Semi-preparative isolation of phosphopeptides derived from bovine casein and dephosphorylation of casein phosphopeptides.

Semi-preparative isolation of casein phosphopeptides (CPP) from a tryptic hydrolysate of bovine casein was performed applying a three-step procedure consisting of solid phase extraction, reversed phase HPLC and ion exchange chromatography. Dephosphorylation of CPP was achieved using immobilized alkaline phosphatase. The purified phosphopeptides and their dephosphorylated forms obtained by these methods are suitable for comparative studies on biological activities, especially mineral binding and immunmodulation.