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Hackett WE, Chang D, Carvalho L, Zaia J. RAMZIS: a bioinformatic toolkit for rigorous assessment of the alterations to glycoprotein composition that occur during biological processes. BIOINFORMATICS ADVANCES 2024; 4:vbae012. [PMID: 38384861 PMCID: PMC10879752 DOI: 10.1093/bioadv/vbae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/15/2023] [Accepted: 01/22/2024] [Indexed: 02/23/2024]
Abstract
Motivation Glycosylation elaborates the structures and functions of glycoproteins; glycoproteins are common post-translationally modified proteins and are heterogeneous and non-deterministically synthesized as an evolutionarily driven mechanism that elaborates the functions of glycosylated gene products. Glycoproteins, accounting for approximately half of all proteins, require specialized proteomics data analysis methods due to micro- and macro-heterogeneities as a given glycosite can be divided into several glycosylated forms, each of which must be quantified. Sampling of heterogeneous glycopeptides is limited by mass spectrometer speed and sensitivity, resulting in missing values. In conjunction with the low sample size inherent to glycoproteomics, a specialized toolset is needed to determine if observed changes in glycopeptide abundances are biologically significant or due to data quality limitations. Results We developed an R package, Relative Assessment of m/z Identifications by Similarity (RAMZIS), that uses similarity metrics to guide researchers to a more rigorous interpretation of glycoproteomics data. RAMZIS uses a permutation test to generate contextual similarity, which assesses the quality of mass spectral data and outputs a graphical demonstration of the likelihood of finding biologically significant differences in glycosylation abundance datasets. Investigators can assess dataset quality, holistically differentiate glycosites, and identify which glycopeptides are responsible for glycosylation pattern change. RAMZIS is validated by theoretical cases and a proof-of-concept application. RAMZIS enables comparison between datasets too stochastic, small, or sparse for interpolation while acknowledging these issues in its assessment. Using this tool, researchers will be able to rigorously define the role of glycosylation and the changes that occur during biological processes. Availability and implementation https://github.com/WillHackett22/RAMZIS.
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Affiliation(s)
| | - Deborah Chang
- Department of Biochemistry, Boston University, Boston, MA 02215, United States
| | - Luis Carvalho
- Bioinformatics Program, Boston University, Boston, MA 02215, United States
- Department of Mathematics, Boston University, Boston, MA 02215, United States
| | - Joseph Zaia
- Bioinformatics Program, Boston University, Boston, MA 02215, United States
- Department of Biochemistry, Boston University, Boston, MA 02215, United States
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2
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Downs M, Curran J, Zaia J, Sethi MK. Analysis of complex proteoglycans using serial proteolysis and EThcD provides deep N- and O-glycoproteomic coverage. Anal Bioanal Chem 2023; 415:6995-7009. [PMID: 37728749 PMCID: PMC10865727 DOI: 10.1007/s00216-023-04934-x] [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: 05/19/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/21/2023]
Abstract
Proteoglycans are a small but diverse family of proteins that play a wide variety of roles at the cell surface and in the extracellular matrix. In addition to their glycosaminoglycan (GAG) chains, they are N- and O-glycosylated. All of these types of glycosylation are crucial to their function but present a considerable analytical challenge. We describe the combination of serial proteolysis followed by the application of higher-energy collisional dissociation (HCD) and electron transfer/higher-energy collisional dissociation (EThcD) to optimize protein sequence coverage and glycopeptide identification from proteoglycans. In many cases, the use of HCD alone allows the identification of more glycopeptides. However, the localization of glycoforms on multiply glycosylated peptides has remained elusive. We demonstrate the use of EThcD for the confident assignment of glycan compositions on multiply glycosylated peptides. Dense glycosylation on proteoglycans is key to their biological function; thus, developing tools to identify and quantify doubly glycosylated peptides is of interest. Additionally, glycoproteomics searches identify glycopeptides in otherwise poorly covered regions of proteoglycans. The development of these and other analytical tools may permit glycoproteomic similarity comparisons in biological samples.
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Affiliation(s)
- Margaret Downs
- Department of Biochemistry and Cell Biology, Center for Biomedical Mass Spectrometry, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA
| | - Jillian Curran
- Department of Biochemistry and Cell Biology, Center for Biomedical Mass Spectrometry, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA
| | - Joseph Zaia
- Department of Biochemistry and Cell Biology, Center for Biomedical Mass Spectrometry, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
| | - Manveen K Sethi
- Department of Biochemistry and Cell Biology, Center for Biomedical Mass Spectrometry, Boston University Chobanian and Avedisian School of Medicine, Boston, MA, USA.
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3
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Hackett WE, Chang D, Carvalho L, Zaia J. RAMZIS: a bioinformatic toolkit for rigorous assessment of the alterations to glycoprotein structure that occur during biological processes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542895. [PMID: 37398011 PMCID: PMC10312533 DOI: 10.1101/2023.05.30.542895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Motivation Glycosylation elaborates the structures and functions of glycoproteins; glycoproteins are common post-translationally modified proteins and are heterogeneous and non-deterministically syn-thesized as an evolutionarily driven mechanism that elaborates the functions of glycosylated gene products. While glycoproteins account for approximately half of all proteins, their macro- and micro-heterogeneity requires specialized proteomics data analysis methods as a given glycosite can be divided into several glycosylated forms, each of which must be quantified. Sampling of heterogeneous glycopeptides is limited by mass spectrometer speed and sensitivity, resulting in missing values. In conjunction with the low sample size inherent to glycoproteomics, this necessitated specialized statistical metrics to identify if observed changes in glycopeptide abundances are biologically significant or due to data quality limitations. Results We developed an R package, Relative Assessment of m/z Identifications by Similarity (RAMZIS), that uses similarity metrics to guide biomedical researchers to a more rigorous interpretation of glycoproteomics data. RAMZIS uses contextual similarity to assess the quality of mass spectral data and generates graphical output that demonstrates the likelihood of finding biologically significant differences in glycosylation abundance dataset. Investigators can assess dataset quality, holistically differentiate glycosites, and identify which glycopeptides are responsible for glycosylation pattern expression change. Herein RAMZIS approach is validated by theoretical cases and by a proof-of-concept application. RAMZIS enables comparison between datasets too stochastic, small, or sparse for interpolation while acknowledging these issues in its assessment. Using our tool, researchers will be able to rigor-ously define the role of glycosylation and the changes that occur during biological processes.
