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Malaker SA. Glycoproteomics: Charting new territory in mass spectrometry and glycobiology. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5034. [PMID: 38726698 DOI: 10.1002/jms.5034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 05/24/2024]
Abstract
Glycosylation is an incredibly common and diverse post-translational modification that contributes widely to cellular health and disease. Mass spectrometry is the premier technique to study glycoproteins; however, glycoproteomics has lagged behind traditional proteomics due to the challenges associated with studying glycosylation. For instance, glycans dissociate by collision-based fragmentation, thus necessitating electron-based fragmentation for site-localization. The vast glycan heterogeneity leads to lower overall abundance of each glycopeptide, and often, ion suppression is observed. One of the biggest issues facing glycoproteomics is the lack of reliable software for analysis, which necessitates manual validation and serves as a massive bottleneck in data processing. Here, I will discuss each of these challenges and some ways in which the field is attempting to address them, along with perspectives on how I believe we should move forward.
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Affiliation(s)
- Stacy A Malaker
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
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2
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Lin CW, Canonica F, Wüthrich S, Fettelschoss-Gabriel A, Schlapbach R, Nanni P. m-nitrobenzyl alcohol supercharging reagent enhances the chromatographic separation and the charging of disulfide bond linked and His-tag peptides. J Chromatogr A 2024; 1722:464828. [PMID: 38581973 DOI: 10.1016/j.chroma.2024.464828] [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: 12/29/2023] [Revised: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 04/08/2024]
Abstract
The linkages of disulfide bond (DSB) play important roles in protein stability and activity. Mass spectrometry-based (MS-based) techniques become accepted tools for DSB analysis in the recent decade. In the bottom-up approach, after enzyme digestion, the neighbouring amino acids of cysteines have great impacts on the physicochemical properties of resulting disulfide bond peptides, determining their retention behaviour on liquid chromatography (LC) and their MS ionization efficiency. In this study, the addition of supercharging reagent in LC mobile phase was used to examine the impact of supercharging reagent on the charge states of disulfide-bond peptides. The results showed that 0.1 % m-nitrobenzyl alcohol (m-NBA) in LC mobile phase increased the sensitivity and charge states of DSB peptides from our model protein, equine Interleukin-5 (eIL5), as well as the resolution of reversed-phase chromatography. Notably, also the sensitivity of C-terminal peptide with His-tag significantly improved. Our findings highlight the effectiveness of employing m-NBA as a supercharging reagent when investigating disulfide-linked peptides and the C-terminal peptide with a His-tag through nano-liquid chromatography mass spectrometry.
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Affiliation(s)
- Chia-Wei Lin
- Functional Genomics Center Zürich, University of Zürich/ETH Zürich, 8057 Zürich, Switzerland.
| | - Fabia Canonica
- Department of Dermatology, University of Zürich, 8952 Schlieren, Switzerland
| | - Simone Wüthrich
- Functional Genomics Center Zürich, University of Zürich/ETH Zürich, 8057 Zürich, Switzerland
| | | | - Ralph Schlapbach
- Functional Genomics Center Zürich, University of Zürich/ETH Zürich, 8057 Zürich, Switzerland
| | - Paolo Nanni
- Functional Genomics Center Zürich, University of Zürich/ETH Zürich, 8057 Zürich, Switzerland
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3
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Liu S, Ryumin P, Albanese J, Zhang Z, Baba T. Analysis of Sialic Acid Linkage in N-Linked Glycopeptides Using Liquid Chromatography-Electron-Activated Dissociation Time-of-Flight Mass Spectrometry. Anal Chem 2023; 95:7458-7467. [PMID: 37146167 DOI: 10.1021/acs.analchem.2c04581] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Herein, we report a novel liquid chromatography coupled with tandem mass spectrometry method to characterize N-acetylneuraminic acid (Neu5Ac, Sa) linkage in N-linked glycans in glycopeptides with no sialic acid derivatization. First, we established a separation in reversed-phase high-performance liquid chromatography (HPLC) using a higher formic acid concentration in the mobile phases, which separated the N-glycopeptides depending on the Sa linkage. We also demonstrated a novel characterization method of Sa linkages in N-glycopeptides using electron-activated dissociation. We found that hot electron capture dissociation using an electron beam energy higher than 5 eV cleaved glycosidic bonds in glycopeptides, resulting in each glycosidic bond in the antennas being broken on both sides of the oxygen atom. Such glycosidic bond cleavage at the reducing end (C-type ion) showed the difference in Sa linkages between Sa-Gal, Gal-GlcNAc, and GlcNAc-Man. We proposed a rule to characterize the Sa linkages using the Sa-Gal products. This method was applied to N-glycopeptides in tryptic fetuin digest separated by an optimized reversed-phase HPLC. We successfully identified a number of isomeric glycoforms in the glycopeptides with different Sa links, whose peptide backbones were also simultaneously sequenced by hot ECD.
