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. 1991 Nov 15;280(Pt 1):267–271. doi: 10.1042/bj2800267

High-affinity folate binding in human choroid plexus. Characterization of radioligand binding, immunoreactivity, molecular heterogeneity and hydrophobic domain of the binding protein.

J Holm 1, S I Hansen 1, M Høier-Madsen 1, L Bostad 1
PMCID: PMC1130630  PMID: 1660267

Abstract

High-affinity [3H]folate binding in solubilized human choroid plexus homogenate displayed characteristics, e.g. apparent positive co-operativity, which are typical of specific folate binding. The highest folate-binding activity per g of protein was associated with the 27000 g membrane pellet where the membrane-marker enzyme gamma-glutamyltransferase had its main localization. Ultrogel AcA 44 chromatography revealed two major folate-binding proteins (molecular masses greater than 110 kDa and approx. 100 kDa) and one minor one (molecular mass approx. 25 kDa) and approx. 100 kDa) and one minor one (molecular mass approx. 25 kDa) in the Triton X-100-solubilized membrane pellet. After exposure of the membrane pellet to phosphatidylinositol-specific phospholipase C there was only one large 25 kDa peak of folate binding. This could suggest that the folate-binding protein is anchored to the membrane by a glycosylphosphatidylinositol moiety, which can be inserted into Triton X-100 micelles and thus can give rise to forms of large molecular size on gel filtration. This notion was supported by the identical molecular masses of the greater than 110 kDa and 25 kDa folate-binding peaks determined by SDS/PAGE and immunoblotting. The folate-binding protein in choroid plexus cross-reacted with rabbit antibodies against the 25 kDa human milk folate-binding protein, and paraffin-embedded sections of choroid plexus showed immunostaining after exposure to rabbit anti-(human milk folate-binding protein) serum (1:8000 dilution).

