Conformation of hyaluronate in neutral and alkaline solutions

Increasing the pH of a neutral salt solution of sodium hyaluronate to 12.5 produces a rapid drop in viscosity which is reversible upon restoring the pH to neutrality. Light scattering data showing a decrease in radius of gyration with no change in molecular weight and negative results with chondroitin and other acidic glycosaminoglycans suggest that the conformational change is specific for hyaluronate molecules.