88 results on '"Glycan biosynthesis"'
Search Results
2. A Higher Abundance of Actinomyces spp. in the Gut Is Associated with Spontaneous Preterm Birth.
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Yu, Hong-Ren, Tsai, Ching-Chang, Chan, Julie Y. H., Lee, Wei-Chia, Wu, Kay L. H., Tain, You-Lin, Hsu, Te-Yao, Cheng, Hsin-Hsin, Huang, Hsin-Chun, Huang, Cheng-Hsieh, Pan, Wen-Harn, and Yeh, Yao-Tsung
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GUT microbiome ,PREMATURE labor ,ACTINOMYCES ,FISHER discriminant analysis ,MEDICAL registries ,RIBOSOMAL RNA - Abstract
Preterm birth is a major challenge in pregnancy worldwide. Prematurity is the leading cause of death in infants and may result in severe complications. Nearly half of preterm births are spontaneous, but do not have recognizable causes. This study investigated whether the maternal gut microbiome and associated functional pathways might play a key role in spontaneous preterm birth (sPTB). Two hundred eleven women carrying singleton pregnancies were enrolled in this mother-child cohort study. Fecal samples were freshly collected at 24–28 weeks of gestation before delivery, and the 16S ribosomal RNA gene was sequenced. Microbial diversity and composition, core microbiome, and associated functional pathways were then statistically analyzed. Demographic characteristics were collected using records from the Medical Birth Registry and questionnaires. The result showed that the gut microbiome of mothers with over-weight (BMI ≥ 24) before pregnancy have lower alpha diversity than those with normal BMI before pregnancy. A higher abundance of Actinomyces spp. was filtered out from the Linear discriminant analysis (LDA) effect size (LEfSe), Spearman correlation, and random forest model, and was inversely correlated with gestational age in sPTB. The multivariate regression model showed that the odds ratio of premature delivery was 3.274 [95% confidence interval (CI): 1.349; p = 0.010] in the group with over-weight before pregnancy with a cutoff Hit% > 0.022 for Actinomyces spp. The enrichment of Actinomyces spp. was negatively correlated with glycan biosynthesis and metabolism in sPTB by prediction from the Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) platform. Maternal gut microbiota showing a lower alpha diversity, increased abundance of Actinomyces spp., and dysregulated glycan metabolism may be associated with sPTB risk. [ABSTRACT FROM AUTHOR]
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- 2023
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3. A Higher Abundance of Actinomyces spp. in the Gut Is Associated with Spontaneous Preterm Birth
- Author
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Hong-Ren Yu, Ching-Chang Tsai, Julie Y. H. Chan, Wei-Chia Lee, Kay L. H. Wu, You-Lin Tain, Te-Yao Hsu, Hsin-Hsin Cheng, Hsin-Chun Huang, Cheng-Hsieh Huang, Wen-Harn Pan, and Yao-Tsung Yeh
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spontaneous preterm birth ,maternal microbiome ,Actinomyces spp. ,glycan biosynthesis ,Biology (General) ,QH301-705.5 - Abstract
Preterm birth is a major challenge in pregnancy worldwide. Prematurity is the leading cause of death in infants and may result in severe complications. Nearly half of preterm births are spontaneous, but do not have recognizable causes. This study investigated whether the maternal gut microbiome and associated functional pathways might play a key role in spontaneous preterm birth (sPTB). Two hundred eleven women carrying singleton pregnancies were enrolled in this mother-child cohort study. Fecal samples were freshly collected at 24–28 weeks of gestation before delivery, and the 16S ribosomal RNA gene was sequenced. Microbial diversity and composition, core microbiome, and associated functional pathways were then statistically analyzed. Demographic characteristics were collected using records from the Medical Birth Registry and questionnaires. The result showed that the gut microbiome of mothers with over-weight (BMI ≥ 24) before pregnancy have lower alpha diversity than those with normal BMI before pregnancy. A higher abundance of Actinomyces spp. was filtered out from the Linear discriminant analysis (LDA) effect size (LEfSe), Spearman correlation, and random forest model, and was inversely correlated with gestational age in sPTB. The multivariate regression model showed that the odds ratio of premature delivery was 3.274 [95% confidence interval (CI): 1.349; p = 0.010] in the group with over-weight before pregnancy with a cutoff Hit% > 0.022 for Actinomyces spp. The enrichment of Actinomyces spp. was negatively correlated with glycan biosynthesis and metabolism in sPTB by prediction from the Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) platform. Maternal gut microbiota showing a lower alpha diversity, increased abundance of Actinomyces spp., and dysregulated glycan metabolism may be associated with sPTB risk.
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- 2023
- Full Text
- View/download PDF
4. Computational Modeling of O -Linked Glycan Biosynthesis in CHO Cells.
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Kouka, Thukaa, Akase, Sachiko, Sogabe, Isami, Jin, Chunsheng, Karlsson, Niclas G., and Aoki-Kinoshita, Kiyoko F.
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CHO cell , *BIOSYNTHESIS , *CELL lines , *GLYCANS , *GLYCOSYLTRANSFERASES - Abstract
Glycan biosynthesis simulation research has progressed remarkably since 1997, when the first mathematical model for N-glycan biosynthesis was proposed. An O-glycan model has also been developed to predict O-glycan biosynthesis pathways in both forward and reverse directions. In this work, we started with a set of O-glycan profiles of CHO cells transiently transfected with various combinations of glycosyltransferases. The aim was to develop a model that encapsulated all the enzymes in the CHO transfected cell lines. Due to computational power restrictions, we were forced to focus on a smaller set of glycan profiles, where we were able to propose an optimized set of kinetics parameters for each enzyme in the model. Using this optimized model we showed that the abundance of more processed glycans could be simulated compared to observed abundance, while predicting the abundance of glycans earlier in the pathway was less accurate. The data generated show that for the accurate prediction of O-linked glycosylation, additional factors need to be incorporated into the model to better reflect the experimental conditions. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Computational Modeling of O-Linked Glycan Biosynthesis in CHO Cells
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Thukaa Kouka, Sachiko Akase, Isami Sogabe, Chunsheng Jin, Niclas G. Karlsson, and Kiyoko F. Aoki-Kinoshita
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glycoinformatics ,computational biology ,O-linked glycans ,glycan biosynthesis ,systems biology ,Organic chemistry ,QD241-441 - Abstract
Glycan biosynthesis simulation research has progressed remarkably since 1997, when the first mathematical model for N-glycan biosynthesis was proposed. An O-glycan model has also been developed to predict O-glycan biosynthesis pathways in both forward and reverse directions. In this work, we started with a set of O-glycan profiles of CHO cells transiently transfected with various combinations of glycosyltransferases. The aim was to develop a model that encapsulated all the enzymes in the CHO transfected cell lines. Due to computational power restrictions, we were forced to focus on a smaller set of glycan profiles, where we were able to propose an optimized set of kinetics parameters for each enzyme in the model. Using this optimized model we showed that the abundance of more processed glycans could be simulated compared to observed abundance, while predicting the abundance of glycans earlier in the pathway was less accurate. The data generated show that for the accurate prediction of O-linked glycosylation, additional factors need to be incorporated into the model to better reflect the experimental conditions.
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- 2022
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6. Assembly of Bacterial Capsular Polysaccharides and Exopolysaccharides.
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Whitfield, Chris, Wear, Samantha S., and Sande, Caitlin
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Polysaccharides are dominant features of most bacterial surfaces and are displayed in different formats. Many bacteria produce abundant long-chain capsular polysaccharides, which can maintain a strong association and form a capsule structure enveloping the cell and/or take the form of exopolysaccharides that are mostly secreted into the immediate environment. These polymers afford the producing bacteria protection from a wide range of physical, chemical, and biological stresses, support biofilms, and play critical roles in interactions between bacteria and their immediate environments. Their biological and physical properties also drive a variety of industrial and biomedical applications. Despite the immense variation in capsular polysaccharide and exopolysaccharide structures, patterns are evident in strategies used for their assembly and export. This review describes recent advances in understanding those strategies, based on a wealth of biochemical investigations of select prototypes, supported by complementary insight from expanding structural biology initiatives. This provides a framework to identify and distinguish new systems emanating from genomic studies. [ABSTRACT FROM AUTHOR]
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- 2020
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7. ENPP3-Mediated Regulation of Glycan Biosynthesis
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Korekane, Hiroaki, Park, Jong Yi, Taniguchi, Naoyuki, Taniguchi, Naoyuki, editor, Endo, Tamao, editor, Hart, Gerald W., editor, Seeberger, Peter H., editor, and Wong, Chi-Huey, editor
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- 2015
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8. O-Mannosyl Glycan and Muscular Dystrophy
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Manya, Hiroshi, Endo, Tamao, Suzuki, Tadashi, editor, Ohtsubo, Kazuaki, editor, and Taniguchi, Naoyuki, editor
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- 2015
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9. The N-Glycosylation Processing Potential of the Mammalian Golgi Apparatus
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Peter Fisher, Jane Thomas-Oates, A. Jamie Wood, and Daniel Ungar
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computational modeling ,Golgi apparatus ,glycan biosynthesis ,cisternal number ,glycan heterogeneity ,Biology (General) ,QH301-705.5 - Abstract
Heterogeneity is an inherent feature of the glycosylation process. Mammalian cells often produce a variety of glycan structures on separate molecules of the same protein, known as glycoforms. This heterogeneity is not random but is controlled by the organization of the glycosylation machinery in the Golgi cisternae. In this work, we use a computational model of the N-glycosylation process to probe how the organization of the glycosylation machinery into different cisternae drives N-glycan biosynthesis toward differing degrees of heterogeneity. Using this model, we demonstrate the N-glycosylation potential and limits of the mammalian Golgi apparatus, for example how the number of cisternae limits the goal of achieving near homogeneity for N-glycans. The production of specific glycoforms guided by this computational study could pave the way for “glycoform engineering,” which will find uses in the functional investigation of glycans, the modulation of glycan-mediated physiological functions, and in biotechnology.
