Blood, 1953, Vol. 8, No. 6, pp. 491-501.
© 1953 American Society of Hematology, Inc.
Concentration of Intrinsic Factor and Vitamin B12-Binding
Activities of Fractions of Desiccated Hog Stomach
W. H. PRUSOFF PH.D.1,
A. D. WELCH M.D.1,
R. W. HEINLE M.D.1, and
G. C. MEACHAM M.D.1
1 Departments of Pharmacology and Medicine, School of Medicine, Western
Reserve University and University Hospitals, Cleveland, Ohio.
Fractionation of desiccated defatted hog stomach through the use of isoelectric
and ammonium sulfate precipitation technics, and guided by assays in patients
with pernicious anemia in relapse given daily oral doses of 5 µg. of vitamin B12,
has led to the concentration of intrinsic factor activity in an amount of protein
equivalent to 0.03 per cent of the original weight of crude material. The electrophoretic pattern of this active fraction indicated a lack of homogeneity.
The vitamin B12-binding activities of three fractions obtained by precipitation
with ammonium sulfate were investigated by microbial inhibition and dialysis
methods. There was no correlation between the ability of the fractions to bind
vitamin B12 and to exert intrinsic factor activity. Among these fractions, that
with the highest intrinsic factor activity in patients with pernicious anemia in
relapse bound the least amount of vitamin B12.
Submitted on October 28, 1952
Accepted on November 26, 1952
