Transferrin,10 mg

Product is the lyophilized powder of human transferrin and buffer salts. ransferrin is a glycoprotein with homologous N-terminal and C-terminal iron-binding domains. The N-terminal and C-terminal domains of this protein are globular moieties of about 330 amino acids. Each of these domains is divided into two sub-domains, with the iron- and anion-binding sites found within the intersubdomain cleft. The binding cleft opens with iron release and closes with iron binding. Transferrin binds iron with an association constant of approximately 1022 M-1. Ferric iron couples to transferrin only in the presence of an anion (usually carbonate) that serves as a bridging ligand between metal and protein, excluding water from the two coordination sites. Without the anion cofactor, iron binding to transferrin is negligible. In the presence of anions, ferric transferrin is resistant to all but the most potent chelators. The remaining four coordination sites are provided by the transferrin protein - a histidine nitrogen, an aspartic acid carboxylate oxygen, and two tyrosine phenolate oxygens. Available evidence suggests that anion-binding takes place prior to iron-binding. Iron release from transferrin involves protonation of the carbonate anion, loosening the metal-protein bond.

Application Notes

Transferrin delivers iron to cells in a physiologically safe and effective form.

Key Applications

Immunoassays | Iron binding Protein