Preparation and Characterization of Glycosaminoglycan Chemokine Coreceptors

Interactions between chemokines and glycosaminoglycans (GAGs) are crucial for the physiological and pathophysiological activities of chemokines. GAGs are therefore commonly designated as chemokine coreceptors which are deeply involved in the chemokine-signaling network. Studying the interaction of chemokines with GAGs is therefore a major prerequisite to fully understand the biological function of chemokines. GAGs are, however, a very complex class of biomacromolecules which cannot be produced by conventional recombinant methods and which, if purchased from commercial suppliers, are often not subjected to rigorous quality control and therefore frequently differ in batch characteristics. This naturally impacts chemokine-GAG interaction studies. In order to standardize the quality of our GAG ligands, we have therefore established protocols for the preparation and characterization of GAGs from various cells and tissues, for which we give practical examples relating to the major GAG classes heparin, heparan sulfate, and chondroitin sulfate. We will also outline robust and sensitive protocols for chemokine-GAG interaction studies. By this means, a better and more common understanding of the involvement of GAGs in chemokine-signaling networks can be envisaged.