Binding Characteristics of Folate to High Affinity Folate Binding Protein Purified from Porcine Serum.

1999 ◽  
Vol 61 (7) ◽  
pp. 743-748 ◽  
Author(s):  
Masahiro NATSUHORI ◽  
Maki OKADA ◽  
Ryo IDA ◽  
Kazuaki SASAKI ◽  
Minoru SHIMODA ◽  
...  
Keyword(s):  
Binding Protein ◽  
Folate Binding Protein ◽  
Binding Characteristics ◽  
Porcine Serum ◽  
High Affinity

A high-affinity folate binding protein in human urine. Radioligand binding characteristics, immunological properties and molecular size

1989 ◽  
Vol 9 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Steen Ingemann Hansen ◽  
Jan Holm ◽  
Mimi Høier-Madsen
Keyword(s):  
Human Urine ◽  
Radioligand Binding ◽  
Binding Protein ◽  
Molecular Size ◽  
Enzyme Linked Immunosorbent Assay ◽  
Folate Binding Protein ◽  
Binding Characteristics ◽  
High Affinity ◽  
Large Peak ◽  
Apparently Healthy

High-affinity binding of [3H]folate in human urine displayed characteristics, e.g. apparent positive cooperativity, which are typical of specific folate binding. By means of a two-site enzyme-linked immunosorbent assay (ELISA) with rabbit antibodies against the low molecular weight folate binding protein from human milk, we measured folate binding protein concentrations in the range of 0.51 to 4.13 nM in urine samples from 16 apparently healthy individuals. Ultrogel AcA 44 chromatography of the urine showed that immunoreactive and radioligand bound folate binding protein coeluted in one large peak (Mr∼25,000).

A high-affinity folate binding protein in normal human leukocytes: Ligand binding characteristics, ionic charge and molecular size

1985 ◽  
Vol 5 (8) ◽  
pp. 683-688 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
J⊘rgen Lyngbye
Keyword(s):  
Binding Protein ◽  
Molecular Size ◽  
Binding Activity ◽  
Ionic Charge ◽  
Folate Binding Protein ◽  
Human Leukocytes ◽  
Binding Characteristics ◽  
High Affinity ◽  
Chromatographic Profile ◽  
Triton X

High-affinity binding of [3H]folate to supernatant from homogenized human leukocytes containing large amounts of binding protein displayed apparent positive cooperativity. The DEAE-Sepharose® CL-6B chromatographic profile of the supernatant at pH 6.3 contained a major peak of folate binding (Mr approx. 25 000) in the front effluent and a smaller more acidic peak (Mr approx. 25 000) that emerged after a rise in NaCl from 30 mmol/l to 1 mol/l. Triton X-100 solubilized ceil sediment from the leukocyte homogenate contained some high-affinity folate binding activity (Mr approx 25 000), typically 5–10% of the total binding activity.

A high-affinity folate binding protein in human amniotic fluid. Radioligand binding characteristics, immunological properties and molecular size

1990 ◽  
Vol 10 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
Mimi Høier-Madsen
Keyword(s):  
Amniotic Fluid ◽  
Radioligand Binding ◽  
Binding Protein ◽  
Equilibrium Dialysis ◽  
Affinity Constant ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Amniotic Fluid ◽  
Folate Binding Protein ◽  
Binding Characteristics ◽  
High Affinity

The presence of a folate binding protein of high-affinity type (affinity constant 5 · 109M−1, maximum folate binding 3 nM) in human amniotic fluid was demonstrated in equilibrium dialysis experiments (37°C, pH 7.4) with the radioligand3H-folate. Dissociation of3H-folate from the binding protein was slow at pH 7.4 but rapid at pH 3.5. By use of rabbit antibodies against low molecular weight folate binding protein from human milk we determined the concentration of folate binding protein in 5 amniotic fluids (range 1.5–2.3 nM) in an Enzyme-Linked Immunosorbent Assay (ELISA). ultrogel AcA 44 chromatography of amniotic fluid showed that immunoreactive and radioligand bound folate binding protein coeluted in two peaks: a major one (Mr~25 000) and a minor one (Mr~100 000).

A high affinity folate binding protein in umbilical cord serum

1980 ◽  
Vol 40 (6) ◽  
pp. 523-527 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
Jörgen Lyngbye
Keyword(s):  
Umbilical Cord ◽  
Binding Protein ◽  
Folate Binding Protein ◽  
Cord Serum ◽  
High Affinity

High-affinity folate binding in human prostate

1993 ◽  
Vol 13 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
Mimi Høier-Madsen
Keyword(s):  
Human Milk ◽  
Binding Protein ◽  
Cross Reactivity ◽  
Human Prostate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gel Chromatography ◽  
Folate Binding Protein ◽  
High Affinity ◽  
Sds Page ◽  
Triton X

Binding of 3H-folate in Triton X-100 solubilized human prostate homogenate was of a high-affinity type and displayed apparent positive cooperativity typical of specific folate binding. Radioligand dissociation was slow at pH 7.4, but rapid at pH 3.5. Gel chromatography reveled two major folate binding proteins (Mr≈100 and 25kDa), but only one single band (Mr ≈ 65–70 kDa) was detectable on SDS-PAGE and immunoblotting with rabbit-anti human milk folate binding protein. Concentration of folate binding protein in prostate homogenate expressed as maximum 3H-folate binding was 1.10 nmol/g protein, and the cross-reactivity with rabbit-anti human milk folate binding protein serum was 15% as determined by an enzyme-linked immunosorbent assay (median values; n = 6).

