Glycan array
Glycan arrays,{{cite journal|vauthors=Carroll GT, Wang D, Turro NJ, Koberstein JT|title=Photochemical Micropatterning of Carbohydrates on a Surface|journal=Langmuir|date=2006|volume=22|issue=6 |pages=2899–2905|doi=10.1021/la0531042|pmid=16519501 }} like that offered by the Consortium for Functional Glycomics (CFG), National Center for Functional Glycomics (NCFG) and [http://www.zbiotech.com/ 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 or protein interaction Protein microarrays.
Glycan arrays are composed of various oligosaccharides and/or polysaccharides immobilised on a solid support in a spatially-defined arrangement.{{cite journal|vauthors=Oyelaran O, Gildersleeve JC|title=Glycan arrays: recent advances and future challenges|journal=Curr Opin Chem Biol|date=Oct 2009|volume=13|issue=4|pages=406–413|doi=10.1016/j.cbpa.2009.06.021|pmid=19625207|pmc=2749919 }} 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 receptors or possibly a whole organism such as a virus. Binding is quantified using fluorescence-based detection methods. Certain types of glycan microarrays can even be re-used for multiple samples using a method called Microwave Assisted Wet-Erase.{{cite journal |last1=Mehta |first1=Akul Y |last2=Tilton |first2=Catherine A |last3=Muerner |first3=Lukas |last4=von Gunten |first4=Stephan |last5=Heimburg-Molinaro |first5=Jamie |last6=Cummings |first6=Richard D |title=Reusable glycan microarrays using a microwave assisted wet-erase (MAWE) process |journal=Glycobiology |date=14 November 2023 |volume=34 |issue=2 |doi=10.1093/glycob/cwad091 |pmid=37962922|pmc=10969520 }}
Applications
Glycan arrays have been used to characterize previously unknown biochemical interactions. For example, photo-generated glycan arrays have been used to characterize the immunogenic properties of a tetrasaccharide found on the surface of anthrax spores.{{cite journal|vauthors=Wang D, Carroll GT, Turro NJ, Koberstein JT, Kováč P, Saksena R, Adamo R, Herzenberg LA, Herzenberg LA, Steinman L|title=Photogenerated glycan arrays identify immunogenic sugar moieties of Bacillus anthracis exosporium|journal=Proteomics|date=2007|volume=7|issue=2 |pages=180–184|doi=10.1002/pmic.200600478|doi-access=free|pmid=17205603 }} Hence, glycan array technology can be used to study the specificity of host-pathogen interactions.
Early on, glycan arrays were proven useful in determining the specificity of the Hemagglutinin (influenza) of the Influenza A virus binding to the host and distinguishing across different strains of flu (including avian from mammalian). This was shown with CFG arrays {{cite journal|vauthors=Stevens J, Blixt O, Tumpey TM, Taubenberger JK, Paulson JC, Wilson IA|title=Structure and receptor specificity of the hemagglutinin from an H5N1 influenza virus|journal=Science|date=Apr 2006|volume=312|issue=5772|pages=404–410|doi=10.1126/science.1124513|pmid=16543414|bibcode=2006Sci...312..404S|doi-access=}} as well as customised arrays.{{cite journal|vauthors=Childs RA, Palma AS, Wharton S, Matrosovich T, Liu Y, Chai W, Campanero-Rhodes MA, Zhang Y, Eickmann M, Kiso M, Hay A, Matrosovich M, Feizi T|title=Receptor-binding specificity of pandemic influenza A (H1N1) 2009 virus determined by carbohydrate microarray|journal=Nat Biotechnol|date=Sep 2009 |volume=27|issue=9|pages=797–799|doi=10.1038/nbt0909-797|pmid=19741625|pmc=3771066}}
Cross-platform benchmarks led to highlight the effect of glycan presentation and spacing on binding.{{cite journal |vauthors=Wang L, Cummings RD, Smith DF, Huflejt M, Campbell CT, Gildersleeve JC, Gerlach JQ, Kilcoyne M, Joshi L, Serna S, Reichardt NC, Parera Pera N, Pieters RJ, Eng W, Mahal LK|title=Cross-platform comparison of glycan microarray formats|journal= Glycobiology |date= Jun 2014|volume=24|issue=6|pages=507–17|doi=10.1093/glycob/cwu019|pmid= 24658466 |pmc=4001710}}
Glycan arrays are possibly combined with other techniques such as Surface Plasmon Resonance (SPR) to refine the characterisation of glycan-binding. For example, this combination led to demonstrate the calcium-dependent heparin binding of Annexin A1 that is involved in several biological processes including inflammation, apoptosis and membrane trafficking.{{cite journal |vauthors=Horlacher T, Noti C, de Paz JL, Bindschädler P, Hecht ML, Smith DF, Fukuda MN, Seeberger PH|title=Characterization of annexin A1 glycan binding reveals binding to highly sulfated glycans with preference for highly sulfated heparan sulfate and heparin|journal=Biochemistry|date=Apr 2011|volume=50|issue=13|pages=2650–9|doi=10.1021/bi101121a|pmid= 21370880 |pmc=3068229}}