, Walczak-Skierska J, Pomastowski PP, Buszewski B. Combination of electrochemical unit and ESI-MS in fragmentation of flavonoids. PHYTOCHEMICAL ANALYSIS : PCA 2021; 32:601-620. [PMID: 33200453 DOI: 10.1002/pca.3009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 06/11/2023]
Abstract
INTRODUCTION Predictive approaches on the activity of natural compounds based on the fragmentation by instrumental techniques are important for consideration of such molecules as drug candidates and defining new structures with promising properties. Since flavonoids are well-known antioxidants, their redox properties can be related to their pharmacological activity. OBJECTIVES In this work, the potential of electrochemical unit coupled to electrospray ionisation mass spectrometry (ESI-MS) was assessed for fragmentation activity relationships studies of selected flavonoids. METHODOLOGY Methodology of this research included electrochemical conversion of standards of flavonoids at different pH values and their further analysis with the use of ESI-MS. In addition, signals obtained from the blank samples were also identified and used for interpretation due to electrochemical nature of the ESI source. Half maximal inhibitory concentration (IC50 ) values of flavonoids for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity assays were analysed for possible correlation with the structures of flavonoids and products of electrochemical conversion. RESULTS Fragmentation activity relationships were suggested using the proposed approach and for some of the flavonoids it was not specific enough to determine the input of a particular structural feature to the activity, but for others they were in agreement with those found in the literature. Obtained results showed potential of the proposed approach for application in plant sciences as a fast pre-screening tool for newly isolated bioactive compounds.
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Affiliation(s)
- Gulyaim N Sagandykova
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Toruń, Poland
- Interdisciplinary Centre for Modern Technologies, Nicolaus Copernicus University, Toruń, Poland
| | - Małgorzata Szultka-Młyńska
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Toruń, Poland
| | | | - Paweł P Pomastowski
- Interdisciplinary Centre for Modern Technologies, Nicolaus Copernicus University, Toruń, Poland
| | - Bogusław Buszewski
- Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, Toruń, Poland
- Interdisciplinary Centre for Modern Technologies, Nicolaus Copernicus University, Toruń, Poland
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19
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König S. Spectral quality overrides software score-A brief tutorial on the analysis of peptide fragmentation data for mass spectrometry laymen. JOURNAL OF MASS SPECTROMETRY : JMS 2021; 56:e4616. [PMID: 32955142 DOI: 10.1002/jms.4616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/16/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
The use of mass spectrometry has dramatically increased the research pace in the life sciences. The influence of the technique is enormous and its results can have far-reaching consequences such as jail time when applied in forensics. Therefore, analytical chemists trained in proper procedure know that they must validate their experiments. However, those quality measures have not been adopted in a similar manner in the omics technologies even though the stakes are equally high. Reasons are, among others, the segregation of the data generation and data mining functions and an undue belief in software capabilities. In this article, problematic issues such as false or overinterpretation of data are discussed, and assistance is provided for mass spectrometry laymen to evaluate the quality of their results; a quick guide to mass spectral data interpretation of peptide fragmentation experiments, the basis of bottom-up proteomics, is offered. Good science can only be generated in tight collaboration of principal investigator, analytical chemist, and bioinformatician so that the limits and the potential of each method and approach can be responsibly communicated.
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Affiliation(s)
- Simone König
- Core Unit Proteomics, Interdisciplinary Center for Clinical Research, Medical Faculty, University of Münster, Münster, Germany
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20
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Bettinger J, Ghaemmaghami S. Methionine oxidation within the prion protein. Prion 2020; 14:193-205. [PMID: 32744136 PMCID: PMC7518762 DOI: 10.1080/19336896.2020.1796898] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/09/2020] [Accepted: 07/11/2020] [Indexed: 11/01/2022] Open
Abstract
Prion diseases are characterized by the self-templated misfolding of the cellular prion protein (PrPC) into infectious aggregates (PrPSc). The detailed molecular basis of the misfolding and aggregation of PrPC remains incompletely understood. It is believed that the transient misfolding of PrPC into partially structured intermediates precedes the formation of insoluble protein aggregates and is a critical component of the prion misfolding pathway. A number of environmental factors have been shown to induce the destabilization of PrPC and promote its initial misfolding. Recently, oxidative stress and reactive oxygen species (ROS) have emerged as one possible mechanism by which the destabilization of PrPC can be induced under physiological conditions. Methionine residues are uniquely vulnerable to oxidation by ROS and the formation of methionine sulfoxides leads to the misfolding and subsequent aggregation of PrPC. Here, we provide a review of the evidence for the oxidation of methionine residues in PrPC and its potential role in the formation of pathogenic prion aggregates.
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Affiliation(s)
- John Bettinger
- Department of Biology, University of Rochester, Rochester, NY, USA
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21
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Lenčo J, Šemlej T, Khalikova MA, Fabrik I, Švec F. Sense and Nonsense of Elevated Column Temperature in Proteomic Bottom-up LC-MS Analyses. J Proteome Res 2020; 20:420-432. [PMID: 33085896 DOI: 10.1021/acs.jproteome.0c00479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Elevated column temperature represents a simple means for improving chromatographic separation of peptides. Here, we demonstrated the advantages of the column temperature in peptide separation using state-of-the-art columns. More importantly, we also determined how temperature can impair proteomic bottom-up analyses. We found that an elevated temperature in combination with the acidic pH of the mobile phase induced in-column peptide hydrolysis with high specificity to Asp and accelerated five modification reactions of amino acids. The positive effects of temperature dominated in the 30 min long gradients since the column operated at 90 °C provided the largest number of identified peptides and proteins. However, the adverse effects of temperature on peptide integrity in longer liquid chromatography-mass spectrometry (LC-MS) analyses required its reduction to obtain optimum results. The largest number of peptides was identified using the column maintained at 75 °C in 60 min long gradients, at 60 °C in 120 min long gradients, and at 45 °C in 240 min long gradients. Our results indicate that no universal column temperature exists for bottom-up LC-MS analyses. Quite the contrary, the temperature setting must be selected rationally to exploit the full capabilities of the state-of-the-art mass spectrometers in proteomic LC-MS analyses, with the gradient time being a critical factor.
