Vitamin B 12 binding by intrinsic factor.

Intrinsic factor antibodies and intrinsic factor mediated vitamin B-12 absorption in pernicious anaemia.

Vitamin B 12-binding Protein of Leukocytes

Much evidence suggests that granulocytes are a major source of serum vitamin B12-binding protein (BBP). The latter has three components: a-iglobulin BBP (Transcobalamin I, TC I), fl-globulin BBP (TC II), and a recently described third BBP. Granulocytic BBP has appeared to be identical to TC I except in electrophoretic mobility. In the present study, the dominant BBP of leukocyte extracts from s...

Longitudinal concentrations of vitamin B(12) and vitamin B(12)-binding proteins during uncomplicated pregnancy.

BACKGROUND Because reference values for vitamin B(12) concentrations and vitamin B(12)-binding capacities for pregnant women have not been established, the reference values for nonpregnant women are often applied to assess vitamin B(12) status. The aim of the present study was to describe ranges of biochemical indices of vitamin B(12) status, including red blood cell (RBC) vitamin B(12), satura...

Role of third serum vitamin B 12 binding protein in vitamin B 12 transport.

A third vitamin B(12) binding protein present in normal serum has been shown to participate in transport of labelled vitamin B(12) absorbed from the gut. All three vitamin B(12) binding proteins in serum were labelled at the same time after oral administration of vitamin B(12), implying that "free" vitamin B(12) reached the portal blood from the gut mucosa.

Isolation of gastric vitamin B 12 -binding proteins using affinity chromatography. I. Purification and properties of human intrinsic factor.

Human intrinsic factor has been isolated from gastric juice. The protein was purified 853-fold with a yield of 85 % utilizing affinity chromatography on vitamin Blz-Sepharose as the sole purification technique. The final preparation was homogeneous based on polyacrylamide gel electrophoresis and sedimentation equilibrium ultracentrifugation. The isolated protein (20 pg) corrected vitamin Blz ma...