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Affiliation(s)
- Suya Liu
- Sciex, 71 Four Valley Dr. Concord, Ontario L4K 4V8, Canada
| | - Pavel Ryumin
- Sciex, 71 Four Valley Dr. Concord, Ontario L4K 4V8, Canada
| | - Jenny Albanese
- Sciex, 1201 Radio Rd, Redwood City, California 94065, United States
| | - Zoe Zhang
- Sciex, 1201 Radio Rd, Redwood City, California 94065, United States
| | - Takashi Baba
- Sciex, 71 Four Valley Dr. Concord, Ontario L4K 4V8, Canada
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4
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Knoot CJ, Wantuch PL, Robinson LS, Rosen DA, Scott NE, Harding CM. Discovery and characterization of a new class of O-linking oligosaccharyltransferases from the Moraxellaceae family. Glycobiology 2022; 33:57-74. [PMID: 36239418 PMCID: PMC9829042 DOI: 10.1093/glycob/cwac070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 01/12/2023] Open
Abstract
Bacterial protein glycosylation is commonly mediated by oligosaccharyltransferases (OTases) that transfer oligosaccharides en bloc from preassembled lipid-linked precursors to acceptor proteins. Natively, O-linking OTases usually transfer a single repeat unit of the O-antigen or capsular polysaccharide to the side chains of serine or threonine on acceptor proteins. Three major families of bacterial O-linking OTases have been described: PglL, PglS, and TfpO. TfpO is limited to transferring short oligosaccharides both in its native context and when heterologously expressed in glycoengineered Escherichia coli. On the other hand, PglL and PglS can transfer long-chain polysaccharides when expressed in glycoengineered E. coli. Herein, we describe the discovery and functional characterization of a novel family of bacterial O-linking OTases termed TfpM from Moraxellaceae bacteria. TfpM proteins are similar in size and sequence to TfpO enzymes but can transfer long-chain polysaccharides to acceptor proteins. Phylogenetic analyses demonstrate that TfpM proteins cluster in distinct clades from known bacterial OTases. Using a representative TfpM enzyme from Moraxella osloensis, we determined that TfpM glycosylates a C-terminal threonine of its cognate pilin-like protein and identified the minimal sequon required for glycosylation. We further demonstrated that TfpM has broad substrate tolerance and can transfer diverse glycans including those with glucose, galactose, or 2-N-acetyl sugars at the reducing end. Last, we find that a TfpM-derived bioconjugate is immunogenic and elicits serotype-specific polysaccharide IgG responses in mice. The glycan substrate promiscuity of TfpM and identification of the minimal TfpM sequon renders this enzyme a valuable additional tool for expanding the glycoengineering toolbox.
