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Mass Spectrometry Reviews Aug 2019Protein glycosylation is ubiquitous in biological systems and plays essential roles in many cellular events. Global and site-specific analysis of glycoproteins in... (Review)
Review
Protein glycosylation is ubiquitous in biological systems and plays essential roles in many cellular events. Global and site-specific analysis of glycoproteins in complex biological samples can advance our understanding of glycoprotein functions and cellular activities. However, it is extraordinarily challenging because of the low abundance of many glycoproteins and the heterogeneity of glycan structures. The emergence of mass spectrometry (MS)-based proteomics has provided us an excellent opportunity to comprehensively study proteins and their modifications, including glycosylation. In this review, we first summarize major methods for glycopeptide/glycoprotein enrichment, followed by the chemical and enzymatic methods to generate a mass tag for glycosylation site identification. We next discuss the systematic and quantitative analysis of glycoprotein dynamics. Reversible protein glycosylation is dynamic, and systematic study of glycoprotein dynamics helps us gain insight into glycoprotein functions. The last part of this review focuses on the applications of MS-based proteomics to study glycoproteins in different biological systems, including yeasts, plants, mice, human cells, and clinical samples. Intact glycopeptide analysis is also included in this section. Because of the importance of glycoproteins in complex biological systems, the field of glycoproteomics will continue to grow in the next decade. Innovative and effective MS-based methods will exponentially advance glycoscience, and enable us to identify glycoproteins as effective biomarkers for disease detection and drug targets for disease treatment. © 2019 Wiley Periodicals, Inc. Mass Spec Rev 9999: XX-XX, 2019.
Topics: Animals; Glycomics; Glycopeptides; Glycoproteins; Glycosylation; Humans; Mass Spectrometry; Polysaccharides; Proteomics
PubMed: 30605224
DOI: 10.1002/mas.21586 -
Current Opinion in Structural Biology Aug 2022The structure and post-translational processing of the SARS-CoV-2 spike glycoprotein (S) is intimately associated with the function of the virus and of sterilising... (Review)
Review
The structure and post-translational processing of the SARS-CoV-2 spike glycoprotein (S) is intimately associated with the function of the virus and of sterilising vaccines. The surface of the S protein is extensively modified by glycans, and their biosynthesis is driven by both the wider cellular context, and importantly, the underlining protein structure and local glycan density. Comparison of virally derived S protein with both recombinantly derived and adenovirally induced proteins, reveal hotspots of protein-directed glycosylation that drive conserved glycosylation motifs. Molecular dynamics simulations revealed that, while the S surface is extensively shielded by N-glycans, it presents regions vulnerable to neutralising antibodies. Furthermore, glycans have been shown to influence the accessibility of the receptor binding domain and the binding to the cellular receptor. The emerging picture is one of unifying, principles of S protein glycosylation and an intimate role of glycosylation in immunogen structure and efficacy.
Topics: COVID-19; Glycosylation; Humans; Polysaccharides; Protein Binding; SARS-CoV-2
PubMed: 35717706
DOI: 10.1016/j.sbi.2022.102402 -
Biochimica Et Biophysica Acta Nov 2013N-linked protein glycosylation in the endoplasmic reticulum (ER) is a conserved two phase process in eukaryotic cells. It involves the assembly of an oligosaccharide on... (Review)
Review
N-linked protein glycosylation in the endoplasmic reticulum (ER) is a conserved two phase process in eukaryotic cells. It involves the assembly of an oligosaccharide on a lipid carrier, dolichylpyrophosphate and the transfer of the oligosaccharide to selected asparagine residues of polypeptides that have entered the lumen of the ER. The assembly of the oligosaccharide (LLO) takes place at the ER membrane and requires the activity of several specific glycosyltransferases. The biosynthesis of the LLO initiates at the cytoplasmic side of the ER membrane and terminates in the lumen where oligosaccharyltransferase (OST) selects N-X-S/T sequons of polypeptide and generates the N-glycosidic linkage between the side chain amide of asparagine and the oligosaccharide. The N-glycosylation pathway in the ER modifies a multitude of proteins at one or more asparagine residues with a unique carbohydrate structure that is used as a signalling molecule in their folding pathway. In a later stage of glycoprotein processing, the same systemic modification is used in the Golgi compartment, but in this process, remodelling of the N-linked glycans in a protein-, cell-type and species specific manner generates the high structural diversity of N-linked glycans observed in eukaryotic organisms. This article summarizes the current knowledge of the N-glycosylation pathway in the ER that results in the covalent attachment of an oligosaccharide to asparagine residues of polypeptide chains and focuses on the model organism Saccharomyces cerevisiae. This article is part of a Special Issue entitled: Functional and structural diversity of endoplasmic reticulum.
