The conformation and structure of GAGs: recent progress and perspectives.

The glycosaminoglycan (GAG) family of linear sulphated polysaccharides are involved in most regulatory processes in the extracellular matrix of higher organisms. The relationship between GAG substitution pattern and activity, however, remains unclear and experimental evidence suggests that subtle conformational factors play an important role. The difficulty of modelling these complex charged molecules shifts the burden of investigation towards experimental techniques. Recent advances in complementary physical-chemical, particularly spectroscopy-based approaches are reviewed, together with methods for analysing the resulting complex data. The prospects for combining some of these approaches and fitting them into the wider context of interactions, are also discussed.