Abstract
Radioiron- and radioiodine-labeled forms of human diferric and monoferric transferrin and apotransferrin, isolated by preparative isoelectric focusing, were used to define transferrin-iron uptake by human reticulocytes. In mixtures of human diferric and monoferric transferrin, the diferric molecule had a constant 7-fold advantage in delivering iron to reticulocytes, as compared with the 2-fold advantage when single solutions of mono- and diferric transferrins were compared. This was shown to be due to competitive interaction in iron delivery, probably at a common membrane-receptor binding site for transferrin. Apotransferrin did not interfere with the iron-donating process and its limited cellular uptake was inhibited in noncompetitive fashion by diferric transferrin.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cook J. D. An evaluation of adsorption methods for measurement of plasma iron-binding capacity. J Lab Clin Med. 1970 Sep;76(3):497–506. [PubMed] [Google Scholar]
- DIXON M. The determination of enzyme inhibitor constants. Biochem J. 1953 Aug;55(1):170–171. doi: 10.1042/bj0550170. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eakins J. D., Brown D. A. An improved method for the simultaneous determination of iron-55 and iron-59 in blood by liquid scintillation counting. Int J Appl Radiat Isot. 1966 Jul;17(7):391–397. doi: 10.1016/0020-708x(66)90065-2. [DOI] [PubMed] [Google Scholar]
- Grahm G., Bates G. W. Approaches to the standardization of serum unsaturated iron-binding capacity. J Lab Clin Med. 1976 Sep;88(3):477–486. [PubMed] [Google Scholar]
- Harris D. C., Aisen P. Iron-donating properties of transferrin. Biochemistry. 1975 Jan 28;14(2):262–268. doi: 10.1021/bi00673a011. [DOI] [PubMed] [Google Scholar]
- Hemmaplardh D., Morgan E. H. The role of endocytosis in transferrin uptake by reticulocytes and bone marrow cells. Br J Haematol. 1977 May;36(1):85–96. doi: 10.1111/j.1365-2141.1977.tb05758.x. [DOI] [PubMed] [Google Scholar]
- Huebers H., Bauer W., Huebers E., Csiba E., Finch C. The behavior of transferrin iron in the rat. Blood. 1981 Feb;57(2):218–228. [PubMed] [Google Scholar]
- Huebers H., Csiba E., Josephson B., Huebers E., Finch C. Interaction of human diferric transferrin with reticulocytes. Proc Natl Acad Sci U S A. 1981 Jan;78(1):621–625. doi: 10.1073/pnas.78.1.621. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huebers H., Huebers E., Csiba E., Finch C. A. Iron uptake from rat plasma transferrin by rat reticulocytes. J Clin Invest. 1978 Nov;62(5):944–951. doi: 10.1172/JCI109223. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huebers H., Josephson B., Huebers E., Csiba E., Finch C. Uptake and release of iron from human transferrin. Proc Natl Acad Sci U S A. 1981 Apr;78(4):2572–2576. doi: 10.1073/pnas.78.4.2572. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Iacopetta B. J., Morgan E. H., Yeoh G. C. Transferrin receptors and iron uptake during erythroid cell development. Biochim Biophys Acta. 1982 May 7;687(2):204–210. doi: 10.1016/0005-2736(82)90547-8. [DOI] [PubMed] [Google Scholar]
- Kornfeld S. The effect of metal attachment to human apotransferrin on its binding to reticulocytes. Biochim Biophys Acta. 1969 Nov 11;194(1):25–33. doi: 10.1016/0005-2795(69)90175-5. [DOI] [PubMed] [Google Scholar]
- Van der Heul C., Kroos M. J., Van Noort W. L., Van Eijk H. G. No functional difference of the two iron-binding sites of human transferrin in vitro. Clin Sci (Lond) 1981 Feb;60(2):185–190. doi: 10.1042/cs0600185. [DOI] [PubMed] [Google Scholar]
- Zapolski E. J., Princiotto J. V. Preferential utilization in vitro of iron bound to diferric transferrin by rabbit reticulocytes. Biochem J. 1977 Aug 15;166(2):175–179. doi: 10.1042/bj1660175. [DOI] [PMC free article] [PubMed] [Google Scholar]