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Pace CL, Angel PM, Drake RR, Muddiman DC. Mass Spectrometry Imaging of N-Linked Glycans in a Formalin-Fixed Paraffin-Embedded Human Prostate by Infrared Matrix-Assisted Laser Desorption Electrospray Ionization. J Proteome Res 2022; 21:243-249. [PMID: 34860526 PMCID: PMC9944006 DOI: 10.1021/acs.jproteome.1c00822] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
N-Linked glycans are structurally diverse polysaccharides that represent significant biological relevance due to their involvement in disease progression and cancer. Due to their complex nature, N-linked glycans pose many analytical challenges requiring the continued development of analytical technologies. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) is a hybrid ionization technique commonly used for mass spectrometry imaging (MSI) applications. Previous work demonstrated IR-MALDESI to significantly preserve sialic acid containing N-linked glycans that otherwise require chemical derivatization prior to detection. Here, we demonstrate the first analysis of N-linked glycans in situ by IR-MALDESI MSI. A formalin-fixed paraffin-embedded human prostate tissue was analyzed in negative ionization mode after tissue washing, antigen retrieval, and pneumatic application of PNGase F for enzymatic digestion of N-linked glycans. Fifty-three N-linked glycans were confidently identified in the prostate sample where more than 60% contained sialic acid residues. This work demonstrates the first steps in N-linked glycan imaging of biological tissues by IR-MALDESI MSI. Raw data files are available in MassIVE (identifier: MSV000088414).
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Affiliation(s)
- Crystal L. Pace
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, USA, 27606
| | - Peggi M. Angel
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, USA, 29425
| | - Richard R. Drake
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, USA, 29425
| | - David C. Muddiman
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, USA, 27606,Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC, USA 27695,Author for Correspondence: David C. Muddiman, Ph.D., FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Phone: 919-513-0084,
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2
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Butler KE, Kalmar JG, Muddiman DC, Baker ES. Utilizing liquid chromatography, ion mobility spectrometry, and mass spectrometry to assess INLIGHT™ derivatized N-linked glycans in biological samples. Anal Bioanal Chem 2022; 414:623-637. [PMID: 34347113 PMCID: PMC8336533 DOI: 10.1007/s00216-021-03570-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/06/2021] [Accepted: 07/20/2021] [Indexed: 02/07/2023]
Abstract
Glycosylation is a ubiquitous co- and post-translational modification involved in the sorting, folding, and trafficking of proteins in biological systems; in humans, >50% of gene products are glycosylated with the cellular machinery of glycosylation compromising ~2% of the genome. Perturbations in glycosylation have been implicated in a variety of diseases including neurodegenerative diseases and certain types of cancer. However, understanding the relationship between a glycan and its biological role is often difficult due to the numerous glycan isomers that exist. To address this challenge, nanoflow liquid chromatography, ion mobility spectrometry, and mass spectrometry (nLC-IMS-MS) were combined with the Individuality Normalization when Labeling with the Isotopic Glycan Hydrazide Tags (INLIGHT™) strategy to study a series of glycan standards and those enzymatically released from the glycoproteins horseradish peroxidase, fetuin, and pooled human plasma. The combination of IMS and the natural (NAT) and stable-isotope label (SIL) in the INLIGHT™ strategy provided additional confidence for each glycan identification due to the mobility aligned NAT- and SIL-labeled glycans and further capabilities for isomer examinations. Additionally, molecular trend lines based on the IMS and MS dimensions were investigated for the INLIGHT™ derivatized glycans, facilitating rapid identification of putative glycans in complex biological samples.
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Affiliation(s)
- Karen E Butler
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Jaclyn Gowen Kalmar
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - David C Muddiman
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
- Molecular Education, Technology, and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC, 27695, USA
| | - Erin S Baker
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, 27695, USA.
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3
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Cho BG, Gutierrez Reyes CD, Mechref Y. N-Glycomics of Cerebrospinal Fluid: Method Comparison. Molecules 2021; 26:molecules26061712. [PMID: 33808573 PMCID: PMC8003558 DOI: 10.3390/molecules26061712] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/14/2021] [Accepted: 03/15/2021] [Indexed: 12/12/2022] Open
Abstract
Cerebrospinal fluid (CSF) contains valuable biological and neurological information. However, its glycomics analysis is hampered due to the low amount of protein in the biofluid, as has been demonstrated by other glycomics studies using a substantial amount of CSF. In this work, we investigated different N-glycan sample preparation approaches to develop a more sensitive method. These methods, one with an increased amount of buffer solution during the N-glycan release step with a lower amount of sample volume and the other with Filter-Aided N-Glycan Separation (FANGS), were compared with recent work to demonstrate their effectiveness. It was demonstrated that an increased amount of buffer solution showed higher intensity in comparison to the previously published method and FANGS. This suggested that digestion efficiency during the N-glycan release step was not in an optimal condition from the previously published method, and that there is a substantial loss of sample with FANGS when preparing N-glycans from CSF.
