Purification and characterization of human plasma Zn-alpha 2-glycoprotein

Zn-alpha 2-glycoprotein (Zn alpha 2gp) was purified from fresh human plasma approximately 670-fold in a yield of 18% over the fractions from DEAE-Sephadex A-50 column chromatography. The purified protein was a glycoprotein with molecular weights of 56,000 and 57,000 on Superose and Sephadex G-150 column chromatographies and of 41,000 and 42,000 on nonreduced SDS-PAGE. Characterization, which included a determination of molecular weight, amino acid composition, amino terminus, and antigenicity, correlated well with known values previously reported for human Zn alpha 2gp.