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- 2019
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10. KEGG GLYCAN for Integrated Analysis of Pathways, Genes, and Structures
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Hashimoto, Kosuke, Kanehisa, Minoru, Taniguchi, Naoyuki, editor, Suzuki, Akemi, editor, Ito, Yukishige, editor, Narimatsu, Hisashi, editor, Kawasaki, Toshisuke, editor, and Hase, Sumihiro, editor
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- 2008
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11. Comparative analysis of the gut microbiota of mice fed a diet supplemented with raw and cooked beef loin powder
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Hye-Jin Kim, Kwan-Woo Kim, Sang-Hoon Lee, Dongwook Kim, and Aera Jang
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Male ,0301 basic medicine ,Glycan biosynthesis ,Science ,Gut flora ,Loin ,Biochemistry ,Article ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Animals ,Dietary supplementation ,Cooking ,Food science ,Fatty acid synthesis ,Mice, Inbred BALB C ,Multidisciplinary ,biology ,Gastroenterology ,Raw beef ,food and beverages ,biology.organism_classification ,Animal Feed ,Gastrointestinal Microbiome ,Red Meat ,030104 developmental biology ,chemistry ,Medicine ,030211 gastroenterology & hepatology ,Bacteroides - Abstract
We used 16S ribosomal RNA sequencing to evaluate changes in the gut microbiota of mice fed a diet supplemented with either raw or cooked beef loin powder for 9 weeks. Male BALB/c mice (n = 60) were randomly allocated to five groups: mice fed AIN-93G chow (CON), chow containing 5% (5RB) and 10% (10RB) raw beef loin powder, and chow containing 5% (5CB) and 10% (10CB) cooked beef loin powder. Dietary supplementation with both RB and CB increased the relative abundance of Clostridiales compared to the CON diet (p p = 0.018) and Lactobacillus (p = 0.001) than CON mice, and the ratio of Firmicutes/Bacteroidetes showed an increasing trend in the 10RB mice (p > 0.05). Mice fed 10CB showed a higher abundance of Peptostreptococcaceae and a lower abundance of Desulfovibrionaceae compared with the CON mice (p Bacteroides. Overall, dietary RB and CB changed the gut microbiota of mice (p
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- 2021
12. Glycan chip based on structure-switchable DNA linker for on-chip biosynthesis of cancer-associated complex glycans
- Author
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Heo, Hye Ryoung, Joo, Kye Il, Seo, Jeong Hyun, Kim, Chang Sup, and Cha, Hyung Joon
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0301 basic medicine ,Glycan biosynthesis ,Cholera Toxin ,Glycan ,Glycosylation ,Science ,Carbohydrates ,Glycobiology ,General Physics and Astronomy ,G(M1) Ganglioside ,010402 general chemistry ,01 natural sciences ,Article ,General Biochemistry, Genetics and Molecular Biology ,Tumour biomarkers ,03 medical and health sciences ,chemistry.chemical_compound ,Biosynthesis ,Polysaccharides ,Neoplasms ,Humans ,Antigens, Tumor-Associated, Carbohydrate ,Analytical biochemistry ,Oligonucleotide Array Sequence Analysis ,Multidisciplinary ,biology ,Assay systems ,DNA ,General Chemistry ,Hydrogen-Ion Concentration ,Chip ,0104 chemical sciences ,carbohydrates (lipids) ,Protein Subunits ,030104 developmental biology ,chemistry ,Biochemistry ,MCF-7 Cells ,biology.protein ,Breast cancer cells ,Linker - Abstract
On-chip glycan biosynthesis is an effective strategy for preparing useful complex glycan sources and for preparing glycan-involved applications simultaneously. However, current methods have some limitations when analyzing biosynthesized glycans and optimizing enzymatic reactions, which could result in undefined glycan structures on a surface, leading to unequal and unreliable results. In this work, a glycan chip is developed by introducing a pH-responsive i-motif DNA linker to control the immobilization and isolation of glycans on chip surfaces in a pH-dependent manner. On-chip enzymatic glycosylations are optimized for uniform biosynthesis of cancer-associated Globo H hexasaccharide and its related complex glycans through stepwise quantitative analyses of isolated products from the surface. Successful interaction analyses of the anti-Globo H antibody and MCF-7 breast cancer cells with on-chip biosynthesized Globo H-related glycans demonstrate the feasibility of the structure-switchable DNA linker-based glycan chip platform for on-chip complex glycan biosynthesis and glycan-involved applications., Current methods for on-chip glycan biosynthesis suffer from analysing products, often resulting in poor purity and yield. Here the authors report a glycan chip developed by introducing a pH-responsive i-motif DNA linker to control the immobilization and isolation of glycans on chips.
- Published
- 2021
13. Glycosylation with ribitol-phosphate in mammals: New insights into the O-mannosyl glycan.
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Manya, Hiroshi and Endo, Tamao
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GLYCOSYLATION , *PHOSPHATES , *GLYCANS , *MAMMAL physiology , *BIOSYNTHESIS - Abstract
Background O -mannosyl glycans have been found in a limited number of glycoproteins of the brain, nerves, and skeletal muscles, particularly in α-dystroglycan (α-DG). Defects in O -mannosyl glycan on α-DG are the primary cause of a group of congenital muscular dystrophies, which are collectively termed α-dystroglycanopathy. Recent studies have revealed various O -mannosyl glycan structures, which can be classified as core M1, core M2, and core M3 glycans. Although many dystroglycanopathy genes are involved in core M3 processing, the structure and biosynthesis of core M3 glycan remains only partially understood. Scope of review This review presents recent findings about the structure, biosynthesis, and pathology of O -mannosyl glycans. Major conclusions Recent studies have revealed that the entire structure of core M3 glycan, including ribitol-5-phosphate, is a novel structure in mammals; its unique biosynthetic pathway has been elucidated by the identification of new causative genes for α-dystroglycanopathies and their functions. General significance O -mannosyl glycan has a novel, unique structure that is important for the maintenance of brain and muscle functions. These findings have opened up a new field in glycoscience. These studies will further contribute to the understanding of the pathomechanism of α-dystroglycanopathy and the development of glycotherapeutics. This article is part of a Special Issue entitled Neuro-glycoscience, edited by Kenji Kadomatsu and Hiroshi Kitagawa. [ABSTRACT FROM AUTHOR]
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- 2017
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14. Bacterial phosphoglycosyl transferases: initiators of glycan biosynthesis at the membrane interface.
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Lukose, Vinita, Walvoort, Marthe T. C., and Imperiali, Barbara
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GLYCANS , *GLYCOCONJUGATES , *MICROBIAL virulence , *MEMBRANE proteins , *MUTAGENESIS - Abstract
Phosphoglycosyl transferases (PGTs) initiate the biosynthesis of both essential and virulence-associated bacterial glycoconjugates including lipopolysaccharide, peptidoglycan and glycoproteins. PGTs catalyze the transfer of a phosphosugar moiety from a nucleoside diphosphate sugar to a polyprenol phosphate, to form a membrane-bound polyprenol diphosphosugar product. PGTs are integral membrane proteins, which include between 1 and 11 predicted transmembrane domains. Despite this variation, common motifs have been identified in PGT families through bioinformatics and mutagenesis studies. Bacterial PGTs represent important antibacterial and virulence targets due to their significant role in initiating the biosynthesis of key bacterial glycoconjugates. Considerable effort has gone into mechanistic and inhibition studies for this class of enzymes, both of which depend on reliable, high-throughput assays for easy quantification of activity. This review summarizes recent advances made in the characterization of this challenging but important class of enzymes. [ABSTRACT FROM AUTHOR]
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- 2017
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15. Single polysaccharide assembly protein that integrates polymerization, termination, and chain-length quality control.
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Williams, Danielle M., Ovchinnikova, Olga G., Akihiko Koizumi, Mainprize, Iain L., Kimber, Matthew S., Lowary, Todd L., and Whitfield, Chris
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LIPOPOLYSACCHARIDE structure , *PHYSIOLOGICAL effects of lipopolysaccharides , *GLYCOLIPIDS , *GLYCOCONJUGATES , *GLYCAN analysis - Abstract
Lipopolysaccharides (LPS) are essential outer membrane glycolipids in most gram-negative bacteria. Biosynthesis of the O-antigenic polysaccharide (OPS) component of LPS follows one of three widely distributed strategies, and similar processes are used to assemble other bacterial surface glycoconjugates. This study focuses on the ATP-binding cassette (ABC) transporter-dependent pathway, where glycans are completed on undecaprenyl diphosphate carriers at the cytosol:membrane interface, before export by the ABC transporter. We describe Raoultella terrigena WbbB, a prototype for a family of proteins that, remarkably, integrates several key activities in polysaccharide biosynthesis into a single polypeptide. WbbB contains three glycosyltransferase (GT) modules. Each of the GT102 and GT103 modules characterized here represents a previously unrecognized GT family. They form a polymerase, generating a polysaccharide of [4)-α-Rhap-(1→3)-β-GlcpNAc-(1→] repeat units. The polymer chain is terminated by a β-linked Kdo (3-deoxy-D-manno-oct-2-ulosonic acid) residue added by a third GT module belonging to the recently discovered GT99 family. The polymerase GT modules are separated from the GT99 chain terminator by a coiled-coil structure that forms a molecular ruler to determine product length. Different GT modules in the polymerase domains of other family members produce diversified OPS structures. These findings offer insight into glycan assembly mechanisms and the generation of antigenic diversity as well as potential tools for glycoengineering. [ABSTRACT FROM AUTHOR]
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- 2017
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16. Emerging facets of prokaryotic glycosylation.