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Affiliation(s)
- Cory J Knoot
- Omniose, 4340 Duncan Ave, Suite 202, St. Louis, MO 63110, USA
| | - Paeton L Wantuch
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, 4990 Children’s Place, St. Louis, MO 63110, USA
| | | | - David A Rosen
- Department of Pediatrics, Division of Infectious Diseases, Washington University School of Medicine, 4990 Children’s Place, St. Louis, MO 63110, USA,Department of Molecular Microbiology, Washington University School of Medicine, 660 Euclid Ave, St. Louis, MO 63110, USA
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, VIC 3010, Australia
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Martin LM, Konermann L. Sulfolane-Induced Supercharging of Electrosprayed Salt Clusters: An Experimental/Computational Perspective. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:486-496. [PMID: 33334096 DOI: 10.1021/jasms.0c00377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
It is well-known that supercharging agents (SCAs) such as sulfolane enhance the electrospray ionization (ESI) charge states of proteins, although the mechanistic origins of this effect remain contentious. Only very few studies have explored SCA effects on analytes other than proteins or peptides. This work examines how sulfolane affects electrosprayed NaI salt clusters. Such alkali metal halide clusters have played a key role for earlier ESI mechanistic studies, making them interesting targets for supercharging investigations. ESI of aqueous NaI solutions predominantly generated singly charged [NanI(n-1)]+ clusters. The addition of sulfolane resulted in abundant doubly charged [NanI(n-2)Sulfolanes]2+ species. These experimental data for the first time demonstrate that electrosprayed salt clusters can undergo supercharging. Molecular dynamics (MD) simulations of aqueous ESI nanodroplets containing Na+/I- with and without sulfolane were conducted to obtain atomistic insights into the supercharging mechanism. The simulations produced [NanIi]z+ and [NanIiSulfolanes]z+ clusters similar to those observed experimentally. The MD trajectories demonstrated that these clusters were released into the gas phase upon droplet evaporation to dryness, in line with the charged residue model. Sulfolane was found to evaporate much more slowly than water. This slow evaporation, in conjunction with the large dipole moment of sulfolane, resulted in electrostatic stabilization of the shrinking ESI droplets and the final clusters. Hence, charge-dipole stabilization causes the sulfolane-containing droplets and clusters to retain more charge, thereby providing the mechanistic foundation of salt cluster supercharging.
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Affiliation(s)
- Leanne M Martin
- 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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Persaud RR, Dieke NE, Jing X, Lambert S, Parsa N, Hartmann E, Vincent JB, Cassady CJ, Dixon DA. Mechanistic Study of Enhanced Protonation by Chromium(III) in Electrospray Ionization: A Superacid Bound to a Peptide. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:308-318. [PMID: 32031389 DOI: 10.1021/jasms.9b00078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Addition of trivalent chromium, Cr(III), to solutions undergoing electrospray ionization (ESI) enhances protonation and leads to formation of [M + 2H]2+ for peptides that normally produce [M + H]+. This effect is explored using electronic structure calculations at the density functional theory (DFT) level to predict the energetics of various species that are potentially important to the mechanism. Gas- and solution-phase reaction free energies for glycine and its anion reacting with [Cr(III)(H2O)6]3+ and for dehydration of these species have been predicted, where glycine is used as a simple model for a peptide. For comparison, calculations were also performed with Fe(III), Al(III), Sc(III), Y(III), and La(III). Removal of water from these complexes, as would occur during the ESI desolvation process, results in species that are highly acidic. The calculated pKa of Cr(III) with a single solvation shell is -10.8, making [Cr(III)(H2O)6]3+ a superacid that is more acidic than sulfuric acid (pKa = -8.8). Binding to glycine requires removal of two aqua ligands, which gives [Cr(III)(H2O)4]3+ that has an extremely acidic pKa of -28.8. Removal of additional water further enhances acidity, reaching a pKa of -84.7 for [Cr(III)(H2O)]3+. A mechanism for enhanced protonation is proposed that incorporates computational and experiment results, as well as information on the known chemistry of Cr(III), which is substitutionally inert. The initial step involves binding of [Cr(III)(H2O)4]3+ to the deprotonated C-terminus of a peptide. As the drying process during ESI strips water from the complex, the resulting superacid transfers protons to the bound peptide, eventually leading to formation of [M + 2H]2+.
