Characterization of a folate receptor in parotid gland and a folate binding protein in saliva from humans. Epitope relatedness to human milk folate binding proteinNote

Apmis ◽  
2000 ◽  
Vol 108 (7-8) ◽  
pp. 517-524 ◽  
Author(s):  
JAN HOLM ◽  
STEEN INGEMANN HANSEN ◽  
MIMI HOIER-MADSEN ◽  
CARL W. NICHOLS
Keyword(s):  
Parotid Gland ◽  
Human Milk ◽  
Binding Protein ◽  
Folate Receptor ◽  
Folate Binding Protein

Characterization of a folate receptor in parotid gland and a folate binding protein in saliva from humans: Epitope relatedness to human milk folate binding protein

Apmis ◽  
2008 ◽  
Vol 108 (7-8) ◽  
pp. 517-524
Author(s):  
JAN Holm ◽  
STEEN INGEMANN Hansen ◽  
MIMI HØIer-Madsen ◽  
CARL W. Nichols
Keyword(s):  
Parotid Gland ◽  
Human Milk ◽  
Binding Protein ◽  
Folate Receptor ◽  
Folate Binding Protein

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.

Ligand Binding Characteristics of Two Molecular Forms, One Equipped with a Hydrophobic Glycosyl Phosphatidylinositol Tail, of the Folate Binding Protein Purified from Human Milk

2002 ◽  
Vol 22 (3-4) ◽  
pp. 455-463 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen
Keyword(s):  
Ligand Binding ◽  
Human Milk ◽  
Radioligand Binding ◽  
Binding Protein ◽  
Folate Receptor ◽  
Molecular Size ◽  
Molecular Forms ◽  
Folate Binding Protein ◽  
Binding Characteristics ◽  
Scatchard Plots

Two molecular forms of the folate binding protein were isolated and purified from human milk by a combination of cation exchange- and affinity chromatography. One protein (27 kDa) was a cleavage product of the other 100 kDa protein as evidenced by N-terminal amino acid sequence homology and a reduction in the molecular size of the latter protein to 27 kDa after cleavage of its hydrophobic glycosylphosphatidylinositol tail by phosphatidylinositol-specific phospholipase C. High-affinity binding of [3H]folate was characterized by upward convex Scatchard plots and increasing ligand binding affinity with decreasing concentrations of both proteins. Downward convex Scatchard plots and binding affinities showing no dependence on the protein concentration were, however, observed in highly diluted solutions of both proteins. Radioligand binding was inhibited by folate analogs, and dissociation of radioligand was slow at pH 7.4 but rapid and complete at pH 5.0 and 3.5. Ligand binding quenched the tryptophan fluorescence of the 27 kDa protein suggesting that tryptophan is present at the binding site and/or ligand binding induces a conformation change that affects tryptophan environment in the protein. The 27 kDa protein representing soluble folate binding protein exhibited a greater affinity for ligand binding than the 100 kDa protein which possesses a hydrophobic tail identical to the one that anchors the folate receptor to the cell membrane.

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).

Purification and characterization of a folate binding protein from porcine choroid plexus

1981 ◽  
Vol 208 (1) ◽  
pp. 87-94 ◽  
Author(s):  
Suleiman A. Suleiman ◽  
Reynold Spector
Keyword(s):  
Choroid Plexus ◽  
Binding Protein ◽  
Purification And Characterization ◽  
Folate Binding Protein

A Folate Binding Protein in Ascitic Fluid, Serum and Ovarian Tissue of Patients with Ovarian Adenocarcinoma Immunoreacts with Antibodies Against Human Milk Folate Binding Protein

1998 ◽  
Vol 18 (2) ◽  
pp. 49-57 ◽  
Author(s):  
Jan Holm ◽  
Steen Ingemann Hansen ◽  
Mimi Høier-Madsen ◽  
Poul-Erik Helkjær
Keyword(s):  
Human Milk ◽  
Ovarian Carcinoma ◽  
Ascitic Fluid ◽  
Radioligand Binding ◽  
Binding Protein ◽  
Ovarian Tissue ◽  
Tissue Homogenate ◽  
Ovarian Adenocarcinoma ◽  
Folate Binding Protein ◽  
Carcinoma Tissue

The presence of a folate binding protein which immunoreacts with antibodies against human milk folate binding protein was demonstrated in ascitic fluids from seven patients with ovarian adenocarcinoma. Ascitic fluids collected from two patients with other malignancies contained non-immunoreactive FBP. Tumor tissue specimens from five patients with ovarian carcinoma contained immunoreactive FBP. By contrast to normal ovaries ovarian carcinoma tissue showed positive immunostaining on immunohistochemistry. Ascitic fluids from two patients with ovarian carcinoma exhibited single distinct bands on SDS-PAGE immunoblotting. The gel filtration profile of ovarian carcinoma tissue homogenate from two patients contained 25 and 100 kDa peaks of radioligand-bound and immunoreactive folate binding protein, while ascitic fluid from one of the patients exhibited a large 100 kDa immunoreactive peak with no radioligand binding activity. The immunoreactive non-functional 100 kDa FBP could represent unprocessed precursor FBP. Future studies are necessary to evaluate whether determination of immunoreactive FBP in ovarian adenocarcinomatosis is of any diagnostic value.

Role of the membrane-associated folate binding protein (folate receptor) in methotrexate transport by human KB cells

1989 ◽  
Vol 274 (2) ◽  
pp. 327-337 ◽  
Author(s):  
John C. Deutsch ◽  
Patrick C. Elwood ◽  
Raul M. Portillo ◽  
Michelle G. Macey ◽  
J.Fred Kolhouse
Keyword(s):  
Binding Protein ◽  
Folate Receptor ◽  
Kb Cells ◽  
Folate Binding Protein
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