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Selected References

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  1. Antony A. C., Bruno E., Briddell R. A., Brandt J. E., Verma R. S., Hoffman R. Effect of perturbation of specific folate receptors during in vitro erythropoiesis. J Clin Invest. 1987 Dec;80(6):1618–1623. doi: 10.1172/JCI113249. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Antony A. C., Kincade R. S., Verma R. S., Krishnan S. R. Identification of high affinity folate binding proteins in human erythrocyte membranes. J Clin Invest. 1987 Sep;80(3):711–723. doi: 10.1172/JCI113126. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Hansen S. I., Holm J., Høier-Madsen M. A high-affinity folate binding protein in human urine. Radioligand binding characteristics, immunological properties and molecular size. Biosci Rep. 1989 Feb;9(1):93–97. doi: 10.1007/BF01117515. [DOI] [PubMed] [Google Scholar]
  4. Hansen S. I., Holm J., Lyngbye J. A high-affinity folate binding protein in human cerebrospinal fluid. Acta Neurol Scand. 1985 Feb;71(2):133–135. doi: 10.1111/j.1600-0404.1985.tb03177.x. [DOI] [PubMed] [Google Scholar]
  5. Hansen S. I., Holm J., Lyngbye J. Cooperative binding of folate to a protein isolated from cow's whey. Biochim Biophys Acta. 1978 Aug 21;535(2):309–318. doi: 10.1016/0005-2795(78)90097-1. [DOI] [PubMed] [Google Scholar]
  6. Hansen S. I., Holm J., Lyngbye J. Folate binding by human milk protein. Scand J Clin Lab Invest. 1977 Jun;37(4):363–367. doi: 10.3109/00365517709092643. [DOI] [PubMed] [Google Scholar]
  7. Hansen S. I., Holm J., Lyngbye J., Pedersen T. G., Svendsen I. Dependence of aggregation and ligand affinity on the concentration of the folate-binding protein from cow's milk. Arch Biochem Biophys. 1983 Oct 15;226(2):636–642. doi: 10.1016/0003-9861(83)90333-8. [DOI] [PubMed] [Google Scholar]
  8. Holm J., Hansen S. I., Lyngbye J. A high-affinity folate binding protein in normal human leukocytes: ligand binding characteristics, ionic charge and molecular size. Biosci Rep. 1985 Aug;5(8):683–688. doi: 10.1007/BF01117000. [DOI] [PubMed] [Google Scholar]
  9. Holm J., Hansen S. I., Lyngbye J. High and low affinity binding of folate to proteins in serum of pregnancy women. Biochim Biophys Acta. 1980 May 22;629(3):539–545. doi: 10.1016/0304-4165(80)90159-2. [DOI] [PubMed] [Google Scholar]
  10. Hsu S. M., Raine L. Protein A, avidin, and biotin in immunohistochemistry. J Histochem Cytochem. 1981 Nov;29(11):1349–1353. doi: 10.1177/29.11.6172466. [DOI] [PubMed] [Google Scholar]
  11. Høier-Madsen M., Hansen S. I., Holm J. Rabbit antibodies against the low molecular weight folate binding protein from human milk. Use for immunological characterization of human folate binding proteins in an enzyme-linked immunosorbent assay (ELISA). Biosci Rep. 1987 Jul;7(7):553–557. doi: 10.1007/BF01119771. [DOI] [PubMed] [Google Scholar]
  12. Kamen B. A., Capdevila A. Receptor-mediated folate accumulation is regulated by the cellular folate content. Proc Natl Acad Sci U S A. 1986 Aug;83(16):5983–5987. doi: 10.1073/pnas.83.16.5983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Kessler M., Acuto O., Storelli C., Murer H., Müller M., Semenza G. A modified procedure for the rapid preparation of efficiently transporting vesicles from small intestinal brush border membranes. Their use in investigating some properties of D-glucose and choline transport systems. Biochim Biophys Acta. 1978 Jan 4;506(1):136–154. doi: 10.1016/0005-2736(78)90440-6. [DOI] [PubMed] [Google Scholar]
  14. Kyhse-Andersen J. Electroblotting of multiple gels: a simple apparatus without buffer tank for rapid transfer of proteins from polyacrylamide to nitrocellulose. J Biochem Biophys Methods. 1984 Dec;10(3-4):203–209. doi: 10.1016/0165-022x(84)90040-x. [DOI] [PubMed] [Google Scholar]
  15. Lacey S. W., Sanders J. M., Rothberg K. G., Anderson R. G., Kamen B. A. Complementary DNA for the folate binding protein correctly predicts anchoring to the membrane by glycosyl-phosphatidylinositol. J Clin Invest. 1989 Aug;84(2):715–720. doi: 10.1172/JCI114220. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  17. Luhrs C. A., Pitiranggon P., da Costa M., Rothenberg S. P., Slomiany B. L., Brink L., Tous G. I., Stein S. Purified membrane and soluble folate binding proteins from cultured KB cells have similar amino acid compositions and molecular weights but differ in fatty acid acylation. Proc Natl Acad Sci U S A. 1987 Sep;84(18):6546–6549. doi: 10.1073/pnas.84.18.6546. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Luhrs C. A., Slomiany B. L. A human membrane-associated folate binding protein is anchored by a glycosyl-phosphatidylinositol tail. J Biol Chem. 1989 Dec 25;264(36):21446–21449. [PubMed] [Google Scholar]
  19. O'Broin J. D., Temperley I. J., Brown J. P., Scott J. M. Nutritional stability of various naturally occurring monoglutamate derivatives of folic acid. Am J Clin Nutr. 1975 May;28(5):438–444. doi: 10.1093/ajcn/28.5.438. [DOI] [PubMed] [Google Scholar]
  20. Osterman T. M., Juntunen K. O., Gothoni G. D. Enzyme immunoassay of estrogen-like substances in plasma, with polyethylene glycol as precipitant. Clin Chem. 1979 May;25(5):716–718. [PubMed] [Google Scholar]
  21. Salgó L., Szabó A. Gamma-glutamyl transpeptidase activity in human urine. Clin Chim Acta. 1982 Nov 24;126(1):9–16. doi: 10.1016/0009-8981(82)90357-6. [DOI] [PubMed] [Google Scholar]
  22. Salter D. N., Scott K. J., Slade H., Andrews P. The preparation and properties of folate-binding protein from cow's milk. Biochem J. 1981 Feb 1;193(2):469–476. doi: 10.1042/bj1930469. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Spector R. Affinity of folic acid for the folate-binding protein of choroid plexus. Arch Biochem Biophys. 1979 May;194(2):632–634. doi: 10.1016/0003-9861(79)90658-1. [DOI] [PubMed] [Google Scholar]
  24. Spector R. Identification of folate binding macromolecule in rabbit choroid plexus. J Biol Chem. 1977 May 25;252(10):3364–3370. [PubMed] [Google Scholar]
  25. Spector R. Micronutrient homeostasis in mammalian brain and cerebrospinal fluid. J Neurochem. 1989 Dec;53(6):1667–1674. doi: 10.1111/j.1471-4159.1989.tb09229.x. [DOI] [PubMed] [Google Scholar]
  26. Spector R. The effect of pronase on choroid plexus transport. Brain Res. 1977 Oct 14;134(3):573–576. doi: 10.1016/0006-8993(77)90833-2. [DOI] [PubMed] [Google Scholar]
  27. Suleiman S. A., Spector R., Cancilla P. Partial purification and characterization of a folate-binding protein from human choroid plexus. Neurochem Res. 1981 Mar;6(3):333–341. doi: 10.1007/BF00964048. [DOI] [PubMed] [Google Scholar]
  28. Suleiman S. A., Spector R. Purification and characterization of a folate binding protein from porcine choroid plexus. Arch Biochem Biophys. 1981 Apr 15;208(1):87–94. doi: 10.1016/0003-9861(81)90126-0. [DOI] [PubMed] [Google Scholar]

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