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Affiliation(s)
| | - Deborah Chang
- Department of Biochemistry, Boston University, One Silber Way, Boston 02215
| | - Luis Carvalho
- Boston University, Bioinformatics Program, One Silber Way, Boston 02215, MA, USA
- Department of Mathematics, Boston University, One Silber Way, Boston 02215
| | - Joseph Zaia
- Boston University, Bioinformatics Program, One Silber Way, Boston 02215, MA, USA
- Department of Biochemistry, Boston University, One Silber Way, Boston 02215
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4
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Baboo S, Diedrich JK, Martínez-Bartolomé S, Wang X, Schiffner T, Groschel B, Schief WR, Paulson JC, Yates JR. DeGlyPHER: Highly sensitive site-specific analysis of N-linked glycans on proteins. Methods Enzymol 2022; 682:137-185. [PMID: 36948700 PMCID: PMC11032187 DOI: 10.1016/bs.mie.2022.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Traditional mass spectrometry-based glycoproteomic approaches have been widely used for site-specific N-glycoform analysis, but a large amount of starting material is needed to obtain sampling that is representative of the vast diversity of N-glycans on glycoproteins. These methods also often include a complicated workflow and very challenging data analysis. These limitations have prevented glycoproteomics from being adapted to high-throughput platforms, and the sensitivity of the analysis is currently inadequate for elucidating N-glycan heterogeneity in clinical samples. Heavily glycosylated spike proteins of enveloped viruses, recombinantly expressed as potential vaccines, are prime targets for glycoproteomic analysis. Since the immunogenicity of spike proteins may be impacted by their glycosylation patterns, site-specific analysis of N-glycoforms provides critical information for vaccine design. Using recombinantly expressed soluble HIV Env trimer, we describe DeGlyPHER, a modification of our previously reported sequential deglycosylation strategy to yield a "single-pot" process. DeGlyPHER is an ultrasensitive, simple, rapid, robust, and efficient approach for site-specific analysis of protein N-glycoforms, that we developed for analysis of limited quantities of glycoproteins.
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Affiliation(s)
- Sabyasachi Baboo
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.
| | - Jolene K Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | | | - Xiaoning Wang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| | - Torben Schiffner
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, United States; IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, United States; The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard, Cambridge, MA, United States
| | - Bettina Groschel
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, United States; IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, United States
| | - William R Schief
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, United States; IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, United States; The Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard, Cambridge, MA, United States
| | - James C Paulson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, United States
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.
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5
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Riley NM, Bertozzi CR. Deciphering O-glycoprotease substrate preferences with O-Pair Search. Mol Omics 2022; 18:908-922. [PMID: 36373229 PMCID: PMC10010678 DOI: 10.1039/d2mo00244b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
O-Glycoproteases are an emerging class of enzymes that selectively digest glycoproteins at positions decorated with specific O-linked glycans. O-Glycoprotease substrates range from any O-glycoprotein (albeit with specific O-glycan modifications) to only glycoproteins harboring specific O-glycosylated sequence motifs, such as those found in mucin domains. Their utility for multiple glycoproteomic applications is driving the search to both discover new O-glycoproteases and to understand how structural features of characterized O-glycoproteases influence their substrate specificities. One challenge of defining O-glycoprotease specificity restraints is the need to characterize O-glycopeptides with site-specific analysis of O-glycosites. Here, we demonstrate how O-Pair Search, a recently developed O-glycopeptide-centric identification platform that enables rapid searches and confident O-glycosite localization, can be used to determine substrate specificities of various O-glycoproteases de novo from LC-MS/MS data of O-glycopeptides. Using secreted protease of C1 esterase inhibitor (StcE) from enterohemorrhagic Escherichia coli and O-endoprotease OgpA from Akkermansia mucinophila, we explore numerous settings that effect O-glycopeptide identification and show how non-specific and semi-tryptic searches of O-glycopeptide data can produce candidate cleavage motifs. These putative motifs can be further used to define new protease cleavage settings that lower search times and improve O-glycopeptide identifications. We use this platform to generate a consensus motif for the recently characterized immunomodulating metalloprotease (IMPa) from Pseudomonas aeruginosa and show that IMPa is a favorable O-glycoprotease for characterizing densely O-glycosylated mucin-domain glycoproteins.
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Affiliation(s)
- Nicholas M Riley
- Department of Chemistry, Sarafan ChEM-H, Stanford University, Stanford, California, USA.
| | - Carolyn R Bertozzi
- Department of Chemistry, Sarafan ChEM-H, Stanford University, Stanford, California, USA.
- Howard Hughes Medical Institute, Stanford, California, USA
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6
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Chang D, Zaia J. Methods to improve quantitative glycoprotein coverage from bottom-up LC-MS data. MASS SPECTROMETRY REVIEWS 2022; 41:922-937. [PMID: 33764573 DOI: 10.1002/mas.21692] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/24/2020] [Accepted: 03/11/2021] [Indexed: 05/18/2023]
Abstract
Advances in mass spectrometry instrumentation, methods development, and bioinformatics have greatly improved the ease and accuracy of site-specific, quantitative glycoproteomics analysis. Data-dependent acquisition is the most popular method for identification and quantification of glycopeptides; however, complete coverage of glycosylation site glycoforms remains elusive with this method. Targeted acquisition methods improve the precision and accuracy of quantification, but at the cost of throughput and discoverability. Data-independent acquisition (DIA) holds great promise for more complete and highly quantitative site-specific glycoproteomics analysis, while maintaining the ability to discover novel glycopeptides without prior knowledge. We review additional features that can be used to increase selectivity and coverage to the DIA workflow: retention time modeling, which would simplify the interpretation of complex tandem mass spectra, and ion mobility separation, which would maximize the sampling of all precursors at a giving chromatographic retention time. The instrumentation and bioinformatics to incorporate these features into glycoproteomics analysis exist. These improvements in quantitative, site-specific analysis will enable researchers to assess glycosylation similarity in related biological systems, answering new questions about the interplay between glycosylation state and biological function.
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Affiliation(s)
- Deborah Chang
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Joseph Zaia
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, USA
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Bouchard G, Garcia Marques FJ, Karacosta LG, Zhang W, Bermudez A, Riley NM, Varma S, Mehl LC, Benson JA, Shrager JB, Bertozzi CR, Pitteri S, Giaccia AJ, Plevritis SK. Multiomics Analysis of Spatially Distinct Stromal Cells Reveals Tumor-Induced O-Glycosylation of the CDK4-pRB Axis in Fibroblasts at the Invasive Tumor Edge. Cancer Res 2022; 82:648-664. [PMID: 34853070 PMCID: PMC9075699 DOI: 10.1158/0008-5472.can-21-1705] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/02/2021] [Accepted: 11/24/2021] [Indexed: 11/16/2022]
Abstract
The invasive leading edge represents a potential gateway for tumor metastasis. The role of fibroblasts from the tumor edge in promoting cancer invasion and metastasis has not been comprehensively elucidated. We hypothesize that cross-talk between tumor and stromal cells within the tumor microenvironment results in activation of key biological pathways depending on their position in the tumor (edge vs. core). Here we highlight phenotypic differences between tumor-adjacent-fibroblasts (TAF) from the invasive edge and tumor core fibroblasts from the tumor core, established from human lung adenocarcinomas. A multiomics approach that includes genomics, proteomics, and O-glycoproteomics was used to characterize cross-talk between TAFs and cancer cells. These analyses showed that O-glycosylation, an essential posttranslational modification resulting from sugar metabolism, alters key biological pathways including the cyclin-dependent kinase 4 (CDK4) and phosphorylated retinoblastoma protein axis in the stroma and indirectly modulates proinvasive features of cancer cells. In summary, the O-glycoproteome represents a new consideration for important biological processes involved in tumor-stroma cross-talk and a potential avenue to improve the anticancer efficacy of CDK4 inhibitors. SIGNIFICANCE A multiomics analysis of spatially distinct fibroblasts establishes the importance of the stromal O-glycoproteome in tumor-stroma interactions at the leading edge and provides potential strategies to improve cancer treatment. See related commentary by De Wever, p. 537.
