Bovine nasal proteoglycans: study of the cyanogen bromide fragments from the protein-keratan sulphate core and the hyaluronic acid-binding region

The protein-keratan sulphate core has been obtained by chondroztinase treatment of the proteoglycan monomers. The hyaluronic acid-binding region of the proteoglycans was prepared by trypsin treatment of the proteoglycans under their associated form. Both preparations were submitted to cyanogen bromide treatemnt. The fragments were separated by gel filtrations and polyacrylamide gel electrophoreses. The protein-keratan sulphate core gave rise to two main classes of fragments: the larger ones apparently arose from the polysaccharide attachment region of the monomers; among the smaller ones four appeared to be connected to one of the larger fragments by disulphide bridges. The hyaluronic acid-binding region gave rise to fragments whose electrophoretic mobilities were similar to those of some of the smaller fragments characterized in the cyanogen bromide treated protein keratan sulphate core. The molecular weights as well as the amino acid and sugar compositions of all the cyanogen bromide fragments are reported.