Abstract
A method for the purification of intrinsic factor from normal human gastric juice was described. The pepsin-inactivated neutralized gastric juice was saturated or partially saturated with radioactive vitamin B12 and purified by a sequential column chromatography using Sephadex G-100 gel, DEAE-cellulose and Sephadex G-50 gel. The purified materials obtained by this purification proved intrinsic factor active by Schilling test in a total gastrectomy patient. This material had about 60-fold increase in vitamin B12 binding capacity as compared with the dialyzed gastric juice. The final product was homogeneous on ultracentrifugal analysis, and showed the sedimentation coefficient of 10.5 S with the estimated molecular weight of approximately 150, 000. This was composed of 16 amino acids, of which threonine, serine, proline, glutamic acid, glycine, alanine and aspartic acid were relatively high in amount. The minimal molecular weight was considered to be approximately 10, 000.