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Affiliation(s)
- Gina Bouchard
- Department of Biomedical Data Science, Stanford University, Stanford, CA 94305, USA
- Department of Radiology, Canary Center for Cancer Early Detection, Palo Alto CA, 94304, USA
- Department of Radiation Oncology, Stanford, CA 94305, USA
| | | | | | - Weiruo Zhang
- Department of Biomedical Data Science, Stanford University, Stanford, CA 94305, USA
| | - Abel Bermudez
- Department of Radiology, Canary Center for Cancer Early Detection, Palo Alto CA, 94304, USA
| | | | - Sushama Varma
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | | | - Jalen Anthony Benson
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Joseph B Shrager
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | | | - Sharon Pitteri
- Department of Radiology, Canary Center for Cancer Early Detection, Palo Alto CA, 94304, USA
| | - Amato J Giaccia
- Department of Radiation Oncology, Stanford, CA 94305, USA
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Sylvia Katina Plevritis
- Department of Biomedical Data Science, Stanford University, Stanford, CA 94305, USA
- Department of Radiology, Canary Center for Cancer Early Detection, Palo Alto CA, 94304, USA
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8
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Data-independent acquisition mass spectrometry for site-specific glycoproteomics characterization of SARS-CoV-2 spike protein. Anal Bioanal Chem 2021; 413:7305-7318. [PMID: 34635934 PMCID: PMC8505113 DOI: 10.1007/s00216-021-03643-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 11/21/2022]
Abstract
The spike protein of SARS-CoV-2, the virus responsible for the global pandemic of COVID-19, is an abundant, heavily glycosylated surface protein that plays a key role in receptor binding and host cell fusion, and is the focus of all current vaccine development efforts. Variants of concern are now circulating worldwide that exhibit mutations in the spike protein. Protein sequence and glycosylation variations of the spike may affect viral fitness, antigenicity, and immune evasion. Global surveillance of the virus currently involves genome sequencing, but tracking emerging variants should include quantitative measurement of changes in site-specific glycosylation as well. In this work, we used data-dependent acquisition (DDA) and data-independent acquisition (DIA) mass spectrometry to quantitatively characterize the five N-linked glycosylation sites of the glycoprotein standard alpha-1-acid glycoprotein (AGP), as well as the 22 sites of the SARS-CoV-2 spike protein. We found that DIA compared favorably to DDA in sensitivity, resulting in more assignments of low-abundance glycopeptides. However, the reproducibility across replicates of DIA-identified glycopeptides was lower than that of DDA, possibly due to the difficulty of reliably assigning low-abundance glycopeptides confidently. The differences in the data acquired between the two methods suggest that DIA outperforms DDA in terms of glycoprotein coverage but that overall performance is a balance of sensitivity, selectivity, and statistical confidence in glycoproteomics. We assert that these analytical and bioinformatics methods for assigning and quantifying glycoforms would benefit the process of tracking viral variants as well as for vaccine development.
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Schulze S, Igiraneza AB, Kösters M, Leufken J, Leidel SA, Garcia BA, Fufezan C, Pohlschroder M. Enhancing Open Modification Searches via a Combined Approach Facilitated by Ursgal. J Proteome Res 2021; 20:1986-1996. [PMID: 33514075 DOI: 10.1021/acs.jproteome.0c00799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The identification of peptide sequences and their post-translational modifications (PTMs) is a crucial step in the analysis of bottom-up proteomics data. The recent development of open modification search (OMS) engines allows virtually all PTMs to be searched for. This not only increases the number of spectra that can be matched to peptides but also greatly advances the understanding of the biological roles of PTMs through the identification, and the thereby facilitated quantification, of peptidoforms (peptide sequences and their potential PTMs). Whereas the benefits of combining results from multiple protein database search engines have been previously established, similar approaches for OMS results have been missing so far. Here we compare and combine results from three different OMS engines, demonstrating an increase in peptide spectrum matches of 8-18%. The unification of search results furthermore allows for the combined downstream processing of search results, including the mapping to potential PTMs. Finally, we test for the ability of OMS engines to identify glycosylated peptides. The implementation of these engines in the Python framework Ursgal facilitates the straightforward application of the OMS with unified parameters and results files, thereby enabling yet unmatched high-throughput, large-scale data analysis.
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Affiliation(s)
- Stefan Schulze
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Aime Bienfait Igiraneza
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Manuel Kösters
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Johannes Leufken
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Sebastian A Leidel
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Christian Fufezan
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, 69120 Heidelberg, Germany
| | - Mechthild Pohlschroder
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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10
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Hackett WE, Zaia J. Calculating Glycoprotein Similarities From Mass Spectrometric Data. Mol Cell Proteomics 2021; 20:100028. [PMID: 32883803 PMCID: PMC8724611 DOI: 10.1074/mcp.r120.002223] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/24/2020] [Accepted: 09/03/2020] [Indexed: 12/23/2022] Open
Abstract
Complex protein glycosylation occurs through biosynthetic steps in the secretory pathway that create macro- and microheterogeneity of structure and function. Required for all life forms, glycosylation diversifies and adapts protein interactions with binding partners that underpin interactions at cell surfaces and pericellular and extracellular environments. Because these biological effects arise from heterogeneity of structure and function, it is necessary to measure their changes as part of the quest to understand nature. Quite often, however, the assumption behind proteomics that posttranslational modifications are discrete additions that can be modeled using the genome as a template does not apply to protein glycosylation. Rather, it is necessary to quantify the glycosylation distribution at each glycosite and to aggregate this information into a population of mature glycoproteins that exist in a given biological system. To date, mass spectrometric methods for assigning singly glycosylated peptides are well-established. But it is necessary to quantify glycosylation heterogeneity accurately in order to gauge the alterations that occur during biological processes. The task is to quantify the glycosylated peptide forms as accurately as possible and then apply appropriate bioinformatics algorithms to the calculation of micro- and macro-similarities. In this review, we summarize current approaches for protein quantification as they apply to this glycoprotein similarity problem.
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Affiliation(s)
- William E Hackett
- Bioinformatics Program, Boston University, Boston, Massachusetts, USA
| | - Joseph Zaia
- Bioinformatics Program, Boston University, Boston, Massachusetts, USA; Department of Biochemistry, Boston University, Boston, Massachusetts, USA.
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11
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Lisacek F, Alagesan K, Hayes C, Lippold S, de Haan N. Bioinformatics in Immunoglobulin Glycosylation Analysis. EXPERIENTIA SUPPLEMENTUM (2012) 2021; 112:205-233. [PMID: 34687011 DOI: 10.1007/978-3-030-76912-3_6] [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: 06/13/2023]
Abstract
Analytical methods developed for studying immunoglobulin glycosylation rely heavily on software tailored for this purpose. Many of these tools are now used in high-throughput settings, especially for the glycomic characterization of IgG. A collection of these tools, and the databases they rely on, are presented in this chapter. Specific applications are detailed in examples of immunoglobulin glycomics and glycoproteomics data processing workflows. The results obtained in the glycoproteomics workflow are emphasized with the use of dedicated visualizing tools. These tools enable the user to highlight glycan properties and their differential expression.
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Affiliation(s)
- Frédérique Lisacek
- Proteome Informatics Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland.
- Computer Science Department, University of Geneva, Geneva, Switzerland.
