Clinical and laboratory observations on serum folate-binding protein

Clinical and laboratory observations on serum folate-binding protein.

We studied the effect of serum folate-binding protein (FBP) on folate radioassays and the relationship of the serum level of unsaturated FBP to the serum folate level in various clinical states. Our modification of a heat-extracted radioassay was compared to a whole serum radioassay. Our results confirmed the existence of elevated serum levels of unsaturated FBP in some normal subjects, in some...

Binding characteristics of folate to high affinity folate binding protein purified from porcine serum.

High affinity folate binding protein (HFBP) in porcine serum was purified 2,000-fold to a specific activity of 1.4 nmol of tetrahydrofolic acid (THF) bound per mg of protein, using folic acid (FA) coupled EAH-Sepharose gel affinity chromatography. Binding activity of purified HFBP to folate was examined by ultrafiltration method linked to high-performance liquid chromatography with electrochemi...

Characteristics of folic acid-binding protein in folate-deficient serum.

Immobilized purified folate-binding protein: binding characteristics and use for quantifying folate in erythrocytes.

Purified folate-binding protein from cow's milk was immobilized on monodisperse polymer particles (Dynospheres) activated by rho-toluenesulfonyl chloride. Leakage from the spheres was less than 0.1%, and the binding properties were similar to those of the soluble protein with regard to dissociation, pH optimum for binding pteroylglutamic acid, and specificity for binding various folate derivati...

The weak binding reaction between folate and human serum proteins.

New evidence is presented that folic acid in serum binds with low affinity to major serum proteins. This low affinity binding is distinct from the high affinity binding by folate binding protein (FBP), a minor protein which is known to occur in serum with great quantitative variability. These conclusions are based on results obtained by equilibrium dialysis of serum containing only negligible a...