Glycan arrays, like that offered by the
Consortium for Functional Glycomics
The Consortium for Functional Glycomics (CFG) is a large research initiative funded in 2001 by a glue grant from the National Institute of General Medical Sciences (NIGMS) to “define paradigms by which protein-carbohydrate interactions mediate ...
(CFG),
National Center for Functional Glycomics
The National Center for Functional Glycomics is an organization that is focused on the development of technology development in glycosciences. They are specifically focused on glycan analysis and molecular mechanisms of glycan recognition by protei ...
(NCFG) an
Z Biotech, LLC contain carbohydrate compounds that can be screened with lectins, antibodies or cell receptors to define carbohydrate specificity and identify ligands. Glycan array screening works in much the same way as other microarray that is used for instance to study gene expression
DNA microarrays
A DNA microarray (also commonly known as DNA chip or biochip) is a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to g ...
or protein interaction
Protein microarray
A protein microarray (or protein chip) is a high-throughput method used to track the interactions and activities of proteins, and to determine their function, and determining function on a large scale. Its main advantage lies in the fact that larg ...
s.
Glycan arrays are composed of various
oligosaccharides
An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/; from the Greek ὀλίγος ''olígos'', "a few", and σάκχαρ ''sácchar'', "sugar") is a saccharide polymer containing a small number (typically two to ten) of monosaccharides (simple suga ...
and/or
polysaccharides
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with w ...
immobilised on a solid support in a spatially-defined arrangement.
This technology provides the means of studying glycan-protein interactions in a high-throughput environment. These natural or synthetic (see
carbohydrate synthesis) glycans are then incubated with any glycan-binding protein such as
lectins,
cell surface receptor
Cell surface receptors (membrane receptors, transmembrane receptors) are receptors that are embedded in the plasma membrane of cells. They act in cell signaling by receiving (binding to) extracellular molecules. They are specialized integral m ...
s or possibly a whole organism such as a
virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
. Binding is quantified using fluorescence-based detection methods.
Applications
The glycan array technology has been and still is applied to study the specificity of
host-pathogen interactions.
Early on, glycan arrays were proven useful in determining the specificity of the
Hemagglutinin (influenza)
Influenza hemagglutinin (HA) or haemagglutinin .html" ;"title="/sup>">/sup> (British English) is a homotrimeric glycoprotein found on the surface of influenza viruses and is integral to its infectivity.
Hemagglutinin is a Class I Fusion Pro ...
of the
Influenza A virus
''Influenza A virus'' (''IAV'') causes influenza in birds and some mammals, and is the only species of the genus ''Alphainfluenzavirus'' of the virus family ''Orthomyxoviridae''. Strain (biology)#Microbiology or virology, Strains of all subtypes ...
binding to the host and distinguishing across different strains of flu (including avian from mammalian). This was shown with CFG arrays
as well as customised arrays.
Cross-platform benchmarks led to highlight the effect of glycan presentation and spacing on binding.
Glycan arrays are possibly combined with other techniques such as
Surface Plasmon Resonance
Surface plasmon resonance (SPR) is the resonant oscillation of conduction electrons at the interface between negative and positive permittivity material in a particle stimulated by incident light. SPR is the basis of many standard tools for measu ...
(SPR) to refine the characterisation of
glycan-binding. For example, this combination led to demonstrate the calcium-dependent heparin binding of
Annexin A1
Annexin A1, also known as lipocortin I, is a protein that is encoded by the ''ANXA1'' gene in humans.
Function
Annexin A1 belongs to the annexin family of Ca2+-dependent phospholipid-binding proteins that have a molecular weight of approximat ...
that is involved in several biological processes including
inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
,
apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...
and
membrane trafficking Membrane vesicle trafficking in eukaryotic animal cells involves movement of biochemical signal molecules from synthesis-and-packaging locations in the Golgi body to specific release locations on the inside of the plasma membrane of the secretory ...
.
References
{{Reflist
Microarrays
Glycobiology
Glycomics
Carbohydrates