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Affiliation(s)
- Juraj Lenčo
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Tomáš Šemlej
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Maria A Khalikova
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
| | - Ivo Fabrik
- Biomedical Research Center, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic
| | - František Švec
- Department of Analytical Chemistry, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovského 1203/8, 500 05 Hradec Králové, Czech Republic
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22
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Bauer LG, Hoelterhoff S, Graf T, Bell C, Bathke A. Monitoring modifications in biopharmaceuticals: Toolbox for a generic and robust high-throughput quantification method. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1148:122134. [PMID: 32422530 DOI: 10.1016/j.jchromb.2020.122134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 10/24/2022]
Abstract
Monoclonal antibodies (mAbs) constitute one of the most important and fastest growing sector within the pharmaceutical industry. The variety of different formats and the large molecule sizes of the mAbs result in an inherent complexity. In addition, the posttranslational modifications (PTMs) that can occur during production, formulation and storage pose a major analytical challenge for their characterization. These PTMs may affect the safety, efficacy and/or pharmacokinetic profile of the medicinal product. Therefore, strict quality and stability monitoring, in particular of (potentially) critical quality attributes (CQAs), is mandatory. Focusing on these needs, a toolbox for different approaches of peptide mapping in the routine quality control (QC) environment was developed. This toolbox includes an automated sample preparation with an optimized buffer system in combination with a Single Quad LC-MS system, which provides the flexibility to handle a high-throughput workflow. Our results demonstrate that a Single Quad LC-MS system is suitable for a routine work environment to monitor modifications by using a user-friendly system.
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Affiliation(s)
| | - Sina Hoelterhoff
- F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Tobias Graf
- Roche Diagnostics GmbH, Nonnenwald 2, 82377 Penzberg, Germany
| | - Christian Bell
- F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Anja Bathke
- F. Hoffmann-La Roche, Grenzacherstrasse 124, 4070 Basel, Switzerland.
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23
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Wang D, Nowak C, Mason B, Katiyar A, Liu H. Analytical artifacts in characterization of recombinant monoclonal antibody therapeutics. J Pharm Biomed Anal 2020; 183:113131. [DOI: 10.1016/j.jpba.2020.113131] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 01/12/2023]
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24
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Bettinger JQ, Welle KA, Hryhorenko JR, Ghaemmaghami S. Quantitative Analysis of in Vivo Methionine Oxidation of the Human Proteome. J Proteome Res 2020; 19:624-633. [PMID: 31801345 DOI: 10.1021/acs.jproteome.9b00505] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation of methionine is an important post-translational modification of proteins with numerous roles in physiology and pathology. However, the quantitative analysis of methionine oxidation on a proteome-wide scale has been hampered by technical limitations. Methionine is readily oxidized in vitro during sample preparation and analysis. In addition, there is a lack of enrichment protocols for peptides that contain an oxidized methionine residue, making the accurate quantification of methionine oxidation difficult to achieve on a global scale. Herein, we report a methodology to circumvent these issues by isotopically labeling unoxidized methionines with 18O-labeled hydrogen peroxide and quantifying the relative ratios of 18O- and 16O-oxidized methionines. We validate our methodology using artificially oxidized proteomes made to mimic varying degrees of methionine oxidation. Using this method, we identify and quantify a number of novel sites of in vivo methionine oxidation in an unstressed human cell line.
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Affiliation(s)
- John Q Bettinger
- Department of Biology , University of Rochester , Rochester , New York 14627 , United States
| | - Kevin A Welle
- University of Rochester Mass Spectrometry Resource Laboratory , Rochester , New York 14627 , United States
| | - Jennifer R Hryhorenko
- University of Rochester Mass Spectrometry Resource Laboratory , Rochester , New York 14627 , United States
| | - Sina Ghaemmaghami
- Department of Biology , University of Rochester , Rochester , New York 14627 , United States.,University of Rochester Mass Spectrometry Resource Laboratory , Rochester , New York 14627 , United States
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25
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Jeanneret RA, Dalton CE, Gardiner JM. Synthesis of Heparan Sulfate- and Dermatan Sulfate-Related Oligosaccharides via Iterative Chemoselective Glycosylation Exploiting Conformationally Disarmed [2.2.2] l-Iduronic Lactone Thioglycosides. J Org Chem 2019; 84:15063-15078. [PMID: 31674785 DOI: 10.1021/acs.joc.9b01594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Heparan sulfate (HS) and dermatan sulfate (DS) are l-iduronic acid containing glycosaminoglycans (GAGs) which are implicated in a number of biological processes and conditions including cancer and viral infection. Chemical synthesis of HS and DS is required to generate structurally defined oligosaccharides for a biological study. Herein, we present a new synthetic approach to HS and DS oligosaccharides using chemoselective glycosylation which relies on a disarmed [2.2.2] l-ido lactone motif. The strategy provides a general approach for iterative-reducing end chain extension, using only shelf-stable thioglycoside building blocks, exploiting a conformational switch to control reactivity, and thus requires no anomeric manipulation steps between glycosylations.
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Affiliation(s)
- Robin A Jeanneret
- School of Chemistry and Manchester Institute of Biotechnology , The University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Charlotte E Dalton
- School of Chemistry and Manchester Institute of Biotechnology , The University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - John M Gardiner
- School of Chemistry and Manchester Institute of Biotechnology , The University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
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26
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Lazzaro S, Ogrinc N, Lamont L, Vecchio G, Pappalardo G, Heeren RMA. Ion mobility spectrometry combined with multivariate statistical analysis: revealing the effects of a drug candidate for Alzheimer's disease on Aβ1-40 peptide early assembly. Anal Bioanal Chem 2019; 411:6353-6363. [PMID: 31407050 PMCID: PMC6718366 DOI: 10.1007/s00216-019-02030-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 07/04/2019] [Accepted: 07/10/2019] [Indexed: 12/20/2022]
Abstract
Inhibition of the initial stages of amyloid-β peptide self-assembly is a key approach in drug development for Alzheimer's disease, in which soluble and highly neurotoxic low molecular weight oligomers are produced and aggregate in the brain over time. Here we report a high-throughput method based on ion mobility mass spectrometry and multivariate statistical analysis to rapidly select statistically significant early-stage species of amyloid-β1-40 whose formation is inhibited by a candidate theranostic agent. Using this method, we have confirmed the inhibition of a Zn-porphyrin-peptide conjugate in the early self-assembly of Aβ40 peptide. The MS/MS fragmentation patterns of the species detected in the samples containing the Zn-porphyrin-peptide conjugate suggested a porphyrin-catalyzed oxidation at Met-35(O) of Aβ40. We introduce ion mobility MS combined with multivariate statistics as a systematic approach to perform data analytics in drug discovery/amyloid research that aims at the evaluation of the inhibitory effect on the Aβ early assembly in vitro models at very low concentration levels of Aβ peptides.