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Affiliation(s)
- Rudradatt R Persaud
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - Nnenna E Dieke
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - Xinyao Jing
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - Skyler Lambert
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - Nicholas Parsa
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - Elizabeth Hartmann
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - John B Vincent
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - Carolyn J Cassady
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
| | - David A Dixon
- Department of Chemistry & Biochemistry , The University of Alabama , Tuscaloosa , Alabama 35487-0336 , United States
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7
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Glycan size and attachment site location affect electron transfer dissociation (ETD) fragmentation and automated glycopeptide identification. Glycoconj J 2019; 36:487-493. [DOI: 10.1007/s10719-019-09888-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/09/2019] [Accepted: 08/09/2019] [Indexed: 10/25/2022]
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8
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Yang L, Sun Z, Zhang L, Cai Y, Peng Y, Cao T, Zhang Y, Lu H. Chemical labeling for fine mapping of IgG N-glycosylation by ETD-MS. Chem Sci 2019; 10:9302-9307. [PMID: 32110292 PMCID: PMC7006626 DOI: 10.1039/c9sc02491c] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/21/2019] [Indexed: 12/25/2022] Open
Abstract
Immunoglobulin G (IgG), which contains four subclasses (IgG1-4), is one of the most important classes of glycoproteins in the immune system. Because of its importance in the immune system, a steady increase of interest in developing IgG as the biomarker or biotherapeutic agent for the treatment of diseases has been seen, as most therapeutic mAbs were IgG-based. N-Glycosylation of IgG is crucial for its effector function and makes IgG highly heterogeneous both in structure and function, although all four subclasses of IgG contain only a single N-glycosylation site in the Fc region with a highly similar amino acid sequence. Therefore, fine mapping of IgG glycosylation is necessary for understanding the IgG function and avoiding aberrant glycosylation in mAbs. However, site-specific and comprehensive N-glycosylation analysis of IgG subclasses still cannot be achieved by MS alone due to the partial sequence coverage and loss of connections among glycosylation of the protein sequence. We report here a chemical labeling strategy to improve the electron transfer dissociation efficiency in mass spectrometry analysis, which enables a 100% peptide sequence coverage of N-glycopeptides in all subclasses of IgG. Combined with high-energy collisional dissociation for the fragmentation of glycans, fine mapping of the N-glycosylation profile of IgG is achieved. This comprehensive glycosylation analysis strategy for the first time allows the discrimination of IgG3 and IgG4 intact N-glycopeptides with high similarity in sequence without the antibody-based pre-separation. Using this strategy, aberrant serum IgG N-glycosylation for four IgG subclasses associated with cirrhosis and hepatocellular carcinoma was revealed. Moreover, this method identifies 5 times more intact glycopeptides from human serum than the native-ETD method, implying that the approach can also accommodate large-scale site-specific profiling of glycoproteomes.
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Affiliation(s)
- Lijun Yang
- Shanghai Cancer Center , Department of Chemistry , Fudan University , Shanghai 200032 , China . ;
| | - Zhenyu Sun
- Institutes of Biomedical Sciences , NHC Key Laboratory of Glycoconjugates Research , Fudan University , Shanghai 200032 , China
| | - Lei Zhang
- Institutes of Biomedical Sciences , NHC Key Laboratory of Glycoconjugates Research , Fudan University , Shanghai 200032 , China
| | - Yan Cai
- Institutes of Biomedical Sciences , NHC Key Laboratory of Glycoconjugates Research , Fudan University , Shanghai 200032 , China
| | - Ye Peng
- Institutes of Biomedical Sciences , NHC Key Laboratory of Glycoconjugates Research , Fudan University , Shanghai 200032 , China
| | - Ting Cao
- Shanghai Cancer Center , Department of Chemistry , Fudan University , Shanghai 200032 , China . ;
| | - Ying Zhang
- Shanghai Cancer Center , Department of Chemistry , Fudan University , Shanghai 200032 , China . ; .,Institutes of Biomedical Sciences , NHC Key Laboratory of Glycoconjugates Research , Fudan University , Shanghai 200032 , China
| | - Haojie Lu
- Shanghai Cancer Center , Department of Chemistry , Fudan University , Shanghai 200032 , China . ; .,Institutes of Biomedical Sciences , NHC Key Laboratory of Glycoconjugates Research , Fudan University , Shanghai 200032 , China
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9
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Assessing mixtures of supercharging agents to increase the abundance of a specific charge state of Neuromedin U. Talanta 2019; 198:206-214. [PMID: 30876551 DOI: 10.1016/j.talanta.2019.01.098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 11/24/2022]
Abstract
With increasing evidence of the important role of peptides in pathophysiological processes, a trend towards the development of highly sensitive bioanalytical methods is ongoing. Inherent to the electrospray ionization process of peptides and proteins is the production of multiple charge states which may hamper proper and sensitive method development. Supercharging agents allow modifying the maximal charge state and the corresponding distribution of charges, thereby potentially increasing the number of ions reaching the detector in selected reaction monitoring mode. In this study, the use of mixtures of charge state modifying additives, i.e. m-nitrobenzylalcohol (mNBA), sulfolane and dimethyl sulfoxide (DMSO), to specifically increase the abundance of one charge state of interest has been investigated. Screening experiments were performed to define an experimental domain, which was then further investigated via a response surface design to predict the optimal combination and concentration of superchargers. Using a combination of mNBA and DMSO (0.008% and 0.5% m/v respectively), we were able to increase the abundance of the +4 charge state of the investigated peptide neuromedin U from 64% to 87%. Unfortunately, charge state coalescence did not result in repeatable sensitivity improvements in this case study. However, it remains an attractive approach during method development of peptide bioanalytical methods, as coalescence to a particular intermediate charge state is difficult to obtain by using only one supercharging agent.