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4
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Kalmar JG, Butler KE, Baker ES, Muddiman DC. Enhanced protocol for quantitative N-linked glycomics analysis using Individuality Normalization when Labeling with Isotopic Glycan Hydrazide Tags (INLIGHT)™. Anal Bioanal Chem 2020; 412:7569-7579. [PMID: 32844281 PMCID: PMC7541788 DOI: 10.1007/s00216-020-02892-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/09/2020] [Accepted: 08/17/2020] [Indexed: 01/10/2023]
Abstract
The analysis of N-linked glycans using liquid chromatography and mass spectrometry (LC-MS) presents significant challenges, particularly owing to their hydrophilic nature. To address these difficulties, a variety of derivatization methods have been developed to facilitate improved ionization and detection sensitivity. One such method, the Individuality Normalization when Labeling with Isotopic Glycan Hydrazide Tags (INLIGHT)™ strategy for labeling glycans, has previously been utilized in the analysis of N- and O-linked glycans in biological samples. To assess the maximum sensitivity and separability of the INLIGHT™ preparation and analysis pipeline, several critical steps were investigated. First, recombinant and nonrecombinant sources of PNGase F were compared to assess variations in the released glycans. Second, modifications in the INLIGHT™ derivatization step were evaluated including temperature optimization, solvent composition changes, reaction condition length and tag concentration. Optimization of the modified method resulted in 20-100 times greater peak areas for the detected N-linked glycans in fetuin and horseradish peroxidase compared with the standard method. Furthermore, the identification of low-abundance glycans, such as (Fuc)1(Gal)2(GlcNAc)4(Man)3(NeuAc)1 and (Gal)3(GlcNAc)5(Man)3(NeuAc)3, was possible. Finally, the optimal LC setup for the INLIGHT™ derivatized N-linked glycan analyses was found to be a C18 reverse-phase (RP) column with mobile phases typical of RPLC.
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Affiliation(s)
- Jaclyn Gowen Kalmar
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Karen E Butler
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Erin S Baker
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
| | - David C Muddiman
- Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.
- Molecular Education, Technology, and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC, 27695, USA.
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5
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Pace CL, Muddiman DC. Direct Analysis of Native N-Linked Glycans by IR-MALDESI. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:10.1021/jasms.0c00176. [PMID: 32603137 PMCID: PMC8285077 DOI: 10.1021/jasms.0c00176] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Glycan analysis by mass spectrometry has rapidly progressed due to the interest in understanding the role of glycans in disease and tumor progression. Glycans are complex molecules that pose analytical challenges due to their isomeric compositions, labile character, and ionization preferences. This study sought to demonstrate infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) as a novel approach for the direct analysis of N-linked glycans. The glycoprotein bovine fetuin was chosen for this analysis as its glycome is well-characterized and heavily composed of sialylated glycans. Native N-linked glycans produced by enzymatic cleavage (via PNGase F) of bovine fetuin were analyzed directly by IR-MALDESI in both positive and negative ionization mode. In this study, we detected 12 N-linked glycans in negative mode and 4 N-linked glycans in positive mode, a significant increase in the amount of underivatized glycans detected by other ionization sources. Importantly, all N-linked glycans detected contained at least one sialic acid residue, which are known to be labile. This work represents a critical first step for N-linked glycan analysis by IR-MALDESI with future efforts directed at mass spectrometry imaging.
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Affiliation(s)
- Crystal L. Pace
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, USA 27695
| | - David C. Muddiman
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, USA 27695
- Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC, USA 27695
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6
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Sethi MK, Downs M, Zaia J. Serial in-solution digestion protocol for mass spectrometry-based glycomics and proteomics analysis. Mol Omics 2020; 16:364-376. [PMID: 32309832 DOI: 10.1039/d0mo00019a] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Advancement in mass spectrometry has revolutionized the field of proteomics. However, there remains a gap in the analysis of protein post-translational modifications (PTMs), particularly for glycosylation. Glycosylation, the most common form of PTM, is involved in most biological processes; thus, analysis of glycans along with proteins is crucial to answering important biologically relevant questions. Of particular interest is the brain extracellular matrix (ECM), which has been called the "final Frontier" in neuroscience, which consists of highly glycosylated proteins. Among these, proteoglycans (PGs) contain large glycan structures called glycosaminoglycans (GAGs) that form crucial ECM components, including perineuronal nets (PNNs), shown to be altered in neuropsychiatric diseases. Thus, there is a growing need for high-throughput methods that combine GAG (glycomics) and PGs (proteomics) analysis to unravel the complete biological picture. The protocol presented here integrates glycomics and proteomics to analyze multiple classes of biomolecules. We use a filter-aided sample preparation (FASP) type serial in-solution digestion of GAG classes, including hyaluronan (HA), chondroitin sulfate (CS), and heparan sulfate (HS), followed by peptides. The GAGs and peptides are then cleaned and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This protocol is an efficient and economical way of processing tissue or cell lysates to isolate various GAG classes and peptides from the same sample. The method is more efficient (single-pot) than available parallel (multi-pot) release methods, and removal of GAGs facilitates the identification of the proteins with higher peptide-coverage than using conventional-proteomics. Overall, we demonstrate a high-throughput & efficient protocol for mass spectrometry-based glycomic and proteomic analysis (data are available via ProteomeXchange with identifier PXD017513).