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Affiliation(s)
- Serena Lazzaro
- Institute of Biostructures and Bioimaging (IBB), National Research Council, Via Paolo Gaifami N.18, 95126, Catania, Italy
| | - Nina Ogrinc
- The Maastricht Multimodal Molecular Imaging institute M4I- Division of Imaging Mass Spectrometry, Maastricht University, Minderbroedersberg 4-6, 6211 LK, Maastricht, The Netherlands
| | - Lieke Lamont
- The Maastricht Multimodal Molecular Imaging institute M4I- Division of Imaging Mass Spectrometry, Maastricht University, Minderbroedersberg 4-6, 6211 LK, Maastricht, The Netherlands
| | - Graziella Vecchio
- Department of Chemical Sciences, Catania University, Viale Andrea Doria, 6, 95125, Catania, Italy
| | - Giuseppe Pappalardo
- Institute of Biostructures and Bioimaging (IBB), National Research Council, Via Paolo Gaifami N.18, 95126, Catania, Italy
| | - Ron M A Heeren
- The Maastricht Multimodal Molecular Imaging institute M4I- Division of Imaging Mass Spectrometry, Maastricht University, Minderbroedersberg 4-6, 6211 LK, Maastricht, The Netherlands.
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27
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Zhu L, Liu Y, Ding X, Wu X, Sand W, Zhou H. A novel method for textile odor removal using engineered water nanostructures. RSC Adv 2019; 9:17726-17736. [PMID: 35520538 PMCID: PMC9064573 DOI: 10.1039/c9ra01988j] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 05/15/2019] [Indexed: 12/14/2022] Open
Abstract
The malodor attached to textiles not only causes indoor environmental pollution but also endangers people's health even at low concentrations. Existing technologies cannot effectively eliminate the odor. Herein, an effective and environmentally friendly technology was proposed to address this challenging issue. This technology utilizes electrospraying process to produce Engineered Water Nanostructures (EWNS) in a controllable manner. Upon application of a high voltage to the Taylor cone, EWNS can be generated from the condensed vapor water through a Peltier element. Smoking, cooking and perspiration, considered the typical indoor malodorous gases emitted from human activities, were studied in this paper. A headspace SPME method in conjunction with GC-MS was employed for the extraction, detection and quantification of any odor residues. Results indicated that EWNS played a significant role in the deodorization process with removal efficiencies for the three odors were 95.3 ± 0.1%, 100.0 ± 0.0% and 43.7 ± 2.3%, respectively. The Reactive Oxygen Species (ROS) contained in the EWNS, mainly hydroxyl (OH˙) and superoxide radicals are the possible mechanisms for the odor removal. These ROS are strong oxidative and highly reactive and have the ability to convert odorous compounds to non-odorous compounds through various chemical reaction mechanisms. This study showed clearly the potential of the proposed method in the field of odor removal and can be applied in the battle against indoor air pollution.
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Affiliation(s)
- Lisha Zhu
- Fashion Institute, Donghua University Shanghai 200051 P. R. China
- Shanghai International Institute of Design & Innovation Shanghai 200080 P. R. China
- Key Laboratory of Clothing Design & Technology, Donghua University, Ministry of Education Shanghai 200051 P. R. China
| | - Yanbiao Liu
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University 2999 North Renmin Road Shanghai 201620 P. R. China
- Shanghai Institute of Pollution Control and Ecological Security 1239 Siping Road Shanghai 200092 P. R. China
| | - Xuemei Ding
- Fashion Institute, Donghua University Shanghai 200051 P. R. China
- Shanghai International Institute of Design & Innovation Shanghai 200080 P. R. China
- Key Laboratory of Clothing Design & Technology, Donghua University, Ministry of Education Shanghai 200051 P. R. China
| | - Xiongying Wu
- Shanghai Customs District Shanghai 200002 P. R. China
| | - Wolfgang Sand
- Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University 2999 North Renmin Road Shanghai 201620 P. R. China
- Institute of Biosciences, Freiberg University of Mining and Technology Freiberg 09599 Germany
| | - Huiling Zhou
- Fashion Institute, Donghua University Shanghai 200051 P. R. China
- Shanghai International Institute of Design & Innovation Shanghai 200080 P. R. China
- Key Laboratory of Clothing Design & Technology, Donghua University, Ministry of Education Shanghai 200051 P. R. China
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28
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Poltash ML, Shirzadeh M, McCabe JW, Moghadamchargari Z, Laganowsky A, Russell DH. New insights into the metal-induced oxidative degradation pathways of transthyretin. Chem Commun (Camb) 2019; 55:4091-4094. [PMID: 30887985 PMCID: PMC6452628 DOI: 10.1039/c9cc00682f] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The amyloidogenic mechanism of transthyretin is still debated but understanding it fully could lend insight into disease progression and potential therapeutics. Transthyretin was investigated revealing a metal-induced (Cr/Cu) oxidation pathway leading to N-terminal backbone fragmentation and oligomer formation; previously hidden details were revealed only by FT-IM-Orbitrap MS and surface-induced dissociation.
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Affiliation(s)
- Michael L Poltash
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
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29
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Schweikart F, Hulthe G. HPLC–UV–MS Analysis: A Source for Severe Oxidation Artifacts. Anal Chem 2019; 91:1748-1751. [DOI: 10.1021/acs.analchem.8b05845] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fritz Schweikart
- Advanced Drug Delivery, Pharmaceutical Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg 43183, Sweden
| | - Gustaf Hulthe
- Pharmaceutical Technology & Development, AstraZeneca R&D, Gothenburg 43183, Sweden
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30
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A Sensitive LC-MS/MS Method for Palytoxin Using Lithium Cationization. Toxins (Basel) 2018; 10:toxins10120537. [PMID: 30558165 PMCID: PMC6316396 DOI: 10.3390/toxins10120537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/10/2018] [Accepted: 12/11/2018] [Indexed: 12/31/2022] Open
Abstract
Palytoxin (PlTX) and analogues are produced by certain dinoflagellates, sea anemones, corals and cyanobacteria. PlTX can accumulate in the food chain and when consumed it may cause intoxication with symptoms like myalgia, weakness, fever, nausea, and vomiting. The analysis of PlTXs is challenging, and because of the large molecular structure, it is difficult to develop a sensitive and selective liquid chromatography-mass spectrometry (LC-MS/MS) method. In this work, an LC-MS/MS method was developed to analyse PlTXs with use of lithium iodine and formic acid as additives in the mobile phase. For method development, initially, LC-hrMS was used to accurately determine the elemental composition of the precursor and product ions. The main adduct formed was [M + H + 2Li]3+. Fragments were identified with LC-hrMS and these were incorporated in the LC-MS/MS method. A method of 10 min was developed and a solid phase extraction clean-up procedure was optimised for shellfish matrix. The determined limits of detection were respectively 8 and 22 µg PlTX kg-1 for mussel and oyster matrix. Oysters gave a low recovery of approximately 50% for PlTX during extraction. The method was successfully in-house validated, repeatability had a relative standard deviation less than 20% (n = 5) at 30 µg PlTX kg-1 in mussel, cockle, and ensis, and at 60 µg PlTX kg-1 in oyster.