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10
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Jing X, Edwards KC, Vincent JB, Cassady CJ. The use of chromium(III) complexes to enhance peptide protonation by electrospray ionization mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2018; 53:1198-1206. [PMID: 30281192 DOI: 10.1002/jms.4297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/27/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
The addition of trivalent chromium, Cr(III), reagents to peptide solutions can increase the intensity of doubly protonated peptides, [M + 2H]2+ , through electrospray ionization (ESI). Three model heptapeptides were studied: neutral (AAAAAAA), acidic (AAEEEAA), and basic (AAAKAAA). The neutral and acidic peptides form almost no 2+ ions in the absence of Cr(III). Twenty Cr(III) complexes were used as potential enhanced protonation reagents, including 11 complexes with nonlabile ligands and nine with labile ligands. The complexes that provide the most abundant [M + 2H]2+ , the greatest [M + 2H]2+ to [M + H]+ ratio, and the cleanest mass spectra are [Cr(H2 O)6 ](NO3 )3 ·3H2 O and [Cr(THF)3 ]Cl3 . Anions in Cr(III) reagents can also affect the intensity of [M + 2H]2+ and the [M + 2H]2+ to [M + H]+ ratio through cation-anion interactions. The influence of anions on the extent of peptide protonation follows the trend ClO4 - ˃ SO4 2- ˃ Br- ˃ Cl- ˃ F- ≈ NO3 - . Solvent effects and complexes with varying number of water ligands were investigated to study the importance of water in enhanced protonation. Aqueous solvent systems and Cr(III) complexes that have at least one bound water ligand in solution must be used for successful increase in the intensity of [M + 2H]2+ , which indicates that water is involved in the mechanism of Cr(III)-induced enhanced protonation. The ESI source design is also important because no enhanced protonation was observed using a Z-spray source. The current results suggest that this Cr(III)-induced effect occurs during the ESI desolvation process.
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Affiliation(s)
- Xinyao Jing
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama
| | - Kyle C Edwards
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama
| | - John B Vincent
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama
| | - Carolyn J Cassady
- Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama
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11
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Zhang Q, Li Z, Wang Y, Zheng Q, Li J. Mass spectrometry for protein sialoglycosylation. MASS SPECTROMETRY REVIEWS 2018; 37:652-680. [PMID: 29228471 DOI: 10.1002/mas.21555] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/17/2017] [Indexed: 06/07/2023]
Abstract
Sialic acids are a family of structurally unique and negatively charged nine-carbon sugars, normally found at the terminal positions of glycan chains on glycoproteins and glycolipids. The glycosylation of proteins is a universal post-translational modification in eukaryotic species and regulates essential biological functions, in which the most common sialic acid is N-acetyl-neuraminic acid (2-keto-5-acetamido-3,5-dideoxy-D-glycero-D-galactononulopyranos-1-onic acid) (Neu5NAc). Because of the properties of sialic acids under general mass spectrometry (MS) conditions, such as instability, ionization discrimination, and mixed adducts, the use of MS in the analysis of protein sialoglycosylation is still challenging. The present review is focused on the application of MS related methodologies to the study of both N- and O-linked sialoglycans. We reviewed MS-based strategies for characterizing sialylation by analyzing intact glycoproteins, proteolytic digested glycopeptides, and released glycans. The review concludes with future perspectives in the field.
