![Journal cover image](https://secure.syndetics.com/index.aspx?isbn=/lc.gif&issn=1520-4995&client=dukeuniv)
Redox properties of human transferrin bound to its receptor.
Virtually all organisms require iron, and iron-dependent cells of vertebrates (and some more ancient species) depend on the Fe(3+)-binding protein of the circulation, transferrin, to meet their needs. In its iron-donating cycle, transferrin is first captured by the transferrin receptor on the cell membrane, and then internalized to a proton-pumping endosome where iron is released. Iron exits the endosome to enter the cytoplasm via the ferrous iron transporter DMT1, a molecule that accepts only Fe(2+), but the reduction potential of ferric iron in free transferrin at endosomal pH (approximately 5.6) is below -500 mV, too low for reduction by physiological agents such as the reduced pyridine nucleotides with reduction potentials of -284 mV. We now show that in its complex with the transferrin receptor, which persists throughout the transferrin-to-cell cycle of iron uptake, the potential is raised by more than 200 mV. Reductive release of iron from transferrin, which binds Fe(2+) very weakly, is therefore physiologically feasible, a further indication that the transferrin receptor is more than a passive conveyor of transferrin and its iron.
Duke Scholars
Altmetric Attention Stats
Dimensions Citation Stats
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Transferrin
- Thermodynamics
- Receptors, Transferrin
- Protein Binding
- Peptide Fragments
- Oxidation-Reduction
- Kinetics
- Humans
- Ferrous Compounds
- Ferric Compounds
Citation
![Journal cover image](https://secure.syndetics.com/index.aspx?isbn=/lc.gif&issn=1520-4995&client=dukeuniv)
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Transferrin
- Thermodynamics
- Receptors, Transferrin
- Protein Binding
- Peptide Fragments
- Oxidation-Reduction
- Kinetics
- Humans
- Ferrous Compounds
- Ferric Compounds