Topics: Animals; Endoplasmic Reticulum; Glycoproteins; Glycosylation; Humans; Protein Processing, Post-Translational
PubMed: 23583305
DOI: 10.1016/j.bbamcr.2013.04.001 -
Cells Dec 2020Glycosylation is the most common post-translational modification of proteins; it mediates their correct folding and stability, as well as their transport through the... (Review)
Review
Glycosylation is the most common post-translational modification of proteins; it mediates their correct folding and stability, as well as their transport through the secretory transport. Changes in and linked glycans have been associated with multiple pathological conditions including congenital disorders of glycosylation, inflammatory diseases and cancer. Glycoprotein glycosylation at the Golgi involves the coordinated action of hundreds of glycosyltransferases and glycosidases, which are maintained at the correct location through retrograde vesicle trafficking between Golgi cisternae. In this review, we describe the molecular machinery involved in vesicle trafficking and tethering at the Golgi apparatus and the effects of mutations in the context of glycan biosynthesis and human diseases.
Topics: Animals; Glycoproteins; Glycoside Hydrolases; Glycosylation; Glycosyltransferases; Golgi Apparatus; Humans; Protein Stability; Protein Transport
PubMed: 33321764
DOI: 10.3390/cells9122652 -
Journal of Separation Science Sep 2012Protein glycosylation plays key roles in many biological processes. In addition, alterations in protein glycosylation have been related to different diseases, as well as... (Review)
Review
Protein glycosylation plays key roles in many biological processes. In addition, alterations in protein glycosylation have been related to different diseases, as well as may affect the properties of recombinant proteins used as human therapeutics. For this reason, protein glycosylation analysis is of main interest in biomedical and biopharmaceutical research. Although recent advances in LC-MS analysis have made possible glycoprotein glycosylation site identification, characterization of glycoprotein glycan structures, as well as glycoprotein identification and quantification, protein glycosylation analysis in complex samples still remains a difficult task. This is due to low proportions of glycopeptides in comparison to peptides obtained after glycoprotein digestion, the suppression of the glycopeptide MS signals in the presence of peptides, and the high heterogeneity of glycopeptides. Thus, in the recent years, continuous efforts have been devoted to the development of glycopeptide enrichment and separation strategies to facilitate and improve glycoprotein glycosylation analysis in complex samples. This review summarizes the different methodologies that can be employed for glycopeptide enrichment/separation from complex samples including methods based on lectin affinity enrichment, covalent interactions, or chromatographic separations and solid-phase extraction.
Topics: Analytic Sample Preparation Methods; Chromatography; Glycopeptides; Glycoproteins; Glycosylation; Polysaccharides; Solid Phase Extraction
PubMed: 22997027
DOI: 10.1002/jssc.201200434 -
Frontiers in Endocrinology 2023Osteoarthritis (OA) is the most common degenerative and progressive joint disease. Cellular senescence is an irreversible cell cycle arrest progressive with age, while...
Osteoarthritis (OA) is the most common degenerative and progressive joint disease. Cellular senescence is an irreversible cell cycle arrest progressive with age, while protein glycosylation is the most abundant post-translational modification, regulating various cellular and biological pathways. The implication of either chondrocyte senescence or protein glycosylation in the OA pathogenesis has been extensively and individually studied. In this study, we aimed to investigate the possible relationship between chondrocyte senescence and protein glycosylation on the pathogenesis of OA using single-cell RNA sequencing datasets of clinical OA specimens deposited in the Gene Expression Omnibus database with a different cohort. We demonstrated that both cellular senescence signal and protein glycosylation pathways in chondrocytes are validly associated with OA pathogenesis. In addition, the cellular senescence signal is well-connected to the O-linked glycosylation pathway in OA chondrocyte and vice-versa. The expression levels of the polypeptide N-acetylgalactosaminyltransferase (GALNT) family, which is essential for the biosynthesis of O-Glycans at the early stage, are highly upregulated in OA chondrocytes. Moreover, the expression levels of the GALNT family are prominently associated with chondrocyte senescence as well as pathological features of OA. Collectively, these findings uncover a crucial relationship between chondrocyte senescence and O-linked glycosylation on the OA pathophysiology, thereby revealing a potential target for OA.
