Purification of Hageman factor (factor XII) on columns of popcorn-agarose.

Purification of Hageman factor (HF, factor XII) from human plasma is a tedious procedure and the product is not always in the precursor form. Hojima has described a protein derived from corn kernels that inhibits the enzymatic properties of HF. This inhibitor binds to the precursor form of HF. Rapid purification of HF was achieved by using as the major purification step adsorption of this clotting factor to popcorn inhibitor bound to agarose. The product had a specific activity of 50.0 to 67.1 coagulant units of HF per milligram protein, and the yield was 33% to 40% of the HF content of the starting plasma. The purified protein displayed a single band upon unreduced or reduced sodium dodecyl sulfate polyacrylamide gel electrophoresis and less than 0.1% was in an activated form, as measured in coagulant assays. The technique described is more rapid and reliable than methods described earlier.