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Shipman JT, Go EP, Desaire H. Method for Quantifying Oxidized Methionines and Application to HIV-1 Env. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:2041-2047. [PMID: 29987661 PMCID: PMC6326892 DOI: 10.1007/s13361-018-2010-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/25/2018] [Accepted: 06/12/2018] [Indexed: 06/08/2023]
Abstract
Recombinantly expressed proteins are susceptible to oxidation during expression, purification, storage, and analysis; the residue most susceptible to oxidation is methionine. Methionine oxidation can be overestimated using current quantitative analysis methods because oxidation can occur during sample preparation, and researchers often do not use methods that account for this possibility. An experimental strategy had been developed previously to solve this problem through the use of an 18O-labeled hydrogen peroxide reagent. However, the method did not address the analysis of peptides that contained multiple methionine residues. Herein, we develop and validate a new analysis method that uses theoretical isotope distributions and experimental spectra to quantify methionine oxidation that is present prior to sample preparation. The newly described approach is more rapid than the previously described method, and it needs only half the amount of protein for analysis. This method was validated using model proteins; then, it was applied to the analysis of recombinant HIV-1 Env, the key protein in HIV vaccine candidates. While Met oxidation of this protein could not be analyzed using previous methods, the approach described herein was useful for determining the oxidation state of HIV-Env. Graphical Abstract ᅟ.
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Affiliation(s)
- Joshua T Shipman
- Department of Chemistry, University of Kansas, Lawrence, KS, 66045, USA
| | - Eden P Go
- Department of Chemistry, University of Kansas, Lawrence, KS, 66045, USA
| | - Heather Desaire
- Department of Chemistry, University of Kansas, Lawrence, KS, 66045, USA.
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32
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Time-resolved method to distinguish protein/peptide oxidation during electrospray ionization mass spectrometry. Anal Chim Acta 2018; 1011:59-67. [PMID: 29475486 DOI: 10.1016/j.aca.2018.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 01/05/2018] [Accepted: 01/08/2018] [Indexed: 11/21/2022]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) is one of the most prevalent techniques used to monitor protein/peptide oxidation induced by reactive oxygen species (ROSs). However, both corona discharge (CD) and electrochemistry (EC) can also lead to protein/peptide oxidation during ESI. Because the two types of oxidation occur almost simultaneously, determining the extent to which the two pathways contribute to protein/peptide oxidation is difficult. Herein, a time-resolved method was introduced to identify and differentiate CD- and EC-induced oxidation. Using this approach, we separated the instantaneous CD-induced oxidation from the hysteretic EC-induced oxidation, and the effects of the spray voltage and flow rate of the ESI source on both oxidation types were investigated with a homemade ESI source. For angiotensin II analogue (b-DRVYVHPF-y), the dehydrogenation and oxygenation species were the detected EC-induced oxidation products, while the oxygenation species were the major CD-induced oxidation products. This time-resolved approach was also applicable to a commercial HESI source, in which both CD and EC were responsible for hemoglobin and cytochrome c oxidation with upstream grounding while CD dominated the oxidation without upstream grounding.
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33
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Balakrishnan G, Barnett GV, Kar SR, Das TK. Detection and Identification of the Vibrational Markers for the Quantification of Methionine Oxidation in Therapeutic Proteins. Anal Chem 2018; 90:6959-6966. [PMID: 29741878 DOI: 10.1021/acs.analchem.8b01238] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Methionine oxidation is a major degradation pathway in therapeutic proteins which can impact the structure and function of proteins as well as risk to drug product quality. Detecting Met oxidation in proteins by peptide mapping followed by liquid chromatography with mass spectrometry (LC-MS) is the industry standard but is also labor intensive and susceptible to artifacts. In this work, vibrational difference spectroscopy in combination with 18O isotopic shift enabled us to demonstrate the application of Raman and FTIR techniques for the detection and quantification of Met oxidation in various therapeutic proteins, including mAbs, fusion proteins, and antibody drug conjugate. Vibrational markers of Met oxidation products, such as sulfoxide and sulfone, corresponding to S═O and C-S═O stretching frequencies were unequivocally identified based 18O isotoptic shifts. The intensity of the isolated νC-S Raman band at 702 cm-1 was successfully applied to quantify the average Met oxidation level in multiple proteins. These results are further corroborated by oxidation levels measured by tryptic peptide mapping, and thus the confirmed Met oxidation levels derived from Raman and mass spectrometry are indeed consistent with each other. Thus, we demonstrate the broader application of vibrational spectroscopy to detect the subtle spectral changes associated with various chemical or physical degradation of proteins, including Met oxidation as well as higher order structural changes.
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Affiliation(s)
- Gurusamy Balakrishnan
- Molecular and Analytical Development , Bristol-Myers Squibb , 311 Pennington Rocky Hill Road , Pennington , New Jersey 08534 , United States
| | - Gregory V Barnett
- Molecular and Analytical Development , Bristol-Myers Squibb , 311 Pennington Rocky Hill Road , Pennington , New Jersey 08534 , United States
| | - Sambit R Kar
- Molecular and Analytical Development , Bristol-Myers Squibb , 311 Pennington Rocky Hill Road , Pennington , New Jersey 08534 , United States
| | - Tapan K Das
- Molecular and Analytical Development , Bristol-Myers Squibb , 311 Pennington Rocky Hill Road , Pennington , New Jersey 08534 , United States
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34
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Giesen JA, Diament BJ, Grayson SM. Iodine-Containing Mass-Defect-Tuned Dendrimers for Use as Internal Mass Spectrometry Calibrants. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:490-500. [PMID: 29260455 DOI: 10.1007/s13361-017-1849-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 10/18/2017] [Accepted: 11/13/2017] [Indexed: 06/07/2023]
Abstract
Calibrants based on synthetic dendrimers have been recently proposed as a versatile alternative to peptides and proteins for both MALDI and ESI mass spectrometry calibration. Because of their modular synthetic platform, dendrimer calibrants are particularly amenable to tailoring for specific applications. Utilizing this versatility, a set of dendrimers has been designed as an internal calibrant with a tailored mass defect to differentiate them from the majority of natural peptide analytes. This was achieved by incorporating a tris-iodinated aromatic core as an initiator for the dendrimer synthesis, thereby affording multiple calibration points (m/z range 600-2300) with an optimized mass-defect offset relative to all peptides composed of the 20 most common proteinogenic amino acids. Graphical abstract ᅟ.
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Affiliation(s)
- Joseph A Giesen
- Department of Chemistry, 2015 Stern Hall, Tulane University, New Orleans, LA, 70118-5636, USA
| | - Benjamin J Diament
- Department of Computer Science and Engineering, University of Washington, Box 352350, Seattle, WA, 98195-2350, USA
| | - Scott M Grayson
- Department of Chemistry, 2015 Stern Hall, Tulane University, New Orleans, LA, 70118-5636, USA.