Characterization of a High-Affinity Folate Receptor in Normal and Malignant Human Testicular Tissue

1999 ◽  
Vol 19 (6) ◽  
pp. 571-580 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
Mimi Høier-Madsen ◽  
Thomas Broe Christensen ◽  
Carl W. Nichols
Keyword(s):  
Human Milk ◽  
G Protein ◽  
Radioligand Binding ◽  
Binding Protein ◽  
Folate Receptor ◽  
Testicular Tissue ◽  
Hydrophobic Membrane ◽  
Folate Binding Protein ◽  
High Affinity ◽  
Triton X

We have characterized the folate receptor in normal and malignant tissue from male gonads. Radioligand binding displayed characteristics typical of other folate receptors. Those included a high-affinity type of binding (K = 1010 M−1), apparent positive cooperativity changing into non-cooperativity at low receptor concentrations, a tendency to increased binding affinity with decreasing receptor concentrations, a slow dissociation at pH 7.4 becoming rapid at pH 3.5 and inhibition by folates, in particular oxidized forms. The gel filtration profile of Triton X-100 solubilized tissue contained a 25 and 100 kDa peak of radioligand-receptor. The latter peak could represent receptor equipped with a hydrophobic membrane anchor that inserts into Triton X-100 micelles. The concentration of radiolabelled receptor ranged from 0.41 nmol/g protein to 1.68 nmol/g protein in specimens of normal testicular tissue from patients with prostatic carcinomas and from 1.54 nmol/g protein to 3.82 nmol/g protein in testicular tissue from young individuals. Compared to normal testicular tissue the concentration of receptor in seminoma tissue was low (0.38–1.27 nmol/g protein) but showed a higher degree of immunoreactivity in the presence of antibodies against human milk folate binding protein as evidenced by ELISA and immunohistochemistry data. Hence a folate receptor isoform homologous to human milk folate binding protein is apparently expressed in seminomas where the total expression of receptor, however, seems to be lower than in normal testicles.

Role of high-affinity folate-binding protein in the plasma distribution of tetrahydrofolate in pigs

1996 ◽  
Vol 270 (1) ◽  
pp. R105-R110 ◽  
Author(s):  
K. Sasaki ◽  
M. Natsuhori ◽  
M. Shimoda ◽  
Y. Saima ◽  
E. Kokue
Keyword(s):  
Protein Binding ◽  
Binding Capacity ◽  
Binding Protein ◽  
Folate Binding Protein ◽  
High Affinity ◽  
Plasma Distribution ◽  
The Stability ◽  
Plasma Ultrafiltrate

Stability and protein-binding properties of tetrahydrofolate (THF) in pig plasma were studied in vitro. THF in plasma was stable for more than 120 min when it existed in a bound form, whereas THF both in plasma ultrafiltrate and in plasma ultrafiltrate plus porcine albumin was degraded rapidly and disappeared soon after its addition. These results suggest that high-affinity folate-binding protein (HFBP) is related to the stability of THF. THF-protein binding kinetic analysis showed that porcine plasma had HFBP and low-affinity binding protein (albumin) for THF. Dissociation constant and maximal binding capacity of HFBP were calculated to be 0.4 and 70 nM, respectively, indicating that > 98% of endogenous plasma THF existed in bound form with HFBP. Porcine albumin was not essentially a protein that binds and protects endogenous THF from degradation. We conclude that most endogenous THF binds to HFBP and only the unbound form of THF is rapidly degraded in pig plasma. HFBP protects THF from degradation and allows THF to exist stably in pig plasma. In addition, HFBP may govern the species specificity of plasma folate distribution in pigs.

Effect of Hydrogen Ion Concentration and Buffer Composition on Ligand Binding Characteristics and Polymerization of Cow's Milk Folate Binding Protein

2001 ◽  
Vol 21 (6) ◽  
pp. 745-753 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen
Keyword(s):  
Ligand Binding ◽  
Binding Protein ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Cow’S Milk ◽  
Folate Binding Protein ◽  
Hydrogen Ion Concentration ◽  
Binding Characteristics ◽  
Cow's Milk ◽  
Buffer Composition

The ligand binding and aggregation behavior of cow's milk folate binding protein depends on hydrogen ion concentration and buffer composition. At pH 5.0, the protein polymerizes in Tris-HCl subsequent to ligand binding. No polymerization occurs in acetate, and binding is markedly weaker in acetate or citrate buffers as compared to Tris-HCl. Polymerization of ligand-bound protein was far more pronounced at pH 7.4 as compared to pH 5.0 regardless of buffer composition. Binding affinity increased with decreasing concentration of protein both at pH 7.4 and 5.0. At pH 5.0 this effect seemed to level off at a protein concentration of 10−6 M which is 100–1000 fold higher than at pH 7.4. The data can be interpreted in terms of complex models for ligand binding systems polymerizing both in the absence or presence of ligand (pH 7.4) as well as only subsequent to ligand binding (pH 5.0).

A high-affinity folate binding protein in human cerebrospinal fluid

2009 ◽  
Vol 71 (2) ◽  
pp. 133-135 ◽  
Author(s):  
Steen Ingemann Hansen ◽  
Jan Holm ◽  
Jørgen Lyngbye
Keyword(s):  
Cerebrospinal Fluid ◽  
Binding Protein ◽  
Folate Binding Protein ◽  
High Affinity ◽  
Human Cerebrospinal Fluid
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