|Based in the School of Chemistry at Newcastle University, we are organic chemists performing creative and imaginative research in the fields of polymer and supramolecular chemistry. Here you can find out more about what’s going on in our laboratory, including our current and research. The DAF group are based in the School of Chemistry's Chemical Nanoscience Laboratory, and have received generous funding from EPSRC, EU-FP7, The Royal Society, and the regional development agency OneNorthEast.|
News and Research Highlights
Orthogonal Bond Breaking and Forming
The design and study of functional systems of molecules is an area of interest within the growing field of systems chemistry. The concept of orthogonality, which is well-established in synthetic chemistry, has started to emerge as a powerful tool to embed increased sophistication into functional systems. Stunning examples of e.g. molecular machines, interlocked molecules, dynamic combinatorial libraries and responsive materials have all recently emerged where orthogonal supramolecular interactions lie at the heart of their unique features.
So-called dynamic covalent bonds (DCBs) present possibilities as potential orthogonal supramolecular interactions, and in this work (click here) we demonstrate how two well-known DCBs—disulfide and imine bonds—can be selectively cleaved and reformed in the presence of the other upon the application of orthogonal stimuli. Key to this achievement is the judicious choice of reaction partners to ensure that no unwanted competing processes are present, and the establishment of well-defined operating limits within which the system is shown to retain its orthogonality.
This work will pave the way for the future development of more complex responsive chemical systems and materials.
Templating carbohydrate polymers with lectins
Carbohydrate-protein interactions are important in biology, playing important roles in cell-cell interactions and infections caused by viral and bacterial pathogens. For example, cholera is caused by proteins secreted by the Vibrio cholera bacteria and which start their process of cell infection by binding to carbohydrates displayed on the surfaces of cells. Consequently, there has been much effort to understand better carbohydrate-protein interactions with the aim of developing effective inhibitors which may lessen the effects of the cholera toxin.
In work described in Organic and Biomolecular Chemistry (click here), we describe a conceptually new method for preparing synthetic polymers which can bind to heat labile toxin, a carbohydrate binding protein which is structurally very similar to cholera toxin. Our method uses the protein itself to act as a template, onto which the polymer binds and selects carbohydrate residues which improve its binding affinity from a pool of residues. These residues can adapt their positions upon the polymer to maximize their binding with toxin. We show that the polymer is able to enhance its binding by about one order of magnitude, selecting those carbohydrate residues which presumably promote stronger binding and discarding those which do not. We anticipate that we will be able to build upon this proof of concept and develop polymers which can bind more strongly to carbohydrate-binding proteins.
May 2016 DAF gave a Xuetong lecture at Tsinghua University in Beijing, hosted by Prof Xi Jiang. The trip also included visits to the groups of Yapei Wang at Renmin University and Shu Wang at the Chinese Academy of Sciences, Institute of Chemistry.