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

Suleiman, Suleiman A.; Spector, Reynold

doi:10.1016/0003-9861(81)90126-0

Cited by 35 publications

(15 citation statements)

References 19 publications

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“…They reported that at pH values greater than 9.5 or less than 5.5, the binding activity was dramatically decreased. Suleiman and Spector [18] have reported similar observation of pH dependent binding activity of HFBP purified from porcine choroid plexus, where the activity decreased below pH 6.0 and above pH 8.0. Iwai et al [6] however, reported rather pH sensitive binding activity of purified bovine HFBP to [ 14 C]FA from cow milk, which had maximum binding activity between pH 8 and 9.…”

Section: Discussionsupporting

confidence: 53%

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

Natsuhori

Okada

Ida

et al. 1999

The Journal of Veterinary Medical Science

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ABSTRACT. 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 electrochemical detection or to liquid scintillation counting. Binding affinity of HFBP to folate was characterized by dissociation constants (Kd): 13, 17, and 31 pM for tritiated FA ( 3 HFA), THF, and N 5 -methyltetrahydrofolic acid (5MF), respectively. FA, THF, and 5MF significantly inhibited binding of HFBP to 3 HFA, and according to the magnitude of intensity of the binding inhibition, the order of affinity of each folate was confirmed to be FA > THF > 5MF. Binding activity was rather high and stable for THF and 5MF at pH ranging from 6.0 to 10.0. The binding activity, however, rapidly decreased at pH below 6.0 and over 10.0. No binding activity was observed pH below 3.0 and over 12. Gel filtration analysis showed that the prepared HFBP solution had specific binding activity at around 77 kDa of apparent molecular weight, which was 82 kDa by SDS-PAGE. It is considered that this specific and stable binding enables THF to distribute in porcine plasma.-KEY WORDS: binding protein, folate, serum, swine.

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Section: Discussionsupporting

confidence: 53%

“…Although porcine HFBPs derived from choroid plexus [18] and kidney [7,8], were identified, purified and characterized, porcine serum HFBP has not been purified and characterized, yet. In this study, porcine serum HFBPs were purified about 2,100 fold to a specific binding activity of 1.4 nM of THF per 1 mg of protein.…”

Section: Discussionmentioning

confidence: 99%

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

Natsuhori

Okada

Ida

et al. 1999

The Journal of Veterinary Medical Science

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“…Proteins which specifically bind folate have been isolated from various body fluids and tissues of mammals (1,7,12,14,15,16,18,19,20) and also from bacteria (9), In order to understand the function of these proteins it is important to know their structures, In a previous communication we have shown the partial amino acid sequence of the folate binding protein from cow's milk based on the cyanogen bromide fragments (16). Homology between this protein and the high and low molecular weight folate binding protein from human milk has been demonstrated (17).…”

Section: Introductionmentioning

confidence: 99%

The complete amino acid sequence of the folate-binding protein from cow's milk

Svendsen

Hansen

Holm

et al. 1984

Carlsberg Res. Commun.

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The complete amino acid sequence of the folate binding protein from cow's milk has been determined by automated sequencing of fragments obtained by cleavage with cyanogen bromide, trypsin, S. aureus V8 protease and clostripain. The molecule consists of a single polypeptide chain of 222 amino acid residues and eight disulphide bridges. The molecular weight of the protein part is 25,700. The folate binder contains carbohydrate which gives it a final molecular weight of about 30,000. No sequence homology with other proteins has been observed.

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“…Folate is known to occur in higher concentrations in CSF than plasma. As it is not synthesized within CNS, folate must enter the CSF against a concentration gradient from the blood (Chen and Wagner 1975;Suleiman et al 1981). In various species, a folate binder was found in plasma membrane of choroid plexuses, suggesting a role for this protein in transport of folate to CSF and CNS (Chen and Wagner 1975;Suleiman et al 1981).…”

Section: Discussionmentioning

confidence: 99%

CSF 5-Methyltetrahydrofolate Serial Monitoring to Guide Treatment of Congenital Folate Malabsorption Due to Proton-Coupled Folate Transporter (PCFT) Deficiency

et al. 2015

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Hereditary folate malabsorption is characterized by folate deficiency with impaired folate transport into the central nervous system (CNS). This disease is characterized by megaloblastic anemia of early appearance, combined immunodeficiency, seizures, and cognitive impairment. The anemia and immunologic disease are responsive but neurological signs are refractory to folic-acid treatment. We report a 7-year-old girl who has congenital folate deficiency and SLC46A1 gene mutation who is unable to transport folate from her gut to the circulatory system and consequently from the blood to the cerebrospinal fluid (CSF). As a result she developed undetectable 5-methyltetrahydrofolate levels in her plasma and CSF and became immunocompromised and quite ill. Intramuscular treatment with 5-formyltetrahydrofolate (folinic acid) was therapeutic at her presentation and has been successful preventing other signs and symptoms of hereditary folate malabsorption even at relatively low CSF levels. Although difficult, early detection and diagnosis of cerebral folate deficiency are important because folinic acid at a pharmacologic dose may normalize outcome in PCFT gene defects, as well as bypass autoantibody-blocked folate receptors and enter the cerebrospinal fluid by way of the reduced folate carrier. This route elevates the 5-methyltetrahydrofolate level within the central nervous system and can prevent the neuropsychiatric disorder. CSF levels of 5-methyltetrahydrofolate between 18 and 46 nmol/L may be sufficient to eradicate CNS disease.

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

Cited by 35 publications

References 19 publications

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

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

The complete amino acid sequence of the folate-binding protein from cow's milk

CSF 5-Methyltetrahydrofolate Serial Monitoring to Guide Treatment of Congenital Folate Malabsorption Due to Proton-Coupled Folate Transporter (PCFT) Deficiency

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