Extraction and purification of protein and proteoglycan from bovine bone

To establish a method for extracting and purificating proteins and proteoglycans from bovine bone, the extracting method using different step solutions on the basis of collagen and proteoglycans exiting state was analyzed. First, alkaline and acidic proteins were extracted by 0.6 mol/L KCl and 0.5 mol/L K-P(K₂HPO₄/KH₂PO₄) solution, respectively. The 0.1 mol/L HCl extracts contain acidic and neutral (or alkaline) proteins, and they can alternatively disjoin from extraction by neutralize the solution to pH 7.0, the acidic protein deposit with hydroxyapatite, and the neutral protein in the supernatant. Other non-collagenous proteins, which bound to the collagen fibrils could be extracted by 0.5 mol/L NaCl and 1% Na₂CO₃ solution respectively. The acidic and alkaline proteins were detected by SDS-polyacrylamide gel electrophoresis, Stains All staining, Alcine blue staining and CBB staining. The alkaline protein, acidic protein and proteoglycans were effectively purified from each fraction by using DEAE-sephacel column.