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Schäffer, Christina and Messner, Paul
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GLYCOSYLATION , *POST-translational modification , *GLYCOCONJUGATES , *PATHOGENIC microorganisms , *GLYCOPROTEINS - Abstract
Glycosylation of proteins is one of the most prevalent post-translational modifications occurring in nature, with a wide repertoire of biological implications. Pathways for the main types of this modification, the N- and O-glycosylation, can be found in all three domains of life--the Eukarya, Bacteria and Archaea--thereby following common principles, which are valid also for lipopolysaccharides, lipooligosaccharides and glycopolymers. Thus, studies on any glycoconjugate can unravel novel facets of the still incompletely understood fundamentals of protein N- and O-glycosylation. While it is estimated that more than two-thirds of all eukaryotic proteins would be glycosylated, no such estimate is available for prokaryotic glycoproteins, whose understanding is lagging behind, mainly due to the enormous variability of their glycan structures and variations in the underlying glycosylation processes. Combining glycan structural information with bioinformatic, genetic, biochemical and enzymatic data has opened up an avenue for in-depth analyses of glycosylation processes as a basis for glycoengineering endeavours. Here, the common themes of glycosylation are conceptualised for the major classes of prokaryotic (i.e. bacterial and archaeal) glycoconjugates, with a special focus on glycosylated cell-surface proteins. We describe the current knowledge of biosynthesis and importance of these glycoconjugates in selected pathogenic and beneficial microbes. [ABSTRACT FROM AUTHOR]
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- 2017
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17. Computational Modeling of Glycan Processing in the Golgi for Investigating Changes in the Arrangements of Biosynthetic Enzymes
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A. Jamie Wood, Daniel Ungar, and Ben West
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Glycan biosynthesis ,Glycan ,Glycosylation ,biology ,Computer science ,Computational biology ,Golgi apparatus ,Biosynthetic enzyme ,carbohydrates (lipids) ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Proof of concept ,Stochastic simulation ,biology.protein ,symbols ,Approximate Bayesian computation - Abstract
Modeling glycan biosynthesis is becoming increasingly important due to the far-reaching implications that glycosylation can exhibit, from pathologies to biopharmaceutical manufacturing. Here we describe a stochastic simulation approach, to overcome the deterministic nature of previous models, that aims to simulate the action of glycan modifying enzymes to produce a glycan profile. This is then coupled with an approximate Bayesian computation methodology to systematically fit to empirical data in order to determine which set of parameters adequately describes the organization of enzymes within the Golgi. The model is described in detail along with a proof of concept and therapeutic applications.
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- 2021
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18. Alteration of serum N-glycan profile in patients with autoimmune pancreatitis.
- Author
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Tomoda, Takeshi, Nouso, Kazuhiro, Kato, Hironari, Miyahara, Koji, Dohi, Chihiro, Morimoto, Yuki, Kinugasa, Hideaki, Akimoto, Yutaka, Matsumoto, Kazuyuki, Yamamoto, Naoki, Noma, Yasuhiro, Horiguchi, Shigeru, Tsutsumi, Koichiro, Amano, Maho, Nishimura, Shin-Ichiro, and Yamamoto, Kazuhide
- Abstract
Objectives The aims of this study were to determine the change in whole-serum N-glycan profile in autoimmune pancreatitis (AIP) patients and to investigate its clinical utility. Methods We collected serum from 21 AIP patients before any treatment, and from 60 healthy volunteers (HLTs). Serum glycan profile was measured by comprehensive and quantitative high-throughput glycome analysis. Results Of the 53 glycans detected, 14 were differentially expressed in AIP patients. Pathway analysis demonstrated that agalactosyl and monogalactosyl bi-antennary glycans were elevated in AIP patients. Among the 14 glycans, #3410, #3510, and #4510 showed high area under receiver operating characteristic (AUROC) values (0.955, 0.964, and 0.968 respectively) for the diagnosis of AIP. These three glycans were mainly bound to immunoglobulin G; however, their serum levels were significantly higher, even in AIP patients who showed lower serum IgG4 levels, than in HLTs. Conclusions We demonstrated, for the first time, whole-serum glycan profiles of AIP patients and showed that the levels of glycans #3410, #3510, and #4510 were increased in AIP patients. These glycans might be valuable biomarkers of AIP. [ABSTRACT FROM AUTHOR]
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- 2016
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19. Successive remodeling of IgG glycans using a solid-phase enzymatic platform
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Shuwen Sun, Yen-Pang Hsu, Deeptak Verma, Caroline McGregor, Benjamin F. Mann, and Ian Mangion
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Glycan biosynthesis ,chemistry.chemical_classification ,Glycan ,Glycosylation ,biology ,Medicine (miscellaneous) ,Immunoglobulin G ,General Biochemistry, Genetics and Molecular Biology ,carbohydrates (lipids) ,chemistry.chemical_compound ,Enzyme ,chemistry ,Biochemistry ,IgG binding ,Polysaccharides ,biology.protein ,Humans ,Glycoprotein ,General Agricultural and Biological Sciences ,Glycoproteins - Abstract
The success of glycoprotein-based drugs in various disease treatments has become widespread. Frequently, therapeutic glycoproteins exhibit a heterogeneous array of glycans that are intended to mimic human glycopatterns. While immunogenic responses to biologic drugs are uncommon, enabling exquisite control of glycosylation with minimized microheterogeneity would improve their safety, efficacy and bioavailability. Therefore, close attention has been drawn to the development of glycoengineering strategies to control the glycan structures. With the accumulation of knowledge about the glycan biosynthesis enzymes, enzymatic glycan remodeling provides a potential strategy to construct highly ordered glycans with improved efficiency and biocompatibility. In this study, we quantitatively evaluate more than 30 enzymes for glycoengineering immobilized immunoglobulin G, an impactful glycoprotein class in the pharmaceutical field. We demonstrate successive glycan remodeling in a solid-phase platform, which enabled IgG glycan harmonization into a series of complex-type N-glycoforms with high yield and efficiency while retaining native IgG binding affinity.SignificanceGlycosylation plays critical functional and structural roles in protein biology. However, our understanding of how discrete glycan structures affect protein behaviors remains extremely limited due to the naturally occurring microheterogeneity. Through the use of characterized glycoengineering enzyme combination, we report a solid-phase glycan remodeling (SPGR) platform that enables efficient IgG glycan harmonization into several glycoforms of interest with high biocompatibility to the substrates. It provides an efficient strategy to screen the biological behavior of distinct glycoforms, building a fundamental understanding of glycosylation.
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- 2021
20. Correcting for sparsity and interdependence in glycomics by accounting for glycan biosynthesis
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Benjamin P. Kellman, James T. Sorrentino, Austin K. York, Austin W. T. Chiang, Lars Bode, Morey W. Haymond, Mahmoud A. Mohammad, Bokan Bao, Nathan E. Lewis, and Yujie Zhang
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Glycan biosynthesis ,Data Analysis ,Glycan ,Glycosylation ,Fucosyltransferase ,Statistical methods ,Computer science ,Science ,Glycobiology ,General Physics and Astronomy ,Computational biology ,Biosynthesis ,General Biochemistry, Genetics and Molecular Biology ,Article ,Glycomics ,chemistry.chemical_compound ,Gene Knockout Techniques ,Polysaccharides ,Gangliosides ,Biochemical reaction networks ,Humans ,Cluster Analysis ,Erythropoietin ,Multidisciplinary ,biology ,Mucins ,Biological Transport ,General Chemistry ,Mutant cell ,Fucosyltransferases ,Biosynthetic Pathways ,carbohydrates (lipids) ,chemistry ,biology.protein - Abstract
Glycans are fundamental cellular building blocks, involved in many organismal functions. Advances in glycomics are elucidating the essential roles of glycans. Still, it remains challenging to properly analyze large glycomics datasets, since the abundance of each glycan is dependent on many other glycans that share many intermediate biosynthetic steps. Furthermore, the overlap of measured glycans can be low across samples. We address these challenges with GlyCompare, a glycomic data analysis approach that accounts for shared biosynthetic steps for all measured glycans to correct for sparsity and non-independence in glycomics, which enables direct comparison of different glycoprofiles and increases statistical power. Using GlyCompare, we study diverse N-glycan profiles from glycoengineered erythropoietin. We obtain biologically meaningful clustering of mutant cell glycoprofiles and identify knockout-specific effects of fucosyltransferase mutants on tetra-antennary structures. We further analyze human milk oligosaccharide profiles and find mother’s fucosyltransferase-dependent secretor-status indirectly impact the sialylation. Finally, we apply our method on mucin-type O-glycans, gangliosides, and site-specific compositional glycosylation data to reveal tissues and disease-specific glycan presentations. Our substructure-oriented approach will enable researchers to take full advantage of the growing power and size of glycomics data., Glycomics can uncover important molecular changes but measured glycans are highly interconnected and incompatible with common statistical methods, introducing pitfalls during analysis. Here, the authors develop an approach to identify glycan dependencies across samples to facilitate comparative glycomics.
