A glycoprotein of 78,000 molecular mass (78 kDa), associated with the membrane of Leishmania infantum promastigotes, was identified and immunopurified by monoclonal antibody (mAb) LD9 produced against isolated membrane preparations. mAb LD9 was subsequently found to bind to human transferrin, also of 78 kDa. Binding of LD9 to transferrin was completely abolished when the mAb was preabsorbed by ...

Transferrin receptors are transmembrane proteins present on the surface of most cells. Under normal circumstances, the iron required for cellular metabolism is acquired via transferrin receptors. Several recent reviews detail the methods of iron acquisition, the intracellular throughput of transferrin receptors, and the controlling mechanisms in the cell‘s quest to acquire and store iron [1–3]....

Purified human transferrin, when saturated with iron or zinc, decreased the production of granulocyte-macrophage colony-stimulating factors (GM-CSF) by human T lymphocytes that had been stimulated by phytohemagglutin or concanavalin-A. The iron-saturated transferrin was more active than the zinc-saturated transferrin. This effect was not seen for copper-saturated transferrin or for apotransferr...

The role of transferrin in iron delivery to tissues is described. Transferrin-dependent iron uptake by erythroid cells in the bone marrow is essential for the development of erythrocytes, while nontransferrin-bound iron can be taken up in tissues such as liver. On the basis of the evidence that iron distribution in the body is changed by iron saturation of plasma transferrin, the role of transf...

In previous analyses of transferrin saturation data in African Americans and Caucasians from the second National Health and Nutrition Examination Survey (NHANES II), subpopulations were found consistent with population genetics for common loci that influence iron metabolism. The goal of this new study was to determine if these transferrin saturation subpopulations have different levels of iron ...

Transferrin is an essential requirement for lymphocyte proliferation, because it supplies activated lymphocytes with iron needed for cell proliferation. However, during inflammation or an immune response, the iron content of circulating transferrin, which is of hepatic origin, decreases. It is hypothesized that activated lymphocytes may therefore obtain transferrin-iron from an alternative sour...

At 4°C transferrin bound to receptors on the reticulocyte plasma membrane, and at 37°C receptor-mediated endocytosis of transferrin occurred. Uptake at 37°C exceeded binding at 4°C by 2.5-fold and saturated after 20-30 min. During uptake at 37°C, bound transferrin was internalized into a trypsin-resistant space. Trypsinization at 4°C destroyed surface receptors, but with subsequent incubation a...

BACKGROUND Recent data shows an increased mortality risk associated with elevated transferrin saturation. Because ingestion of dietary iron may contribute to iron overload in persons with elevated transferrin saturation, we investigated the relationship between elevated transferrin saturation, ingestion of dietary iron and red meat, and mortality. METHODS This 12-year cohort study used data f...

When it is incompletely saturated with iron, transferrin may exist in four molecular forms: apotransferrin, monoferric (A) transferrin (with iron occupying only the A site of the protein), monoferric (B) transferrin, and diferric transferrin. By combining electrophoresis in urea-polyacrylamide gels with crossed immunoelectrophoresis using specific antihuman transferin antiserum, it is possible ...

A Chinese hamster ovary cell mutant defective in the receptor-mediated endocytosis of several unrelated ligands (Robbins, A. R., S. S. Peng, and J. L. Marshall, 1983, J. Cell Biol., 96:1064-1071) failed to accumulate iron provided in the form of diferric transferrin. Analysis of the steps of the transferrin cycle indicated that binding and internalization of transferrin proceeded normally in mu...