Glycosaminoglycans (GAG) bind cationic metal ions because of their ability to form complexes. The molecular basis of this complex formation is largely not understood. A06 investigates the relationship between the binding affinity of cationic imaging probes and GAG structure. For this purpose, GAG sequences of defined structure, identified in disease models, are chemically synthesised. The binding affinity to cationic imaging probes will be investigated with in vitro binding assays. Binding with corresponding imaging probes in tissue sections will be characterised in co-localisation experiments using monoclonal antibodies (mAb) generated against the synthesised GAG sequences. mAb labelled with Gd chelate will be used for in vivo imaging experiments. The results will contribute to a better understanding of the binding of cationic imaging probes to GAGs at the molecular level.