- Published
- 2021
21. Association between metabolic status and gut microbiome in obese populations
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Yongli Li, Shuangcheng Li, Toby Kenney, Su Feng, Hong Gu, Zhenyu Yang, Xin Feng, Yu Wang, Daxi Wang, Jiaxing Chen, Wenkui Dai, Xiaolan Zhao, Yuan He, Fei Wang, Dongfang Li, Qiang Zeng, Yuejie Zheng, Yanhong Liu, Ximing Xu, and Yinhu Li
- Subjects
Glycan biosynthesis ,China ,obesity ,gut microbiome ,Physiology ,clinical indicators ,two cohorts ,Cohort Studies ,Feces ,Metabolic Diseases ,medicine ,Humans ,Alistipes ,Research Articles ,Bacteria ,biology ,General Medicine ,biology.organism_classification ,medicine.disease ,Obesity ,Gut microbiome ,Diet ,Gastrointestinal Microbiome ,Microbial Communities ,Cohort ,Red meat ,Metagenome ,metabolic abnormality ,Odoribacter ,Biomarkers - Abstract
Despite that obesity is associated with many metabolic diseases, a significant proportion (10–30 %) of obese individuals is recognized as ‘metabolically healthy obeses’ (MHOs). The aim of the current study is to characterize the gut microbiome for MHOs as compared to ‘metabolically unhealthy obeses’ (MUOs). We compared the gut microbiome of 172 MHO and 138 MUO individuals from Chongqing (China) (inclined to eat red meat and food with a spicy taste), and performed validation with selected biomarkers in 40 MHOs and 33 MUOs from Quanzhou (China) (inclined to eat seafood and food with a light/bland taste). The genera Alistipes , Faecalibacterium and Odoribacter had increased abundance in both Chongqing and Quanzhou MHOs. We also observed different microbial functions in MUOs compared to MHOs, including an increased abundance of genes associated with glycan biosynthesis and metabolism. In addition, the microbial gene markers identified from the Chongqing cohort bear a moderate accuracy [AUC (area under the operating characteristic curve)=0.69] for classifying MHOs distinct from MUOs in the Quanzhou cohort. These findings indicate that gut microbiome is significantly distinct between MHOs and MUOs, implicating the potential of the gut microbiome in stratification and refined management of obesity.
- Published
- 2021
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- View/download PDF
22. Deciphering the glycogenome of schistosomes
- Author
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Megan Lee Mickum, Nina Salinger Prasanphanich, Jamie eHeimburg-Molinaro, Kristoffer Edgar Leon, and Richard D. Cummings
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Genome ,Glycoconjugates ,Schistosomiasis ,Glycans ,Glycosyltranferases ,Glycan biosynthesis ,Genetics ,QH426-470 - Abstract
Schistosoma mansoni and other Schistosoma sp. are multicellular parasitic helminths (worms) that infect humans and mammals worldwide. Infection by these parasites, which results in developmental maturation and sexual differentiation over a period of five to six weeks, induces antibodies to glycan antigens expressed in surface and secreted glycoproteins and glycolipids. There is growing interest in defining these unusual parasite-synthesized glycan antigens and using them to understand immune responses, their roles in immunomodulation, and in using glycan antigens as potential vaccine targets. A key problem in this area, however, has been the lack of information about the enzymes involved in elaborating the complex repertoire of glycans represented by the schistosome glycome. Recent availability of the nuclear genome sequences for Schistosoma sp. has created the opportunity to define the glycogenome, which represents the specific genes and cognate enzymes that generate the glycome. Here we describe the current state of information in regard to the schistosome glycogenome and glycome and highlight the important classes of glycans and glycogenes that may be important in their generation.
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- 2014
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23. Glycobiology of α-dystroglycan and muscular dystrophy.
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Tamao Endo
- Subjects
- *
GLYCAN structure , *EUKARYOTES , *GLYCOPROTEINS , *PEPTIDES , *MANNOSYLTRANSFERASE - Abstract
Most proteins are modified by glycans, which can modulate the biological properties and functions of glycoproteins. The major glycans can be classified into N-glycans and O-glycans according to their glycan-peptide linkage. This review will provide an overview of the O-mannosyl glycans, one subtype of O-glycans. Originally, O-mannosyl glycan was only known to be present on a limited number of glycoproteins, especially α-dystroglycan (α-DG). However, once a clear relationship was established between O-mannosyl glycan and the pathological mechanisms of some congenital muscular dystrophies in humans, research on the biochemistry and pathology of O-mannosyl glycans has been expanding. Because α-DG glycosylation is defective in congenital muscular dystrophies, which also feature abnormal neuronal migration, these disorders are collectively called α-dystroglycanopathies. In this article, I will describe the structure, biosynthesis and pathology of O-mannosyl glycans. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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- View/download PDF
24. The role of glycosylation in health and disease
- Author
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Salomé Pinho, Irena Trbojevic Akmacic, Ana Dias, Lauc, Gordan, and Trbojević-Akmačić, Irena
- Subjects
carbohydrates (lipids) ,aberrant glycosylation ,biomarker research ,critical quality attribute ,glycan biosynthesis ,glycan function ,glycans in pathogenesis ,glycoconjugates ,glycosylation of biotherapeutics ,human glycome - Abstract
Glycobiology is an emerging field of studying glycans (sugars) and glycoconjugates that are essentially involved in almost all biological processes, from fine-tuning glycoprotein function to protein-protein interactions, signaling, immune response, host-pathogen interactions, etc. However, due to structural complexity of glycans and analytical challenges this exciting field was lagging behind other areas of biology. With technological advancements growing number of glycans’ functions are being discovered and the study of glycans is becoming a cutting-edge discipline in basic and clinical research. Despite recent developments in glycobiology field, many aspects of glycosylation process still remain unknown, both in a healthy human organism and in pathological states. Human glycome is dynamic and changes with physiological triggers, immune challenges and disease. Atypical glycosylation is consequently a subject of disease biomarker research, and a target for therapeutic interventions. On the other hand, properties of glycosylated biotherapeutics are predominantly determined by their glycans. The Role of Glycosylation in Health and Disease provides a comprehensive overview of types and functions of glycans in a healthy human organism as well as their role in pathophysiology of different diseases and efficiency of glycosylated biotherapeutics. Written by the experts in the field, this book aims to bring glycobiology field closer to students, researchers in life sciences and professionals in biopharmaceutical industry.
- Published
- 2021
- Full Text
- View/download PDF
25. The Golgi localized bifunctional UDP-rhamnose/ UDP-galactose transporter family of Arabidopsis.
- Author
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Rautengarten, Carsten, Ebert, Berit, Moreno, Ignacio, Temple, Henry, Herter, Thomas, Link, Bruce, Doñas-Cofré, Daniela, Moreno, Adriàn, Saéz-Aguayo, Susana, Blanco, Francisca, Mortimer, Jennifer C., Schultink, Alex, Reiter, Wolf-Dieter, Dupree, Paul, Pauly, Markus, Heazlewood, Joshua L., Scheller, Henrik V., and Orellana, Ariel
- Subjects
- *
RHAMNOSE , *PLANT cells & tissues , *PLANT cell walls , *POLYSACCHARIDES , *NUCLEOTIDES , *MASS spectrometry , *LIPOSOMES - Abstract
Plant cells are surrounded by a cell wall that plays a key role in plant growth, structural integrity, and defense. The cell wall is a complex and diverse structure that is mainly composed of polysaccharides. The majority of noncellulosic cell wall polysaccharides are produced in the Golgi apparatus from nucleotide sugars that are predominantly synthesized in the cytosol. The transport of these nucleotide sugars from the cytosol into the Golgi lumen is a critical process for cell wall biosynthesis and is mediated by a family of nucleotide sugar transporters (NSTs). Numerous studies have sought to characterize substrate-specific transport by NSTs; however, the availability of certain substrates and a lack of robust methods have proven problematic. Consequently, we have developed a novel approach that combines reconstitution of NSTs into liposomes and the subsequent assessment of nucleotide sugar uptake by mass spectrometry. To address the limitation of substrate availability, we also developed a two-step reaction for the enzymatic synthesis of UDP-L-rhamnose (Rha) by expressing the two active domains of the Arabidopsis UDP-L-Rha synthase. The liposome approach and the newly synthesized substrates were used to analyze a clade of Arabidopsis NSTs, resulting in the identification and characterization of six bifunctional UDP-L-Rha/UDP-D-galactose (Gal) transporters (URGTs). Further analysis of loss-of-function and overexpression plants for two of these URGTs supported their roles in the transport of UDP-L-Rha and UDP-D-Gal for matrix polysaccharide biosynthesis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
26. Deciphering the glycogenome of schistosomes.
- Author
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Schnorr, Kirk Matthew, Fonseca, Cristina Toscano, and Kusel, John
- Subjects
SCHISTOSOMA ,PARASITES ,HELMINTHS ,SEX differentiation (Embryology) ,IMMUNOGLOBULINS ,IMMUNE response - Abstract
Schistosoma mansoni and other Schistosoma sp. are multicellular parasitic helminths (worms) that infect humans and mammals worldwide. Infection by these parasites, which results in developmental maturation and sexual differentiation of the worms over a period of 5-6 weeks, induces antibodies to glycan antigens expressed in surface and secreted glycoproteins and glycolipids. There is growing interest in defining these unusual parasite-synthesized glycan antigens and using them to understand immune responses, their roles in immunomodulation, and in using glycan antigens as potential vaccine targets. A key problem in this area, however, has been the lack of information about the enzymes involved in elaborating the complex repertoire of glycans represented by the schistosome glycome. Recent availability of the nuclear genome sequences for Schistosoma sp. has created the opportunity to define the glycogenome, which represents the specific genes and cognate enzymes that generate the glycome. Here we describe the current state of information in regard to the schistosome glycogenome and glycome and highlight the important classes of glycans and glycogenes that may be important in their generation. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
27. Insights into miRNA regulation of the human glycome.
- Author
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Kasper, Brian T., Koppolu, Sujeethraj, and Mahal, Lara K.
