Binding of Folic Acid Activity by Body Fluids

Carrier Proteins of Folic Acid Activity in Human Serum

“…In our earlier studies we have been able to show that serum FAA was divided into 3 maxima: the largest (about 60%) outside the protein band, a small portion (about 5%) in the band of large-molecular proteins, and the vast majority of the FAA of the protein band (about 30-35% of the total FAA) in the band of small-molecular proteins [3][4][5]. As a result of the present study, it was seen that the last mentioned FAA-carrying serum fraction was albumin.…”

“…1). The technical solution of this problem may be very difficult, for according to preliminary studies these fractions carry several high-molecular proteins [5], difficult to differentiate. It may be pointed out, however, that FAA is firmly bound even in these fractions, for the complex withstands chemical and physical manipulations without degradation.…”

“…Carrier proteins of folic acid Disc electrophoresis Folic acid fractions Folic acid in human serum Hydroxyapatite chromato graphy According to our earlier studies, the folic acid activity (FAA) in the serum of healthy human subjects was divided, on Sephadex® G-25 gel filtration, into 2 main fractions: some 40% were inside and 60% outside the protein band [5], Continued studies revealed that the FAA of the protein band is firmly attached to proteins. No separation was achieved either by ammonium sulphate precipitation or by repeated Sephadex filtrations.…”

“…One of these was filtered with the highmolecular proteins [4,5] and amounted to some 5% of the total serum FAA. The other, about 30-40% of the total FAA, was filtered from the column with the small-molecular proteins [5], This fraction will be reviewed in detail in the following study. …”

Comparison between the Unsaturated Plasma Folate Binder and <i>in vivo</i> Labelled Plasma Folate Binder

“…The binder of endogenous plasma folate has been reported to bind ap proximately one-third [19,20] to one-half [15] of plasma folate, or 1-5 pg/l in normal plasma [2]. The main endogenous binder is chromatographically albumin-associated [8,13,19,20] on DEAE-A50 columns, although minor binders associated with a2-macroglobulins [21] and even transferrin [22] have been suggested.…”