A loop in the N-lobe of human serum transferrin is critical for binding to the transferrin receptor as revealed by mutagenesis, isothermal titration calorimetry, and epitope mapping.

ABSTRACT: Transferrin (TF) is a bilobal transport protein that acquires ferric iron from the diet and holds it tightly within the cleft of each lobe (thereby preventing its hydrolysis). The iron is delivered to actively dividing cells by receptor mediated endocytosis in which diferric TF preferentially binds to TF receptors (TFRs) on the cell surface and the entire complex is taken into an acidic endosome. A combination of lower pH, a chelator, inorganic anions, and the TFR leads to the efficient release of iron from each lobe. Identification of residues/regions within both TF and TFR required for high affinity binding has been an ongoing goal in the field. In the current study, we created human TF (hTF) mutants to identify a region critical to the interaction with the TFR which also constitutes par

SUBMITTER: Mason AB 

PROVIDER: S-EPMC4479294 | biostudies-literature | 2009 Nov-Dec

REPOSITORIES: biostudies-literature