- Section of Biology, University of Geneva, Geneva, Switzerland.
| | | | - Catherine Hayes
- Proteome Informatics Group, SIB Swiss Institute of Bioinformatics, Geneva, Switzerland
- Computer Science Department, University of Geneva, Geneva, Switzerland
| | - Steffen Lippold
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Noortje de Haan
- Copenhagen Center for Glycomics, University of Copenhagen, Copenhagen, Denmark
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12
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Abstract
Glycoproteomics is unquestionably on the rise and its current development benefits from past experience in proteomics, in particular when attending to bioinformatics needs. An extensive range of software solutions is available, but the reproducibility of mass spectrometry data processing remains challenging. One of the key issues in running automated glycopeptide identification software is the selection of a reference glycan composition file. The default choices are often too broad, and a fastidious literature search to properly target this selection can be avoided. This chapter suggests the use of GlyConnect Compozitor to collect relevant information on glycosylation in a given tissue or cell line and shape an appropriate glycan composition set that can be input in the majority of search engines accommodating user-defined compositions.
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13
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Lu L, Riley NM, Shortreed MR, Bertozzi CR, Smith LM. O-Pair Search with MetaMorpheus for O-glycopeptide characterization. Nat Methods 2020. [PMID: 33106676 DOI: 10.1101/2020.05.18.102327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
We report O-Pair Search, an approach to identify O-glycopeptides and localize O-glycosites. Using paired collision- and electron-based dissociation spectra, O-Pair Search identifies O-glycopeptides via an ion-indexed open modification search and localizes O-glycosites using graph theory and probability-based localization. O-Pair Search reduces search times more than 2,000-fold compared to current O-glycopeptide processing software, while defining O-glycosite localization confidence levels and generating more O-glycopeptide identifications. Beyond the mucin-type O-glycopeptides discussed here, O-Pair Search also accepts user-defined glycan databases, making it compatible with many types of O-glycosylation. O-Pair Search is freely available within the open-source MetaMorpheus platform at https://github.com/smith-chem-wisc/MetaMorpheus .
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Affiliation(s)
- Lei Lu
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
| | - Nicholas M Riley
- Department of Chemistry, University of Stanford, Stanford, CA, USA
| | | | - Carolyn R Bertozzi
- Department of Chemistry, University of Stanford, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin, Madison, WI, USA.
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14
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Lu L, Riley NM, Shortreed MR, Bertozzi CR, Smith LM. O-Pair Search with MetaMorpheus for O-glycopeptide characterization. Nat Methods 2020; 17:1133-1138. [PMID: 33106676 PMCID: PMC7606753 DOI: 10.1038/s41592-020-00985-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 09/21/2020] [Indexed: 11/23/2022]
Abstract
We report O-Pair Search, a new approach to identify O-glycopeptides and localize O-glycosites. Using paired collision- and electron-based dissociation spectra, O-Pair Search identifies O-glycopeptides using an ion-indexed open modification search and localizes O-glycosites using graph theory and probability-based localization. O-Pair Search reduces search times more than 2,000-fold compared to current O-glycopeptide processing software, while defining O-glycosite localization confidence levels and generating more O-glycopeptide identifications. Beyond the mucin-type O-glycopeptides discussed here, O-Pair Search also accepts user-defined glycan databases, making it compatible with many types of O-glycosylation. O-Pair Search is freely available within the open-source MetaMorpheus platform at https://github.com/smith-chem-wisc/MetaMorpheus.
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Affiliation(s)
- Lei Lu
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
| | - Nicholas M Riley
- Department of Chemistry, University of Stanford, Stanford, CA, USA
| | | | - Carolyn R Bertozzi
- Department of Chemistry, University of Stanford, Stanford, CA, USA.,Howard Hughes Medical Institute, Stanford, CA, USA
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin, Madison, WI, USA.
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15
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Ahmad Izaham AR, Scott NE. Open Database Searching Enables the Identification and Comparison of Bacterial Glycoproteomes without Defining Glycan Compositions Prior to Searching. Mol Cell Proteomics 2020. [PMID: 32576591 DOI: 10.1101/2020.04.21.052845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023] Open
Abstract
Mass spectrometry has become an indispensable tool for the characterization of glycosylation across biological systems. Our ability to generate rich fragmentation of glycopeptides has dramatically improved over the last decade yet our informatic approaches still lag behind. Although glycoproteomic informatics approaches using glycan databases have attracted considerable attention, database independent approaches have not. This has significantly limited high throughput studies of unusual or atypical glycosylation events such as those observed in bacteria. As such, computational approaches to examine bacterial glycosylation and identify chemically diverse glycans are desperately needed. Here we describe the use of wide-tolerance (up to 2000 Da) open searching as a means to rapidly examine bacterial glycoproteomes. We benchmarked this approach using N-linked glycopeptides of Campylobacter fetus subsp. fetus as well as O-linked glycopeptides of Acinetobacter baumannii and Burkholderia cenocepacia revealing glycopeptides modified with a range of glycans can be readily identified without defining the glycan masses before database searching. Using this approach, we demonstrate how wide tolerance searching can be used to compare glycan use across bacterial species by examining the glycoproteomes of eight Burkholderia species (B. pseudomallei; B. multivorans; B. dolosa; B. humptydooensis; B. ubonensis, B. anthina; B. diffusa; B. pseudomultivorans). Finally, we demonstrate how open searching enables the identification of low frequency glycoforms based on shared modified peptides sequences. Combined, these results show that open searching is a robust computational approach for the determination of glycan diversity within bacterial proteomes.
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Affiliation(s)
- Ameera Raudah Ahmad Izaham
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.
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16
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Ahmad Izaham AR, Scott NE. Open Database Searching Enables the Identification and Comparison of Bacterial Glycoproteomes without Defining Glycan Compositions Prior to Searching. Mol Cell Proteomics 2020; 19:1561-1574. [PMID: 32576591 PMCID: PMC8143609 DOI: 10.1074/mcp.tir120.002100] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/27/2020] [Indexed: 12/23/2022] Open
Abstract
Mass spectrometry has become an indispensable tool for the characterization of glycosylation across biological systems. Our ability to generate rich fragmentation of glycopeptides has dramatically improved over the last decade yet our informatic approaches still lag behind. Although glycoproteomic informatics approaches using glycan databases have attracted considerable attention, database independent approaches have not. This has significantly limited high throughput studies of unusual or atypical glycosylation events such as those observed in bacteria. As such, computational approaches to examine bacterial glycosylation and identify chemically diverse glycans are desperately needed. Here we describe the use of wide-tolerance (up to 2000 Da) open searching as a means to rapidly examine bacterial glycoproteomes. We benchmarked this approach using N-linked glycopeptides of Campylobacter fetus subsp. fetus as well as O-linked glycopeptides of Acinetobacter baumannii and Burkholderia cenocepacia revealing glycopeptides modified with a range of glycans can be readily identified without defining the glycan masses before database searching. Using this approach, we demonstrate how wide tolerance searching can be used to compare glycan use across bacterial species by examining the glycoproteomes of eight Burkholderia species (B. pseudomallei; B. multivorans; B. dolosa; B. humptydooensis; B. ubonensis, B. anthina; B. diffusa; B. pseudomultivorans). Finally, we demonstrate how open searching enables the identification of low frequency glycoforms based on shared modified peptides sequences. Combined, these results show that open searching is a robust computational approach for the determination of glycan diversity within bacterial proteomes.