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Affiliation(s)
- Manveen K Sethi
- Boston University School of Medicine, Boston University, Department of Biochemistry, Boston, 02118, USA.
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O'Rourke MB, Town SEL, Dalla PV, Bicknell F, Koh Belic N, Violi JP, Steele JR, Padula MP. What is Normalization? The Strategies Employed in Top-Down and Bottom-Up Proteome Analysis Workflows. Proteomes 2019; 7:proteomes7030029. [PMID: 31443461 PMCID: PMC6789750 DOI: 10.3390/proteomes7030029] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 12/20/2022] Open
Abstract
The accurate quantification of changes in the abundance of proteins is one of the main applications of proteomics. The maintenance of accuracy can be affected by bias and error that can occur at many points in the experimental process, and normalization strategies are crucial to attempt to overcome this bias and return the sample to its regular biological condition, or normal state. Much work has been published on performing normalization on data post-acquisition with many algorithms and statistical processes available. However, there are many other sources of bias that can occur during experimental design and sample handling that are currently unaddressed. This article aims to cast light on the potential sources of bias and where normalization could be applied to return the sample to its normal state. Throughout we suggest solutions where possible but, in some cases, solutions are not available. Thus, we see this article as a starting point for discussion of the definition of and the issues surrounding the concept of normalization as it applies to the proteomic analysis of biological samples. Specifically, we discuss a wide range of different normalization techniques that can occur at each stage of the sample preparation and analysis process.
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Affiliation(s)
- Matthew B O'Rourke
- Bowel Cancer & Biomarker Lab, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney Lvl 8, Kolling Institute. Royal North Shore Hospital, St. Leonards, NSW 2065, Australia
| | - Stephanie E L Town
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia
| | - Penelope V Dalla
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia
- Respiratory Cellular and Molecular Biology, Woolcock Institute of Medical Research, The University of Sydney, Glebe 2037, Australia
| | - Fiona Bicknell
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia
| | - Naomi Koh Belic
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia
| | - Jake P Violi
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia
| | - Joel R Steele
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia
| | - Matthew P Padula
- School of Life Sciences and Proteomics Core Facility, Faculty of Science, The University of Technology Sydney, Ultimo 2007, Australia.
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Hecht ES, Loziuk PL, Muddiman DC. Xylose Migration During Tandem Mass Spectrometry of N-Linked Glycans. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:729-732. [PMID: 28127681 PMCID: PMC5373971 DOI: 10.1007/s13361-016-1588-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 12/13/2016] [Accepted: 12/25/2016] [Indexed: 05/15/2023]
Abstract
Understanding the rearrangement of gas-phase ions via tandem mass spectrometry is critical to improving manual and automated interpretation of complex datasets. N-glycan analysis may be carried out under collision induced (CID) or higher energy collision dissociation (HCD), which favors cleavage at the glycosidic bond. However, fucose migration has been observed in tandem MS, leading to the formation of new bonds over four saccharide units away. In the following work, we report the second instance of saccharide migration ever to occur for N-glycans. Using horseradish peroxidase as a standard, the beta-1,2 xylose was observed to migrate from a hexose to a glucosamine residue on the (Xyl)Man3GlcNac2 glycan. This investigation was followed up in a complex N-linked glycan mixture derived from stem differentiating xylem tissue, and the rearranged product ion was observed for 75% of the glycans. Rearrangement was not favored in isomeric glycans with a core or antennae fucose and unobserved in glycans predicted to have a permanent core-fucose modification. As the first empirical observation of this rearrangement, this work warrants dissemination so it may be searched in de novo sequencing glycan workflows. Graphical Abstract ᅟ.
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Affiliation(s)
- Elizabeth S Hecht
- W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - Philip L Loziuk
- W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA
| | - David C Muddiman
- W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC, 27695, USA.