Topics: Humans; Chondrocytes; Glycosylation; Osteoarthritis; Cellular Senescence; Protein Processing, Post-Translational
PubMed: 37265706
DOI: 10.3389/fendo.2023.1153689 -
Postepy Biochemii Sep 2023Glycosylated proteins play a key role in the various stages of bacterial and viral invasions. Glycosylation is a common process across all domains of life. Initially,...
Glycosylated proteins play a key role in the various stages of bacterial and viral invasions. Glycosylation is a common process across all domains of life. Initially, this process was attributed only to eukaryotic organisms, in which the synthesis takes place in the rough endoplasmic reticulum and the Golgi apparatus. Over time, it has been shown that many bacteria and viruses express N-glycans and O-glycans on their surface. Prokaryotes are able to synthesize glycans, while virions take over the host's cellular machinery to produce glycans. Pathogens use glycoproteins to regulate adhesion to infected cells (Ebola virus), protect receptor-binding epitopes (HIV) and evade the immune system detection by molecular mimicry (Helicobacter pylori, Haemophilus influenzae). Successful infection also depends on the host surface glycans, mainly in determining the tissue tropism of viruses (Influenza A viruses) and the sliding motility of bacteria (Mycoplasma sp.). Modification of glycan structures, important at various levels of the infectious cycle, creates new therapeutic possibilities that gives a chance to limit the spread of infectious diseases.
Topics: Humans; Glycosylation; Viruses; Polysaccharides; Virus Diseases; Bacteria
PubMed: 38019747
DOI: 10.18388/pb.2021_488 -
Glycobiology Sep 2009In the biopharmaceutical industry, mammalian cell culture systems, especially Chinese hamster ovary (CHO) cells, are predominantly used for the production of therapeutic... (Review)
Review
In the biopharmaceutical industry, mammalian cell culture systems, especially Chinese hamster ovary (CHO) cells, are predominantly used for the production of therapeutic glycoproteins. Glycosylation is a critical protein quality attribute that can modulate the efficacy of a commercial therapeutic glycoprotein. Obtaining a consistent glycoform profile in production is desired due to regulatory concerns because a molecule can be defined by its carbohydrate structures. An optimal profile may involve a spectrum of product glycans that confers a desired therapeutic efficacy, or a homogeneous glycoform profile that can be systemically screened for. Studies have shown some degree of protein glycosylation control in mammalian cell culture, through cellular, media, and process effects. Studies upon our own bioprocesses to produce fusion proteins and monoclonal antibodies have shown an intricate relationship between these variables and the resulting protein quality. Glycosylation optimization will improve therapeutic efficacy and is an ongoing goal for researchers in academia and industry alike. This review will focus on the advancements made in glycosylation control in a manufacturing process, as well as the next steps in understanding and controlling protein glycosylation.
Topics: Animals; CHO Cells; Cricetinae; Cricetulus; Glycosylation; Proteins
PubMed: 19494347
DOI: 10.1093/glycob/cwp079 -
Clinical and Translational... Jul 2023Colorectal cancer (CRC) remains a leading cause of cancer-related deaths despite being the most preventable and treatable forms of cancer when caught early through... (Review)
Review
Colorectal cancer (CRC) remains a leading cause of cancer-related deaths despite being the most preventable and treatable forms of cancer when caught early through screening. There is an unmet need for novel screening approaches with improved accuracy, less invasiveness, and reduced costs. In recent years, evidence has accumulated around particular biological events that happen during the adenoma-to-carcinoma transition, especially focusing on precancerous immune responses in the colonic crypt. Protein glycosylation plays a central role in driving those responses, and recently, numerous reports have been published on how aberrant protein glycosylation both in colonic tissue and on circulating glycoproteins reflects these precancerous developments. The complex field of glycosylation, which exceeds complexity of proteins by several orders of magnitude, can now be studied primarily because of the availability of new high-throughput technologies such as mass spectrometry and artificial intelligence-powered data processing. This has now opened new avenues for studying novel biomarkers for CRC screening. This review summarizes the early events taking place from the normal colon mucosa toward adenoma and adenocarcinoma formation and associated critical protein glycosylation phenomena, both on the tissue level and in the circulation. These insights will help establish an understanding in the interpretation of novel CRC detection modalities that involve high-throughput glycomics.
Topics: Humans; Glycosylation; Artificial Intelligence; Colorectal Neoplasms; Adenoma; Precancerous Conditions
PubMed: 37141103
DOI: 10.14309/ctg.0000000000000592 -
Biochemistry Nov 1987
Review
Topics: Animals; Endoplasmic Reticulum; Glycoproteins; Glycosylation; Proteins
PubMed: 3322396
DOI: 10.1021/bi00397a001