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Affiliation(s)
- Ameera Raudah Ahmad Izaham
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia.
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17
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Riley N, Malaker SA, Driessen MD, Bertozzi CR. Optimal Dissociation Methods Differ for N- and O-Glycopeptides. J Proteome Res 2020; 19:3286-3301. [PMID: 32500713 PMCID: PMC7425838 DOI: 10.1021/acs.jproteome.0c00218] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Indexed: 01/29/2023]
Abstract
Site-specific characterization of glycosylation requires intact glycopeptide analysis, and recent efforts have focused on how to best interrogate glycopeptides using tandem mass spectrometry (MS/MS). Beam-type collisional activation, i.e., higher-energy collisional dissociation (HCD), has been a valuable approach, but stepped collision energy HCD (sceHCD) and electron transfer dissociation with HCD supplemental activation (EThcD) have emerged as potentially more suitable alternatives. Both sceHCD and EThcD have been used with success in large-scale glycoproteomic experiments, but they each incur some degree of compromise. Most progress has occurred in the area of N-glycoproteomics. There is growing interest in extending this progress to O-glycoproteomics, which necessitates comparisons of method performance for the two classes of glycopeptides. Here, we systematically explore the advantages and disadvantages of conventional HCD, sceHCD, ETD, and EThcD for intact glycopeptide analysis and determine their suitability for both N- and O-glycoproteomic applications. For N-glycopeptides, HCD and sceHCD generate similar numbers of identifications, although sceHCD generally provides higher quality spectra. Both significantly outperform EThcD methods in terms of identifications, indicating that ETD-based methods are not required for routine N-glycoproteomics even if they can generate higher quality spectra. Conversely, ETD-based methods, especially EThcD, are indispensable for site-specific analyses of O-glycopeptides. Our data show that O-glycopeptides cannot be robustly characterized with HCD-centric methods that are sufficient for N-glycopeptides, and glycoproteomic methods aiming to characterize O-glycopeptides must be constructed accordingly.
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Affiliation(s)
- Nicholas
M. Riley
- Department
of Chemistry, Stanford University, Stanford, California 94305-6104, United States
| | - Stacy A. Malaker
- Department
of Chemistry, Stanford University, Stanford, California 94305-6104, United States
| | - Marc D. Driessen
- Department
of Chemistry, Stanford University, Stanford, California 94305-6104, United States
| | - Carolyn R. Bertozzi
- Department
of Chemistry, Stanford University, Stanford, California 94305-6104, United States
- Howard
Hughes Medical Institute, Stanford, California 94305-6104, United States
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18
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Taherzadeh G, Dehzangi A, Golchin M, Zhou Y, Campbell MP. SPRINT-Gly: predicting N- and O-linked glycosylation sites of human and mouse proteins by using sequence and predicted structural properties. Bioinformatics 2020; 35:4140-4146. [PMID: 30903686 DOI: 10.1093/bioinformatics/btz215] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/03/2019] [Accepted: 03/21/2019] [Indexed: 12/19/2022] Open
Abstract
MOTIVATION Protein glycosylation is one of the most abundant post-translational modifications that plays an important role in immune responses, intercellular signaling, inflammation and host-pathogen interactions. However, due to the poor ionization efficiency and microheterogeneity of glycopeptides identifying glycosylation sites is a challenging task, and there is a demand for computational methods. Here, we constructed the largest dataset of human and mouse glycosylation sites to train deep learning neural networks and support vector machine classifiers to predict N-/O-linked glycosylation sites, respectively. RESULTS The method, called SPRINT-Gly, achieved consistent results between ten-fold cross validation and independent test for predicting human and mouse glycosylation sites. For N-glycosylation, a mouse-trained model performs equally well in human glycoproteins and vice versa, however, due to significant differences in O-linked sites separate models were generated. Overall, SPRINT-Gly is 18% and 50% higher in Matthews correlation coefficient than the next best method compared in N-linked and O-linked sites, respectively. This improved performance is due to the inclusion of novel structure and sequence-based features. AVAILABILITY AND IMPLEMENTATION http://sparks-lab.org/server/SPRINT-Gly/. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Ghazaleh Taherzadeh
- School of Information and Communication Technology, Griffith University, Gold Coast, QLD, Australia
| | - Abdollah Dehzangi
- Department of Computer Science, Morgan State University, Baltimore, MD, USA
| | - Maryam Golchin
- School of Information and Communication Technology, Griffith University, Gold Coast, QLD, Australia
| | - Yaoqi Zhou
- School of Information and Communication Technology, Griffith University, Gold Coast, QLD, Australia.,Institute for Glycomics, Griffith University, Parklands Drive, Gold Coast, QLD, Australia
| | - Matthew P Campbell
- Institute for Glycomics, Griffith University, Parklands Drive, Gold Coast, QLD, Australia
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19
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Klein JA, Zaia J. A Perspective on the Confident Comparison of Glycoprotein Site-Specific Glycosylation in Sample Cohorts. Biochemistry 2019; 59:3089-3097. [PMID: 31833756 DOI: 10.1021/acs.biochem.9b00730] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein glycosylation, resulting from glycosyl transferase reactions under complex control in the secretory pathway, consists of a distribution of related glycoforms at each glycosylation site. Because the biosynthetic substrate concentration and transport rates depend on architecture and other aspects of cellular phenotypes, site-specific glycosylation cannot be predicted accurately from genomic, transcriptomic, or proteomic information. Rather, it is necessary to quantify glycosylation at each protein site and how this changes among a sample cohort to provide information about disease mechanisms. At present, mature mass spectrometry-based methods allow for qualitative assignment of the glycan composition and glycosylation site of singly glycosylated proteolytic peptides. To make such quantitative comparisons, it is necessary to sample the glycosylation distribution with sufficient coverage and accuracy for confident assessment of the glycosylation changes that occur in the biological cohort. In this Perspective, we discuss the unmet needs for mass spectrometry acquisition methods and bioinformatics for the confident comparison of protein site-specific glycosylation among sample cohorts.
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20
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Chang D, Zaia J. Why Glycosylation Matters in Building a Better Flu Vaccine. Mol Cell Proteomics 2019; 18:2348-2358. [PMID: 31604803 PMCID: PMC6885707 DOI: 10.1074/mcp.r119.001491] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/18/2019] [Indexed: 12/20/2022] Open
Abstract
Low vaccine efficacy against seasonal influenza A virus (IAV) stems from the ability of the virus to evade existing immunity while maintaining fitness. Although most potent neutralizing antibodies bind antigenic sites on the globular head domain of the IAV envelope glycoprotein hemagglutinin (HA), the error-prone IAV polymerase enables rapid evolution of key antigenic sites, resulting in immune escape. Significantly, the appearance of new N-glycosylation consensus sequences (sequons, NXT/NXS, rarely NXC) on the HA globular domain occurs among the more prevalent mutations as an IAV strain undergoes antigenic drift. The appearance of new glycosylation shields underlying amino acid residues from antibody contact, tunes receptor specificity, and balances receptor avidity with virion escape, all of which help maintain viral propagation through seasonal mutations. The World Health Organization selects seasonal vaccine strains based on information from surveillance, laboratory, and clinical observations. Although the genetic sequences are known, mature glycosylated structures of circulating strains are not defined. In this review, we summarize mass spectrometric methods for quantifying site-specific glycosylation in IAV strains and compare the evolution of IAV glycosylation to that of human immunodeficiency virus. We argue that the determination of site-specific glycosylation of IAV glycoproteins would enable development of vaccines that take advantage of glycosylation-dependent mechanisms whereby virus glycoproteins are processed by antigen presenting cells.