- Subjects
- *
GENETIC regulation , *MICRORNA , *GLYCAN structure , *GLYCOSYLATION , *PROTEIN expression , *PROTEIN engineering , *NON-coding RNA - Abstract
Highlights: [•] MicroRNA are an underappreciated regulator of glycosylation. [•] Key glycosylation enzymes are highly regulated by microRNA. [•] “Redudant” glycosylation enzymes are non-redundant in microRNA regulation. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
28. A systems based framework to computationally predict putative transcription factors and signaling pathways regulating glycan biosynthesis
- Author
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Theodore Groth and Sriram Neelamegham
- Subjects
Glycan biosynthesis ,chemistry.chemical_compound ,Glycan ,Glycosylation ,chemistry ,biology ,Disease progression ,biology.protein ,Computational biology ,Disease ,Signal transduction ,Transcription factor ,Chromatin Immunoprecipitation Sequencing - Abstract
Glycosylation is a common post-translational modification, and glycan biosynthesis is regulated by a set of ‘glycogenes’. The role of transcription factors (TFs) in regulating the glycogenes and related glycosylation pathways is largely unknown. This manuscript presents a multi-omics data-mining framework to computationally predict putative, tissue-specific TF regulators of glycosylation. It combines existing ChIP-Seq (Chromatin Immunoprecipitation Sequencing) and RNA-Seq data to suggest 22,519 potentially significant TF-glycogene relationships. This includes interactions involving 524 unique TFs and 341 glycogenes that span 29 TCGA (The Cancer Genome Atlas) cancer types. Here, TF-glycogene interactions appeared in clusters or ‘communities’, suggesting that changes in single TF expression during both health and disease may affect multiple carbohydrate structures. Upon applying the Fisher’s exact test along with glycogene pathway classification, we identify TFs that may specifically regulate the biosynthesis of individual glycan types. Integration with knowledge from the Reactome database provided an avenue to relate cell-signaling pathways to TFs and cellular glycosylation state. Whereas analysis results are presented for all 29 cancer types, specific focus is placed on human luminal and basal breast cancer disease progression. Overall, the computational predictions in this manuscript present a starting point for systems-wide validation of TF-glycogene relationships.
- Published
- 2020
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- View/download PDF
29. How Sweet it is! Cell Wall Biogenesis and Polysaccharide Capsule Formation in Cryptococcus neoformans.
- Author
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Doering, Tamara Lea
- Subjects
- *
BACTERIAL cell walls , *CELL membrane formation , *CRYPTOCOCCUS neoformans , *OPPORTUNISTIC infections , *BIOCOMPLEXITY , *POLYSACCHARIDE synthesis , *BIOSYNTHESIS , *MOLECULAR structure - Abstract
Cryptococcus neoformans is a pathogenic fungus responsible for severe opportunistic infections. The most prominent feature of this yeast is its elaborate polysaccharide capsule, a complex structure that is required for virulence. The capsule is intimately associated with the cell wall, which underlies the capsule and offers the organism strength and flexibility in potentially hostile environments. Both structures are primarily composed of polysaccharides, offering a glimpse of the tremendous variation inherent in natural carbohydrate structures and their multiple biological functions. The steps in cell wall and capsule biosynthesis and assembly pose fascinating questions of metabolism, enzymology, cell biology, and regulation; the answers have potential application to treatment of a deadly infection. This article reviews current knowledge of cryptococcal cell wall and capsule biosynthesis and outstanding questions for the future. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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- View/download PDF
30. Tools for Studying Glycans: Recent Advances in Chemoenzymatic Glycan Labeling
- Author
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Ben Ovryn, Matthew S. Macauley, Aime Lopez Aguilar, Jennie G. Briard, Linette Yang, and Peng Wu
- Subjects
0301 basic medicine ,Glycan biosynthesis ,Glycan ,Glycosylation ,Nucleotide sugar ,Biochemistry ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Human health ,Polysaccharides ,Glycosyltransferase ,Animals ,chemistry.chemical_classification ,biology ,Cell Membrane ,General Medicine ,carbohydrates (lipids) ,030104 developmental biology ,chemistry ,Molecular Probes ,biology.protein ,Molecular Medicine ,Bioorthogonal chemistry ,Glycoprotein - Abstract
The study of cellular glycosylation presents many challenges due, in large part, to the non-template driven nature of glycan biosynthesis and their structural complexity. Chemoenzymatic glycan labeling (CEGL) has emerged as a new technique to address the limitations of existing methods for glycan detection. CEGL combines glycosyltransferases and unnatural nucleotide sugar donors equipped with a bioorthogonal chemical tag to directly label specific glycan acceptor substrates in situ within biological samples. This article reviews the current CEGL strategies that are available to characterize cell-surface and intracellular glycans. Applications include imaging glycan expression status in live cells and tissue samples, proteomic analysis of glycoproteins, and target validation. Combined with genetic and biochemical tools, CEGL provides new opportunities to elucidate the functional roles of glycans in human health and disease.
- Published
- 2017
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- View/download PDF
31. Chemoenzymatic Approach for the Preparation of Asymmetric Bi-, Tri-, and Tetra-Antennary N-Glycans from a Common Precursor
- Author
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Albert J. R. Heck, John A. W. Kruijtzer, Tiehai Li, Tomislav Čaval, Javier Sastre Toraño, Geert-Jan Boons, Ivan A. Gagarinov, and Apoorva D. Srivastava
- Subjects
Glycan biosynthesis ,Glycan ,Glycoside Hydrolases ,Stereochemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Chemical synthesis ,Article ,Catalysis ,Colloid and Surface Chemistry ,Polysaccharides ,Glycosyltransferase ,Animals ,Humans ,Moiety ,chemistry.chemical_classification ,biology ,010405 organic chemistry ,fungi ,Substrate (chemistry) ,General Chemistry ,Oligosaccharide ,biology.organism_classification ,Combinatorial chemistry ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry ,biology.protein ,Tetra - Abstract
Progress in glycoscience is hampered by a lack of well-defined complex oligosaccharide standards that are needed to fabricate the next generation of microarrays, to develop analytical protocols to determine exact structures of isolated glycans, and to elucidate pathways of glycan biosynthesis. We describe here a chemoenzymatic methodology that makes it possible, for the first time, to prepare any bi-, tri-, and tetra-antennary asymmetric N-glycan from a single precursor. It is based on the chemical synthesis of a tetra-antennary glycan that has N-acetylglucosamine (GlcNAc), N-acetyllactosamine (LacNAc), and unnatural Galα(1,4)-GlcNAc and Manβ(1,4)-GlcNAc appendages. Mammalian glycosyltransferases recognize only the terminal LacNAc moiety as a substrate, and thus this structure can be uniquely extended. Next, the β-GlcNAc terminating antenna can be converted into LacNAc by galactosylation and can then be enzymatically modified into a complex structure. The unnatural α-Gal and β-Man terminating antennae can sequentially be decaged by an appropriate glycosidase to liberate a terminal β-GlcNAc moiety, which can be converted into LacNAc and then elaborated by a panel of glycosyltransferases. Asymmetric bi- and triantennary glycans could be obtained by removal of a terminal β-GlcNAc moiety by treatment with β-N-acetylglucosaminidase and selective extension of the other arms. The power of the methodology is demonstrated by the preparation of an asymmetric tetra-antennary N-glycan found in human breast carcinoma tissue, which represents the most complex N-glycan ever synthesized. Multistage mass spectrometry of the two isomeric triantennary glycans uncovered unique fragment ions that will facilitate identification of exact structures of glycans in biological samples.
- Published
- 2017
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- View/download PDF
32. ROLES OF N-LINKED GLYCANS IN THE ENDOPLASMIC RETICULUM.
- Author
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Helenius, Ari and Aebi, Markus
- Subjects
- *
GLYCOPROTEINS , *BIOSYNTHESIS , *SECRETION , *GOLGI apparatus , *LECTINS - Abstract
From a process involved in cell wall synthesis in archaea and some bacteria, N-linked glycosylation has evolved into the most common covalent protein modification in eukaryotic cells. The sugars are added to nascent proteins as a core oligosaccharide unit, which is then extensively modified by removal and addition of sugar residues in the endoplasmic reticulum (ER) and the Golgi complex. It has become evident that the modifications that take place in the ER reflect a spectrum of functions related to glycoprotein folding, quality control, sorting, degradation, and secretion. The glycans not only promote folding directly by stabilizing polypeptide structures but also indirectly by serving as recognition "tags" that allow glycoproteins to interact with a variety of lectins, glycosidases, and glycosyltranferases. Some of these (such as glucosidases I and II, calnexin, and calreticulin) have a central role in folding and retention, while others (such as α-mannosidases and EDEM) target unsalvageable glycoproteins for ER-associated degradation. Each residue in the core oligosaccharide and each step in the modification program have significance for the fate of newly synthesized glycoproteins. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
33. Genetic organization of chromosomal S-layer glycan biosynthesis loci of Bacillaceae.
- Author
-
Novotny, René, Pfoestl, Andreas, Messner, Paul, and Schäffer, Christina
- Abstract
S-layer glycoproteins are cell surface glycoconjugates that have been identified in archaea and in bacteria. Usually, S-layer glycoproteins assemble into regular, crystalline arrays covering the entire bacterium. Our research focuses on thermophilic Bacillaceae, which are considered a suitable model system for studying bacterial glycosylation. During the past decade, investigations of S-layer glycoproteins dealt with the elucidation of the highly variable glycan structures by a combination of chemical degradation methods and nuclear magnetic resonance spectroscopy. It was only recently that the molecular characterization of the genes governing the formation of the S-layer glycoprotein glycan chains has been initiated. The S-layer glycosylation (slg) gene clusters of four of the 11 known S-layer glycan structures from members of the Bacillaceae have now been studied. The clusters are ∼16 to ∼25 kb in size and transcribed as polycistronic units. They include nucleotide sugar pathway genes that are arranged as operons, sugar transferase genes, glycan processing genes, and transporter genes. So far, the biochemical functions only of the genes required for nucleotide sugar biosynthesis have been demonstrated experimentally. The presence of insertion sequences and the decrease of the G+C content at the slg locus suggest that the investigated organisms have acquired their specific S-layer glycosylation potential by lateral gene transfer. In addition, S-layer protein glycosylation requires the participation of housekeeping genes that map outside the cluster. The gene encoding the respective S-layer target protein is transcribed monocistronically and independently of the slg cluster genes. Its chromosomal location is not necessarily in close vicinity to the slg gene cluster. Published in 2004. [ABSTRACT FROM AUTHOR]
- Published
- 2003
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- View/download PDF
34. Synthetically Useful Glycosyltransferases for the Access of Mammalian Glycomes
- Author
-
Garrett Edmunds, Wanyi Guan, Lei Li, and Zhigang Wu
- Subjects
carbohydrates (lipids) ,Glycan biosynthesis ,Glycan ,biology ,Chemistry ,Glycosyltransferase ,biology.protein ,Computational biology - Abstract
Glycans play key roles in biological processes. However, complex glycans are not easily accessible and affordable to support diverse functional study. In the efforts of glycan syntheses, one of the most practical approaches is the strategy that employs glycosyltransferases (GTs) – the natural catalysts for glycan biosynthesis. This chapter summarizes the synthetically useful bacterial and mammalian GTs for the preparation of glycans, with an emphasis on mammalian glycans.
