Isolation of bovine corneal keratan sulfate and its growth factor and morphogen binding

Abstract

Keratan sulfate (KS) is an important glycosaminoglycan that is found in cartilage, reproductive, and neural tissues. Corneal KS glycosaminoglycan is found N-linked to lumican, keratocan, and mimecan proteoglycans and has been widely studied by investigators interested in corneal development and diseases. Recently, the availability of corneal KS has become severely limited due to restricted the shipment of bovine central nervous system by-products across international borders in efforts to prevent additional cases of mad cow disease. We report a simple method for the purification of multi-milligram quantities of bovine corneal KS and characterize its structural properties. We also examined its protein-binding properties and discovered that corneal KS bound with high affinity to fibroblast growth factor-2 and sonic hedgehog, a growth factor and a morphogen involved in corneal development and healing.