Glycomics, an analogous term to genomics and proteomics, is the comprehensive study of glycomes (the entire complement of sugars, whether free or present in more complex molecules, of an organism), including genetic, physiologic, pathologic, and other aspects.^[1][2] Glycomics "is the systematic study of all glycan structures of a given cell type or organism" and is a subset of glycobiology.^[3] The term glycomics is derived from the chemical prefix for sweetness or a sugar, "glyco-", and was formed to follow the naming convention established by genomics (which deals with genes) and proteomics (which deals with proteins).

Contents 1 Challenges 2 Importance 3 Tools used 3.1 High Resolution Mass Spectrometry 3.2 Lectin and Antibody Array 3.3 Metabolic and covalent labeling of glycans 4 See also 5 References 6 External links

[edit] Challenges

• The complexity of sugars: regarding their structures, they are not linear instead they are highly branched. Moreover, glycans can be modified (modified sugars), this increase its complexity.
• Complex biosynthetic pathways for glycans.
• Usually glycans are found either bound to protein (glycoprotein) or conjugated with lipids (glycolipids).
• Unlike genomes, glycans are highly dynamic.

This area of research has to deal with an inherent level of complexity not seen in other areas of applied biology. 68 building blocks (molecules for DNA, RNA and proteins; categories for lipids; types of sugar linkages for saccharides) provide the structural basis for the molecular choreography that constitutes the entire life of a cell. DNA and RNA have four building blocks each (the nucleosides or nucleotides). Lipids are divided into eight categories based on ketoacyl and isoprene. Proteins have 20 (the amino acids). Saccharides have 32 types of sugar linkages.^[4]. While these building blocks can be attached only linearly for proteins and genes, they can be arranged in a branched array for saccharides, further increasing the degree of complexity.

[edit] Importance

To answer of this question one should know the different and important functions of glycans. The following are some of those functions:

• Gylcoproteins found on the cell surface play a critical role in bacterial and viral recognition.
• They are involved in cellular signaling pathways.
• They affect the stability and folding of proteins.
• There are many glycan-specific diseases.

[edit] Tools used

The following are examples of the commonly used techniques in glycan analysis ^[5]

[edit] High Resolution Mass Spectrometry

The most applied method in which the glycan part of a glycoprotein is separated from the protein and subjected to analysis by multiple rounds of mass spectrometry. In case of glycolipids, they can be analyzed directly without separation of the lipid component. Mass spectrometry can be used in conjunction with HPLC.

Table 1:Advantages and disadvantages of mass spectrometry in glycan analysis

Advantages	Disadvantages
Applicable for small sample size. Useful if the sample contain multiple glycan of any type. For glycoprotein, can identify the site of attachment between the glycan and the protein.	Destructive method. No information about the modified glycan ( e.g. sulfation and acetylation). Need separate experimental design for every glycan subtype.

[edit] Lectin and Antibody Array

It provides high-throughput screening of many samples containing glycans. This method uses either naturally occurring lectins or artificial monoclonal antibodies, where both are immobilized on a certain chip and incubated with a fluorescent glycoprotein sample.

[edit] Metabolic and covalent labeling of glycans

Metabolic labeling of glycans can be used as a way to detect glycan structures. A well known strategy involves the use of azide-labeled sugars which can be reacted using the Staudinger ligation. This method has been used for in vitro and in vivo imaging of glycans.

[edit] See also

• Proteomics
• Omics
• List of omics topics in biology
• Metabolomics
• Lipidomics
• Cytomics
• Interactomics
• systems biology

[edit] References

[edit] External links

• Functional Glycomics Gateway, a collaboration between the Consortium for Functional Glycomics and the Nature Publishing Group
• glycosciences.de This site provides databases and bioinformatics tools for glycobiology and glycomics.
• Technology for Glycomics and Glycotechnology A list at The National Institutes of Health (NIH)

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