- Published
- 2019
- Full Text
- View/download PDF
35. Structures and functions of invertebrate glycosylation
- Author
-
Dong Li, Feifei Zhu, and Keping Chen
- Subjects
Glycan biosynthesis ,Glycan ,animal structures ,Glycosylation ,glycosylation ,Glycoconjugate ,invertebrate ,Immunology ,ved/biology.organism_classification_rank.species ,glycan profiling ,Review ,Review Article ,Computational biology ,Genome ,Glycosphingolipids ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Species Specificity ,Polysaccharides ,Animals ,Caenorhabditis elegans ,Model organism ,lcsh:QH301-705.5 ,Glycosaminoglycans ,Invertebrate ,chemistry.chemical_classification ,biology ,ved/biology ,General Neuroscience ,biology.organism_classification ,Invertebrates ,glycoconjugates ,carbohydrates (lipids) ,Caenorhabditis ,Drosophila melanogaster ,lcsh:Biology (General) ,chemistry ,biology.protein ,structure and function ,lipids (amino acids, peptides, and proteins) - Abstract
Glycosylation refers to the covalent attachment of sugar residues to a protein or lipid, and the biological importance of this modification has been widely recognized. While glycosylation in mammals is being extensively investigated, lower level animals such as invertebrates have not been adequately interrogated for their glycosylation. The rich diversity of invertebrate species, the increased database of sequenced invertebrate genomes and the time and cost efficiency of raising and experimenting on these species have enabled a handful of the species to become excellent model organisms, which have been successfully used as tools for probing various biologically interesting problems. Investigation on invertebrate glycosylation, especially on model organisms, not only expands the structural and functional knowledgebase, but also can facilitate deeper understanding on the biological functions of glycosylation in higher organisms. Here, we reviewed the research advances in invertebrate glycosylation, including N- and O-glycosylation, glycosphingolipids and glycosaminoglycans. The aspects of glycan biosynthesis, structures and functions are discussed, with a focus on the model organisms Drosophila and Caenorhabditis . Analytical strategies for the glycans and glycoconjugates are also summarized.
- Published
- 2019
- Full Text
- View/download PDF
36. Glycome informatics: using systems biology to gain mechanistic insights into glycan biosynthesis
- Author
-
Kiyoko F. Aoki-Kinoshita
- Subjects
Glycan biosynthesis ,Glycan ,Glycosylation ,biology ,Glycobiology ,Systems biology ,02 engineering and technology ,Computational biology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Glycome ,0104 chemical sciences ,carbohydrates (lipids) ,Glycomics ,chemistry.chemical_compound ,General Energy ,chemistry ,Informatics ,biology.protein ,0210 nano-technology - Abstract
Glycobiology entails the study of glycans, or carbohydrate sugar chains. Much research has been made in understanding individual glycogenes such as glycosyltransferases, and glycan structures using glycomics technologies. However, to get an overall understanding of the importance of glycosylation, current technologies are lacking, and systems biology approaches have recently been incorporated to gain better insight into glycosylation mechanisms and their applicability to biological function. Many databases organizing glycobiology data have been developed, and a variety of methods for mathematically modeling glycosylation pathways have shown to be effective. While it is known that glycans modulate signaling pathways, however, the future is wide open for systems glycobiology research.
- Published
- 2021
- Full Text
- View/download PDF
37. Mechanisms of O-Mannosyl Glycan Biosynthesis in Mammals
- Author
-
Hiroshi Manya
- Subjects
Glycan biosynthesis ,Biochemistry ,Chemistry ,Organic Chemistry ,medicine ,α dystroglycan ,Muscular dystrophy ,medicine.disease ,Fukutin - Published
- 2019
- Full Text
- View/download PDF
38. Bacterial phosphoglycosyl transferases: initiators of glycan biosynthesis at the membrane interface
- Author
-
Marthe T. C. Walvoort, Barbara Imperiali, Vinita Lukose, Massachusetts Institute of Technology. Department of Chemistry, and Massachusetts Institute of Technology. Department of Biology
- Subjects
CELL WALL SYNTHESIS ,0301 basic medicine ,Glycoconjugate ,phosphoglycosyl transferase ,Review ,Biology ,HIGH-THROUGHPUT ,CAMPYLOBACTER-JEJUNI ,Biochemistry ,Substrate Specificity ,03 medical and health sciences ,chemistry.chemical_compound ,Polyprenol ,Protein Domains ,N-linked glycosylation ,Biosynthesis ,GENERAL PROTEIN GLYCOSYLATION ,N-LINKED GLYCOSYLATION ,Escherichia coli ,membrane protein ,Enzyme Inhibitors ,NUCLEOSIDE ANTIBIOTIC MUREIDOMYCIN ,Integral membrane protein ,Conserved Sequence ,chemistry.chemical_classification ,C-TERMINAL DOMAIN ,030102 biochemistry & molecular biology ,Escherichia coli Proteins ,Cell Membrane ,PHOSPHATE GLCNAC-1-PHOSPHATE TRANSFERASE ,Gene Expression Regulation, Bacterial ,PENTAPEPTIDE TRANSLOCASE ,High-Throughput Screening Assays ,glycan biosynthesis ,Kinetics ,Transmembrane domain ,030104 developmental biology ,Hexosyltransferases ,Membrane protein ,chemistry ,ESCHERICHIA-COLI ,Carbohydrate Metabolism ,Peptidoglycan ,Glycoconjugates - Abstract
Phosphoglycosyl transferases (PGTs) initiate the biosynthesis of both essential and virulence-associated bacterial glycoconjugates including lipopolysaccharide, peptidoglycan and glycoproteins. PGTs catalyze the transfer of a phosphosugar moiety from a nucleoside diphosphate sugar to a polyprenol phosphate, to form a membrane-bound polyprenol diphosphosugar product. PGTs are integral membrane proteins, which include between 1 and 11 predicted transmembrane domains. Despite this variation, common motifs have been identified in PGT families through bioinformatics and mutagenesis studies. Bacterial PGTs represent important antibacterial and virulence targets due to their significant role in initiating the biosynthesis of key bacterial glycoconjugates. Considerable effort has gone into mechanistic and inhibition studies for this class of enzymes, both of which depend on reliable, high-throughput assays for easy quantification of activity. This review summarizes recent advances made in the characterization of this challenging but important class of enzymes., National Institutes of Health (Grant GM-039334)
- Published
- 2017
39. Structure of the N-glycans from the chlorovirus NE-JV-1
- Author
-
Cristina De Castro, Irina Agarkova, James L. Van Etten, Immacolata Speciale, Garry A. Duncan, Speciale, Immacolata, Agarkova, Irina, Duncan, Garry A., Van Etten, James L., and De Castro, Cristina
- Subjects
0301 basic medicine ,Glycan biosynthesis ,Glycan ,Glycosylation ,food.ingredient ,Proton Magnetic Resonance Spectroscopy ,Oligosaccharides ,Micractinium conductrix ,Chlorella ,Biology ,010402 general chemistry ,Rhamnose ,01 natural sciences ,Microbiology ,Viral Proteins ,03 medical and health sciences ,Residue (chemistry) ,food ,Polysaccharides ,Chlorovirus ,Phycodnaviridae ,Gene ,Molecular Biology ,Glycopeptides ,NMR analysi ,General Medicine ,Chloroviru ,0104 chemical sciences ,carbohydrates (lipids) ,Pbi viru ,030104 developmental biology ,Capsid ,Biochemistry ,Acetylation ,Virus NE-JV-1 ,biology.protein ,Capsid Proteins - Abstract
Results from recent studies are breaking the paradigm that all viruses depend on their host machinery to glycosylate their proteins. Chloroviruses encode several genes involved in glycan biosynthesis and some of their capsid proteins are decorated with N-linked oligosaccharides with unique features. Here we describe the elucidation of the N-glycan structure of an unusual chlorovirus, NE-JV-1, that belongs to the Pbi group. The host for NE-JV-1 is the zoochlorella Micractinium conductrix. Spectroscopic analyses established that this N-glycan consists of a core region that is conserved in all of the chloroviruses. The one difference is that the residue 3OMe-L-rhamnose is acetylated at the O-2 position in a non-stoichiometric fashion.
