Abstract
Hog intrinsic factor (IF) was purified by DEAE-cellulose batchwise elution and DEAE- and CM-cellulose column chromatography. Only one B12 binding protein (PHIF) was obtained, which was IF-active at the dose as low as 0.4mg. PHIF had B12 binding capacity of 23.0μg/mg protein when studied by dialysis, and was found homogeneous, when studied by paper electrophoresis, ultracentrifugation and absorption spectrometry. The molecular weight of PHIF was calculated from the sedimentation coefficient of 3.4S, and was found to be about 50, 000.
On chemical analysis, it consisted of 18 amino acids, and hexose, hexosamines, fucose, and sialic acid. The composition of amino acids was determined.
The possible model of B12 binding was also discussed on the basis of the molar ratio of PHIF's molecular weight to B12.
