Hyaluronan binding to link module of TSG-6 and to G1 domain of aggrecan is differently regulated by pH.

The physiological functions of hyaluronan (HA) in the extracellular matrix of vertebrate tissues involve a range of specific protein interactions. In this study, the interaction of HA with the Link module from TSG-6 (Link_TSG6) and G1 domain of aggrecan (G1), were investigated by a biophysical analysis of translational diffusion in dilute solution using confocal fluorescence recovery after photobleaching (confocal FRAP). Both Link_TSG6 and G1 were shown to bind to polymeric HA and these interactions could be competed with HA(8) and HA(10) oligosaccharides, respectively.