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35
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Son G, Lee BI, Chung YJ, Park CB. Light-triggered dissociation of self-assembled β-amyloid aggregates into small, nontoxic fragments by ruthenium (II) complex. Acta Biomater 2018; 67:147-155. [PMID: 29221856 DOI: 10.1016/j.actbio.2017.11.048] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 11/16/2017] [Accepted: 11/28/2017] [Indexed: 10/18/2022]
Abstract
The self-assembly of β-amyloid (Aβ) peptides into highly stable plaques is a major hallmark of Alzheimer's disease. Here, we report visible light-driven dissociation of β-sheet-rich Aβ aggregates into small, nontoxic fragments using ruthenium (II) complex {[Ru(bpy)3]2+} that functions as a highly sensitive, biocompatible, photoresponsive anti-Aβ agent. According to our multiple analyses using thioflavin T, bicinchoninic acid, dynamic light scattering, atomic force microscopy, circular dichroism, and Fourier transform infrared spectroscopy, [Ru(bpy)3]2+ successfully disassembled Aβ aggregates by destabilizing the β-sheet secondary structure under illumination of white light-emitting diode light. We validated that photoexcited [Ru(bpy)3]2+ causes oxidative damages of Aβ peptides, resulting in the dissociation of Aβ aggregates. The efficacy of [Ru(bpy)3]2+ is attributed to reactive oxygen species, such as singlet oxygen, generated from [Ru(bpy)3]2+ that absorbed photon energy in the visible range. Furthermore, photoexcited [Ru(bpy)3]2+ strongly inhibited the self-assembly of Aβ monomers even at concentrations as low as 1 nM and reduced the cytotoxicity of Aβ aggregates. STATEMENT OF SIGNIFICANCE Alzheimer's disease is the most common progressive neurodegenerative disease, affecting more than 13% of the population over age 65. Over the last decades, researchers have focused on understanding the mechanism of amyloid formation, the hallmark of various amyloid diseases including Alzheimer's and Parkinson's. In this paper, we successfully demonstrate the dissociation of β-Amyloid (Aβ) aggregates into small, less-amyloidic fragments by photoexcited [Ru(bpy)3]2+ through destabilization of β-sheet secondary structure. We validated the light-triggered dissociation of amyloid structure using multiple analytical tools. Furthermore, we confirmed that photoexcited [Ru(bpy)3]2+ reduces cytotoxicity of Aβ aggregates. Our work should open a new horizon in the study of Alzheimer's amyloid aggregation by showing the potential of photoexcited dye molecules as an alternative therapeutic strategy for treating Alzheimer's disease in future.
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36
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Irvine GW, Heinlein L, Renaud JB, Sumarah MW, Stillman MJ. Formation of oxidative and non-oxidative dimers in metallothioneins: Implications for charge-state analysis for structural determination. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:2118-2124. [PMID: 28987027 DOI: 10.1002/rcm.8006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/19/2017] [Accepted: 09/24/2017] [Indexed: 05/10/2023]
Abstract
RATIONALE Metallothioneins (MTs) are a class of dynamic proteins that have been investigated extensively using mass spectrometric methods due to their amenability to ionization. Here we detect the formation of oxidative and non-oxidative MT dimers using high-resolution mass spectrometry (HRMS) which has previously been overlooked with lower-resolution techniques. METHODS Recombinant human MT1a and its isolated domain fragments were analyzed by high-resolution Thermo Q-Exactive and Bruker time-of-flight (TOF) mass spectrometers. Covalent Cys modification was performed using N-ethylmalemide to probe the effect of Cys oxidation on dimer formation. RESULTS Dimerization was detected in the analysis of select charge states of Zn7 MT and apo-βMT. Specifically, high resolution (140 k) revealed the +6 dimer peaks overlapping with the +3 charge state, but not with the other charge states (+4, +5, +6). The proteins with covalently modified Cys did not show dimer formation in any of their charge states. Apo-α and apo-βαMT also did not form dimers under the conditions tested. CONCLUSIONS Dimerization of MT was detected for zinc metalated and certain apo-MT forms with HRMS, which was not seen with lower-resolution techniques. These dimers appear overlapped only with certain charge states, confounding their analysis for structural characterization of MTs. The Zn-MT dimers appeared to be non-oxidative; however, the formation of dimers in the apo-protein is likely dependent on Cys oxidation.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Lina Heinlein
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
- Department of Food Chemistry and Toxicology, University of Karlsruhe, Profach 6980, D-76128, Karlsruhe, Germany
| | - Justin B Renaud
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Mark W Sumarah
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON, N5V 4T3, Canada
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
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37
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Pei J, Hsu CC, Zhang R, Wang Y, Yu K, Huang G. Unexpected Reduction of Iminoquinone and Quinone Derivatives in Positive Electrospray Ionization Mass Spectrometry and Possible Mechanism Exploration. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2454-2461. [PMID: 28786093 DOI: 10.1007/s13361-017-1770-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 07/13/2017] [Accepted: 07/21/2017] [Indexed: 06/07/2023]
Abstract
Unexpected reduction of iminoquinone (IQ) and quinone derivatives was first reported during positive electrospray ionization mass spectrometry. Upon increasing spray voltage, the intensities of IQ and quinone derivatives decreased drastically, accompanying the increase of the intensities of the reduction products, amodiaquine (AQ) and phenol derivatives. To gain more insight into the mechanism of such reduction, we explored the experimental factors that are influential to corona discharge (CD). The results show that experimental parameters that favor severe CD, including metal spray emitter, using water as spray solvent, sheath gas with low dielectric strength (e.g., nitrogen), and shorter spray tip-to-mass spectrometer inlet distance, facilitated the reduction of IQ and quinone derivatives, implying that the reduction should be closely related to CD in the gas phase. Graphical Abstract ᅟ.
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Affiliation(s)
- Jiying Pei
- School of Marine Sciences, Guangxi University, Nanning, 530004, People's Republic of China
- Department of Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China (USTC), Hefei, 230026, People's Republic of China
| | - Cheng-Chih Hsu
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Ruijie Zhang
- School of Marine Sciences, Guangxi University, Nanning, 530004, People's Republic of China
| | - Yinghui Wang
- School of Marine Sciences, Guangxi University, Nanning, 530004, People's Republic of China
| | - Kefu Yu
- School of Marine Sciences, Guangxi University, Nanning, 530004, People's Republic of China
| | - Guangming Huang
- Department of Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China (USTC), Hefei, 230026, People's Republic of China.
