Screening Carbohydrate-Active Enzymes - a Fluorescent Solution

In all domains of life, the formation of complex carbohydrates requires the concerted action of a multitude of glycosyltransferases (GTs), enzymes that catalyse the transfer of a sugar from a sugar-nucleotide donor onto an acceptor oligosaccharide chain. Such glycosylation reactions are central to many fundamental biological processes, such as cell signalling, cellular adhesion, carcinogenesis, the evasion of the immune system by human pathogens and, of particular interest in the context of this proposed study, the generation of the complex and dynamic 3D architecture that is the plant cell wall. In contrast to other protein families of comparable size and biological significance, our understanding of GT biology remains fragmented, due to a lack of molecular tools for the investigation of GT substrate specificity. Existing GT assays are generally labour- and/or cost-intensive and/or require specialist equipment. Our approach to this problem is through the design, synthesis and application of novel fluorescent sugar probes, which can be used to identify GTs and to determine their substrate specificity.

Novel fluorescent sugar nucleotide probes developed in the Wagner group possess several advantages over conventional fluorophores previously used in protein bioassays: (i) the structural difference to the natural donor substrate is minimal; (ii) the binding characteristics are very similar to those of the natural ligand; (iii) the chemical synthesis of the fluorescent sugar-nucleotides is straightforward; and (iv) the same synthetic strategy can be used for the development of different fluorescent UDP-sugars, both with regard to the identity of the sugar and the properties of the fluorophore. The novel fluorophores proposed herein are therefore ideally suited for the efficient development of fluorescent probes for the investigation of sugar-nucleotide-dependent enzymes.

Who will benefit from this research and how will they benefit? Carbohydrates play a central role in life as we know, whether in relation to diet, energy or the (biorenewable) materials around us. Outcomes from this project will thus have direct relevance for a number of key stakeholder groups. For industry (e.g. pharmaceutical companies), there is the prospect of new technologies for high through-put screening against therapeutic targets. Indirectly, therefore, the public in general will benefit from improved therapeutic treatments in the future. Furthermore, carbohydrates are key dietary components as well as contributing to feedstocks for bioenergy production, again providing broad impact on and benefit to the public. What will be done to ensure that they benefit from this research? The applicants will work closely with JIC and UEA to effect knowledge transfer to the private sector, policy bodies and consumers and to maximise the potential for the fundamental science described in the proposal to be transferred to the appropriate stakeholders. Any intellectual property arising from the project will be protected via the normal JIC/UEA routes supported by expertise at PBL (Plant Bioscience Limited), the commercialisation company on the Norwich Research Park. Knowledge transfer will be crucial and at key points during the project we would expect to discuss progress with appropriate stakeholders. The Communications teams at JIC/UEA will provide advice and support on public engagement and wider social impact issues as the importance of consumer ownership of outcomes emanating from this knowledge cannot be underestimated. A number of dissemination techniques will be employed (web/print/event/media), to encourage science participation, and support understanding amongst Technology Transfer and Knowledge Transfer recipients. The project offers an opportunity to showcase BBSRC research through the arrangement of conferences, with support through expertise and facilities available on-site.