PURIFICATION OF HEPARIN-BINDING PROTEIN HBP17 AND IDENTIFICATION OF HBP17 HEPARIN-BINDING SITE

HBp17 was purified by Heparin-Copper biaffinity chromatography and HPL C from conditioned medium of A431 cell. The purified HBp17 was digeste d by staphylococcus urcus V-8 protease or chymotrypsin and the heparin -binding fragments were isolated by Heparin-Sepharose. One binding sit e of peptide mapping is HBp17 residues 110-145 produced by V-8. Anothe r one is HBp17 residues 82-143 which were produced by chymotrypsin dig estion. Two binding sites of peptide mapping are overlap. Therefore th e residues 110-143 of HBp17 are the principle heparin binding site. Th e basic amino acid cluster in this region may be contribute to the bin ding of HBp17 to heparin or heparan sulfate proteoglycan on the cell s urface and extracellular matrix.