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38
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Engle SM, Crowder JJ, Watts SG, Indovina CJ, Coffey SZ, Rubenstein EM. Acetylation of N-terminus and two internal amino acids is dispensable for degradation of a protein that aberrantly engages the endoplasmic reticulum translocon. PeerJ 2017; 5:e3728. [PMID: 28848693 PMCID: PMC5571791 DOI: 10.7717/peerj.3728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 08/02/2017] [Indexed: 12/26/2022] Open
Abstract
Conserved homologues of the Hrd1 ubiquitin ligase target for degradation proteins that persistently or aberrantly engage the endoplasmic reticulum translocon, including mammalian apolipoprotein B (apoB; the major protein component of low-density lipoproteins) and the artificial yeast protein Deg1-Sec62. A complete understanding of the molecular mechanism by which translocon-associated proteins are recognized and degraded may inform the development of therapeutic strategies for cholesterol-related pathologies. Both apoB and Deg1-Sec62 are extensively post-translationally modified. Mass spectrometry of a variant of Deg1-Sec62 revealed that the protein is acetylated at the N-terminal methionine and two internal lysine residues. N-terminal and internal acetylation regulates the degradation of a variety of unstable proteins. However, preventing N-terminal and internal acetylation had no detectable consequence for Hrd1-mediated proteolysis of Deg1-Sec62. Our data highlight the importance of empirically validating the role of post-translational modifications and sequence motifs on protein degradation, even when such elements have previously been demonstrated sufficient to destine other proteins for destruction.
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Affiliation(s)
- Sarah M Engle
- Department of Biology, Ball State University, Muncie, IN, United States of America.,Immunology-Translational Science, Eli Lilly and Company, Indianapolis, IN, United States of America
| | - Justin J Crowder
- Department of Biology, Ball State University, Muncie, IN, United States of America.,Center for Medical Education, Indiana University School of Medicine, Muncie, IN, United States of America
| | - Sheldon G Watts
- Department of Biology, Ball State University, Muncie, IN, United States of America.,Marian University College of Osteopathic Medicine, Indianapolis, IN, United States of America
| | | | - Samuel Z Coffey
- Department of Biology, Ball State University, Muncie, IN, United States of America.,Medpace Reference Laboratories, Cincinnati, OH, United States of America
| | - Eric M Rubenstein
- Department of Biology, Ball State University, Muncie, IN, United States of America
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Yang L, Hansen Falkesgaard M, Thulstrup PW, Walmod PS, Lo Leggio L, Krighaar Rasmussen K. Expression, refolding and spectroscopic characterization of fibronectin type III (FnIII)-homology domains derived from human fibronectin leucine rich transmembrane protein (FLRT)-1, -2, and -3. PeerJ 2017; 5:e3550. [PMID: 28698826 PMCID: PMC5502089 DOI: 10.7717/peerj.3550] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/15/2017] [Indexed: 12/28/2022] Open
Abstract
The fibronectin leucine rich transmembrane (FLRT) protein family consists in humans of 3 proteins, FLRT1, -2, and -3. The FLRT proteins contain two extracellular domains separated by an unstructured linker. The most membrane distal part is a leucine rich repeat (LRR) domain responsible for both cis- and trans-interactions, whereas the membrane proximal part is a fibronectin type III (FnIII) domain responsible for a cis-interaction with members of the fibroblast growth factor receptor 1 (FGFR1) family, which results in FGFR tyrosine kinase activation. Whereas the structures of FLRT LRR domains from various species have been determined, the expression and purification of recombinant FLRT FnIII domains, important steps for further structural and functional characterizations of the proteins, have not yet been described. Here we present a protocol for expressing recombinant FLRT-FnIII domains in inclusion bodies in Escherichia coli. His-tags permitted affinity purification of the domains, which subsequently were refolded on a Ni-NTA agarose column by reducing the concentration of urea. The refolding was confirmed by circular dichroism (CD) and 1H-NMR. By thermal unfolding experiments we show that a strand-strand cystine bridge has significant effect on the stability of the FLRT FnIII fold. We further show by Surface Plasmon Resonance that all three FnIII domains bind to FGFR1, and roughly estimate a Kd for each domain, all Kds being in the µM range.
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Affiliation(s)
- Lila Yang
- Biological Chemistry, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Maria Hansen Falkesgaard
- Laboratory of Neural Plasticity, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Waaben Thulstrup
- Biological Chemistry, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Peter Schledermann Walmod
- Laboratory of Neural Plasticity, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Leila Lo Leggio
- Biological Chemistry, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Kim Krighaar Rasmussen
- Biological Chemistry, Department of Chemistry, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Neural Plasticity, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Chen W, Tuladhar A, Rolle S, Lai Y, Rodriguez Del Rey F, Zavala CE, Liu Y, Rein KS. Brevetoxin-2, is a unique inhibitor of the C-terminal redox center of mammalian thioredoxin reductase-1. Toxicol Appl Pharmacol 2017; 329:58-66. [PMID: 28551108 DOI: 10.1016/j.taap.2017.05.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/15/2017] [Accepted: 05/22/2017] [Indexed: 11/15/2022]
Abstract
Karenia brevis, the Florida red tide dinoflagellate produces a suite of neurotoxins known as the brevetoxins. The most abundant of the brevetoxins PbTx-2, was found to inhibit the thioredoxin-thioredoxin reductase system, whereas the PbTx-3 has no effect on this system. On the other hand, PbTx-2 activates the reduction of small disulfides such as 5,5'-dithio-bis-(2-nitrobenzoic acid) by thioredoxin reductase. PbTx-2 has an α, β-unsaturated aldehyde moiety which functions as an efficient electrophile and selenocysteine conjugates are readily formed. PbTx-2 blocks the inhibition of TrxR by the inhibitor curcumin, whereas curcumin blocks PbTx-2 activation of TrxR. It is proposed that the mechanism of inhibition of thioredoxin reduction is via the formation of a Michael adduct between selenocysteine and the α, β-unsaturated aldehyde moiety of PbTx-2. PbTx-2 had no effect on the rates of reactions catalyzed by related enzymes such as glutathione reductase, glutathione peroxidase or glutaredoxin.
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Affiliation(s)
- Wei Chen
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Anupama Tuladhar
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Shantelle Rolle
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Yanhao Lai
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Freddy Rodriguez Del Rey
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Cristian E Zavala
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Yuan Liu
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States; Biomolecular Sciences Institute, School of Integrated Sciences and Humanity, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States
| | - Kathleen S Rein
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th Street, Miami, FL 33199, United States.
