Transferrin

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Related to Apotransferrin: ferritin, hemosiderin, apoferritin

transferrin

[′tranz′fer·ən]
(biochemistry)
Any of various beta globulins in blood serum which bind and transport iron to the bone marrow and storage areas.

Transferrin

 

(also siderophilin), any of a group of related complex proteins (glycoproteins) that transport Fe3+ iron ions in organisms. The carbohydrate component of transferrins constitutes approximately 5.5 percent. The molecular weight is approximately 80,000.

Transferrins occur in blood plasma, milk, and egg albumin (conalbumin). In blood plasma, their main functions are the transport of iron (with one molecule of transferrin binding two atoms of trivalent iron) to the reticulocytes, where hemoglobin is synthesized, and the maintenance of the Fe2+/Fe3+ ratio at a certain level. Upon electrophoresis of plasma proteins, transferrin is found in the β-globulin fraction. Transferrins are found in various genetically dependent forms, which have similar physical and chemical properties. A deficiency of transferrin in organisms leads to a number of pathological states caused by disruption of iron metabolism.

REFERENCE

Glikoproteiny, vol. 2. Moscow, 1969. (Translated from English.)
References in periodicals archive ?
This is explained by the fact that besides being synergistic, chromium can be antagonistic to iron due to competition for binding to apotransferrin. Significantly reduced uptake of iron by serum transferrin has been observed in the presence of chromium [4, 19].
Newly absorbed iron, or iron released from ferritin, is converted from ferrous to ferric iron by ceruloplasmin, transferred to apotransferrin in the cell, and then released into the circulation as transferrin.
The molecular events associated with the TF-bound iron and release of apotransferrin to the plasma for its reutilization or cycling is very well established.
The sorted cells were expanded in N2-S medium, consisting of DMEM/F12 (Gibco) and supplemented with 100 [micro]g/ml apotransferrin, 25 [micro]g/ml insulin, 8.6 mM glucose, 100 gM putrescine, 30 nM selenite, 20 nM progesterone (all purchased from Sigma-Aldrich), 1x GlutaMax and 1% penicillin/streptomycin (both from Gibco), 20 ng/ml epidermal growth factor (EGF) and 20 ng/ml FGF2 (both from R&D).
Four transferrin glycoforms can be distinguished with respect to iron content: apotransferrin, N-terminal and C-terminal monoferric transferrins, and diferric transferrin.
The patients were enrolled in clinical studies for chelation of NTBI by an investigational apotransferrin product.