Studies of the structural changes invoked in proteins by the binding of the glycosaminoglycan (GAG) polysaccharide portion of proteoglycans are of increasing importance to research in a wide range of fields, from biochemistry and molecular biology to biotechnology and medicine. One important aspect is the degree of stabilisation or destabilisation induced in a protein by the binding of these anionic materials, and this can affect enzyme activity, the stability of complexes, folding and the formation of aggregates, including those in neurodegenerative processes.