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Güray MZ, Zheng S, Doucette AA. Mass Spectrometry of Intact Proteins Reveals +98 u Chemical Artifacts Following Precipitation in Acetone. J Proteome Res 2017; 16:889-897. [PMID: 28088865 DOI: 10.1021/acs.jproteome.6b00841] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Protein precipitation in acetone is frequently employed ahead of mass spectrometry for sample preconcentration and purification. Unfortunately, acetone is not chemically inert; mass artifacts have previously been observed on glycine-containing peptides when exposed to acetone under acidic conditions. We herein report a distinct chemical modification occurring at the level of intact proteins when incubated in acetone. This artifact manifests as one or more satellite peaks in the MS spectrum of intact protein, spaced 98 u above the mass of the unmodified protein. Other artifacts (+84, +112 u) also appear upon incubation of proteins or peptides in acetone. The reaction is pH-sensitive, being suppressed when proteins are exposed to acetone under acidic conditions. The +98 u artifact is speculated to originate through an intermediate product of aldol condensation of acetone to form diacetone alcohol and mesityl oxide. A +98 u product could originate from nucleophilic attack on mesityl oxide or through condensation with diacetone alcohol. Given the extent of modification possible upon exposure of proteins to acetone, particularly following overnight solvent exposure or incubation at room temperature, an awareness of the variables influencing this novel modification is valued by proteomics researchers who employ acetone precipitation for protein purification.
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Affiliation(s)
- Melda Z Güray
- Department of Chemistry, Dalhousie University , PO Box 15000, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Shi Zheng
- Department of Chemistry, Dalhousie University , PO Box 15000, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - Alan A Doucette
- Department of Chemistry, Dalhousie University , PO Box 15000, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
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Pei J, Hsu CC, Wang Y, Yu K. Corona discharge-induced reduction of quinones in negative electrospray ionization mass spectrometry. RSC Adv 2017. [DOI: 10.1039/c7ra08523k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Quinone reduction during negative ESI MS was illustrated to be closely related to corona discharge (CD).
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Affiliation(s)
- Jiying Pei
- School of Marine Sciences
- Guangxi University
- Nanning
- P. R. China
- Coral Reef Research Center of China
| | - Cheng-Chih Hsu
- Department of Chemistry
- National Taiwan University
- Taipei 10617
- Taiwan
| | - Yinghui Wang
- School of Marine Sciences
- Guangxi University
- Nanning
- P. R. China
- Coral Reef Research Center of China
| | - Kefu Yu
- School of Marine Sciences
- Guangxi University
- Nanning
- P. R. China
- Coral Reef Research Center of China
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Antimicrobial effect of synergistic interaction between UV-A light and gallic acid against Escherichia coli O157:H7 in fresh produce wash water and biofilm. INNOV FOOD SCI EMERG 2016. [DOI: 10.1016/j.ifset.2016.07.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Jeong JY, Jung EY, Jeong TC, Yang HS, Kim GD. Analysis of Methionine Oxidation in Myosin Isoforms in Porcine Skeletal Muscle by LC-MS/MS Analysis. Korean J Food Sci Anim Resour 2016; 36:254-61. [PMID: 27194935 PMCID: PMC4869553 DOI: 10.5851/kosfa.2016.36.2.254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 03/02/2016] [Accepted: 03/02/2016] [Indexed: 11/06/2022] Open
Abstract
The purpose of this study was to analyze oxidized methionines in the myosin isoforms of porcine longissimus thoracis, psoas major, and semimembranosus muscles by liquid chromatography (LC) and mass spectrometry (MS). A total of 836 queries matched to four myosin isoforms (myosin-1, -2, -4, and -7) were analyzed and each myosin isoform was identified by its unique peptides (7.3-13.3). Forty-four peptides were observed from all three muscles. Seventeen peptides were unique to the myosin isoform and the others were common peptides expressed in two or more myosin isoforms. Five were identified as oxidized peptides with one or two methionine sulfoxides with 16 amu of mass modification. Methionines on residues 215 (215), 438 (438), 853 (851), 856 (854), 1071 (1069), and 1106 (1104) of myosin-1 (myosin-4) were oxidized by the addition of oxygen. Myosin-2 had two oxidized methionines on residues 215 and 438. No queries matched to myosin-7 were observed as oxidized peptides. LC-MS/MS allows analysis of the oxidation of specific amino acids on specific residue sites, as well as in specific proteins in the food system.
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Affiliation(s)
- Jin-Yeon Jeong
- Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52852, Korea
| | - Eun-Young Jung
- Division of Applied Life Science (BK21 plus), Gyeongsang National University, Jinju 52852, Korea
| | - Tae-Chul Jeong
- Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52852, Korea
| | - Han-Sul Yang
- Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52852, Korea
- Division of Applied Life Science (BK21 plus), Gyeongsang National University, Jinju 52852, Korea
| | - Gap-Don Kim
- Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52852, Korea
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, IL 61801, USA
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Abstract
Prion diseases are a heterogeneous class of fatal neurodegenerative disorders associated with misfolding of host cellular prion protein (PrP(C)) into a pathological isoform, termed PrP(Sc). Prion diseases affect various mammals, including humans, and effective treatments are not available. Prion diseases are distinguished from other protein misfolding disorders - such as Alzheimer's or Parkinson's disease - in that they are infectious. Prion diseases occur sporadically without any known exposure to infected material, and hereditary cases resulting from rare mutations in the prion protein have also been documented. The mechanistic underpinnings of prion and other neurodegenerative disorders remain poorly understood. Various proteomics techniques have been instrumental in early PrP(Sc) detection, biomarker discovery, elucidation of PrP(Sc) structure and mapping of biochemical pathways affected by pathogenesis. Moving forward, proteomics approaches will likely become more integrated into the clinical and research settings for the rapid diagnosis and characterization of prion pathogenesis.
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Affiliation(s)
- Roger A Moore
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIH,NIAID, Hamilton, MT 59840, USA
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Sowole MA, Vuong S, Konermann L. Interactions of hemoglobin and myoglobin with their ligands CN(-), CO, and O2 monitored by electrospray ionization-mass spectrometry. Anal Chem 2015; 87:9538-45. [PMID: 26327529 DOI: 10.1021/acs.analchem.5b02506] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Electrospray ionization (ESI)-mass spectrometry (MS) can provide information on protein-ligand interactions via detection of the corresponding complexes as gaseous ions. Unfortunately, some systems are prone to dissociation upon transfer into the gas phase. The reversible oxygen binding to hemoglobin (Hb) has been extensively studied in solution using a wide range of biophysical techniques. In addition to O2, ferrous (Fe(II)) Hb can bind CO. High affinity interactions with CN(-) are limited to the ferric (Fe(III)) state. In analogous fashion, CN(-), CO, and O2 bind to myoglobin (Mb). It remains unclear whether any of these ligand-bound forms can be observed by ESI-MS. In this work we demonstrate the successful detection of MbCN, while MbCO and MbO2 do not survive under ESI-MS conditions. Control experiments suggest that an older report of "MbO2" detection by ESI-MS may involve the misassignment of oxidation artifacts formed under corona discharge conditions. The situation is more favorable for ESI-MS studies on Hb. The most intense signal in the HbCN mass distribution corresponds to the expected complex with four cyanide moieties bound. Ligand loss during ESI-MS is around 20%. HbCO is detectable as well, albeit with a more noticeable level of ligand dissociation (∼50%) which produces the 2CO-bound state as the highest intensity ion in the spectrum. In addition, our data suggest that low levels of HbO2 can survive the transition into the gas phase, evident from +64 Da and +128 Da signals that can be assigned to Hb carrying two and four oxygen molecules, respectively. The application of collisional activation induces neutral ligand loss for all three Hb derivatives. It appears that this is the first report on the detection of MbCN, HbCO, and HbO2 in the gas phase. We hope that this work will pave the way towards future spectroscopic investigations of desolvated Mb and Hb, complementing the extensive literature on CN(-), CO, and O2 bound globins in the condensed phase.
