Human Recombinant Fibroblast Growth Factor, acidic Source : E.coli Cell Culture Tested

Transferrin is a plasma protein that transports iron through the blood to the liver, spleen and bone marrow. It has the highest turn over rate of iron binding. Holo transferrin is synthesized from apo-Transferrin (iron-free) that initially binds iron at the C-terminus, followed by iron binding at the N-terminus to form Holo transferrin (Diferric Transferrin). Holo-Transferrin interacts with the type I Transferrin receptor (TfR) on the surface of cells where it is internalized into acidified endosomes. This process is known as receptor mediated endocytosis. Liver is the main source of manufacturing transferrin. Transferrin has two specific high-affinity Fe(III) binding sites. The affinity of transferrin for Fe(III) is extremely high but decreases if the pH decreases below neutrality. Transferrin releases iron when the pH of vesicle is reduced by hydrogen pumps. The receptor is then transported through the endocytic cycle back to the cell surface, ready for another round of iron uptake. Each transferrin molecule has the ability to carry two iron ions in the ferric form (Fe3+). In cell culture transferrin forms a major serum-free medium supplement. Transferrin is the physiologically appropriate component for providing iron to cells in culture.