Serotransferrin (TF) (TF)

Serotransferrin is a 77 kDa glycoprotein primarily synthesized in the liver that serves as the principal iron transport protein in human plasma (UniProt P02787). Its primary biological function is to maintain iron in a soluble form, transport it to tissues via the systemic circulation, and prevent the formation of toxic free radicals by sequestering ferric ions (StatPearls, 2023). In clinical medicine, transferrin is a critical diagnostic marker; low saturation levels indicate iron deficiency, while high levels suggest iron overload conditions like hemochromatosis (NIH, 2023). Beyond its role in iron metabolism, serotransferrin is a significant target in oncology and drug delivery because its receptor (TfR1) is frequently overexpressed on malignant cells to meet their high iron demands (PubMed, PMC3523395). Therapeutic strategies include the use of transferrin-drug conjugates to enhance tumor-specific uptake and the administration of iron-chelating or iron-supplementing agents that directly modulate transferrin's iron-loading state (PubChem, 2024). Additionally, transferrin is being explored for its ability to cross the blood-brain barrier, making it a candidate for delivering neurotherapeutics (PubMed, PMC6110697).

Other names

TransferrinSiderophilinBeta-1-metal-binding globulinPRO1557PRO2086

Serotransferrin acts as a high-affinity iron carrier, binding two ferric iron (Fe3+) ions per molecule in the presence of bicarbonate. Drugs like iron supplements increase the saturation of these binding sites to treat deficiency, while gallium nitrate competes for these sites to inhibit iron-dependent processes in cancer cells. The resulting holotransferrin complex binds to the Transferrin Receptor 1 (TfR1) on the cell surface, triggering clathrin-mediated endocytosis and subsequent iron release within the acidic endosomal environment (UniProt P02787; PubChem, 2024).