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Affiliation(s)
- Deborah Chang
- Dept. of Biochemistry, Boston University School of Medicine, Boston, MA 02118
| | - Joseph Zaia
- Dept. of Biochemistry, Boston University School of Medicine, Boston, MA 02118.
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21
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Raghunathan R, Sethi MK, Zaia J. On-slide tissue digestion for mass spectrometry based glycomic and proteomic profiling. MethodsX 2019; 6:2329-2347. [PMID: 31660297 PMCID: PMC6807300 DOI: 10.1016/j.mex.2019.09.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/23/2019] [Indexed: 12/11/2022] Open
Abstract
We describe a protocol for glycomic and proteomic profiling that uses serial enzyme digestions from the surface of fresh frozen or fixed tissue slides. The abundances of the extracted glycans and peptides are determined using liquid chromatography-mass spectrometry. In a typical experiment, our method quantifies 14 heparan sulfate disaccharides, 11 chondroitin sulfate disaccharides, 50 N-glycan compositions and approximately 1200 proteins from a 1.8 mm circle, on the surface of a fresh frozen tissue slide from rat brain. Each enzymatic digestion is incubated overnight with direct application of enzyme on the tissue surface. Overall, the sample preparation process for multiple tissue slides takes a day per biomolecule class. This protocol saves time by simultaneous digestion of large N-glycans and small HS disaccharides and subsequent separation using size exclusion chromatography. Compared to wet tissue analysis, this method requires less time by a factor of two. By comparison, MALDI-imaging provides higher spatial resolution of glycans and proteins but lower depth of coverage. MALDI dissociates fragile glycan substituents including sulfates and is not recommended for analysis of glycosaminoglycans (GAGs).
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Affiliation(s)
- Rekha Raghunathan
- Boston University, Molecular and Translational Medicine, Boston, 02118, USA
| | - Manveen K Sethi
- Boston University, Dept. of Biochemistry, Boston, 02118, USA
| | - Joseph Zaia
- Boston University, Molecular and Translational Medicine, Boston, 02118, USA.,Boston University, Dept. of Biochemistry, Boston, 02118, USA
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22
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Capturing site-specific heterogeneity with large-scale N-glycoproteome analysis. Nat Commun 2019; 10:1311. [PMID: 30899004 PMCID: PMC6428843 DOI: 10.1038/s41467-019-09222-w] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 02/19/2019] [Indexed: 11/08/2022] Open
Abstract
Protein glycosylation is a highly important, yet poorly understood protein post-translational modification. Thousands of possible glycan structures and compositions create potential for tremendous site heterogeneity. A lack of suitable analytical methods for large-scale analyses of intact glycopeptides has limited our abilities both to address the degree of heterogeneity across the glycoproteome and to understand how this contributes biologically to complex systems. Here we show that N-glycoproteome site-specific microheterogeneity can be captured via large-scale glycopeptide profiling methods enabled by activated ion electron transfer dissociation (AI-ETD), ultimately characterizing 1,545 N-glycosites (>5,600 unique N-glycopeptides) from mouse brain tissue. Our data reveal that N-glycosylation profiles can differ between subcellular regions and structural domains and that N-glycosite heterogeneity manifests in several different forms, including dramatic differences in glycosites on the same protein. Moreover, we use this large-scale glycoproteomic dataset to develop several visualizations that will prove useful for analyzing intact glycopeptides in future studies. Mass spectrometry facilitates large-scale glycosylation profiling but in-depth analysis of intact glycopeptides is still challenging. Here, the authors show that activated ion electron transfer dissociation is suitable for glycopeptide fragmentation and improves glycoproteome coverage.
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23
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Fu D, Liu Y, Shen A, Xiao Y, Yu L, Liang X. Preparation of glutathione-functionalized zwitterionic silica material for efficient enrichment of sialylated N-glycopeptides. Anal Bioanal Chem 2019; 411:4131-4140. [DOI: 10.1007/s00216-019-01661-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/28/2019] [Accepted: 02/01/2019] [Indexed: 12/13/2022]
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24
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Ruhaak LR, Xu G, Li Q, Goonatilleke E, Lebrilla CB. Mass Spectrometry Approaches to Glycomic and Glycoproteomic Analyses. Chem Rev 2018; 118:7886-7930. [PMID: 29553244 PMCID: PMC7757723 DOI: 10.1021/acs.chemrev.7b00732] [Citation(s) in RCA: 253] [Impact Index Per Article: 42.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Glycomic and glycoproteomic analyses involve the characterization of oligosaccharides (glycans) conjugated to proteins. Glycans are produced through a complicated nontemplate driven process involving the competition of enzymes that extend the nascent chain. The large diversity of structures, the variations in polarity of the individual saccharide residues, and the poor ionization efficiencies of glycans all conspire to make the analysis arguably much more difficult than any other biopolymer. Furthermore, the large number of glycoforms associated with a specific protein site makes it more difficult to characterize than any post-translational modification. Nonetheless, there have been significant progress, and advanced separation and mass spectrometry methods have been at its center and the main reason for the progress. While glycomic and glycoproteomic analyses are still typically available only through highly specialized laboratories, new software and workflow is making it more accessible. This review focuses on the role of mass spectrometry and separation methods in advancing glycomic and glycoproteomic analyses. It describes the current state of the field and progress toward making it more available to the larger scientific community.
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Affiliation(s)
- L. Renee Ruhaak
- Department of Clinical Chemistry and Laboratory Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Gege Xu
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Qiongyu Li
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Elisha Goonatilleke
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Carlito B. Lebrilla
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
- Department of Biochemistry and Molecular Medicine, University of California, Davis, Davis, California 95616, United States
- Foods for Health Institute, University of California, Davis, Davis, California 95616, United States
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25
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Raghunathan R, Polinski NK, Klein JA, Hogan JD, Shao C, Khatri K, Leon D, McComb ME, Manfredsson FP, Sortwell CE, Zaia J. Glycomic and Proteomic Changes in Aging Brain Nigrostriatal Pathway. Mol Cell Proteomics 2018; 17:1778-1787. [PMID: 29915149 PMCID: PMC6126385 DOI: 10.1074/mcp.ra118.000680] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 06/12/2018] [Indexed: 12/19/2022] Open
Abstract
Parkinson's disease (PD) is a neurological disorder characterized by the progressive loss of functional dopaminergic neurons in the nigrostriatal pathway in the brain. Although current treatments provide only symptomatic relief, gene therapy has the potential to slow or halt the degeneration of nigrostriatal dopamine neurons in PD patients. Adeno-associated viruses (AAV) are vectors of choice in gene therapy because of their well-characterized safety and efficacy profiles; however, although gene therapy has been successful in preclinical models of the disease, clinical trials in humans have failed to demonstrate efficacy. Significantly, all primary AAV receptors of the virus are glycans. We thus hypothesize that age related changes in glycan receptors of heparan sulfate (HS) proteoglycans (receptor for rAAV2), and/or N-glycans with terminal galactose (receptor for rAAV9) results in poor adeno-associated virus binding in either the striatum or substantia nigra, or both, affecting transduction and gene delivery. To test our hypothesis we analyzed the striatum and substantia nigra for changes in HS, N-glycans and proteomic signatures in young versus aged rat brain striatum and substantia nigra. We observed different brain region-specific HS disaccharide profiles in aged compared with young adult rats for brain region-specific profiles in striatum versus substantia nigra. We observed brain region- and age-specific N-glycan compositional profiles with respect to the terminal galactose units that serve as receptors for AAV9. We also observed brain region-specific changes in protein expression in the aging nigrostriatal pathway. These studies provide insight into age- and brain region-specific changes in glycan receptors and proteome that will inform design of improved viral vectors for Parkinson Disease (PD) gene therapy.