- Published
- 2017
40. Remote Regulation of Membrane Channel Activity by Site-Specific Localization of Lanthanide-Doped Upconversion Nanocrystals
- Author
-
Fang Liu, Yixi Zhou, Yanxia Tang, Gang Liu, Linna Lyu, Bengang Xing, Jing Mu, Xiangzhao Ai, Yang Zhang, and Zhenghong Zuo
- Subjects
Lanthanide ,Glycan biosynthesis ,Chemistry ,010405 organic chemistry ,Doping ,Nanotechnology ,02 engineering and technology ,General Chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,010402 general chemistry ,01 natural sciences ,Catalysis ,Photon upconversion ,0104 chemical sciences ,Nanocrystal ,Covalent bond ,Membrane channel ,0210 nano-technology ,Ion channel - Abstract
The spatiotemporal regulation of light-gated ion channels is a powerful tool to study physiological pathways and develop personalized theranostic modalities. So far, most existing light-gated channels are limited by their action spectra in the ultraviolet (UV) or visible region. Simple and innovative strategies for the specific attachment of photoswitches on the cell surface without modifying or genetically encoding channel structures, and more importantly, that enable the remote activation of ion-channel functions within near-infrared (NIR) spectral window in living systems, remain a challenging concern. Herein, metabolic glycan biosynthesis is used to achieve site-specific covalent attachment of near-infrared-light-mediated lanthanide-doped upconversion nanocrystals (UCNs) to the cell surface through copper-free click cyclization. Upon irradiation with 808 nm light, the converted emission at 480 nm could activate a light-gated ion channel, channelrhodopsins-2 (ChR2), and thus remotely control the cation influx. This unique strategy provides valuable insights on the specific regulation membrane-associated activities in vivo.
- Published
- 2016
41. Molecular characterization of copper-dependent enzymes involved in Streptomyces morphology
- Author
-
Petrus, Maria Louise Catharina, Wezel, G.P. van, Claessen, D., and Leiden University
- Subjects
Extracellular macromolecules ,Morphogenesis ,Flow cytometry ,Glycan biosynthesis ,Copper ,Streptomyces - Abstract
The filamentous soil bacteria of the genus Streptomyces are commercially exploited for the production of a wide range of natural products such as antibiotics, anticancer agents and immunosuppressants. Additionally, there is a strong interest in the use of these bacteria for the production of industrial proteins. Optimal production of these secondary metabolites and enzymes is tightly coupled to morphology. However, relatively little is known about the genetic determinants influencing the morphology of streptomycetes in liquid-grown cultures. The work presented in this thesis focuses on the formation of extracellular macromolecules and their influence on morphogenesis, with a special emphasis on the role of the cellulose synthase-like protein CslA and the radical copper oxidase GlxA in the production of a tip-localized glycan. This research is of fundamental importance for understanding the determinants of growth and development of this multicellular model organism, and at the same time may help us to further optimize their exploitation for the industrial production of secondary metabolites and enzymes.
- Published
- 2016
42. Regulation of HNK-1 (Human Natural Killer-1) Carbohydrate Expression: Multiple Control Mechanisms of Biosynthetic Enzyme Activity
- Author
-
Yasuhiko Kizuka and Shogo Oka
- Subjects
Glycan biosynthesis ,Biochemistry ,Chemistry ,Organic Chemistry - Abstract
HNK-1 糖鎖は神経系に高発現しており、記憶学習やスパイン構造の成熟に深く関与している。その構造はN- アセチルラクトサミンの非還元末端に硫酸化グルクロン酸が付加した(HSO3)-3GlcA β 1-3Gal β 1-4GlcNAc-) 特徴的なもので、生合成の中心となるのは二種のグルクロン酸転移酵素と硫酸基転移酵素である。我々は、これら転移酵素の活性が細胞内においてどのような機構で調節され、HNK-1 糖鎖の発現がどのように制御されているかに着目した。その結果、これら転移酵素群が複合体を形成して効率的に糖鎖生合成を行っていること、また厳密な細胞内局在制御により生合成活性が調節されていることなどを明らかにした。これらの事実は、HNK-1 糖鎖の発現が合成酵素の多面的な活性調節機構により厳密に制御されることを示唆している。
- Published
- 2010
- Full Text
- View/download PDF
43. Lipopolysaccharide O-antigens-bacterial glycans made to measure.
- Author
-
Whitfield C, Williams DM, and Kelly SD
- Subjects
- Lipid A biosynthesis, Gram-Negative Bacteria physiology, O Antigens biosynthesis
- Abstract
Lipopolysaccharides are critical components of bacterial outer membranes. The more conserved lipid A part of the lipopolysaccharide molecule is a major element in the permeability barrier imposed by the outer membrane and offers a pathogen-associated molecular pattern recognized by innate immune systems. In contrast, the long-chain O-antigen polysaccharide (O-PS) shows remarkable structural diversity and fulfills a range of functions, depending on bacterial lifestyles. O-PS production is vital for the success of clinically important Gram-negative pathogens. The biological properties and functions of O-PSs are mostly independent of specific structures, but the size distribution of O-PS chains is particularly important in many contexts. Despite the vast O-PS chemical diversity, most are produced in bacterial cells by two assembly strategies, and the different mechanisms employed in these pathways to regulate chain-length distribution are emerging. Here, we review our current understanding of the mechanisms involved in regulating O-PS chain-length distribution and discuss their impact on microbial cell biology., Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article., (© 2020 Whitfield et al.)
- Published
- 2020
- Full Text
- View/download PDF
44. Chemical Approaches To Perturb, Profile, and Perceive Glycans
- Author
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Nicholas J. Agard and Carolyn R. Bertozzi
- Subjects
Glycan biosynthesis ,Glycan ,Glycosylation ,Glycoside Hydrolases ,Green Fluorescent Proteins ,Computational biology ,Protein Engineering ,01 natural sciences ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Polysaccharides ,Disease biomarker ,Functional studies ,030304 developmental biology ,0303 health sciences ,biology ,010405 organic chemistry ,Glycosyltransferases ,General Medicine ,General Chemistry ,Glycome ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry ,Biochemistry ,Mutation (genetic algorithm) ,biology.protein ,Function (biology) - Abstract
Glycosylation is an essential form of post-translational modification that regulates intracellular and extracellular processes. Regrettably, conventional biochemical and genetic methods often fall short for the study of glycans, because their structures are often not precisely defined at the genetic level. To address this deficiency, chemists have developed technologies to perturb glycan biosynthesis, profile their presentation at the systems level, and perceive their spatial distribution. These tools have identified potential disease biomarkers and ways to monitor dynamic changes to the glycome in living organisms. Still, glycosylation remains the underexplored frontier of many biological systems. In this Account, we focus on research in our laboratory that seeks to transform the study of glycan function from a challenge to routine practice. In studies of proteins and nucleic acids, functional studies have often relied on genetic manipulations to perturb structure. Though not directly subject to mutation, we can determine glycan structure-function relationships by synthesizing defined glycoconjugates or by altering natural glycosylation pathways. Chemical syntheses of uniform glycoproteins and polymeric glycoprotein mimics have facilitated the study of individual glycoconjugates in the absence of glycan microheterogeneity. Alternatively, selective inhibition or activation of glycosyltransferases or glycosidases can define the biological roles of the corresponding glycans. Investigators have developed tools including small molecule inhibitors, decoy substrates, and engineered proteins to modify cellular glycans. Current approaches offer a precision approaching that of genetic control. Genomic and proteomic profiling form a basis for biological discovery. Glycans also present a rich matrix of information that adapts rapidly to changing environs. Glycomic and glycoproteomic analyses via microarrays and mass spectrometry are beginning to characterize alterations in glycans that correlate with disease. These approaches have already identified several cancer biomarkers. Metabolic labeling can identify recently synthesized glycans and thus directly track glycan dynamics. This approach can highlight changes in physiology or environment and may be more informative than steady-state analyses. Together, glycomic and metabolic labeling techniques provide a comprehensive description of glycosylation as a foundation for hypothesis generation. Direct visualization of proteins via the green fluorescent protein (GFP) and its congeners has revolutionized the field of protein dynamics. Similarly, the ability to perceive the spatial organization of glycans could transform our understanding of their role in development, infection, and disease progression. Fluorescent tagging in cultured cells and developing organisms has revealed important insights into the dynamics of these structures during growth and development. These results have highlighted the need for additional imaging probes.
- Published
- 2009
45. Insights into glycan biosynthesis in chemically-induced hepatocellular carcinoma in rats: A glycomic analysis
- Author
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Nazar Zaki, Sanjida Ahmed, Amr Amin, Diane McCarthy, Asma Bashir, and Mohamed Lotfy
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Glycan biosynthesis ,Male ,Carcinoma, Hepatocellular ,Glycosylation ,Glycomics ,Liver Neoplasms, Experimental ,Polysaccharides ,medicine ,Biomarkers, Tumor ,Animals ,Diethylnitrosamine ,Rats, Wistar ,skin and connective tissue diseases ,integumentary system ,Chemistry ,Gastroenterology ,Computational Biology ,General Medicine ,Basic Study ,medicine.disease ,digestive system diseases ,High-Throughput Screening Assays ,carbohydrates (lipids) ,Biochemistry ,Hepatocellular carcinoma ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,sense organs - Abstract
To evaluate the qualitative and quantitative changes in N-linked glycosylation, which occurred in association with diethyl nitrosamine-induced hepatocellular carcinoma (HCC) in rodents.Liver tissues of (1) normal (non-tumor-bearing) rats; and (2) tumor-bearing rats; were collected and were used for histological and GlycanMap analyses. Briefly, GlycanMap analysis is a high-throughput assay that provides a structural and quantitative readout of protein-associated glycans using a unique, automated 96-well assay technology coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and custom bioinformatics. Histopathological studies were carried out to ensure the development of HCC in the tested animals.The N-glycomic analysis revealed 5 glycans; Glc₁Man₉GlcNAc₂, Gal₂Man₃GlcNac₄Fuc₁Neu₁, Man₄GlcNac₂, Gal₂Man₃GlcNac₄Neu₃OAc₃, and Man₃GlcNac₅ Fuc₁, which showed significant changes in rat HCC tissues when compared with normal liver tissues. Four glycans were increased (P0.05) and Glc₁Man₉GlcNAc₂ was decreased (5.89 ± 0.45 vs 3.54 ± 0.21, P0.01) in HCC tissues compared to normal liver tissues. An increase (66.5 ± 1.05 vs 62.7 ± 1.1, P0.05) in high-mannose structures in HCC rats was observed compared to normal rats. Importantly, HCC rats showed an increase (P0.05) in both tumor-associated carbohydrates and in branched glycans. The changes in glycans correlated well with glycan flow changes reported in the glycan biosynthetic pathway, which indicates the importance of enzyme activities involved in glycan synthesis at different subcellular localizations.The reported HCC-associated changes in glycan flow and subcellular localization explain the increase in high mannose glycans and siayl Lewis glycans common in HCC liver tissues.