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9
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McCord J, Sun Z, Deutsch EW, Moritz RL, Muddiman DC. The PeptideAtlas of the Domestic Laying Hen. J Proteome Res 2017; 16:1352-1363. [PMID: 28166638 DOI: 10.1021/acs.jproteome.6b00952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proteomics-based biological research is greatly expanded by high-quality mass spectrometry studies, which are themselves enabled by access to quality mass spectrometry resources, such as high-quality curated proteome data repositories. We present a PeptideAtlas for the domestic chicken, containing an extensive and robust collection of chicken tissue and plasma samples with substantial value for the chicken proteomics community for protein validation and design of downstream targeted proteome quantitation. The chicken PeptideAtlas contains 6646 canonical proteins at a protein FDR of 1.3%, derived from ∼100 000 peptides at a peptide level FDR of 0.1%. The rich collection of readily accessible data is easily mined for the purposes of data validation and experimental planning, particularly in the realm of developing proteome quantitation workflows. Herein we demonstrate the use of the atlas to mine information on common chicken acute-phase proteins and biomarkers for cancer detection research, as well as their localization and polymorphisms. This wealth of information will support future proteome-based research using this highly important agricultural organism in pursuit of both chicken and human health outcomes.
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Affiliation(s)
- James McCord
- W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695, United States
| | - Zhi Sun
- Institute for Systems Biology , Seattle, Washington 98109, United States
| | - Eric W Deutsch
- Institute for Systems Biology , Seattle, Washington 98109, United States
| | - Robert L Moritz
- Institute for Systems Biology , Seattle, Washington 98109, United States
| | - David C Muddiman
- W.M. Keck FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University , Raleigh, North Carolina 27695, United States
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Coleman O, Henry M, Clynes M, Meleady P. Filter-Aided Sample Preparation (FASP) for Improved Proteome Analysis of Recombinant Chinese Hamster Ovary Cells. Methods Mol Biol 2017; 1603:187-194. [PMID: 28493131 DOI: 10.1007/978-1-4939-6972-2_12] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chinese hamster ovary (CHO) cells are the most commonly used mammalian host cell line for biopharmaceutical production because of their ability to correctly fold and posttranslationally modify recombinant proteins that are compatible with human use. Proteomics, along with other 'omic platforms, are being used to understand the biology of CHO cells with the ultimate aim of enhancing CHO cell factories for more efficient production of biopharmaceuticals. In this chapter, we will describe an efficient protocol called Filter Aided Sample Preparation (FASP) for the extraction of proteins from CHO cells for proteomic studies. FASP uses a common ultrafiltration device whereby the membrane pores are small enough to allow contaminating detergents to pass through, while proteins are too large and are retained and concentrated in the filter unit. This method of sample preparation and protein digestion is universally applicable and can be easily employed in any proteomics facilities as standard everyday laboratory reagents and equipment are used.
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Affiliation(s)
- Orla Coleman
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland.
| | - Michael Henry
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Martin Clynes
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Paula Meleady
- National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
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N-linked glycosite profiling and use of Skyline as a platform for characterization and relative quantification of glycans in differentiating xylem of Populus trichocarpa. Anal Bioanal Chem 2016; 409:487-497. [PMID: 27491298 DOI: 10.1007/s00216-016-9776-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/28/2016] [Accepted: 07/06/2016] [Indexed: 01/02/2023]
Abstract
Our greater understanding of the importance of N-linked glycosylation in biological systems has spawned the field of glycomics and development of analytical tools to address the many challenges regarding our ability to characterize and quantify this complex and important modification as it relates to biological function. One of the unmet needs of the field remains a systematic method for characterization of glycans in new biological systems. This study presents a novel workflow for identification of glycans using Individuality Normalization when Labeling with Isotopic Glycan Hydrazide Tags (INLIGHT™) strategy developed in our lab. This consists of monoisotopic mass extraction followed by peak pair identification of tagged glycans from a theoretical library using an in-house program. Identification and relative quantification could then be performed using the freely available bioinformatics tool Skyline. These studies were performed in the biological context of studying the N-linked glycome of differentiating xylem of the poplar tree, a widely studied model woody plant, particularly with respect to understanding lignin biosynthesis during wood formation. Through our workflow, we were able to identify 502 glycosylated proteins including 12 monolignol enzymes and 1 peroxidase (PO) through deamidation glycosite analysis. Finally, our novel semi-automated workflow allowed for rapid identification of 27 glycans by intact mass and by NAT/SIL peak pairing from a library containing 1573 potential glycans, eliminating the need for extensive manual analysis. Implementing Skyline for relative glycan quantification allowed for improved accuracy and precision of quantitative measurements over current processing tools which we attribute to superior algorithms correction for baseline variation and MS1 peak filtering. Graphical abstract Workflow for FANGS-INLIGHT glycosite profiling of plant xylem and monolignol proteins followed by INLIGHT tagging with semi-automated identification of glycans by light-heavy peak pairs. Finally, manual validation and relative quantification was performed in Skyline.
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