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Affiliation(s)
- Rekha Raghunathan
- From the ‡Department of Molecular and Translational Medicine, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts
| | - Nicole K Polinski
- ‖Department of Translational Science and Molecular Medicine, Michigan State University
| | - Joshua A Klein
- ¶Bioinformatics Program, Boston University, Boston, Massachusetts
| | - John D Hogan
- ¶Bioinformatics Program, Boston University, Boston, Massachusetts
| | - Chun Shao
- §Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts
| | - Kshitij Khatri
- §Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts
| | - Deborah Leon
- §Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts
| | - Mark E McComb
- §Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts
| | - Fredric P Manfredsson
- ‖Department of Translational Science and Molecular Medicine, Michigan State University
| | - Caryl E Sortwell
- ‖Department of Translational Science and Molecular Medicine, Michigan State University
| | - Joseph Zaia
- From the ‡Department of Molecular and Translational Medicine, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts;
- §Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University Medical Campus, Boston, Massachusetts
- ¶Bioinformatics Program, Boston University, Boston, Massachusetts
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26
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Khatri K, Pu Y, Klein JA, Wei J, Costello CE, Lin C, Zaia J. Comparison of Collisional and Electron-Based Dissociation Modes for Middle-Down Analysis of Multiply Glycosylated Peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1075-1085. [PMID: 29663256 PMCID: PMC6004259 DOI: 10.1007/s13361-018-1909-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 01/09/2018] [Accepted: 01/29/2018] [Indexed: 05/12/2023]
Abstract
Analysis of singly glycosylated peptides has evolved to a point where large-scale LC-MS analyses can be performed at almost the same scale as proteomics experiments. While collisionally activated dissociation (CAD) remains the mainstay of bottom-up analyses, it performs poorly for the middle-down analysis of multiply glycosylated peptides. With improvements in instrumentation, electron-activated dissociation (ExD) modes are becoming increasingly prevalent for proteomics experiments and for the analysis of fragile modifications such as glycosylation. While these methods have been applied for glycopeptide analysis in isolated studies, an organized effort to compare their efficiencies, particularly for analysis of multiply glycosylated peptides (termed here middle-down glycoproteomics), has not been made. We therefore compared the performance of different ExD modes for middle-down glycopeptide analyses. We identified key features among the different dissociation modes and show that increased electron energy and supplemental activation provide the most useful data for middle-down glycopeptide analysis. Graphical Abstract.
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Affiliation(s)
- Kshitij Khatri
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, USA
| | - Yi Pu
- Department of Chemistry, Boston University, Boston, MA, USA
| | - Joshua A Klein
- Program in Bioinformatics, Boston University, Boston, MA, USA
| | - Juan Wei
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, USA
| | - Catherine E Costello
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
| | - Cheng Lin
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, USA.
- Boston University Medical Campus, 670 Albany St., Suite 504, Boston, MA, 02118, USA.
| | - Joseph Zaia
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University School of Medicine, Boston, MA, USA.
- Program in Bioinformatics, Boston University, Boston, MA, USA.
- Boston University Medical Campus, 670 Albany St., Suite 504, Boston, MA, 02118, USA.
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27
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Xiao H, Hwang JE, Wu R. Mass spectrometric analysis of the N-glycoproteome in statin-treated liver cells with two lectin-independent chemical enrichment methods. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2018; 429:66-75. [PMID: 30147434 PMCID: PMC6103449 DOI: 10.1016/j.ijms.2017.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Protein N-glycosylation is essential for mammalian cell survival and is well-known to be involved in many biological processes. Aberrant glycosylation is directly related to human disease including cancer and infectious diseases. Global analysis of protein N-glycosylation will allow a better understanding of protein functions and cellular activities. Mass spectrometry (MS)-based proteomics provides a unique opportunity to site-specifically characterize protein glycosylation on a large scale. Due to the complexity of biological samples, effective enrichment methods are critical prior to MS analysis. Here, we compared two lectin-independent methods to enrich glycopeptides for the global analysis of protein N-glycosylation by MS. The first boronic acid-based enrichment (BA) method benefits from the universal and reversible interactions between boronic acid and sugars; the other method utilizes metabolic labeling and click chemistry (MC) to incorporate a chemical handle into glycoproteins for future affinity enrichment. We comprehensively compared the performance of the two methods in the identification and quantification of glycoproteins in statin-treated liver cells. Based on the current results, the BA method is more universal in enriching glycopeptides, while with the MC method, cell surface glycoproteins were highly enriched, and the quantification results appear to be more dynamic because only the newly-synthesized glycoproteins were analyzed. In addition, we normalized the glycosylation site ratios by the corresponding parent protein ratios to reflect the real modification changes. In combination with MS-based proteomics, effective enrichment methods will vertically advance protein glycosylation research.
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Affiliation(s)
- Haopeng Xiao
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Ju Eun Hwang
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Ronghu Wu
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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28
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Klein JA, Meng L, Zaia J. Deep Sequencing of Complex Proteoglycans: A Novel Strategy for High Coverage and Site-specific Identification of Glycosaminoglycan-linked Peptides. Mol Cell Proteomics 2018; 17:1578-1590. [PMID: 29773674 DOI: 10.1074/mcp.ra118.000766] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/09/2018] [Indexed: 12/17/2022] Open
Abstract
Proteoglycans are distributed in all animal tissues and play critical, multifaceted, physiological roles. Expressed in a spatially and temporally regulated manner, these molecules regulate interactions among growth factors and cell surface receptors and play key roles in basement membranes and other extracellular matrices. Because of the high degree of glycosylation by glycosaminoglycan (GAG), N-glycan and mucin-type O-glycan classes, the peptide sequence coverage of complex proteoglycans is revealed poorly by standard mass spectrometry-based proteomics methods. As a result, there is little information concerning how proteoglycan site specific glycosylation changes during normal and pathological processes. Here, we developed a workflow to improve sequence coverage and identification of glycosylated peptides in proteoglycans. We applied this workflow to the small leucine-rich proteoglycan decorin and three hyalectan proteoglycans: neurocan, brevican, and aggrecan.We characterized glycosylation of these proteoglycans using LC-MS methods easily implemented on instruments widely used in proteomics laboratories. For decorin, we assigned the linker-glycosite and three N-glycosylation sites. For neurocan and brevican, we identified densely glycosylated mucin-like regions in the extended domains. For aggrecan, we identified 50 linker-glycosites and mucin-type O-glycosites in the extended region and N-glycosites in the globular domains, many of which are novel and have not been observed previously. Most importantly, we demonstrate an LC-MS and bioinformatics approach that will enable routine analysis of proteoglycan glycosylation from biological samples to assess their role in pathophysiology.