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- 2015
46. Glycan Biosynthesis: Structure, Information, and Heterogeneity
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Anjali Jaiman and Mukund Thattai
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carbohydrates (lipids) ,Glycan biosynthesis ,Factory floor ,Molecular interactions ,Glycan ,Biochemistry ,biology.protein ,Biophysics ,Computational biology ,Biology - Abstract
The surfaces of all living cells are decorated with branched sugar polymers known as glycans. These information-rich structures confer cells with a recognizable molecular identity, and underlie many specific cell-cell interactions. Analytic methods - including NMR, mass-spectrometry, and glycan arrays - now permit the routine profiling of glycans associated with various cells or proteins. This has stimulated efforts to build comprehensive and searchable glycan databases. However, from an informatics perspective glycans present multiple challenges. First, whereas nucleotide and amino acid chains are efficiently represented as strings, sugars can polymerize into complex tree-like objects. The potential combinatorial space of glycans is therefore much larger than that of proteins. Second, many specific molecular interactions appear to be mediated by groups of closely-related glycan variants rather than by a single well-defined structure. This phenomenon of “micro-heterogeneity” makes it difficult to rigorously characterize the glycan repertoire of a cell. In this workshop, I will use ideas from algorithmic self-assembly to show that glycan structure and diversity are best understood through the lens of glycan biosynthesis. I will demonstrate that a specific glycan structure is the outcome of glycosyltransferase enzymes acting according to simple rules in a specific order, like workers on a factory floor. Errors in this process produce a well-defined spectrum of glycan by-products, precisely matching the observed micro-heterogeneity in real glycan profiles. This predictive theoretical framework allows us to use glycans as sensitive cell-biological probes. It provides a unifying perspective within which the rich and growing datasets of glycan structures can be organized and fully utilized.
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- 2015
- Full Text
- View/download PDF
47. Protozoan parasite-specific carbohydrate structures
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Norton Heise, José O. Previato, Lucia Mendonça-Previato, and Adriane R. Todeschini
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Glycan biosynthesis ,Trypanosoma ,Glycan ,Molecular Sequence Data ,Plasmodium falciparum ,Carbohydrates ,Microbiology ,Immune system ,Structural Biology ,Animals ,Humans ,Parasite hosting ,Molecular Biology ,Leishmania ,Protozoan Infections ,biology ,Entamoeba histolytica ,Carbohydrate ,biology.organism_classification ,Pathogenicity ,Protozoan parasite ,Carbohydrate Sequence ,Biochemistry ,biology.protein ,Protozoa ,Glycoconjugates - Abstract
The carbohydrate moieties displayed by pathogenic protozoan parasites exhibit many unusual structural features and their expression is often developmentally regulated. These unique structures suggest a specific relationship between such carbohydrates and parasite pathogenicity. Studies of infected humans indicate that immune responses to protozoan parasites are elicited by glycan determinants on cell-surface or secreted molecules. Infections by protozoa are a major worldwide health problem, and no vaccines or efficacious treatments exist to date. Recent progress has been made in elucidating the structure and function of carbohydrates displayed by major protozoan parasites that infect man. These structures can be used as prototypes for the chemical or combined chemo-enzymatic synthesis of new compounds for diagnosis and vaccine development, or as inhibitors specifically designed to target parasite glycan biosynthesis.
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- 2005
- Full Text
- View/download PDF
48. Deconvoluting the Functions of Polypeptide N-α-Acetylgalactosaminyltransferase Family Members by Glycopeptide Substrate Profiling
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Thomas A. Gerken, Matthew R. Pratt, Howard C. Hang, Lawrence A. Tabak, Jason M. Rarick, Carolyn R. Bertozzi, and Kelly G. Ten Hagen
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Glycan biosynthesis ,Gene isoform ,Scaffold protein ,Glycan ,Molecular Sequence Data ,Clinical Biochemistry ,Enzyme-Linked Immunosorbent Assay ,Biochemistry ,Substrate Specificity ,03 medical and health sciences ,Drug Discovery ,Animals ,Amino Acid Sequence ,Molecular Biology ,030304 developmental biology ,chemistry.chemical_classification ,Pharmacology ,0303 health sciences ,biology ,030302 biochemistry & molecular biology ,Mucin ,Glycopeptides ,General Medicine ,Glycopeptide ,Rats ,carbohydrates (lipids) ,chemistry ,biology.protein ,N-Acetylgalactosaminyltransferases ,Molecular Medicine ,Glycoprotein - Abstract
The polypeptide N-α-acetylgalactosaminyltransferases (ppGalNAcTs) play a key role in mucin-type O-linked glycan biosynthesis by installing the intial GalNAc residue on the protein scaffold. The preferred substrates and functions of the >20 isoforms in mammals are not well understood. However, current data suggest that glycosylated mucin domains are created by the successive, often hierarchical, action of several specific ppGalNAcTs. Herein we analyzed the glycopeptide substrate preferences of several ppGalNAcT family members using a library screening approach. A 56-member glycopeptide library designed to reflect a diversity of glycan clustering was assayed for substrate activity with ppGalNAcT isoforms using an azido-ELISA. The data suggest that the ppGalNAcTs can be classified into at least four types, which working together, are able to produce densely glycosylated mucin glycoproteins.
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- 2004
- Full Text
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49. An Inhibitor of the Human UDP-GlcNAc 4-Epimerase Identified from a Uridine-Based Library
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Katharine A. Winans and Carolyn R. Bertozzi
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Glycan biosynthesis ,Glycosylation ,Clinical Biochemistry ,Uridine metabolism ,Biology ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Drug Discovery ,Peptide library ,Molecular Biology ,030304 developmental biology ,chemistry.chemical_classification ,Pharmacology ,0303 health sciences ,010405 organic chemistry ,Substrate (chemistry) ,General Medicine ,Uridine ,0104 chemical sciences ,carbohydrates (lipids) ,Enzyme ,chemistry ,O-linked glycosylation ,Molecular Medicine ,lipids (amino acids, peptides, and proteins) - Abstract
The biological study of O-linked glycosylation is particularly problematic, as chemical tools to control this modification are lacking. An inhibitor of the UDP-GlcNAc 4-epimerase that synthesizes UDP-GalNAc, the donor initiating O-linked glycosylation, would be a powerful reagent for reversibly inhibiting O-linked glycosylation. We synthesized a 1338 member library of uridine analogs directed to the epimerase by virtue of substrate mimicry. Screening of the library identified an inhibitor with a K(i) value of 11 microM. Tests against related enzymes confirmed the compound's specificity for the UDP-GlcNAc 4-epimerase. Inhibitors of a key step of O-linked glycan biosynthesis can be discovered from a directed library screen. Progeny thereof may be powerful tools for controlling O-linked glycosylation in cells.
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- 2002
- Full Text
- View/download PDF
50. Deciphering the glycogenome of schistosomes
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Nina Salinger Prasanphanich, Jamie Heimburg-Molinaro, Megan L. Mickum, Richard D. Cummings, and Kristoffer E. Leon
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Glycan ,lcsh:QH426-470 ,030231 tropical medicine ,Review Article ,Biology ,Microbiology ,Genome ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Antigen ,schistosomiasis ,glycosyltransferases ,parasitic diseases ,Genetics ,genome ,Genetics (clinical) ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Developmental maturation ,Glycosyltranferases ,biology.organism_classification ,Glycome ,glycoconjugates ,3. Good health ,glycan biosynthesis ,lcsh:Genetics ,chemistry ,Immunology ,biology.protein ,glycans ,Molecular Medicine ,Schistosoma mansoni ,Glycoprotein - Abstract
Schistosoma mansoni and other Schistosoma sp. are multicellular parasitic helminths (worms) that infect humans and mammals worldwide. Infection by these parasites, which results in developmental maturation and sexual differentiation of the worms over a period of 5–6 weeks, induces antibodies to glycan antigens expressed in surface and secreted glycoproteins and glycolipids. There is growing interest in defining these unusual parasite-synthesized glycan antigens and using them to understand immune responses, their roles in immunomodulation, and in using glycan antigens as potential vaccine targets. A key problem in this area, however, has been the lack of information about the enzymes involved in elaborating the complex repertoire of glycans represented by the schistosome glycome. Recent availability of the nuclear genome sequences for Schistosoma sp. has created the opportunity to define the glycogenome, which represents the specific genes and cognate enzymes that generate the glycome. Here we describe the current state of information in regard to the schistosome glycogenome and glycome and highlight the important classes of glycans and glycogenes that may be important in their generation.
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- 2014
- Full Text
- View/download PDF
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