Molecular dynamics simulations of hyaluronan have revealed the inherent flexibility of this glycosaminoglycan in solution. Crystal structures of hyaluronan-digesting enzymes have provided the first direct insights into the molecular basis of hyaluronan-protein interactions. Various studies on hyaluronan-binding proteins suggest there is considerable diversity in their mode of interaction with hyaluronan, which might result in many different bound conformations of the polysaccharide.