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Affiliation(s)
- Joshua A Klein
- From the ‡Department of Biochemistry, Center for Biomedical Mass Spectrometry.,§Bioinformatics Program Boston University, Boston, Massachusetts 02118
| | - Le Meng
- From the ‡Department of Biochemistry, Center for Biomedical Mass Spectrometry
| | - Joseph Zaia
- From the ‡Department of Biochemistry, Center for Biomedical Mass Spectrometry; .,§Bioinformatics Program Boston University, Boston, Massachusetts 02118
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29
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Cao L, Diedrich JK, Ma Y, Wang N, Pauthner M, Park SKR, Delahunty CM, McLellan JS, Burton DR, Yates JR, Paulson JC. Global site-specific analysis of glycoprotein N-glycan processing. Nat Protoc 2018; 13:1196-1212. [PMID: 29725121 PMCID: PMC5941933 DOI: 10.1038/nprot.2018.024] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
N-glycans contribute to the folding, stability and functions of the proteins they decorate. They are produced by transfer of the glycan precursor to the sequon Asn-X-Thr/Ser, followed by enzymatic trimming to a high-mannose-type core and sequential addition of monosaccharides to generate complex-type and hybrid glycans. This process, mediated by the concerted action of multiple enzymes, produces a mixture of related glycoforms at each glycosite, making analysis of glycosylation difficult. To address this analytical challenge, we developed a robust semiquantitative mass spectrometry (MS)-based method that determines the degree of glycan occupancy at each glycosite and the proportion of N-glycans processed from high-mannose type to complex type. It is applicable to virtually any glycoprotein, and a complete analysis can be conducted with 30 μg of protein. Here, we provide a detailed description of the method that includes procedures for (i) proteolytic digestion of glycoprotein(s) with specific and nonspecific proteases; (ii) denaturation of proteases by heating; (iii) sequential treatment of the glycopeptide mixture with two endoglycosidases, Endo H and PNGase F, to create unique mass signatures for the three glycosylation states; (iv) LC-MS/MS analysis; and (v) data analysis for identification and quantitation of peptides for the three glycosylation states. Full coverage of site-specific glycosylation of glycoproteins is achieved, with up to thousands of high-confidence spectra hits for each glycosite. The protocol can be performed by an experienced technician or student/postdoc with basic skills for proteomics experiments and takes ∼7 d to complete.
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Affiliation(s)
- Liwei Cao
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA.,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery and IAVI Neutralizing Antibody Center, Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, USA
| | - Jolene K Diedrich
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Yuanhui Ma
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Nianshuang Wang
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Matthias Pauthner
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery and IAVI Neutralizing Antibody Center, Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, USA
| | - Sung-Kyu Robin Park
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Claire M Delahunty
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - Jason S McLellan
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Dennis R Burton
- Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery and IAVI Neutralizing Antibody Center, Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, USA.,Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, USA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA
| | - James C Paulson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, USA.,Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery and IAVI Neutralizing Antibody Center, Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, USA
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30
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Xiao H, Wu R. Simultaneous Quantitation of Glycoprotein Degradation and Synthesis Rates by Integrating Isotope Labeling, Chemical Enrichment, and Multiplexed Proteomics. Anal Chem 2017; 89:10361-10367. [PMID: 28850217 PMCID: PMC5678942 DOI: 10.1021/acs.analchem.7b02241] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Protein glycosylation is essential for cell survival and regulates many cellular events. Reversible glycosylation is also dynamic in biological systems. The functions of glycoproteins are regulated by their dynamics to adapt the ever-changing inter- and intracellular environments. Glycans on proteins not only mediate a variety of protein activities, but also creates a steric hindrance for protecting the glycoproteins from degradation by proteases. In this work, a novel strategy integrating isotopic labeling, chemical enrichment and multiplexed proteomics was developed to simultaneously quantify the degradation and synthesis rates of many glycoproteins in human cells. We quantified the synthesis rates of 847 N-glycoproteins and the degradation rates of 704 glycoproteins in biological triplicate experiments, including many important glycoproteins such as CD molecules. Through comparing the synthesis and degradation rates, we found that most proteins have higher synthesis rates since cells are still growing throughout the time course, while a small group of proteins with lower synthesis rates mainly participate in adhesion, locomotion, localization, and signaling. This method can be widely applied in biochemical and biomedical research and provide insights into elucidating glycoprotein functions and the molecular mechanism of many biological events.
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Affiliation(s)
- Haopeng Xiao
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Ronghu Wu
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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31
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Khatri K, Klein JA, Haserick JR, Leon DR, Costello CE, McComb ME, Zaia J. Microfluidic Capillary Electrophoresis-Mass Spectrometry for Analysis of Monosaccharides, Oligosaccharides, and Glycopeptides. Anal Chem 2017; 89:6645-6655. [PMID: 28530388 PMCID: PMC5554952 DOI: 10.1021/acs.analchem.7b00875] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Glycomics and glycoproteomics analyses by mass spectrometry require efficient front-end separation methods to enable deep characterization of heterogeneous glycoform populations. Chromatography methods are generally limited in their ability to resolve glycoforms using mobile phases that are compatible with online liquid chromatography-mass spectrometry (LC-MS). The adoption of capillary electrophoresis-mass spectrometry methods (CE-MS) for glycomics and glycoproteomics is limited by the lack of convenient interfaces for coupling the CE devices to mass spectrometers. Here, we describe the application of a microfluidics-based CE-MS system for analysis of released glycans, glycopeptides and monosaccharides. We demonstrate a single CE method for three different modalities, thus contributing to comprehensive glycoproteomics analyses. In addition, we explored compatible sample derivatization methods. We used glycan TMT-labeling to improve electrophoretic migration and enable multiplexed quantitation by tandem MS. We used sialic acid linkage-specific derivatization methods to improve separation and the level of information obtained from a single analytical step. Capillary electrophoresis greatly improved glycoform separation for both released glycans and glycopeptides over that reported for chromatography modes more frequently employed for such analyses. Overall, the CE-MS method described here enables rapid setup and analysis of glycans and glycopeptides using mass spectrometry.
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Affiliation(s)
- Kshitij Khatri
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University, Boston, Massachusetts 02215, United States
| | - Joshua A. Klein
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, United States
| | - John R. Haserick
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University, Boston, Massachusetts 02215, United States
| | - Deborah R. Leon
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University, Boston, Massachusetts 02215, United States
| | - Catherine E. Costello
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University, Boston, Massachusetts 02215, United States
| | - Mark E. McComb
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University, Boston, Massachusetts 02215, United States
| | - Joseph Zaia
- Department of Biochemistry, Center for Biomedical Mass Spectrometry, Boston University, Boston, Massachusetts 02215, United States
- Bioinformatics Program, Boston University, Boston, Massachusetts 02215, United States
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32
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Campbell MP. A Review of Software Applications and Databases for the Interpretation of Glycopeptide Data. TRENDS GLYCOSCI GLYC 2017. [DOI: 10.4052/tigg.1601.1e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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