The structural basis for the interaction of carbohydrates with PfEMP1 proteins in malaria pathogenicity. (360G-Wellcome-083181_Z_07_Z)

We have developed an expression system that allows us to produce large quantities of correctly folded, functional DBL domains from carbohydrate binding PfEMP1 proteins. We have also produced crystals of a chondroitin sulphate A (CSA) binding DBL domain. We will use these tools to investigate the structural basis for binding of CSA to this domain. (i) We will determine the structure of a CSA binding DBL domain. (ii) We will develop a quantitative binding assay to investigate the interaction be tween CSA and the DBL domain. (iii) We will use this assay to determine the minimum fragment of CSA that binds to the DBL domain. We will also mutate residues of the DBL domain that are predicted to play a role in CSA binding and determine the effect of these mutations on the interaction. (iv) We will grow crystals of the DBL domain in the presence of CSA disaccharides, and short defined fragments of CSA, enabling us to determine the structure of the complex between the DBL domain and CSA. ( v) We will express and purify heparan sulphate binding DBL domains and use similar structural and biochemical studies to investigate the interaction between the DBL domains and heparan sulphates.