The complexity of Glycomics is set to overtake that of the field of proteomics and genomics due to the vast diversity of glycosylation on both lipids and proteins. Over 95% of the mammalian cell surface is decorated with both glycolipids and glycoproteins, and scientists are only now beginning to understand the complex nature of the binding events between carbohydrates and pathogens such as bacteria, viruses and parasites. The development of glycotechnologies has enabled studies into the identification and characterisation of glycan binding properties of various pathogens.
The Institute for Glycomics array facility has the technology to decipher the glycan binding profile of whole bacterial cells, viruses, eukaryotic cell lines as well as purified proteins. Flexibility of the array enables the determination of the “glycocode” of bacteria can aid in deciphering the role glycans have in bacterial adherence, colonisation and disease progression. These glycan interactions can also be further elucidated through quantitative methods such as surface Plasmon resonance (SPR) and isothermal titration calorimetry (ITC). In vitro studies are performed utilising techniques such as SPR, flow cytometry, ELISA and NMR, to understand the nature of these glycan binding interactions and use them in the development of diagnostics and therapeutics.
Here we describe how glycan array technology identified specific glycan targets of F9 fimbriae of UPEC by comparative analysis of the binding profiles of wild-type and mutant bacteria. The recombinant protein was further analysed to ensure specificity. By taking specific host cell expressed glycans, we demonstrated that pre-treating the bacteria with free glycans, inhibited binding to structures on the array and associated human cell lines. Therefore we determined not only the role this specific protein has in glycan binding, but whether these events are important in host-bacterial interactions.