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Affiliation(s)
- Modupeola A Sowole
- Department of Chemistry, The University of Western Ontario , London, Ontario N6A 5B7, Canada
| | - Stephanie Vuong
- Department of Chemistry, The University of Western Ontario , London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario , London, Ontario N6A 5B7, Canada
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Baez NOD, Reisz JA, Furdui CM. Mass spectrometry in studies of protein thiol chemistry and signaling: opportunities and caveats. Free Radic Biol Med 2015; 80:191-211. [PMID: 25261734 PMCID: PMC4355329 DOI: 10.1016/j.freeradbiomed.2014.09.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 09/08/2014] [Accepted: 09/11/2014] [Indexed: 12/13/2022]
Abstract
Mass spectrometry (MS) has become a powerful and widely utilized tool in the investigation of protein thiol chemistry, biochemistry, and biology. Very early biochemical studies of metabolic enzymes have brought to light the broad spectrum of reactivity profiles that distinguish cysteine thiols with functions in catalysis and protein stability from other cysteine residues in proteins. The development of MS methods for the analysis of proteins using electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) coupled with the emergence of high-resolution mass analyzers has been instrumental in advancing studies of thiol modifications, both in single proteins and within the cellular context. This article reviews MS instrumentation and methods of analysis employed in investigations of thiols and their reactivity toward a range of small biomolecules. A selected number of studies are detailed to highlight the advantages brought about by the MS technologies along with the caveats associated with these analyses.
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Affiliation(s)
- Nelmi O Devarie Baez
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Julie A Reisz
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Cristina M Furdui
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
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48
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Silva CJ. Applying the tools of chemistry (mass spectrometry and covalent modification by small molecule reagents) to the detection of prions and the study of their structure. Prion 2015; 8:42-50. [PMID: 24509645 DOI: 10.4161/pri.27891] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Prions are molecular pathogens, able to convert a normal cellular prion protein (PrP(C)) into a prion (PrP(Sc)). The information necessary for this conversion is contained in the conformation of PrP(Sc). Mass spectrometry (MS) and small-molecule covalent reactions have been used to study prions. Mass spectrometry has been used to detect and quantitate prions in the attomole range (10⁻¹⁸ mole). MS-based analysis showed that both possess identical amino acid sequences, one disulfide bond, a GPI anchor, asparagine-linked sugar antennae, and unoxidized methionines. Mass spectrometry has been used to define elements of the secondary and tertiary structure of wild-type PrP(Sc) and GPI-anchorless PrP(Sc). It has also been used to study the quaternary structure of the PrP(Sc) multimer. Small molecule reagents react differently with the same lysine in the PrP(C) conformation than in the PrP(Sc) conformation. Such differences can be detected by Western blot using mAbs with lysine-containing epitopes, such as 3F4 and 6D11. This permits the detection of PrP(Sc) without the need for proteinase K pretreatment and can be used to distinguish among prion strains. These results illustrate how two important chemical tools, mass spectrometry and covalent modification by small molecules, are being applied to the detection and structural study of prions. Furthermore these tools are or can be applied to the study of the other protein misfolding diseases such as Alzheimer Disease, Parkinson Disease, or ALS.
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49
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Pei J, Zhou X, Wang X, Huang G. Alleviation of electrochemical oxidation for peptides and proteins in electrospray ionization: obtaining more accurate mass spectra with induced high voltage. Anal Chem 2015; 87:2727-33. [PMID: 25626082 DOI: 10.1021/ac503990a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Accurate mass spectrometry (MS) signal for peptide/protein analysis, which could be affected by various MS conditions, plays an essential role in identification and quantification of biological samples. Herein, we tried to alleviate the possible interferences from electrochemical oxidations during electrospray ionization (ESI). Three most common electrochemical oxidation reactions in ESI include oxidation of analyte, solvent, and electrode. With introduction of induced electrospray ionization (IESI) (a variant form of ESI), these interferences were significantly alleviated for peptides/proteins. That effect was also tested with flow injection experiments with different solution flow rates, electrolyte concentrations and solvent compositions, which was to simulate various chromatography conditions in conventional liquid chromatography (LC) separations. For all chromatography conditions tested, electrochemical oxidation was significantly alleviated for the absence of physical contact between spray solution and electrode.
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Affiliation(s)
- Jiying Pei
- Department of Chemistry, School of Chemistry and Materials Science, University of Science and Technology of China , Hefei 230026, People's Republic of China
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50
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Yue X, Vahidi S, Konermann L. Insights into the mechanism of protein electrospray ionization from salt adduction measurements. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1322-1331. [PMID: 24839193 DOI: 10.1007/s13361-014-0905-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 04/03/2014] [Indexed: 06/03/2023]
Abstract
The mechanisms whereby protein ions are liberated from charged droplets during electrospray ionization (ESI) remain under investigation. Compact conformers electrosprayed from aqueous solution in positive ion mode likely follow the charged residue model (CRM), which envisions analyte release after solvent evaporation to dryness. The concentration of nonvolatile salts such as NaCl increases sharply within vanishing CRM droplets, promoting nonspecific pairing of Cl(-) and Na(+) with charged groups on the protein surface. For unfolded proteins, it has been proposed that ion formation occurs via the chain ejection model (CEM). During the CEM proteins are expelled from the droplet long before complete solvent evaporation has taken place. Here we examine whether salt adduction levels support the view that folded and unfolded proteins follow different ESI mechanisms. Solvent evaporation during the CEM is expected to be less extensive and, hence, the salt concentration at the point of protein release should be substantially lower than for the CRM. CEM ions should therefore exhibit lower adduction levels than CRM species. We explore the adduction behavior of several proteins that were chosen to allow comparative studies on folded and unfolded structures in the same solution. In-source activation eliminates chloride adducts via HCl release, generating protein ions that are heterogeneously charged because of sodiation and protonation. Sodiation levels measured under such conditions provide estimates of the salt adduction behavior experienced by the "nascent" analyte ions. Sodiation levels are significantly reduced for unfolded proteins, supporting the view that these species are indeed formed via the CEM.
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Affiliation(s)
- Xuanfeng Yue
- Department of Chemistry, The University of Western Ontario, London, ON, N6A 5B7, Canada
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