The diversity and size of the human glycome is unknown. Recent studies have revealed that the human genome encodes thousands of glycoproteins, and that glycosylation is likely the most common type of post-translational modification. But how many different glycans are there? What are their relative levels of expression? Does each glycan structure have a function, either in human biology or in disease processes, such as innate immunity and resistance to infection? How does glycan expression change in response to age and disease? It has been known for decades that different cells and tissues make different glycan structures, and recent advances in methods for analysis of glycan structures has led to modern glycomics, which is mainly devoted to identifying glycan structures. Unfortunately, while knowing chemical structures is important, in a sense it only confirms what we already know;different cells make different glycan structures. While knowledge of all glycan structures may solve a chemical puzzle, it does not provide a biological solution to glycan function. We propose a new glycomic approach to link glycan structure to function/recognition using our new developments in """"""""glyco-chemistry"""""""" that allow us to fluorescently tag free glycans released from specific cell or tissue glycoconjugates. These novel, bifunctional, fluorescent tags allow us to detect sub-microgram quantities of glycans that are otherwise undetectable, and purify them by chromatographic methods to obtain tissue- and/or cell- specific tagged-glycan libraries (TGLs). The tagged glycans retain a functional group to allow covalent """"""""printing"""""""" of these libraries as microarrays. Such microarrays can subsequently be interrogated with glycan binding proteins (GBPs), pathogens, and cells to identify functionally recognized and biologically significant glycans, which will then be structurally defined. This novel approach avoids the laborious process of defining all glycan structures in a glycome regardless of their functional or recognition, and allows us to focus structural analyses on potentially biological relevant glycans. Developing glycomic TGLs is analogous to the """"""""Shotgun"""""""" approach to defining the human genome, but allows us to target our analyses to link glycan structure to function. Defining all of the glycan structures of the human glycome is analogous to sequencing the human genome. The complexity of the human glycome and the lack of automated glycan sequencing methods make a """"""""brute-force"""""""" approach to defining the glycome impractical. Here we propose a paradigm- shifting strategy, which is a combination of """"""""shotgun"""""""" and targeted approaches. We will assemble amino functionalized, fluorescent-tagged glycan libraries from specific cells or tissues, print them as glycan microarrays, identify potentially biologically relevant glycans that are recognized by glycan binding proteins, and structurally define the recognized glycans. The stable, libraries and glycan microarrays produced will remain as a tangible resource for future analyses of both glycan structure and function.

Public Health Relevance

Defining all of the glycan structures of the human glycome is analogous to sequencing the human genome. The complexity of the human glycome and the lack of automated glycan sequencing methods make a brute-force approach to defining the glycome impractical. Here we propose a paradigm- shifting strategy, which is a combination of shotgun and targeted approaches. We will assemble amino functionalized, fluorescent-tagged glycan libraries from specific cells or tissues, print them as glycan microarrays, identify potentially biologically relevant glycans that are recognized by glycan binding proteins, and structurally define the recognized glycans. The stable, libraries and glycan microarrays produced will remain as a tangible resource for future analyses of both glycan structure and function.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM085448-03
Application #
7901072
Study Section
Special Emphasis Panel (ZGM1-GDB-7 (EU))
Program Officer
Marino, Pamela
Project Start
2008-08-01
Project End
2012-07-31
Budget Start
2010-08-01
Budget End
2011-07-31
Support Year
3
Fiscal Year
2010
Total Cost
$306,900
Indirect Cost
Name
Emory University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Jankowska, Ewa; Parsons, Lisa M; Song, Xuezheng et al. (2018) A comprehensive Caenorhabditis elegans N-glycan shotgun array. Glycobiology 28:223-232
Song, Xuezheng; Ju, Hong; Lasanajak, Yi et al. (2016) Oxidative release of natural glycans for functional glycomics. Nat Methods 13:528-34
Mickum, Megan L; Prasanphanich, Nina Salinger; Song, Xuezheng et al. (2016) Identification of Antigenic Glycans from Schistosoma mansoni by Using a Shotgun Egg Glycan Microarray. Infect Immun 84:1371-1386
Yu, Ying; Lasanajak, Yi; Song, Xuezheng et al. (2014) Human milk contains novel glycans that are potential decoy receptors for neonatal rotaviruses. Mol Cell Proteomics 13:2944-60
Smith, David F; Cummings, Richard D (2014) Investigating virus-glycan interactions using glycan microarrays. Curr Opin Virol 7:79-87
Halder, Sujata; Cotmore, Susan; Heimburg-Molinaro, Jamie et al. (2014) Profiling of glycan receptors for minute virus of mice in permissive cell lines towards understanding the mechanism of cell recognition. PLoS One 9:e86909
Song, Xuezheng; Heimburg-Molinaro, Jamie; Cummings, Richard D et al. (2014) Chemistry of natural glycan microarrays. Curr Opin Chem Biol 18:70-7
Byrd-Leotis, Lauren; Liu, Renpeng; Bradley, Konrad C et al. (2014) Shotgun glycomics of pig lung identifies natural endogenous receptors for influenza viruses. Proc Natl Acad Sci U S A 111:E2241-50
Song, Xuezheng; Ju, Hong; Zhao, Chunmei et al. (2014) Novel strategy to release and tag N-glycans for functional glycomics. Bioconjug Chem 25:1881-7
Ashline, David J; Yu, Ying; Lasanajak, Yi et al. (2014) Structural characterization by multistage mass spectrometry (MSn) of human milk glycans recognized by human rotaviruses. Mol Cell Proteomics 13:2961-74

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