Transferrin is a
blood plasma proteinfor iron iondelivery. Transferrin is a glycoprotein, which binds iron very tightly but reversibly. Although iron bound to transferrin is less than 0.1% (4 mg) of the total body iron, dynamically it is the most important iron pool, with the highest rate of turnover (25 mg/24 h). Transferrin has a molecular weight of around 80 kiloDaltons and contains 2 specific high affinity Fe(III) binding sites. The affinity of transferrin for Fe(III) is extremely high (10^23 M^-1 at pH 7.4) but decreases progressively with decreasing pH below neutrality.
When not bound to iron, it is known as "apo-transferrin" (see also
When a transferrin protein loaded with iron encounters a
transferrin receptoron the surface of a cell (importantly, to erythroid precursors in the bone marrow), it binds to it and is consequently transported into the cell in a vesicle. The pH of the vesicle is reduced by hydrogen ion pumps (H+ ATPases), causing transferrin to release its iron ions. The receptor (with its ligand, transferrin, bound) is then transported through the endocytic cycleback to the cell surface, ready for another round of iron uptake.Each transferrin molecule has the ability to carry two iron ions in the ferricform (Fe3+).
genecoding for transferrin in humans is located in chromosomeband 3q21. Research on king snakes by Dessauer and Zwiefel in 1981 revealed that the inheritance of transferrin is a codominanttrait.
Medical professionals may check serum transferrin level in
iron deficiency, hemochromatosisand other iron overload disorders.
Transferrin is also associated with the innate immune system. Transferrin is found in the
mucosaand binds iron, thus creating an environment low in free iron, where few bacteria are able to survive. The levels of transferrin decreases in inflammation cite journal |author=Ritchie RF, Palomaki GE, Neveux LM, Navolotskaia O, Ledue TB, Craig WY |title=Reference distributions for the negative acute-phase serum proteins, albumin, transferrin and transthyretin: a practical, simple and clinically relevant approach in a large cohort |journal=J. Clin. Lab. Anal. |volume=13 |issue=6 |pages=273–9 |year=1999 |pmid=10633294 |doi=] , seeming contradictory to its function.
A decrease in the amount of transferrin would result in hemosiderin in the liver.
The metal binding properties of transferrin have a great influence on the biochemistry of
plutoniumin humans.Transferrin has a bacteriocidal effect on bacteria, in that it makes Fe3+ unavailable to the bacteria.
A deficiency is associated with
Total iron-binding capacity
* [http://macromoleculeinsights.com/transferrin.php The Transferrin Protein]
*cite journal | author=Hershberger CL, Larson JL, Arnold B, "et al." |title=A cloned gene for human transferrin |journal=Ann. N. Y. Acad. Sci. |volume=646 |issue= |pages= 140–54 |year= 1992 |pmid= 1809186 |doi=
*cite journal | author=Bowman BH, Yang FM, Adrian GS |title=Transferrin: evolution and genetic regulation of expression |journal=Adv. Genet. |volume=25 |issue= |pages= 1–38 |year= 1989 |pmid= 3057819 |doi=
*cite journal | author=Parkkinen J, von Bonsdorff L, Ebeling F, Sahlstedt L |title=Function and therapeutic development of apotransferrin |journal=Vox Sang. |volume=83 Suppl 1 |issue= |pages= 321–6 |year= 2003 |pmid= 12617162 |doi=
update_page = yes
require_manual_inspection = no
update_protein_box = yes
update_summary = no
update_citations = yes
Wikimedia Foundation. 2010.
Look at other dictionaries:
transferrin — transferrin. См. трансферрин. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) … Молекулярная биология и генетика. Толковый словарь.
transferrin — [trans fer′in] n. [< TRANS + L ferrum, iron (see FERRO ) + IN1] an iron binding, crystalline globulin in blood plasma, that is important as an iron carrier … English World dictionary
Transferrin — Serotransferrin Vorhandene Strukturdaten … Deutsch Wikipedia
Transferrin — A plasma protein that transports iron through the blood to the liver, spleen and bone marrow. The blood transferrin level is tested for diverse reasons: to determine the cause of anemia, to examine iron metabolism (for example, in iron deficiency … Medical dictionary
transferrin — The iron storage protein (80 kD) found in mammalian serum; a b globulin. Binds ferric iron with a Kass of around 21 at pH 7.4, 18.1 at pH 6.6. An important constituent of growth media. Transferrin receptors on the cell surface bind transferrin as … Dictionary of molecular biology
transferrin — /trans fer in/, n. Biochem. a plasma glycoprotein that transports dietary iron to the liver, spleen, and bone marrow. [1947; TRANS + L ferr(um) iron + IN2] * * * ▪ chemical compound also called Siderophilin, protein (beta1 globulin) in… … Universalium
Transferrin — Trans|fer|rin [↑ trans (2), ↑ Ferri u. ↑ in (3)], das; s, e; Syn.: Serum Transferrin, Siderophilin: ein rotes Nichthäm Eisen Protein (MG 79 600) aus 679 Aminosäuren, ca. 6 % Kohlenhydraten (Glykoprotein) u. 2 Fe(III) Ionen. Im Organismus fungiert … Universal-Lexikon
transferrin — transferinas statusas T sritis chemija apibrėžtis Kraujo plazmos glikoproteinas, pernešantis Fe³⁺. atitikmenys: angl. transferrin rus. трансферрин … Chemijos terminų aiškinamasis žodynas
transferrin — noun Etymology: trans + Latin ferrum iron Date: 1947 a beta globulin in blood plasma capable of combining with ferric ions and transporting iron in the body … New Collegiate Dictionary
transferrin — noun a glycoprotein, a beta globulin, in blood serum that combines with, and transports iron … Wiktionary