Preparation of Highly Purified Intrinsic Factor.

Abstract

A highly potent intrinsic factor preparation was obtained from desiccated hog stomach by ammonium sulfate fractionation, digestion with proteolytic enzymes, alcohol fractionation and finally ultrafiltration. The ultrafiltration residue fraction proved effective in pernicious anemia patients in relapse at a daily dose of 1 or 2 mg together with vitamin B12. This fraction is the most potent intrinsic factor preparation from hog mucosa reported to be effective in the therapy of pernicious anemia patients in relapse. Electrophoresis and ultracentrifuge studies of this fraction showed that the major portion of the material was a component with a molecular weight of about 5000. Preliminary separation in the ultracentrifuge and clinical evaluation of this homogeneous component suggested strongly that it was intrinsic factor. The ultrafiltration residue fraction contained 15.2% glucosamine and 11.8% nitrogen. Ascribing all the binding capacity of UFR fraction to the low molecular weight component would require that over 1000 molecules of this component be necessary to bind 1 molecule of vitamin B12. It appears that vitamin B12 binding is not a property of intrinsic factor.