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Affiliation(s)
- Qiwei Zhang
- Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, Institute for Interdisciplinary Research, Institute of Environment and Health, School of Chemical and Environmental Engineering, Jianghan University, Wuhan, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, Beijing, China
| | - Zack Li
- School of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Yawei Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Haidian District, Beijing, China
| | - Qi Zheng
- Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, Institute for Interdisciplinary Research, Institute of Environment and Health, School of Chemical and Environmental Engineering, Jianghan University, Wuhan, China
| | - Jianjun Li
- National Research Council Canada, Ottawa, Ontario, Canada
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12
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Yang H, Yang C, Sun T. Characterization of glycopeptides using a stepped higher-energy C-trap dissociation approach on a hybrid quadrupole orbitrap. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1353-1362. [PMID: 29873418 DOI: 10.1002/rcm.8191] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 04/23/2018] [Accepted: 05/28/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Accurate characterization of glycopeptides without a prior glycan cleavage could provide valuable information on site-specific glycosylation, which is critical to reveal the biological functions of protein glycosylation. However, due to the distinct nature of oligosaccharides and ploypeptides, it is usually difficult to effectively fragment glycopeptides in mass spectrometry analysis. METHODS Here we applied a stepped normalized collisional energy (NCE) approach, which is able to combine fragment ions from three different collision energies, in a hybrid quadrupole orbitrap (Q Exactive Plus) to characterize glycopeptides. A systematic evaluation was firstly performed to find optimal NCE values for the fragmentation of glycan chains and peptide backbones from glycopeptides. Guided by the results of the systematic evaluation, the stepped NCE method was optimized and employed to analyze glycopeptides enriched from human serum. RESULTS The stepped NCE approach was found to effectively fragment both the glycan chains and peptide backbones from glycopeptides and record these fragments in a single MS/MS spectrum. In comparison with the regular HCD methods, the stepped NCE method identified more glycopeptides with higher scores from human serum samples. CONCLUSIONS Our studies demonstrate the capability of stepped NCE for the effective characterization of glycopeptides on a large scale.
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Affiliation(s)
- Hong Yang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan, 430070, China
| | - Chenxi Yang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan, 430070, China
| | - Taolei Sun
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan, 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 122 Luoshi Road, Wuhan, 430070, China
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13
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Nshanian M, Lakshmanan R, Chen H, Ogorzalek Loo RR, Loo JA. Enhancing Sensitivity of Liquid Chromatography-Mass Spectrometry of Peptides and Proteins Using Supercharging Agents. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2018; 427:157-164. [PMID: 29750076 PMCID: PMC5937529 DOI: 10.1016/j.ijms.2017.12.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Trifluoroacetic acid (TFA) is often used as a mobile phase modifier to enhance reversed phase chromatographic performance. TFA adjusts solution pH and is an ion-pairing agent, but it is not typically suitable for electrospray ionization-mass spectrometry (ESI-MS) and liquid chromatography/MS (LC/MS) because of its significant signal suppression. Supercharging agents elevate peptide and protein charge states in ESI, increasing tandem MS (MS/MS) efficiency. Here, LC/MS protein supercharging was effected by adding agents to LC mobile phase solvents. Significantly, the ionization suppression generally observed with TFA was, for the most part, rescued by supercharging agents, with improved separation efficiency (higher number of theoretical plates) and lowered detection limits.
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Affiliation(s)
- Michael Nshanian
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095
| | - Rajeswari Lakshmanan
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095
| | - Hao Chen
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Edison Biotechnology Institute, Ohio University, Athens, OH 45701
| | - Rachel R. Ogorzalek Loo
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Molecular Biology Institute, and UCLA/DOE Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, CA 90095
| | - Joseph A. Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, CA 90095
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Molecular Biology Institute, and UCLA/DOE Institute for Genomics and Proteomics, University of California-Los Angeles, Los Angeles, CA 90095
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