No abstract

Binding of serum folic acid activity (FAA) to the protein fractions during and after pregnancy was studied by DEAE Sephadex A-50 gel chromatography. Towards the end of pregnancy, this binding increased. The increase was particularly distinct in the binding to transferrin. At the same time, the binding to α-2-macroglobulin decreased. Within a week after delivery, the total protein binding of FAA decreased remarkably. The decrease was also particularly distinct for transferrin

In the serum chromatographies of healthy subjects folic acid activity (FAA) was eluted from the column in the same fractions as α₂- macroglobulin, transferrin and albumin, in this order quantitatively. Diphenylhydantoin markedly increased the binding of FAA to serum proteins, especially transferrin. A similar pronounced increase took place in myeloma, hyperthyreosis and hepatitis. In osteomyelitis the binding had decreased clearly in all protein fractions. Whenever the serum FAA had fallen below 3.0 ng/ml, all activity was bound to serum proteins. The chromatographic aberrations in FAA distribution following various pathological conditions, were seen mainly in the transferrin and α₂-macroglobulin area. No conclusions can as yet be drawn on the basis of the present study concerning the specificity of these aberrations

Sephadex G-200 chromatographies of the liver cell sap of rabbits, 1, 3 and 6 days after an injection of ³H-folic acid activity (FAA) into the circulation, were used in an attempt to study the binding of this labelled FAA to liver proteins. The labelled FAA was quickly accumulated in the liver, and in the cell sap it was grouped chromatographically to two maxima, which corresponded to the two maxima of microbiological FAA (L. casei). The maxima were eluated in the chromatography together with cell sap proteins. The possible coupling of FAA to proteins in the liver is discussed.