A Procedure for Isolation of Human Protein C and Protein S as by-Products of the Purification of Factors VII, IX, X and Prothrombin

Abstract A DEAE-Sephadex column chromatography step utilized to purify human Factor VII consistently yields a protein peak between the factor VII activity peak and prothrombin, factor X and factor IX activity peak (S.P. Bajaj, S.I. Rapaport, and S.F. Brown: J. Biol. Chem. 251., 253-259, 1981). We now report that this protein peak contains protein C and protein S. Preparative disc polyacryla-mide gel electrophoresis of the proteins in this peak 'permitted a complete separation of protein C from protein S. Protein C at this step usually contained approximately 5-10% of Factor X, which could be removed by a goat anti-human Factor X antibody column. For a typical preparation, starting with 10L of plasma, the yield of Protein C was 5 mg and of protein S was 4 mg. Both proteins